Irrawaddy dolphin: Difference between revisions

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
imported>Sarcogypscalvus
Cambodia: removed speculation and numbers of births / deaths that are not current
 
imported>Worldbruce
clean up, reduced MOS:OVERLINK, use a consistent date format, use convert template, typo(s) fixed: 30-40 → 30–40, 25 year old male → 25-year-old male
 
Line 4: Line 4:
| status = EN
| status = EN
| status_system = IUCN3.1
| status_system = IUCN3.1
| status_ref = <ref name="IUCN">{{cite iucn |title=''Orcaella brevirostris'' |author1=Minton, G. |author2=Smith, B.D. |author3=Braulik, G.T. |author4=Kreb, D. |author5=Sutaria, D. |author6=Reeves, R. |name-list-style=amp |year=2017 |errata=2018 |page=e.T15419A123790805 |doi=10.2305/IUCN.UK.2017-3.RLTS.T15419A50367860.en |access-date=19 February 2022}}</ref>
| status_ref = <ref name="IUCN">{{cite iucn |title=''Orcaella brevirostris'' |author1=Minton, G. |author2=Smith, B.D. |author3=Braulik, G.T. |author4=Kreb, D. |author5=Sutaria, D. |author6=Reeves, R. |name-list-style=amp |year=2017 |errata=2018 |article-number=e.T15419A123790805 |doi=10.2305/IUCN.UK.2017-3.RLTS.T15419A50367860.en |access-date=19 February 2022}}</ref>
  | status2 = CITES_A1  
  | status2 = CITES_A1
  | status2_system = CITES  
  | status2_system = CITES
  | status2_ref = <ref>{{Cite web|title=Appendices {{!}} CITES|url=https://cites.org/eng/app/appendices.php|access-date=2022-01-14|website=cites.org}}</ref>
  | status2_ref = <ref>{{Cite web |title=Appendices {{!}} CITES |url=https://cites.org/eng/app/appendices.php |access-date=2022-01-14 |website=cites.org}}</ref>
| image = Irrawaddy dolphin-Orcaella brevirostris by 2eight.jpg
| image = Irrawaddy dolphin-Orcaella brevirostris by 2eight.jpg
| image_caption = Irrawaddy dolphin in Cambodia
| image_caption = Irrawaddy dolphin in Cambodia
Line 28: Line 28:
}}
}}


The '''Irrawaddy dolphin''' ('''''Orcaella brevirostris''''') is a [[euryhaline]] species of [[oceanic dolphin]] found in scattered subpopulations near sea coasts and in estuaries and rivers in parts of the [[Bay of Bengal]] and [[Southeast Asia]]. It closely resembles the [[Australian snubfin dolphin]] (of the same genus, ''[[Orcaella]]''), which was not described as a separate species until 2005. It has a slate blue to a slate gray color. Although found in much of the riverine and marine zones of South and Southeast Asia, the only concentrated lagoon populations are found in [[Chilika Lake]] in [[Odisha]], [[India]] and [[Songkhla Lake]] in southern [[Thailand]].<ref>{{citation |title=Conservation Status of Irrawaddy dolphins (Orcaella Brevirostris) |publisher=CMS |url=https://www.cms.int/sites/default/files/document/ScC14_Doc_08_Irrawaddy_dolphins_Eonly_0.pdf |author=Brian D. Smith, William Perrin |date=March 2007 }}</ref>
The '''Irrawaddy dolphin''' ('''''Orcaella brevirostris''''') is a [[euryhaline]] species of [[oceanic dolphin]] found in scattered subpopulations near sea coasts and in estuaries and rivers in parts of the [[Bay of Bengal]] and Southeast Asia. It closely resembles the [[Australian snubfin dolphin]] (of the same genus, ''[[Orcaella]]''), which was not described as a separate species until 2005. It has a slate blue to a slate gray color. Although found in much of the riverine and marine zones of South and Southeast Asia, the only concentrated lagoon populations are found in [[Chilika Lake]] in [[Odisha]], India, and [[Songkhla Lake]] in southern [[Thailand]].<ref>{{citation |title=Conservation Status of Irrawaddy dolphins (Orcaella Brevirostris) |publisher=CMS |url=https://www.cms.int/sites/default/files/document/ScC14_Doc_08_Irrawaddy_dolphins_Eonly_0.pdf |author=Brian D. Smith, William Perrin |date=March 2007}}</ref>


==Taxonomy==
==Taxonomy==
{{Multiple image|direction=vertical|image1=OrcaellaBrevirostris.JPG|image2=Orcaella brevirostris 3d scan Natural History Museum University of Pisa C 293.stl|footer=Irrawaddy dolphin skeleton specimen exhibited in [[Pisa Charterhouse|Museo di storia naturale e del territorio dell'Università di Pisa]]}}
{{Multiple image|direction=vertical|image1=OrcaellaBrevirostris.JPG|image2=Orcaella brevirostris 3d scan Natural History Museum University of Pisa C 293.stl|footer=Irrawaddy dolphin skeleton specimen exhibited in [[Pisa Charterhouse|Museo di storia naturale e del territorio dell'Università di Pisa]]}}
One of the earliest recorded descriptions of the Irrawaddy dolphin was by [[Richard Owen|Sir Richard Owen]] in 1866 based on a specimen found in 1852, in the harbour of [[Visakhapatnam]] on the east coast of India.<ref name="Sinha">{{cite journal |last=Sinha |first=R. K. |date=2004|title=The Irrawaddy Dolphins ''Orcaella'' of Chilika Lagoon, India |journal=Journal of the Bombay Natural History Society |volume=101 |issue=2 |pages=244–251 |url=http://www.casmbenvis.nic.in/sdnp/lagoon%20pdf/L10.pdf|archive-url=https://web.archive.org/web/20090410010513/http://www.casmbenvis.nic.in/sdnp/lagoon%20pdf/L10.pdf|archive-date=2009-04-10}}</ref> It is one of two species in its genus. It has sometimes been listed variously in a family containing just itself and in the [[Monodontidae]] and [[Oceanic dolphin|Delphinidae]]. Widespread agreement now exists to list it in the family [[Delphinidae]].
One of the earliest recorded descriptions of the Irrawaddy dolphin was by [[Richard Owen|Sir Richard Owen]] in 1866, based on a specimen found in 1852 in the harbour of [[Visakhapatnam]] on the east coast of India.<ref name="Sinha">{{cite journal |last=Sinha |first=R. K. |year=2004 |title=The Irrawaddy Dolphins ''Orcaella'' of Chilika Lagoon, India |journal=Journal of the Bombay Natural History Society |volume=101 |issue=2 |pages=244–251 |url=http://www.casmbenvis.nic.in/sdnp/lagoon%20pdf/L10.pdf |archive-url=https://web.archive.org/web/20090410010513/http://www.casmbenvis.nic.in/sdnp/lagoon%20pdf/L10.pdf |archive-date=2009-04-10}}</ref> It is one of two species in its genus. It has sometimes been listed variously in a family containing just itself and in the [[Monodontidae]] and [[Oceanic dolphin|Delphinidae]]. Widespread agreement now exists to list it in the family [[Delphinidae]].


== Etymology ==
== Etymology ==
The species' name ''brevirostris'' is from the [[Latin]] meaning short-beaked.{{cn|date=October 2023}}
The species' name, ''brevirostris'', is from the [[Latin]] meaning "short beaked".{{citation needed|date=October 2023}}


== Description ==
== Description ==
[[File:Orcaella brevirostris 1878.jpg|thumb|1878 illustration]]
[[File:Orcaella brevirostris 1878.jpg|thumb|1878 illustration]]
The Irrawaddy dolphin's colour is grey to dark slate blue, paler underneath, without a distinctive pattern. The dorsal fin is small and rounded behind the middle of the back. The forehead is high and rounded; the beak is lacking. The front of its snout is blunt. The flippers are broad and rounded. The [[finless porpoise]] (''Neophocaena phocaenoides'') is similar and has no back fin; the [[humpback dolphin]] (''Sousa chinensis'') is larger, and has a longer beak and a larger dorsal fin.<ref name="Sinha"/>
The Irrawaddy dolphin's colour is grey to dark slate blue, paler underneath, without a distinctive pattern. The dorsal fin is small and rounded behind the middle of the back. The forehead is high and rounded; the beak is lacking. The front of its snout is blunt. The flippers are broad and rounded. The [[finless porpoise]] (''Neophocaena phocaenoides'') is similar and has no back fin; the [[humpback dolphin]] (''Sousa chinensis'') is larger and has a longer beak and a larger dorsal fin.<ref name="Sinha"/>
It ranges in weight from {{convert|90|to|200|kg|abbr=on}} with a length of {{convert|2.3|m|ft|abbr=on}} at full maturity.<ref>{{cite web |url=http://www.worldwildlife.org/species/irrawaddy-dolphin |title=Irrawaddy Dolphin |last=Long |first=B. |website=World Wildlife Fund (WWF) |access-date=2014-10-20}}</ref><ref name="NG">{{Cite web |date=5 April 2019 |title=Cambodia's endangered river dolphins at highest population in 20 years |url=https://www.nationalgeographic.com/animals/article/irawaddy-river-dolphin-population-biggest-20-years |archive-url=https://web.archive.org/web/20210419120237/https://www.nationalgeographic.com/animals/article/irawaddy-river-dolphin-population-biggest-20-years |url-status=dead |archive-date=April 19, 2021 |website=Animals<!-- ori title? --> |publisher=[[National Geographic]] |access-date=1 April 2022 }}</ref> Maximum recorded length is {{convert|2.75|m|ft|abbr=on}} of a male in Thailand.<ref name="Stacey">{{cite journal |last1=Stacey |first1=P. J. |last2=Arnold |first2=P. W. |date=1999 |title=''Orcaella brevirostris'' |journal=Mammalian Species |issue=616 |pages=1–8 |doi=10.2307/3504387 |jstor=3504387|doi-access=free }}</ref>
It ranges in weight from {{convert|90|to|200|kg|abbr=on}} with a length of {{convert|2.3|m|ft|abbr=on}} at full maturity.<ref>{{cite web |url=http://www.worldwildlife.org/species/irrawaddy-dolphin |title=Irrawaddy Dolphin |last=Long |first=B. |website=World Wildlife Fund (WWF) |access-date=2014-10-20}}</ref><ref name="NG">{{Cite web |date=5 April 2019 |title=Cambodia's endangered river dolphins at highest population in 20 years |url=https://www.nationalgeographic.com/animals/article/irawaddy-river-dolphin-population-biggest-20-years |archive-url=https://web.archive.org/web/20210419120237/https://www.nationalgeographic.com/animals/article/irawaddy-river-dolphin-population-biggest-20-years |archive-date=19 April 2021 |website=[[National Geographic (magazine)|National Geographic]] |access-date=1 April 2022}}</ref> The maximum recorded length is {{convert|2.75|m|ft|abbr=on}} of a male in Thailand.<ref name="Stacey">{{cite journal |last1=Stacey |first1=P. J. |last2=Arnold |first2=P. W. |year=1999 |title=''Orcaella brevirostris'' |journal=Mammalian Species |issue=616 |pages=1–8 |doi=10.2307/3504387 |jstor=3504387 |doi-access=free}}</ref>


The Irrawaddy dolphin is similar to the [[Beluga (whale)|beluga]] in appearance, though most closely related to the [[Orca|killer whale]]. It has a large [[melon (whale)|melon]] and a blunt, rounded head, and the beak is indistinct. Its [[dorsal fin]], located about two-thirds posterior along the back, is short, blunt, and triangular.<ref name="NG" /> Dorsal fin shapes differ from one Irrawaddy dolphin to another.<ref name="NG" /> The flippers are long and broad.<ref name="SEAMAP">{{Cite web |url=https://seamap.env.duke.edu/species/180471/html |title=Irrawaddy dolphin - ''Orcaella brevirostris'' |date=<!-- ori date unknown --> |website=Spatial Ecological Analysis of Megavertebrate Populations |publisher=Ocean Biodiversity Information System, Marine Geospatial Ecology Lab at [[Duke University]] |access-date=1 April 2022 }}</ref> These dolphins are usually two-toned, with the back and sides being gray to bluish-gray and the belly lighter.<ref name="SEAMAP" /> Unlike any other dolphin, the Irrawaddy's U-shaped blowhole is on the left of the midline and opens towards the front of the dolphin.<ref name="SEAMAP" /> Its short beak appears very different from those of other dolphins, and its mouth is known for having 12-19 peg-like teeth on each side of the jaws.<ref name="SEAMAP" />
The Irrawaddy dolphin is similar to the [[Beluga (whale)|beluga]] in appearance, though most closely related to the [[Orca|killer whale]]. It has a large [[melon (whale)|melon]] and a blunt, rounded head, and the beak is indistinct. Its [[dorsal fin]], located about two-thirds posterior along the back, is short, blunt, and triangular.<ref name="NG" /> Dorsal fin shapes differ from one Irrawaddy dolphin to another.<ref name="NG" /> The flippers are long and broad.<ref name="SEAMAP">{{Cite web |url=https://seamap.env.duke.edu/species/180471/html |title=Irrawaddy dolphin - ''Orcaella brevirostris'' |date=<!-- ori date unknown --> |website=Spatial Ecological Analysis of Megavertebrate Populations |publisher=Ocean Biodiversity Information System, Marine Geospatial Ecology Lab at [[Duke University]] |access-date=1 April 2022 }}</ref> These dolphins are usually two-toned, with the back and sides being gray to bluish-gray and the belly lighter.<ref name="SEAMAP" /> Unlike any other dolphin, the Irrawaddy's U-shaped blowhole is on the left of the midline and opens towards the front of the dolphin.<ref name="SEAMAP" /> Its short beak appears very different from those of other dolphins, and its mouth is known for having 12-19 peg-like teeth on each side of the jaws.<ref name="SEAMAP" />
Line 46: Line 46:
==Behaviour==
==Behaviour==
[[File:DKoehl Irrawaddi Dolphin jumping.jpg|thumb|left|Closeup of an Irrawaddy dolphin jumping in the [[Mekong River]]]]
[[File:DKoehl Irrawaddi Dolphin jumping.jpg|thumb|left|Closeup of an Irrawaddy dolphin jumping in the [[Mekong River]]]]
Communication is carried out with clicks, creaks, and buzzes at a dominant frequency of about 60&nbsp; kilohertz, which is thought to be used for [[Animal echolocation|echolocation]]. Bony fish and fish eggs, [[cephalopod]]s, and [[crustacean]]s are taken as food. Observations of captive animals indicate food may be taken into the mouth by suction. Irrawaddy dolphins are capable of squirting streams of water that can reach up to {{convert|1.5|m}}; this distinct behaviour has been known for herding fish into a general area for hunting.<ref>"Irrawaddy Dolphins, Orcaella brevirostris ~ MarineBio.org." MarineBio Conservation Society. Retrieved 2014-10-20.</ref> They do this sometimes while [[Cetacean surfacing behaviour#Spyhopping|spyhopping]] and during feeding, apparently to expel water ingested during fish capture or possibly to herd fish. Some Irrawaddy dolphins kept in captivity have been trained to do spyhopping on command. The Irrawaddy dolphin is a slow swimmer, but swimming speeds of {{convert|20|-|25|kph}} were reported when dolphins were being chased in a boat.<ref name="Arkive">{{cite web |url=http://www.arkive.org/irrawaddy-dolphin/orcaella-brevirostris/info.html |archive-url=https://web.archive.org/web/20081107092620/http://www.arkive.org/irrawaddy-dolphin/orcaella-brevirostris/info.html |url-status=dead |archive-date=2008-11-07 |title=Irrawaddy dolphin (Orcaella brevirostris) |year=2008 |work=Arkive |publisher=Wildscreen |access-date=2008-12-26}}</ref> In a year, females can sometimes swim as fast as average of 45 km, males can swim up to average of 100 km.<ref name="FS">{{cite book |author=<!-- Staff writer(s); no by-line --> |title=Pesut Mahakam Fact Sheet |url=https://www.ykrasi.org/wp-content/uploads/2022/07/Pesut-Mahakam-fact-sheet-English.pdf |date=2020 |location=Samarinda, East Kalimantan, Indonesia |publisher=Yayasan Konservasi RASI }}</ref>{{rp|2}}
Communication is carried out with clicks, creaks, and buzzes at a dominant frequency of about 60&nbsp; kilohertz, which is thought to be used for [[Animal echolocation|echolocation]]. Bony fish (including [[catfish]]) and fish eggs, [[cephalopod]]s (such as [[squid]], octopus, and [[cuttlefish]]), and [[crustacean]]s are taken as food.<ref>Mark, Carwardine et al.. 2020. Handbook of Whales, Dolphins, and Porpoises of the World. Princeton University Press.</ref> Observations of captive animals indicate food may be taken into the mouth by suction. Irrawaddy dolphins are capable of squirting streams of water that can reach up to {{convert|1.5|m}}; this distinct behaviour has been known for herding fish into a general area for hunting.<ref>"Irrawaddy Dolphins, Orcaella brevirostris ~ MarineBio.org." MarineBio Conservation Society. Retrieved 2014-10-20.</ref> They do this sometimes while [[Cetacean surfacing behaviour#Spyhopping|spyhopping]] and during feeding, apparently to expel water ingested during fish capture or possibly to herd fish. Some Irrawaddy dolphins kept in captivity have been trained to do spyhopping on command. The Irrawaddy dolphin is a slow swimmer, but swimming speeds of {{convert|20|-|25|kph}} were reported when dolphins were being chased in a boat.<ref name="Arkive">{{cite web |url=http://www.arkive.org/irrawaddy-dolphin/orcaella-brevirostris/info.html |archive-url=https://web.archive.org/web/20081107092620/http://www.arkive.org/irrawaddy-dolphin/orcaella-brevirostris/info.html |archive-date=2008-11-07 |title=Irrawaddy dolphin (Orcaella brevirostris) |year=2008 |work=Arkive |publisher=Wildscreen |access-date=2008-12-26}}</ref> In a year, females can sometimes swim as fast as an average of {{convert|45|km}}, and males can swim up to an average of {{convert|100|km}}.<ref name="FS">{{cite book |author=<!-- Staff writer(s); no by-line --> |title=Pesut Mahakam Fact Sheet |url=https://www.ykrasi.org/wp-content/uploads/2022/07/Pesut-Mahakam-fact-sheet-English.pdf |date=2020 |location=Samarinda, East Kalimantan, Indonesia |publisher=Yayasan Konservasi RASI}}</ref>{{rp|2}}


Most Irrawaddy dolphins are shy of boats, not known to bow-ride, and generally dive when alarmed. They are relatively slow moving but can sometimes be seen spyhopping and rolling to one side while waving a flipper and occasionally breaching. They are generally found in groups of 2-3 animals, though sometimes as many as 25 individuals have been known to congregate in deep pools. Groups of fewer than six individuals are most common, but sometimes up to 15 dolphins are seen together.<ref name="Arkive"/><ref name=Culik>{{cite web |url=http://www.cms.int/reports/small_cetaceans/data/O_brevirostris/O_brevirostris.htm |title=Orcaella brevirostris (Gray, 1866) |author=Culik, Boris |author2=Kiel, Germany |year=2000 |work=Review of Small Cetaceans Distribution, Behaviour, Migration and Threats |publisher=[[UNEP]]/[[Convention on Migratory Species|CMS]] Convention on Migratory Species |access-date=2008-12-26 |archive-url=https://web.archive.org/web/20041205063511/http://www.cms.int/reports/small_cetaceans/data/O_brevirostris/O_brevirostris.htm |archive-date=2004-12-05 |url-status=dead }}</ref> Traveling and staying in groups not only enables Irrawaddy dolphins to hunt, but it also creates and maintains social bonds and allows copulation to occur.<ref name=":1" /> There are a few groups of dolphins in [[Brunei Bay]] seen near the mouths of [[Temburong River|Temburong]] and Aloh Besar rivers which are tame and gather around fisherman boats that catch fish during the fishing season from around December to February.<ref name="JMSI">{{cite journal |author1=Nurlisa Azizul<!-- xct nm --> |author2=Saifullah Arifin Jaaman<!-- xct nm --> |author3=Farah Dayana Haji Ismail<!-- xct nm --> |author4=Azmi Marzuki Muda<!-- xct nm --> |author5=Xuelei Zhang<!-- xct nm --> |author6=Hairul Masrini Muhamad<!-- xct nm --> |author7=Mohammad Vol Momin<!-- xct nm --> |author8=Bohari Abdullah<!-- xct nm --> |title=Water Surface Behaviour of Irrawaddy Dolphin ''Orcaella brevirostris'' (Owen in Gray, 1866) and Influencing Factors in the Bay of Brunei, Brunei Darussalam |journal=Journal of Marine Science and Engineering |date=2022 |volume=10 |issue=11 |pages=1711 |doi=10.3390/jmse10111711 |doi-access=free }}</ref>
Most Irrawaddy dolphins are shy of boats, not known to bow-ride, and generally dive when alarmed. They are relatively slow-moving but can sometimes be seen spyhopping and rolling to one side while waving a flipper and occasionally breaching. They are generally found in groups of 2-3 animals, though sometimes as many as 25 individuals have been known to congregate in deep pools. Groups of fewer than six individuals are most common, but sometimes up to 15 dolphins are seen together.<ref name="Arkive"/><ref name=Culik>{{cite web |url=http://www.cms.int/reports/small_cetaceans/data/O_brevirostris/O_brevirostris.htm |title=Orcaella brevirostris (Gray, 1866) |author=Culik, Boris |author2=Kiel, Germany |year=2000 |work=Review of Small Cetaceans Distribution, Behaviour, Migration and Threats |publisher=[[UNEP]]/[[Convention on Migratory Species|CMS]] Convention on Migratory Species |access-date=2008-12-26 |archive-url=https://web.archive.org/web/20041205063511/http://www.cms.int/reports/small_cetaceans/data/O_brevirostris/O_brevirostris.htm |archive-date=2004-12-05}}</ref> Traveling and staying in groups not only enables Irrawaddy dolphins to hunt, but it also creates and maintains social bonds and allows copulation to occur.<ref name=":1" /> There are a few groups of dolphins in [[Brunei Bay]] seen near the mouths of the [[Temburong River|Temburong]] and Aloh Besar rivers, which are tame and gather around fishermen's boats that catch fish during the fishing season from around December to February.<ref name="JMSI">{{cite journal |author1=Nurlisa Azizul<!-- xct nm --> |author2=Saifullah Arifin Jaaman<!-- xct nm --> |author3=Farah Dayana Haji Ismail<!-- xct nm --> |author4=Azmi Marzuki Muda<!-- xct nm --> |author5=Xuelei Zhang<!-- xct nm --> |author6=Hairul Masrini Muhamad<!-- xct nm --> |author7=Mohammad Vol Momin<!-- xct nm --> |author8=Bohari Abdullah<!-- xct nm --> |title=Water Surface Behaviour of Irrawaddy Dolphin ''Orcaella brevirostris'' (Owen in Gray, 1866) and Influencing Factors in the Bay of Brunei, Brunei Darussalam |journal=Journal of Marine Science and Engineering |year=2022 |volume=10 |issue=11 |page=1711 |doi=10.3390/jmse10111711 |bibcode=2022JMSE...10.1711A |doi-access=free}}</ref>


It surfaces in a rolling fashion and lifts its tail fluke clear of the water only for a deep dive. Deep dive times range from 30 to 150&nbsp;seconds to 12&nbsp;minutes. When 277 group dives were timed (time of disappearance of the last dolphin in the group to the emergence of the first dolphin in the group) in [[Laos]], mean duration was 115.3&nbsp; seconds with a range of 19&nbsp; seconds to 7.18&nbsp; minutes.<ref name="Stacey"/>
It surfaces in a rolling fashion and lifts its tail fluke clear of the water only for a deep dive. Deep dive times range from 30 to 150&nbsp;seconds to 12&nbsp;minutes. When 277 group dives were timed (time of disappearance of the last dolphin in the group to the emergence of the first dolphin in the group) in [[Laos]], the mean duration was 115.3&nbsp; seconds with a range of 19&nbsp; seconds to 7.18&nbsp; minutes.<ref name="Stacey"/>


[[Interspecific competition]] has been observed when Irrawaddy dolphins were forced inshore and excluded by more specialized dolphins. When captive humpback dolphins (''Sousa chinensis'') and Irrawaddy dolphins were held together, reportedly the Irrawaddy dolphins were frequently chased and confined to a small portion of the tank by the dominant humpbacks. In [[Chilika Lake]], local fishers say when Irrawaddy dolphins and [[bottlenose dolphins]] meet in the outer channel, the former get frightened and are forced to return toward the lake.<ref name="Sinha"/>
[[Interspecific competition]] has been observed when Irrawaddy dolphins were forced inshore and excluded by more specialized dolphins. When captive humpback dolphins (''Sousa chinensis'') and Irrawaddy dolphins were held together, reportedly the Irrawaddy dolphins were frequently chased and confined to a small portion of the tank by the dominant humpbacks. In [[Chilika Lake]], local fishers say when Irrawaddy dolphins and [[bottlenose dolphins]] meet in the outer channel, the former get frightened and are forced to return toward the lake.<ref name="Sinha"/>


===Mating===
===Mating===
A female or male dolphin will attempt to pursue a mate for about a few minutes. They intertwine facing their bellies together and begin to copulate for 40 seconds. Once copulation has occurred, the dolphins will break away from each other and set off in different directions.<ref name=":1" />
A female or male dolphin will attempt to pursue a mate for about a few minutes. They intertwine, facing their bellies together, and begin to copulate for 40 seconds. Once copulation has occurred, the dolphins will break away from each other and set off in different directions.<ref name=":1" />


===Reproduction===
===Reproduction===
Line 66: Line 66:
There are plenty of food items that this dolphin feeds upon. They include fish, crustaceans, and cephalopods. During foraging periods, herds of about 7 dolphins will circle around prey and trap their victim. These prey entrapments occur slightly below the water surface level.<ref name=":1">{{cite journal |last1=Ponnampalam |first1=Louisa S. |last2=Hines |first2=Ellen M. |last3=Monanunsap |first3=Somchai |last4=Ilangakoon |first4=Anoukchika D. |last5=Junchompoo |first5=Chalatip |last6=Adulyanukosol |first6=Kanjana |last7=Morse |first7=Laura J. |year=2013 |title=Behavioral Observations of Coastal Irrawaddy Dolphins (Orcaella Brevirostris) in Trat Province, Eastern Gulf of Thailand |journal=Aquatic Mammals |volume=39 |issue=4 |pages=401–408 |doi=10.1578/AM.39.4.2013.401}}</ref>
There are plenty of food items that this dolphin feeds upon. They include fish, crustaceans, and cephalopods. During foraging periods, herds of about 7 dolphins will circle around prey and trap their victim. These prey entrapments occur slightly below the water surface level.<ref name=":1">{{cite journal |last1=Ponnampalam |first1=Louisa S. |last2=Hines |first2=Ellen M. |last3=Monanunsap |first3=Somchai |last4=Ilangakoon |first4=Anoukchika D. |last5=Junchompoo |first5=Chalatip |last6=Adulyanukosol |first6=Kanjana |last7=Morse |first7=Laura J. |year=2013 |title=Behavioral Observations of Coastal Irrawaddy Dolphins (Orcaella Brevirostris) in Trat Province, Eastern Gulf of Thailand |journal=Aquatic Mammals |volume=39 |issue=4 |pages=401–408 |doi=10.1578/AM.39.4.2013.401}}</ref>


== Habitat and subpopulations ==
== Distribution and habitat ==
[[File:DSC 0764f.jpg|thumb|Irrawaddy Dolphin in Chilika Lake, Odisha]]
[[File:DSC 0764f.jpg|thumb|Irrawaddy Dolphin in Chilika Lake, Odisha]]
Although sometimes called the Irrawaddy river dolphin, it is not a true [[river dolphin]], but an [[oceanic dolphin]] that lives in [[brackish water]] near coasts, river mouths, and estuaries. It has established subpopulations in freshwater rivers, including the [[Ganges]] and the [[Mekong]], as well as the [[Ayeyarwady River|Irrawaddy River]] from which it takes its name. Its range extends from the [[Bay of Bengal]] to [[New Guinea]] and the [[Philippines]], although it does not appear to venture off shore. It is often seen in estuaries and bays in [[Borneo]] Island, with sightings from [[Sandakan]] in Sabah, [[Malaysia]], to most parts of [[Brunei]] and [[Sarawak]], Malaysia.<ref>{{cite journal |author1=Nurul-Filzati Ali |author2=Leela Rajamani |author3=Azimah Abd Rahman |author4=Lindsay Porter |author5=Sim Yee Kwang |author6=Nik Fadzly |title=Habitat use and behaviour of the Irrawaddy dolphin, ''Orcaella brevirostris'' and the Indo-Pacific finless porpoise, ''Neophocaena phocaenoides'' off the west coast of Penang Island, Malaysia |url=https://lkcnhm.nus.edu.sg/publications/raffles-bulletin-of-zoology/volumes/volume-71/ |journal=Raffles Bulletin of Zoology |date=2023 |volume=71 |pages=169–194 |doi=10.26107/RBZ-2023-0013}}</ref>{{rp|170}} A specimen was collected at [[Mahakam River]] in [[East Kalimantan]],<ref name="IUCN"/> the local name ''pesut mahakam'' comes from it.<ref name="FS"/>{{rp|1}}
The Irrawaddy dolphin is an [[oceanic dolphin]] that lives in [[brackish water]] near coasts, river mouths, and estuaries. It has established subpopulations in freshwater rivers, including the [[Ganges]] and the [[Mekong]], as well as the [[Ayeyarwady River]], from which it takes its name. Its range extends from the [[Bay of Bengal]] to [[New Guinea]] and the [[Philippines]], although it does not appear to venture offshore. It is often seen in estuaries and bays of [[Borneo]], with sightings from [[Sandakan]] in Sabah to most parts of [[Brunei]] and [[Sarawak]],<ref>{{cite journal |author1=Nurul-Filzati Ali |author2=Leela Rajamani |author3=Azimah Abd Rahman |author4=Lindsay Porter |author5=Sim Yee Kwang |author6=Nik Fadzly |title=Habitat use and behaviour of the Irrawaddy dolphin, ''Orcaella brevirostris'' and the Indo-Pacific finless porpoise, ''Neophocaena phocaenoides'' off the west coast of Penang Island, Malaysia |url=https://lkcnhm.nus.edu.sg/publications/raffles-bulletin-of-zoology/volumes/volume-71/ |journal=Raffles Bulletin of Zoology |year=2023 |volume=71 |pages=169–194 |doi=10.26107/RBZ-2023-0013}}</ref>{{rp|170}} and another specimen was collected at [[Mahakam River]] in [[East Kalimantan]].<ref name="IUCN"/> Its presence in Chinese, Taiwanese, and Hong Kong waters has been questioned, as the reported sightings have been considered unreliable.<ref>{{cite journal |last1=Kaiya |first1=Z. |last2=Leatherwood |first2=S. |last3=Jefferson |first3=T. A. |year=1995 |title=Records of Small Cetaceans in Chinese Waters: A Review |journal=Asian Marine Biology |volume=12 |pages=119–139 |url=https://swfsc.noaa.gov/uploadedFiles/Divisions/PRD/Publications/Zhouetal95(26).pdf |archive-url=https://web.archive.org/web/20111019221402/https://swfsc.noaa.gov/uploadedFiles/Divisions/PRD/Publications/Zhouetal95(26).pdf |archive-date=19 October 2011}}</ref>
 
* [[Bangladesh]]: ~3,500 in coastal waters of the Bay of Bengal<ref>{{cite news |year=2018 |title=Half of world's Irrawaddy dolphins in Bangladesh: survey |url=https://www.thedailystar.net/city/news/half-worlds-irrawaddy-dolphins-bangladesh-survey-1651597 |work=The Daily Star}}</ref> and 451 (VU) in the brackish [[Sundarbans]] mangrove forest<ref>{{cite journal |last1=Smith |first1=Brian D. |last2=Braulik |first2=G. |last3=Strindberg |first3=S. |last4=Benazir |first4=A. |last5=Rubaiyat |first5=M. |year=2006 |title=Abundance of Irrawaddy dolphins ''(Orcaella brevirostris)'' and Ganges river dolphins ''(Platanista Gangetica gangetica)'' estimated using concurrent counts made by independent teams in waterways of the Sundarbans mangrove forest in Bangladesh |id={{INIST|17896937}} |journal=Marine Mammal Science |volume=22 |issue=3 |pages=527–547 |doi=10.1111/j.1748-7692.2006.00041.x |bibcode=2006MMamS..22..527S}}</ref>
Presence of the species in Chinese, Taiwanese, and Hong Kong's waters has been questioned as the reported sightings have been considered unreliable,<ref>{{cite journal |last1=Kaiya |first1=Zhou |last2=Leatherwood |first2=Stephen |last3=Jefferson |first3=Thomas A. |date=1995 |title=Records of Small Cetaceans in Chinese Waters: A Review |url=https://swfsc.noaa.gov/uploadedFiles/Divisions/PRD/Publications/Zhouetal95(26).pdf |journal=Asian Marine Biology |volume=12 |pages=119–139 |archive-url=https://web.archive.org/web/20111019221402/https://swfsc.noaa.gov/uploadedFiles/Divisions/PRD/Publications/Zhouetal95(26).pdf |archive-date=19 October 2011}}</ref> and the easternmost of ranges along Eurasian continent is in [[Vietnam]].
* India: 156 in the brackish-water [[Chilika Lake]], [[Odisha]], as of 2021.<ref>{{cite news |year=2021 |title=Dolphin population in Odisha's Chilika Lake rises to 156 |url=https://www.financialexpress.com/lifestyle/science/dolphin-population-in-odishas-chilika-lake-rises-to-156/2172181/ |work=The Financial Express |access-date=2021-01-29}}</ref>
 
* [[Cambodia]]: ~105 in a 190-km (118-mi) freshwater stretch of the [[Mekong River]] as of 2024<ref name=Ryan2011>{{cite journal |last1=Ryan |first1=G. E. |last2=Dove |first2=V. |last3=Trujillo |first3=F. |last4=Doherty |first4=P. F. |year=2011 |title=Irrawaddy dolphin demography in the Mekong River: An application of mark-resight models |journal=Ecosphere |volume=2 |issue=5 |pages=art58 |doi=10.1890/ES10-00171.1 |doi-access=free |bibcode=2011Ecosp...2...58R}}</ref><ref>{{cite news |url=https://www.france24.com/en/live-news/20240701-hope-for-mekong-dolphins-as-cambodia-numbers-increase-minister |title=Hope for Mekong dolphins as Cambodia numbers increase: minister |publisher=France 24 |year=2024 |access-date=24 July 2024}}</ref>
No range-wide survey has been conducted for this vulnerable species; however, the worldwide population appears to be over 7,000. In India, Irawaddy dolphins are mostly found in [[Chilika Lake]]. Known subpopulations of Irrawaddy dolphins are found in eight places, listed here in order of population, including [[conservation status]].
* [[Indonesia]]: ~70, in a 420-km (260-mi) stretch of the freshwater [[Mahakam River]]
[[File:Chilika lake.png|right|thumb|[[Chilka Lake]], [[Odisha]], India, habitat of Irrawaddy dolphins]]
* Philippines: ~35 in the brackish inner [[Malampaya Sound]], [[Palawan]], at least 20 in [[Quezon, Palawan|Quezon]] in southern Palawan,<ref>{{cite news |title=New population of rare Irrawaddy Dolphins found in Palawan |work=WWF |url=https://wwf.panda.org/wwf_news/?208457/New-Population-of-Rare-Irrawaddy-Dolphins-Found-in-Palawan}}</ref> 30–40 in the waters of [[Pulupandan]], [[Bago, Negros Occidental]], [[Guimaras]] and [[Iloilo]] in the Western Visayas Region and Negros Island Region,<ref>{{cite news |title=Rare dolphins make Negros coastal waters their home |url=http://www.gmanews.tv/story/200345/rare-dolphins-make-negros-coastal-waters-their-home |work=GMA News |year=2010 |access-date=22 December 2015}}</ref> and at least two in [[San Miguel Bay]], [[Bicol Region|Bicol]], the easternmost population and the only population in the Pacific Ocean.<ref>{{cite web |title=Survey confirms disappearing population of critically-endangered Irrawaddy dolphins in Bicol |date=12 July 2023 |url=https://science.upd.edu.ph/survey-confirms-disappearing-population-of-critically-endangered-irrawaddy-dolphins-in-bicol/}}</ref><ref>{{cite web |title=Newly-discovered dolphin in Bicol hints at biodiversity under threat - SCIENCE - University of the Philippines Diliman |date=4 November 2022 |url=https://science.upd.edu.ph/newly-discovered-dolphin-in-bicol-hints-at-biodiversity-under-threat/}}</ref>
# [[Bangladesh]]: ~3500 ([[Vulnerable species|VU]]) in coastal waters of the Bay of Bengal<ref>{{cite news |date=2018-10-25 |title=Half of world's Irrawaddy dolphins in Bangladesh: survey |url=https://www.thedailystar.net/city/news/half-worlds-irrawaddy-dolphins-bangladesh-survey-1651597 |newspaper=The Daily Star }}</ref> and 451 (VU) in the brackish [[Sundarbans]] mangrove forest<ref>{{cite journal |last1=Smith |first1=Brian D. |last2=Braulik |first2=Gill |last3=Strindberg |first3=Samantha |last4=Benazir |first4=Ahmed |last5=Rubaiyat |first5=Mansur |date=July 2006 |title=Abundance of Irrawaddy dolphins ''(Orcaella brevirostris)'' and Ganges river dolphins ''(Platanista Gangetica gangetica)'' estimated using concurrent counts made by independent teams in waterways of the Sundarbans mangrove forest in Bangladesh |id={{INIST|17896937}} |journal=Marine Mammal Science |volume=22 |issue=3 |pages=527–547 |doi=10.1111/j.1748-7692.2006.00041.x |bibcode=2006MMamS..22..527S }}</ref>
* [[Myanmar]]: ~58-72 in a 370-km (230-mi) freshwater stretch of the [[Ayeyarwady River]]
# [[India]]: 156 (VU) in the brackish-water [[Chilika Lake]], [[Odisha]].<ref>{{cite news |date=2021-01-16 |title=Dolphin population in Odisha's Chilika Lake rises to 156 |url=https://www.financialexpress.com/lifestyle/science/dolphin-population-in-odishas-chilika-lake-rises-to-156/2172181/ |newspaper=The Financial Express |access-date=2021-01-29}}</ref> Presence recorded from [[Sundarbans National Park]], [[West Bengal]] also.
* [[Thailand]]: less than 50 in the brackish [[Songkhla Lake]],<ref name=IUCN/> perhaps just 14.<ref>{{cite news |title=Irrawaddy dolphin death in Thailand's Songkhla Lake underscores conservation needs |author=Cowan, C. |work=Mongabay |year=2024 |url=https://news.mongabay.com/2024/03/irrawaddy-dolphin-death-in-thailands-songkhla-lake-underscores-conservation-needs/ |access-date=16 April 2024}}</ref>
# [[Cambodia]]: ~105 ([[critically endangered|CR]]) in a 190-km (118-mi) freshwater stretch of the [[Mekong River]]<ref>{{cite news |date=2019-04-05 |title=Cambodia's endangered river dolphins at highest population in 20 years |url=https://www.nationalgeographic.com/animals/article/irawaddy-river-dolphin-population-biggest-20-years |archive-url=https://web.archive.org/web/20210419120237/https://www.nationalgeographic.com/animals/article/irawaddy-river-dolphin-population-biggest-20-years |url-status=dead |archive-date=April 19, 2021 |newspaper=National Geographic }}</ref><ref name="Ryan2011">{{cite journal |last1=Ryan |first1=Gerard Edward |last2=Dove |first2=Verné |last3=Trujillo |first3=Fernando |last4=Doherty |first4=Paul F. |date=May 2011 |title=Irrawaddy dolphin demography in the Mekong River: An application of mark-resight models |journal=Ecosphere |volume=2 |issue=5 |pages=art58 |doi=10.1890/ES10-00171.1 |doi-access=free |bibcode=2011Ecosp...2...58R }}</ref><ref>{{cite news |url=https://www.france24.com/en/live-news/20240701-hope-for-mekong-dolphins-as-cambodia-numbers-increase-minister |title=Hope for Mekong dolphins as Cambodia numbers increase: minister |work=France 24 |date=1 July 2024 |access-date=24 July 2024}}</ref> (extinct in Laos since 2022)<ref name=":2">{{Cite web |title=WWF-Laos is saddened by the death of the last known river dolphin in the transboundary pool in |url=https://www.wwf.org.la/?372355/ |access-date=2025-02-18 |website=www.wwf.org.la |language=en}}</ref>
It has been extinct in Laos since 2022.<ref name=":2">{{Cite web |title=WWF-Laos is saddened by the death of the last known river dolphin in the transboundary pool in |url=https://www.wwf.org.la/?372355/ |access-date=2025-02-18 |website=wwf.org.la |language=en}}</ref>
# [[Indonesia]]: ~70 (CR), in a 420-km (260-mi) stretch of the freshwater [[Mahakam River]]
# [[Philippines]]: ~42 (CR) in the brackish inner [[Malampaya Sound]].<ref>{{cite news |last=Rosero |first=Earl Victor L. |date=2012-02-20 |title=Only 42 left of endangered Irrawaddy dolphins in northern Palawan |url=http://www.gmanetwork.com/news/story/248688/news/regions/only-42-left-of-endangered-irrawaddy-dolphins-in-northern-palawan |work=[[GMA News]]}}</ref> Researchers are studying the recent discovery of 30-40 dolphins sighted in the waters of [[Pulupandan]] and [[Bago, Negros Occidental]], in Western Visayas.<ref>{{cite news |title=Rare dolphins make Negros coastal waters their home |url=http://www.gmanews.tv/story/200345/rare-dolphins-make-negros-coastal-waters-their-home |work=GMA News |date=6 September 2010 |access-date=22 December 2015}}</ref>
# [[Myanmar]] (Burma): ~58-72 (CR) in a 370-km (230-mi) freshwater stretch of the [[Ayeyarwady River]]
# [[Thailand]]: less than 50 (CR) in the brackish [[Songkhla Lake]],<ref name="IUCN"/> perhaps just 14.<ref>{{cite news |url=https://news.mongabay.com/2024/03/irrawaddy-dolphin-death-in-thailands-songkhla-lake-underscores-conservation-needs/ |title=Irrawaddy dolphin death in Thailand's Songkhla Lake underscores conservation needs |author=Carolyn Cowan |work=Mongabay |date=19 March 2024 |access-date=16 April 2024}}</ref>


==Interaction with humans==
==Interaction with humans==
Irrawaddy dolphins have a [[Mutualism (biology)|mutualistic relationship]] of co-operative fishing with traditional fishers. Fishers in India recall when they would call out to the dolphins, by tapping a wooden key also known as a ''lahai kway'',<ref>Koss, Melissa. "Orcaella Brevirostris." Animaldiversity.umich.edu. Animal Diversity Web, n.d. Web. Retrieved 2014-10-19</ref> against the sides of their boats, asking the Irrawaddys to drive fish into their nets.<ref>{{cite web |url=http://www.wdcs.org/submissions_bin/dolphin-human_interactions_chilika.pdf |title=Dolphin-human interactions, Chilika |last=D'Lima |first=Coralie |year=2008 |website=Whale and Dolphin Conservation Society |archive-url=https://web.archive.org/web/20090319102122/http://www.wdcs.org/submissions_bin/dolphin-human_interactions_chilika.pdf |archive-date=2009-03-19 |access-date=2008-12-21}}</ref> In Burma, in the upper reaches of the Ayeyarwady River, Irrawaddy dolphins drive fish towards fishers using [[cast net]]s in response to acoustic signals from them. The fishermen attempt to gain the attention of the dolphins through various efforts such as using a cone-shaped wooden stick to drum the side of their canoes, striking their paddles to the surface of the water, jingling their nets, or making calls that sound turkey-like. A pod of dolphins that agrees to work alongside the fisherman will entrap a school of fish in a semicircle, guiding them towards the boat.<ref name=":0">{{cite journal |last1=Smith |first1=Brian D. |last2=Tunb |first2=Mya Than |last3=Chita |first3=Aung Myo |last4=Winb |first4=Han |last5=Moeb |first5=Thida |date=May 2009 |title=Catch Composition and Conservation Management of a Human–Dolphin Cooperative Cast-Net Fishery in the Ayeyarwady River, Myanmar |journal=Biological Conservation |volume=142 |issue=5 |pages=1042–1049 |doi=10.1016/j.biocon.2009.01.015|bibcode=2009BCons.142.1042S }}</ref> In return, the dolphins are rewarded with some of the fishers' [[bycatch]].<ref>{{cite web|url=http://tinttun.mm.googlepages.com/irrawaddydolphin|title=Castnet Fishing with the Help of Irrawaddy Dolphins|last=Tun|first=Tint|year=2008|work=Irrawaddy Dolphin|publisher=Yangon, Myanmar|access-date=2008-12-25|archive-date=2008-07-25|archive-url=https://web.archive.org/web/20080725115205/http://tinttun.mm.googlepages.com/irrawaddydolphin|url-status=dead}}</ref> Historically, Irrawaddy River fishers claimed particular dolphins were associated with individual fishing villages and chased fish into their nets. An 1879 report indicated legal claims were frequently brought into native courts by fishers to recover a share of the fish from the nets of a rival fisher that the plaintiff's dolphin was claimed to have helped fill.<ref name="Stacey"/>
Irrawaddy dolphins have a [[Mutualism (biology)|mutualistic relationship]] of co-operative fishing with traditional fishers. Fishers in India recall when they would call out to the dolphins by tapping a wooden key, also known as a ''lahai kway'',<ref>Koss, Melissa. "Orcaella Brevirostris." Animaldiversity.umich.edu. Animal Diversity Web, n.d. Web. Retrieved 2014-10-19</ref> against the sides of their boats, asking the Irrawaddys to drive fish into their nets.<ref>{{cite web |url=http://www.wdcs.org/submissions_bin/dolphin-human_interactions_chilika.pdf |title=Dolphin-human interactions, Chilika |last=D'Lima |first=Coralie |year=2008 |website=Whale and Dolphin Conservation Society |archive-url=https://web.archive.org/web/20090319102122/http://www.wdcs.org/submissions_bin/dolphin-human_interactions_chilika.pdf |archive-date=2009-03-19 |access-date=2008-12-21}}</ref> In Burma, in the upper reaches of the Ayeyarwady River, Irrawaddy dolphins drive fish towards fishers using [[cast net]]s in response to acoustic signals from them. The fishermen attempt to gain the attention of the dolphins through various efforts such as using a cone-shaped wooden stick to drum the side of their canoes, striking their paddles to the surface of the water, jingling their nets, or making calls that sound turkey-like. A pod of dolphins that agrees to work alongside the fisherman will entrap a school of fish in a semicircle, guiding them towards the boat.<ref name=":0">{{cite journal |last1=Smith |first1=Brian D. |last2=Tunb |first2=Mya Than |last3=Chita |first3=Aung Myo |last4=Winb |first4=Han |last5=Moeb |first5=Thida |date=May 2009 |title=Catch Composition and Conservation Management of a Human–Dolphin Cooperative Cast-Net Fishery in the Ayeyarwady River, Myanmar |journal=Biological Conservation |volume=142 |issue=5 |pages=1042–1049 |doi=10.1016/j.biocon.2009.01.015 |bibcode=2009BCons.142.1042S}}</ref> In return, the dolphins are rewarded with some of the fishers' [[bycatch]].<ref>{{cite web |url=http://tinttun.mm.googlepages.com/irrawaddydolphin |title=Castnet Fishing with the Help of Irrawaddy Dolphins |last=Tun |first=Tint |year=2008 |work=Irrawaddy Dolphin |publisher=Yangon, Myanmar |access-date=2008-12-25 |archive-date=2008-07-25 |archive-url=https://web.archive.org/web/20080725115205/http://tinttun.mm.googlepages.com/irrawaddydolphin}}</ref> Historically, Irrawaddy River fishers claimed particular dolphins were associated with individual fishing villages and chased fish into their nets. An 1879 report indicated legal claims were frequently brought into native courts by fishers to recover a share of the fish from the nets of a rival fisher that the plaintiff's dolphin was claimed to have helped fill.<ref name="Stacey"/>


=== Folk stories ===
=== Folk stories ===
Laotians and Cambodians have a common belief that the Irrawaddy dolphins are reincarnations of their ancestors. Some even claim that the dolphins have saved drowning villagers and protected people from attacks by crocodiles. Their beliefs and experiences have led the people of Laos and Cambodia to live peacefully alongside one another for ages.<ref name="EIJ"/> The West Kalimantan people have a similar story where the dolphins were naughty children that ate a pot of rice reserved for the shaman, but their mouths scalded and jumped into the water to cool themselves, but later transformed into these dolphins.<ref name="FS"/>{{rp|5-6}}  
Laotians and Cambodians have a common belief that the Irrawaddy dolphins are reincarnations of their ancestors. Some even claim that the dolphins have saved drowning villagers and protected people from attacks by crocodiles. Their beliefs and experiences have led the people of Laos and Cambodia to live peacefully alongside one another for ages.<ref name="EIJ"/> The West Kalimantan people have a similar story where the dolphins were naughty children who ate a pot of rice reserved for the shaman, but their mouths scalded, and they jumped into the water to cool themselves, and later transformed into these dolphins.<ref name="FS"/>{{rp|5–6}}


Buddhist Khmer and Vietnamese fishermen have regarded the ''Orcaella'' as a sacred animal. If caught in fishing nets, they release the dolphin from the rest of the catch. In contrast, Muslim Khmer fisherman kill them for food. This has led to the dolphin becoming reputed to recognize the local languages of the area and it approaching areas of the Khmer Muslim community with caution.<ref>{{cite book |last1=Marsh |first1=H. |last2=Lloze |first2=R. |last3=Heinsohn |first3=G.E. |last4=Kasuya |first4=T. |year=1989 |chapter=Irrawaddy dolphin - ''Orcaella brevirostris'' (Gray, 1866) |editor-last=Ridgway |editor-first1=Sam H. |editor-last2=Harrison |editor-first2=Richard |title=Handbook of marine mammals |volume=4: River dolphins and the larger toothed whales |url= |location=London, UK |publisher= Academic Press |pages= 101–118 |isbn=978-0-08-057316-8}}
Buddhist Khmer and Vietnamese fishermen have regarded the ''Orcaella'' as a sacred animal. If caught in fishing nets, they release the dolphin from the rest of the catch. In contrast, Muslim Khmer fishermen kill them for food. This has led to the dolphin becoming reputed to recognize the local languages of the area and approaching areas of the Khmer Muslim community with caution.<ref>{{cite book |last1=Marsh |first1=H. |last2=Lloze |first2=R. |last3=Heinsohn |first3=G.E. |last4=Kasuya |first4=T. |year=1989 |chapter=Irrawaddy dolphin - ''Orcaella brevirostris'' (Gray, 1866) |editor-last=Ridgway |editor-first1=Sam H. |editor-last2=Harrison |editor-first2=Richard |title=Handbook of marine mammals |volume=4: River dolphins and the larger toothed whales |url= |location=London, UK |publisher=Academic Press |pages=101–118 |isbn=978-0-08-057316-8}}</ref>
</ref>


==Threats==
==Threats==
[[File:BD-fishermen.jpg|thumb|Fishermen with fishnets in [[Bangladesh]]]]
[[File:BD-fishermen.jpg|thumb|Fishermen with fishnets in [[Bangladesh]]]]
Irrawaddy dolphins are more susceptible to human conflict than most other dolphins that live farther out in the ocean. Drowning in [[gillnet]]s is the main threat to them throughout their range. Between 1995 and 2001, 38 deaths were reported and 74% died as a result of entanglement in gillnets with large mesh sizes.<ref name="Kreb 178–188">{{cite journal |last1=Kreb |first1=Daniëlle |title=Conservation management of small core areas: key to survival of a Critically Endangered population of Irrawaddy river dolphins Orcaella brevirostris in Indonesia |journal=Oryx |date=2005 |volume=39 |issue=2 |pages=178–188 |id={{ProQuest|222306641}} |doi=10.1017/S0030605305000426 |s2cid=84589264 |doi-access=free }}</ref> The majority of reported dolphin deaths in all subpopulations is due to accidental capture and drowning in gillnets and [[Trawling|dragnets]], and in the Philippines, bottom-set crabnets. In Burma, [[electrofishing]], [[gold mining]], and dam building are also serious and continuing threats. Though most fishers are sympathetic to the dolphins' plight,  abandoning their traditional livelihood is difficult for them.<ref name="IUCN"/>
Irrawaddy dolphins are more susceptible to human conflict than most other dolphins that live farther out in the ocean. Drowning in [[gillnet]]s is the main threat to them throughout their range. Between 1995 and 2001, 38 deaths were reported, and 74% died as a result of entanglement in gillnets with large mesh sizes.<ref name="Kreb 178–188">{{cite journal |last1=Kreb |first1=Daniëlle |title=Conservation management of small core areas: key to survival of a Critically Endangered population of Irrawaddy river dolphins Orcaella brevirostris in Indonesia |journal=Oryx |year=2005 |volume=39 |issue=2 |pages=178–188 |id={{ProQuest|222306641}} |doi=10.1017/S0030605305000426 |s2cid=84589264 |doi-access=free}}</ref> The majority of reported dolphin deaths in all subpopulations are due to accidental capture and drowning in gillnets and [[Trawling|dragnets]], and in the Philippines, bottom-set crab nets. In Burma, [[electrofishing]], [[gold mining]], and dam building are also serious and continuing threats. Though most fishers are sympathetic to the dolphins' plight,  abandoning their traditional livelihood is difficult for them.<ref name="IUCN"/>


Another identified threat towards the Irrawaddy dolphins was noise pollution from high-speed vessels. This caused the dolphins to dive significantly longer than usual. The Irrawaddy dolphins always changed directions when they encountered these large vessels.<ref name="Kreb 178–188"/>
Another identified threat towards the Irrawaddy dolphins was noise pollution from high-speed vessels. This caused the dolphins to dive significantly longer than usual. The Irrawaddy dolphins always changed directions when they encountered these large vessels.<ref name="Kreb 178–188"/>


In recent years, Laotians and Cambodians developed techniques of using explosives for fishing. The government of Laos has made use of such tactics illegal, but few regulations have been made in neighboring Cambodia, where explosives are sold in local markets and the practice of using fishnets has been abandoned. The practice of using explosives instead has become very popular and led to a steady decline of populations of fish, and especially the dolphins swimming in the area. Although Laotians may not use explosives, they do use nylon gillnets, which pose another large threat to the survival of the Irrawaddy. Some dolphins accidentally become entangled in the net. Poor fishermen refuse to cut and destroy their nets because it would result in too great of an economic loss to save one Irrawaddy dolphin.<ref name="EIJ">{{cite magazine |last=Baird |first=Ian |date=Fall 1992 |title=New Campaign To Save Dolphins In Laos |magazine=Earth Island Journal |publisher=[[Earth Island Institute]] |volume=7 |issue=4 |page=7 |issn=1041-0406}}</ref>
In recent years, Laotians and Cambodians developed techniques of using explosives for fishing. The government of Laos has made the use of such tactics illegal, but few regulations have been made in neighboring Cambodia, where explosives are sold in local markets and the practice of using fishnets has been abandoned. The practice of using explosives instead has become very popular and led to a steady decline of populations of fish, and especially the dolphins swimming in the area. Although Laotians may not use explosives, they do use nylon gillnets, which pose another large threat to the survival of the Irrawaddy. Some dolphins accidentally become entangled in the net. Poor fishermen refuse to cut and destroy their nets because it would result in too great an economic loss to save one Irrawaddy dolphin.<ref name="EIJ">{{cite magazine |last=Baird |first=Ian |date=Fall 1992 |title=New Campaign To Save Dolphins In Laos |magazine=Earth Island Journal |publisher=[[Earth Island Institute]] |volume=7 |issue=4 |page=7 |issn=1041-0406}}</ref>


In Laos, a dam across the Mekong River is planned. This could threaten the existence of the endangered Irrawaddy dolphins in downstream Cambodia. Laos's government decision is to forge the dam upstream of the core habitat of the Irrawaddy dolphins. This could precipitate the extinction of this specific species in the Mekong River. The dam builders' proposal is to use explosives to dig out the tons of rock. This will create strong sound waves that could possibly kill the Irrawaddy dolphins due to their highly sensitive hearing structures.{{citation needed|date=April 2021}}
In Laos, a dam across the Mekong River is planned. This could threaten the existence of the endangered Irrawaddy dolphins in downstream Cambodia. Laos's government decision is to forge the dam upstream of the core habitat of the Irrawaddy dolphins. This could precipitate the extinction of this specific species in the Mekong River. The dam builders propose to use explosives to dig out the tons of rock. This will create strong sound waves that could kill the Irrawaddy dolphins due to their highly sensitive hearing structures.{{citation needed|date=April 2021}}


In several Asian countries, Irrawaddy dolphins have been captured and trained to perform in [[public aquarium|public aquaria]]. Their charismatic appearance and unique behaviors, including spitting water, [[Cetacean surfacing behaviour#Spyhopping|spyhopping]], and [[Cetacean surfacing behaviour#Lobtailing and slapping|fluke-slapping]], make them very popular for shows in [[dolphinarium|dolphinaria]]. The commercial motivation for using this dolphin species is high because it can live in freshwater tanks and the high cost of [[marine aquarium]] systems is avoided. The region within and near the species' range has developed economically; theme parks, casinos, and other entertainment venues that include dolphin shows have increased.
In several Asian countries, Irrawaddy dolphins have been captured and trained to perform in [[public aquarium|public aquaria]]. Their charismatic appearance and unique behaviors, including spitting water, [[Cetacean surfacing behaviour#Spyhopping|spyhopping]], and [[Cetacean surfacing behaviour#Lobtailing and slapping|fluke-slapping]], make them very popular for shows in [[dolphinarium]]s. The commercial motivation for using this dolphin species is high because it can live in freshwater tanks, and the high cost of [[marine aquarium]] systems is avoided. The region within and near the species' range has developed economically; theme parks, casinos, and other entertainment venues that include dolphin shows have increased.


In 2002, there were more than 80 dolphinariums in at least nine Asian countries.<ref name="Vert">{{cite press release |url=http://www.worldwildlife.org/press-releases/irrawaddy-dolphins-gain-trade-protection-under-cites-wwf-urges-countries-to-stop-all-live-captures |title=Irrawaddy Dolphins Gain Trade Protection Under CITES; WWF Urges Countries to Stop All Live Captures |website=World Wildlife Fund |date=2004-10-08 |access-date=2008-12-29}}</ref>
In 2002, there were more than 80 dolphinariums in at least nine Asian countries.<ref name="Vert">{{cite press release |url=http://www.worldwildlife.org/press-releases/irrawaddy-dolphins-gain-trade-protection-under-cites-wwf-urges-countries-to-stop-all-live-captures |title=Irrawaddy Dolphins Gain Trade Protection Under CITES; WWF Urges Countries to Stop All Live Captures |website=World Wildlife Fund |date=2004-10-08 |access-date=2008-12-29}}</ref>
Line 107: Line 102:
[[Collateral damage|Collateral deaths]] of dolphins due to [[blast fishing]] were once common in [[Vietnam]] and [[Thailand]]. In the past, the most direct threat was killing them for their oil.
[[Collateral damage|Collateral deaths]] of dolphins due to [[blast fishing]] were once common in [[Vietnam]] and [[Thailand]]. In the past, the most direct threat was killing them for their oil.


The [[IUCN]] lists five of the seven subpopulations as [[endangered]], primarily due to drowning in fish nets.<ref name="IUCN"/> For example, the Malampaya population, first discovered and described in 1986, at the time consisted of 77 individuals. Due to anthropogenic activities, this number dwindled to 47 dolphins in 2007.<ref name="PInqYan">{{cite news |last=Yan |first=Gregg |title=WWF: Rare Palawan dolphins now down to 47 |newspaper=Philippine Daily Inquirer |date=2007-03-08 |pages=A1, A6 |quote=In 1986, a thriving colony was discovered in the inner portion of Malampaya Sound ... the population was pegged at 77 ... Each month more people come to Malampaya, lured by the bounty of its rich waters. Many use traps that are left untended ... Ever curious, the Irrawaddies play amid the traps. Inevitably, some become entangled ... number of dolphins is estimated to have gone down to 47 ... catching crabs and other sustenance fishing methods have been identified as the main culprits for dolphin deaths.}}</ref> In the Mahakam River in Borneo, 73% of dolphin deaths are related to entanglement in gillnets, due to heavy fishing and boat traffic.<ref>Kreb D, Budiono (2005). Conservation management of small core areas: key to survival of a Critically Endangered population of Irrawaddy river dolphins ''Orcaella brevirostris'' in Indonesia. ''Oryx'' 39: 178-188.</ref>
The [[IUCN]] lists five of the seven subpopulations as [[endangered]], primarily due to drowning in fish nets.<ref name="IUCN"/> For example, the Malampaya population, first discovered and described in 1986, at the time consisted of 77 individuals. Due to anthropogenic activities, this number dwindled to 47 dolphins in 2007,<ref name="PInqYan">{{cite news |last=Yan |first=Gregg |title=WWF: Rare Palawan dolphins now down to 47 |newspaper=Philippine Daily Inquirer |date=2007-03-08 |pages=A1, A6 |quote=In 1986, a thriving colony was discovered in the inner portion of Malampaya Sound ... the population was pegged at 77 ... Each month more people come to Malampaya, lured by the bounty of its rich waters. Many use traps that are left untended ... Ever curious, the Irrawaddies play amid the traps. Inevitably, some become entangled ... number of dolphins is estimated to have gone down to 47 ... catching crabs and other sustenance fishing methods have been identified as the main culprits for dolphin deaths.}}</ref> which further dwindled to 35 by 2013.<ref>{{cite web | title=Malampaya Sound: Watching Rare Irrawaddy Dolphins in Taytay, Palawan &#124; EAZY Traveler | date=28 July 2022 | url=https://eazytraveler.net/2022/07/irrawaddy-dolphin-watching-philippines-palawan-taytay-malampaya-sound/#google_vignette }}</ref> In the Mahakam River in Borneo, 73% of dolphin deaths are related to entanglement in gillnets, due to heavy fishing and boat traffic.<ref>Kreb D, Budiono (2005). Conservation management of small core areas: key to survival of a Critically Endangered population of Irrawaddy river dolphins ''Orcaella brevirostris'' in Indonesia. ''Oryx'' 39: 178-188.</ref>


===Tourism===
===Tourism===
The Irrawaddy dolphins in Asia are increasingly threatened by tourist activity, such as large numbers of boats circulating the areas in which they live. The development of tours and boats has put a large strain on the dolphins.<ref>{{cite news |last=Dash |first=Jatindra |date=2008-03-02 |title=Tourism threatens rare Irrawaddy dolphins |url=http://www.thaindian.com/newsportal/enviornment/tourism-threatens-rare-irrawaddy-dolphins_10023045.html |newspaper=Thainidian News |agency=Indo-Asian News Service |access-date=2015-10-30 |archive-date=2008-04-05 |archive-url=https://web.archive.org/web/20080405144021/http://www.thaindian.com/newsportal/enviornment/tourism-threatens-rare-irrawaddy-dolphins_10023045.html |url-status=dead }}</ref>
The Irrawaddy dolphins in Asia are increasingly threatened by tourist activity, such as large numbers of boats circulating the areas in which they live. The development of tours and boats has put a large strain on the dolphins.<ref>{{cite news |last=Dash |first=Jatindra |date=2008-03-02 |title=Tourism threatens rare Irrawaddy dolphins |url=http://www.thaindian.com/newsportal/enviornment/tourism-threatens-rare-irrawaddy-dolphins_10023045.html |newspaper=Thainidian News |agency=Indo-Asian News Service |access-date=2015-10-30 |archive-date=2008-04-05 |archive-url=https://web.archive.org/web/20080405144021/http://www.thaindian.com/newsportal/enviornment/tourism-threatens-rare-irrawaddy-dolphins_10023045.html}}</ref>


===Disease===
===Disease===
Cutaneous nodules were found present in various vulnerable populations of Irrawaddy dolphins. A more precise estimate of the affected dolphins is six populations. Although the definite fate of this emergent disease is unknown, the species is at risk.<ref>{{Cite web|title = Web of Science [v.5.19] - All Databases Full Record|url = http://apps.webofknowledge.com/full_record.do?product=UA&search_mode=GeneralSearch&qid=1&SID=3BCUyA7bqUOGp6f9duv&page=1&doc=10|website = apps.webofknowledge.com|access-date = 2015-10-30}}</ref>
Cutaneous nodules were found to be present in various vulnerable populations of Irrawaddy dolphins. A more precise estimate of the affected dolphins is six populations. Although the definite fate of this emergent disease is unknown, the species is at risk.<ref>{{Cite web |title=Web of Science [v.5.19] - All Databases Full Record |url=http://apps.webofknowledge.com/full_record.do?product=UA&search_mode=GeneralSearch&qid=1&SID=3BCUyA7bqUOGp6f9duv&page=1&doc=10 |website=apps.webofknowledge.com |access-date=2015-10-30}}</ref>


==Conservation==
==Conservation==
[[File:Stamp of Indonesia - 1996 - Colnect 253526 - Irrawaddy Dolphin Orcaella brevirostris.jpeg|thumb|Irrawaddy dolphin on a 1996 Indonesian stamp]]
[[File:Stamp of Indonesia - 1996 - Colnect 253526 - Irrawaddy Dolphin Orcaella brevirostris.jpeg|thumb|Irrawaddy dolphin on a 1996 Indonesian stamp]]
The Irrawaddy dolphin's proximity to developing communities makes the effort for conservation difficult.<ref>{{cite journal |last1=Beasley |first1=I. |last2=Pollock |first2 = K. |last3=Jefferson |first3=T. A. |last4=Arnold |first4=P. |last5=Morse |first5=L. |last6=Yim |first6=S. |last7=Lor Kim |first7=S. |last8=Marsh |first8=H. |date=July 2013 |title=Likely future extirpation of another Asian river dolphin: The critically endangered population of the Irrawaddy dolphin in the Mekong River is small and declining |journal=Marine Mammal Science |volume=29 |issue=3 |pages=E226–E252 |doi=10.1111/j.1748-7692.2012.00614.x }}</ref> Entanglement in fishnets and degradation of habitats are the main threats to Irrawaddy dolphins. Conservation efforts are being made at international and national levels to alleviate these threats.
The Irrawaddy dolphin's proximity to developing communities makes the effort for conservation difficult.<ref>{{cite journal |last1=Beasley |first1=I. |last2=Pollock |first2 = K. |last3=Jefferson |first3=T. A. |last4=Arnold |first4=P. |last5=Morse |first5=L. |last6=Yim |first6=S. |last7=Lor Kim |first7=S. |last8=Marsh |first8=H. |date=July 2013 |title=Likely future extirpation of another Asian river dolphin: The critically endangered population of the Irrawaddy dolphin in the Mekong River is small and declining |journal=Marine Mammal Science |volume=29 |issue=3 |pages=E226–E252 |doi=10.1111/j.1748-7692.2012.00614.x |bibcode=2013MMamS..29..226B }}</ref> Entanglement in fishnets and degradation of habitats are the main threats to Irrawaddy dolphins. Conservation efforts are being made at international and national levels to alleviate these threats.


===International efforts===
===International efforts===
Protection from international trade is provided by the Convention on International Trade in Endangered Species of Wild Fauna and Flora ([[CITES]]). Enforcement, though, is the responsibility of individual countries.<ref name="IUCN"/> While some international trade for dolphinarium animals may have occurred, this is unlikely to have ever been a major threat to the species.
Protection from international trade is provided by the Convention on International Trade in Endangered Species of Wild Fauna and Flora ([[CITES]]). Enforcement, though, is the responsibility of individual countries.<ref name="IUCN"/> While some international trade for dolphinarium animals may have occurred, this is unlikely to have ever been a major threat to the species.


Some Irrawaddy dolphin populations are classified by the IUCN as critically endangered; in Cambodia, Vietnam (Mekong River sub-population), Indonesia (Mahakam River sub-population, Borneo), Myanmar (Ayeyarwady/Irrawaddy River sub-population), the Philippines (Malampaya Sound sub-population), and Thailand (Songkhla Lake sub-population). Irrawaddy dolphins in general however, are IUCN listed as an [[Endangered species]], which applies throughout their whole range.<ref name="IUCN"/> In 2004, CITES transferred the Irrawaddy dolphin from [[Appendix II]] to [[CITES Appendix I|Appendix I]], which forbids all commercial trade in species that are threatened with extinction.<ref name="CITES">{{cite press release |title=CITES takes action to promote sustainable wildlife |url=https://www.cites.org/eng/news/pr/2004/041014_cop13final.shtml |publisher=Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) |date=2004-10-14 |access-date=2008-12-29}}</ref>
Some Irrawaddy dolphin populations are classified by the IUCN as critically endangered in Cambodia, Vietnam (Mekong River sub-population), Indonesia (Mahakam River sub-population, Borneo), Myanmar (Ayeyarwady/Irrawaddy River sub-population), the Philippines (Malampaya Sound sub-population), and Thailand (Songkhla Lake sub-population). Irrawaddy dolphins in general, however, are IUCN listed as an [[endangered species]], which applies throughout their whole range.<ref name="IUCN"/> In 2004, CITES transferred the Irrawaddy dolphin from [[Appendix II]] to [[CITES Appendix I|Appendix I]], which forbids all commercial trade in species that are threatened with extinction.<ref name="CITES">{{cite press release |title=CITES takes action to promote sustainable wildlife |url=https://www.cites.org/eng/news/pr/2004/041014_cop13final.shtml |publisher=Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) |date=2004-10-14 |access-date=2008-12-29}}</ref>


The [[UNEP]]-[[Bonn Convention|CMS]] Action Plan for the Conservation of Freshwater Populations of Irrawaddy dolphins notes that multiple-use [[protected areas]] will play a key role for conserving freshwater populations. Protected areas in fresh water could be a particularly effective conservation tool and can facilitate management, due to the fidelity of the species to relatively circumscribed areas. The Action Plan provides details on strategies for mitigating [[by-catch]] that includes:
The [[UNEP]]-[[Bonn Convention|CMS]] Action Plan for the Conservation of Freshwater Populations of Irrawaddy dolphins notes that multiple-use [[protected areas]] will play a key role in conserving freshwater populations. Protected areas in fresh water could be a particularly effective conservation tool and can facilitate management, due to the fidelity of the species to relatively circumscribed areas. The Action Plan provides details on strategies for mitigating [[by-catch]], including:
:-establishing core conservation areas where gillnetting is banned or severely restricted
:-establishing core conservation areas where gillnetting is banned or severely restricted
:-promoting net attendance rules and providing training on the safe release of entangled dolphins
:-promoting net attendance rules and providing training on the safe release of entangled dolphins
Line 132: Line 127:
:-experimenting with acoustical deterrents and reflective nets.<ref name="SmithBD">{{cite journal |last=Smith |first=Brian D. |date=2007-03-14 |others=Submitted by William Perrin |title=Conservation status of Irrawaddy Dolphins |journal=Convention on the Conservation Migratory Species of Wild Animals |url=http://www.cms.int/bodies/ScC/14th_scientific_council/pdf/en/ScC14_Doc_08_Irrawaddy_dolphins_Eonly.pdf |location=[[Bonn]], Germany |publisher=CMS/UNEP |volume=14th Meeting of the CMS Scientific Council |archive-url=https://web.archive.org/web/20071218100952/http://www.cms.int/bodies/ScC/14th_scientific_council/pdf/en/ScC14_Doc_08_Irrawaddy_dolphins_Eonly.pdf |archive-date=2007-12-18}}</ref>
:-experimenting with acoustical deterrents and reflective nets.<ref name="SmithBD">{{cite journal |last=Smith |first=Brian D. |date=2007-03-14 |others=Submitted by William Perrin |title=Conservation status of Irrawaddy Dolphins |journal=Convention on the Conservation Migratory Species of Wild Animals |url=http://www.cms.int/bodies/ScC/14th_scientific_council/pdf/en/ScC14_Doc_08_Irrawaddy_dolphins_Eonly.pdf |location=[[Bonn]], Germany |publisher=CMS/UNEP |volume=14th Meeting of the CMS Scientific Council |archive-url=https://web.archive.org/web/20071218100952/http://www.cms.int/bodies/ScC/14th_scientific_council/pdf/en/ScC14_Doc_08_Irrawaddy_dolphins_Eonly.pdf |archive-date=2007-12-18}}</ref>


The Irrawaddy dolphin is listed on both Appendix I and Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals ([[Bonn Convention|CMS]]).<ref name="Appendices">{{cite web |url=http://www.cms.int/documents/appendix/Appendices_COP9_E.pdf |title=Appendix I and Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals (CMS) |website=CMS - Convention on the Conservation of Migratory Species of Wild Animals |publisher=UNEP/CMS |archive-url=https://web.archive.org/web/20110611112003/http://www.cms.int/documents/appendix/Appendices_COP9_E.pdf |archive-date=2011-06-11}}</ref> It is listed on Appendix I<ref name="Appendices" /> as this species has been categorized as being in danger of extinction throughout all or a significant proportion of their range and CMS Parties strive towards strictly protecting these animals, conserving or restoring the places where they live, mitigating obstacles to migration and controlling other factors that might endanger them, as well on Appendix II<ref name="Appendices" /> as it has an unfavourable conservation status or would benefit significantly from international co-operation organized by tailored agreements.<ref>{{cite web|url=http://www.cms.int/reports/small_cetaceans/data/O_brevirostris/O_brevirostris.htm|title=Convention on Migratory Species page on the Irrawaddy Dolphin|website=cms.int|access-date=2008-12-26|archive-url=https://web.archive.org/web/20041205063511/http://www.cms.int/reports/small_cetaceans/data/O_brevirostris/O_brevirostris.htm|archive-date=2004-12-05|url-status=dead}}</ref>
The Irrawaddy dolphin is listed on both Appendix I and Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals ([[Bonn Convention|CMS]]).<ref name="Appendices">{{cite web |url=http://www.cms.int/documents/appendix/Appendices_COP9_E.pdf |title=Appendix I and Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals (CMS) |website=CMS - Convention on the Conservation of Migratory Species of Wild Animals |publisher=UNEP/CMS |archive-url=https://web.archive.org/web/20110611112003/http://www.cms.int/documents/appendix/Appendices_COP9_E.pdf |archive-date=2011-06-11}}</ref> It is listed on Appendix I<ref name="Appendices" /> as this species has been categorized as being in danger of extinction throughout all or a significant proportion of their range, and CMS Parties strive towards strictly protecting these animals, conserving or restoring the places where they live, mitigating obstacles to migration, and controlling other factors that might endanger them, as well as on Appendix II<ref name="Appendices" /> as it has an unfavourable conservation status or would benefit significantly from international co-operation organized by tailored agreements.<ref>{{cite web |url=http://www.cms.int/reports/small_cetaceans/data/O_brevirostris/O_brevirostris.htm |title=Convention on Migratory Species page on the Irrawaddy Dolphin |website=cms.int |access-date=2008-12-26 |archive-url=https://web.archive.org/web/20041205063511/http://www.cms.int/reports/small_cetaceans/data/O_brevirostris/O_brevirostris.htm |archive-date=2004-12-05}}</ref>


The species is also covered by the Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region (MoU).<ref>{{cite web|url=http://www.pacificcetaceans.org/ |title=Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region |publisher=Pacificcetaceans.org |access-date=2014-01-24}}</ref>
The species is also covered by the Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region (MoU).<ref>{{cite web |url=http://www.pacificcetaceans.org/ |title=Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region |publisher=Pacificcetaceans.org |access-date=2014-01-24 |archive-date=2016-03-16 |archive-url=https://web.archive.org/web/20160316143105/http://www.pacificcetaceans.org/ |url-status=dead}}</ref>


===National efforts===
===National efforts===
Line 141: Line 136:
==== Bangladesh ====
==== Bangladesh ====
[[File:Sundarbans.jpg|thumb|right|Satellite image of the [[Sundarbans]]]]
[[File:Sundarbans.jpg|thumb|right|Satellite image of the [[Sundarbans]]]]
Portions of Irrawaddy dolphin habitat in the [[Sundarbans]] mangrove forest of Bangladesh are included within {{convert| 139700|ha|sqmi|adj=on|0|abbr=on}} of [[Sundarbans#Administration|three wildlife sanctuaries]], which are part of the [[List of World Heritage Sites in Asia and Australasia#Bangladesh|Sunderbans World Heritage Site]]. The [[Wildlife Conservation Society]] is working with the Bangladesh Ministry of Environment and Forests to create protected areas for the 6000 remaining dolphins.<ref name=CMS>{{cite web |url=http://www.cms.int/bodies/COP/cop9/Proposals/I_2_Orcaella%20brevirostris_PHL_E.pdf |title=Proposal for inclusion of species on the appendices of the convention on the conservation of migratory species of wild animals |website=CMS - Convention on the Conservation of Migratory Species of Wild Animals |publisher=UNEP/CMS |date=2008-08-27 |archive-url=https://web.archive.org/web/20110611095545/http://www.cms.int/bodies/COP/cop9/Proposals/I_2_Orcaella%20brevirostris_PHL_E.pdf |archive-date=2011-06-11 |access-date=2008-12-26}}</ref><ref>{{cite news| url=https://www.nytimes.com/2009/04/02/science/earth/02dolphins.html | work=The New York Times | title=Asian Dolphin, Feared Dying, Is Thriving | first=Andrew C. | last=Revkin | date=2009-04-02 | access-date=2010-04-02}}</ref>
Portions of Irrawaddy dolphin habitat in the [[Sundarbans]] mangrove forest of Bangladesh are included within {{convert| 139700|ha|sqmi|adj=on|0|abbr=on}} of [[Sundarbans#Administration|three wildlife sanctuaries]], which are part of the [[List of World Heritage Sites in Asia and Australasia#Bangladesh|Sunderbans World Heritage Site]]. The [[Wildlife Conservation Society]] is working with the Bangladesh Ministry of Environment and Forests to create protected areas for the 6000 remaining dolphins.<ref name=CMS>{{cite web |url=http://www.cms.int/bodies/COP/cop9/Proposals/I_2_Orcaella%20brevirostris_PHL_E.pdf |title=Proposal for inclusion of species on the appendices of the convention on the conservation of migratory species of wild animals |website=CMS - Convention on the Conservation of Migratory Species of Wild Animals |publisher=UNEP/CMS |date=2008-08-27 |archive-url=https://web.archive.org/web/20110611095545/http://www.cms.int/bodies/COP/cop9/Proposals/I_2_Orcaella%20brevirostris_PHL_E.pdf |archive-date=2011-06-11 |access-date=2008-12-26}}</ref><ref>{{cite news |url=https://www.nytimes.com/2009/04/02/science/earth/02dolphins.html |work=The New York Times |title=Asian Dolphin, Feared Dying, Is Thriving |first=Andrew C. |last=Revkin |date=2009-04-02 |access-date=2010-04-02}}</ref>


==== Cambodia ====
==== Cambodia ====
Irrawaddy dolphins are fully protected as an endangered species under Cambodian fishery law.<ref>{{cite web |url=http://faolex.fao.org/docs/pdf/cam82001.pdf |title=LAW ON FISHERIES (Unofficial Translation supported by ADB/FAO TA Project on Improving the Regulatory and Management Framework for Inland Fisheries ) |year=2007}}</ref>  In 2005, The [[World Wide Fund For Nature]] (WWF) established the Cambodian Mekong Dolphin Conservation Project with support from government and local communities. The aim is to support the survival of the remaining population through targeted conservation activities, research, and education.<ref name="WWF-M">{{cite web |url=http://www.panda.org/about_wwf/where_we_work/asia_pacific/our_solutions/greatermekong/projects/index.cfm?uProjectID=9S0766 |title=Cambodian Mekong Dolphin Conservation |date=2008-10-21 |website=World Wildlife Fund |archive-url=https://web.archive.org/web/20080505055721/http://www.panda.org/about_wwf/where_we_work/asia_pacific/our_solutions/greatermekong/projects/index.cfm?uProjectID=9S0766 |archive-date=2008-05-05 |access-date=2008-12-31}}</ref> In January 2012, the Cambodian Fisheries Administration, the Commission for Conservation and Development of Mekong River Dolphin Eco-tourism Zone, and WWF signed the Kratie Declaration on the Conservation of the Mekong River Irrawaddy Dolphin, an agreement binding them to work together, and setting out a roadmap for dolphin conservation in the Mekong River.<ref>{{cite web |url=https://awionline.org/awi-quarterly/2012-spring/kratie-declaration-offers-hope-mekong-dolphins |title=Kratie Declaration Offers Hope for Mekong Dolphins |date=Spring 2012 |website=Animal Welfare Institute}}</ref> On 24 August 2012, the Cambodian government announced that {{convert|180|km|mi|adj=mid|-long}} stretch of the Mekong River from eastern Kratie province to the border with Laos has been stated as limit fishing zone which uses floating houses, fishing cages and gill nets are disallowed, but simple fishing is allowed.<ref>{{cite news |date=2012-08-24 |title=Cambodia Creates Safe Zones for Mekong Dolphins |url=http://jakartaglobe.beritasatu.com/archive/cambodia-creates-safe-zones-for-mekong-dolphins/ |newspaper=Jakarta Globe |agency=Agence France-Presse |access-date=2015-12-22 |archive-url=https://web.archive.org/web/20151222233306/http://jakartaglobe.beritasatu.com/archive/cambodia-creates-safe-zones-for-mekong-dolphins/ |archive-date=2015-12-22 |url-status=dead }}</ref> This area is patrolled by a network of river guards, specifically to protect dolphins. Between January and February 2006, a dozen Irrawaddy dolphins were found dead. Since the endangerment was evident, 66 guards have been posted along the Mekong River in Cambodia to protect these dolphins.<ref>{{Cite web|title = Log in to NewsBank|url = http://infoweb.newsbank.com/resources/doc/nb/news/114932B5CEE1A588?p=AWNB|website = infoweb.newsbank.com|access-date = 2015-10-29}}</ref>
Irrawaddy dolphins are fully protected as an endangered species under Cambodian fishery law.<ref>{{cite web |url=http://faolex.fao.org/docs/pdf/cam82001.pdf |title=LAW ON FISHERIES (Unofficial Translation supported by ADB/FAO TA Project on Improving the Regulatory and Management Framework for Inland Fisheries ) |year=2007}}</ref>  In 2005, the [[World Wide Fund for Nature]] (WWF) established the Cambodian Mekong Dolphin Conservation Project with support from government and local communities. The aim is to support the survival of the remaining population through targeted conservation activities, research, and education.<ref name="WWF-M">{{cite web |url=http://www.panda.org/about_wwf/where_we_work/asia_pacific/our_solutions/greatermekong/projects/index.cfm?uProjectID=9S0766 |title=Cambodian Mekong Dolphin Conservation |date=2008-10-21 |website=World Wildlife Fund |archive-url=https://web.archive.org/web/20080505055721/http://www.panda.org/about_wwf/where_we_work/asia_pacific/our_solutions/greatermekong/projects/index.cfm?uProjectID=9S0766 |archive-date=2008-05-05 |access-date=2008-12-31}}</ref> In January 2012, the Cambodian Fisheries Administration, the Commission for Conservation and Development of Mekong River Dolphin Eco-tourism Zone, and WWF signed the Kratie Declaration on the Conservation of the Mekong River Irrawaddy Dolphin, an agreement binding them to work together, and setting out a roadmap for dolphin conservation in the Mekong River.<ref>{{cite web |url=https://awionline.org/awi-quarterly/2012-spring/kratie-declaration-offers-hope-mekong-dolphins |title=Kratie Declaration Offers Hope for Mekong Dolphins |date=Spring 2012 |website=Animal Welfare Institute}}</ref> On 24 August 2012, the Cambodian government announced that a {{convert|180|km|mi|adj=mid|-long}} stretch of the Mekong River from eastern Kratie province to the border with Laos has been designated as a limited fishing zone where using floating houses, fishing cages, and gill nets is disallowed, but simple fishing is allowed.<ref>{{cite news |date=2012-08-24 |title=Cambodia Creates Safe Zones for Mekong Dolphins |url=http://jakartaglobe.beritasatu.com/archive/cambodia-creates-safe-zones-for-mekong-dolphins/ |newspaper=Jakarta Globe |agency=Agence France-Presse |access-date=2015-12-22 |archive-url=https://web.archive.org/web/20151222233306/http://jakartaglobe.beritasatu.com/archive/cambodia-creates-safe-zones-for-mekong-dolphins/ |archive-date=2015-12-22}}</ref> This area is patrolled by a network of river guards, specifically to protect dolphins. Between January and February 2006, a dozen Irrawaddy dolphins were found dead. Since the endangerment was evident, 66 guards have been posted along the Mekong River in Cambodia to protect these dolphins.<ref>{{Cite web |title=Log in to NewsBank |url=http://infoweb.newsbank.com/resources/doc/nb/news/114932B5CEE1A588?p=AWNB |website=infoweb.newsbank.com |access-date=2015-10-29}}</ref>
[[File:Irrawaddy Dolphin at Sundarban National Park 27102012.jpg|thumb|left|Irrawaddy dolphin in the Sundarbans]]
[[File:Irrawaddy Dolphin at Sundarban National Park 27102012.jpg|thumb|left|Irrawaddy dolphin in the Sundarbans]]


==== India ====
==== India ====
The Irrawaddy dolphin (under the common name of snubfin dolphin, with the scientific name misspelled as ''Oreaella brevezastris'') is included the Indian Wildlife Protection Act,<ref name=WPA>{{cite book|author=Parliament of India|title=The Indian Wildlife (Protection) Act, 1972|publisher=Ministry of Environment and Forests|edition=Substituted by Act 44 of 1991|url=http://envfor.nic.in/legis/wildlife/wildlife1.html}}</ref> Schedule I,<ref name="Sch I">{{cite book|author=The Wildlife (Protection) Act, 1972|title=33-A. Snubfin Dolphin (''Orcaella brevirostris'') |volume=Part I Mammals|chapter=Schedule I|chapter-url=http://envfor.nic.in/legis/wildlife/wildlife2s1.pdf}}</ref> which bans their killing, transport and sale of products.<ref Name=CMS/> A major restoration effort to open a new mouth between Chilika Lake and the Bay of Bengal in 2000 was successful in restoring the lake ecology and regulating the salinity gradient in the lake waters, which has resulted in increases in the population of Irrawaddy dolphin due to increase of prey species of fish, prawns, and crabs.<ref>{{Cite news|url=http://www.thehindu.com/sci-tech/energy-and-environment/the-return-of-the-irrawaddy-dolphin/article19559190.ece|title=The return of the Irrawaddy dolphin|work=The Hindu|access-date=2017-08-25}}</ref><ref name="USAID">{{cite web |url=http://pdf.usaid.gov/pdf_docs/pbaaa179.pdf |archive-url=https://web.archive.org/web/20151223105135/http://pdf.usaid.gov/pdf_docs/pbaaa179.pdf |url-status=dead |archive-date=December 23, 2015 |title=Integrating Biodiversity and Hydrological Processes into Conservation Planning at the Landscape Scale |author=Conservation International |author-link=Conservation International |date=2007-03-15 |website=[[USAID]]}}</ref>
The Irrawaddy dolphin (under the common name of snubfin dolphin, with the scientific name misspelled as ''Oreaella brevezastris'') is included in the Indian Wildlife Protection Act,<ref name=WPA>{{cite book|author=Parliament of India|title=The Indian Wildlife (Protection) Act, 1972|publisher=Ministry of Environment and Forests|edition=Substituted by Act 44 of 1991|url=http://envfor.nic.in/legis/wildlife/wildlife1.html}}</ref> Schedule I,<ref name="Sch I">{{cite book|author=The Wildlife (Protection) Act, 1972|title=33-A. Snubfin Dolphin (''Orcaella brevirostris'') |volume=Part I Mammals|chapter=Schedule I|chapter-url=http://envfor.nic.in/legis/wildlife/wildlife2s1.pdf}}</ref> which bans their killing, transport, and sale of products.<ref Name=CMS/> A major restoration effort to open a new mouth between Chilika Lake and the Bay of Bengal in 2000 was successful in restoring the lake ecology and regulating the salinity gradient in the lake waters, which has resulted in increases in the population of Irrawaddy dolphins due to an increase of prey species of fish, prawns, and crabs.<ref>{{Cite news|url=http://www.thehindu.com/sci-tech/energy-and-environment/the-return-of-the-irrawaddy-dolphin/article19559190.ece|title=The return of the Irrawaddy dolphin|work=The Hindu|access-date=2017-08-25}}</ref><ref name="USAID">{{cite web |url=http://pdf.usaid.gov/pdf_docs/pbaaa179.pdf |archive-url=https://web.archive.org/web/20151223105135/http://pdf.usaid.gov/pdf_docs/pbaaa179.pdf |archive-date=December 23, 2015 |title=Integrating Biodiversity and Hydrological Processes into Conservation Planning at the Landscape Scale |author=Conservation International |author-link=Conservation International |date=2007-03-15 |website=[[USAID]]}}</ref>


==== Indonesia ====
==== Indonesia ====
A conservation program, entitled Conservation Foundation for the Protection of Rare Aquatic Species of Indonesia, focused on protecting the Irrawaddy dolphin population and their habitat, the Mahakam River. The program not only educates and surveys the public, but also <!-- controls and --> monitors the dolphin population and their habitat. A prime example of this is the establishment of patrols in several villages.<ref>{{Cite web|title = Scopus - Welcome to Scopus|url = https://www.scopus.com/record/display.url?eid=2-s2.0-33646492434&origin=inward&txGid=93D8B902C9435749CF52E0FE4928AB91.53bsOu7mi7A1NSY7fPJf1g%253a1|website = scopus.com|access-date = 2015-10-30}}</ref>[[File:Utl album fb.jpg|thumb|Specimen in [[Kalimantan]]]]
A conservation program, entitled Conservation Foundation for the Protection of Rare Aquatic Species of Indonesia, focused on protecting the Irrawaddy dolphin population and their habitat, the Mahakam River. The program not only educates and surveys the public, but also controls and monitors the dolphin population and their habitat. A prime example of this is the establishment of patrols in several villages.<ref>{{Cite web|title = Scopus - Welcome to Scopus|url = https://www.scopus.com/record/display.url?eid=2-s2.0-33646492434&origin=inward&txGid=93D8B902C9435749CF52E0FE4928AB91.53bsOu7mi7A1NSY7fPJf1g%253a1|website = scopus.com|access-date = 2015-10-30}}</ref>[[File:Utl album fb.jpg|thumb|Specimen in [[Kalimantan]]]]


==== Laos ====
==== Laos ====
The dolphins have been excinct in Laos since 2022. In the 1970s, many Irrawaddy dolphins were slaughtered for oil, and soon after, intensive fishing practices with explosives and gillnets began. The dolphins were protected in Cambodia and Laos and explosive fishing and use of gillnets were restricted in many of the Irrawaddy dolphin's habitats.<ref name="Ryan2011" /> Canadian conservationist Ian Baird set up the Lao Community Fisheries and Dolphin Protection Project to study the Irrawaddy dolphins in the Laotian part of the Mekong. Part of this project compensated fishers for the loss of nets damaged to free entangled dolphins. This project was expanded to include Cambodia, after the majority of the dolphin population was determined to have been killed or migrated to Cambodia.<ref>{{cite web|url=http://www.newsmekong.org/irrawaddy_dolphins_disappearing_from_the_mekong_0|title=Irrawaddy Dolphins Disappearing from the Mekong|last=Pandawutiyanon|first=Wiwat |year=2005|work=Mekong Currents|publisher=IPS Asia-Pacific/Probe Media Foundation |archive-url=https://web.archive.org/web/20100905023243/http://www.newsmekong.org/irrawaddy_dolphins_disappearing_from_the_mekong_0 |archive-date=2010-09-05 |access-date=2008-12-31}}</ref> The [[Si Phan Don]] Wetlands Project encouraged river communities to set aside conservation zones and establish laws to regulate how and when fish are caught.<ref name="Cranmer">{{cite book |last=Cranmer |first=Jeff |author2=Steven Martin |author3=Kirby Coxon |title=The Rough Guide to Laos |publisher=Rough Guides |year=2002 |page=[https://archive.org/details/laos0000cran/page/309 309] |chapter=The Far South |isbn=9781858289052 |chapter-url=https://books.google.com/books?id=qSTQdorOvr0C&q=%22irrawaddy+dolphin%22+laos+protect++-com&pg=PA309 |url=https://archive.org/details/laos0000cran/page/309 }}</ref>  
The dolphins have been extinct in Laos since 2022. In the 1970s, many Irrawaddy dolphins were slaughtered for oil, and soon after, intensive fishing practices with explosives and gillnets began. The dolphins were protected in Cambodia and Laos, and explosive fishing and use of gillnets were restricted in many of the Irrawaddy dolphins' habitats.<ref name="Ryan2011" /> Canadian conservationist Ian Baird set up the Lao Community Fisheries and Dolphin Protection Project to study the Irrawaddy dolphins in the Laotian part of the Mekong. Part of this project compensated fishers for the loss of nets damaged to free entangled dolphins. This project was expanded to include Cambodia after the majority of the dolphin population was determined to have been killed or migrated to Cambodia.<ref>{{cite web |url=http://www.newsmekong.org/irrawaddy_dolphins_disappearing_from_the_mekong_0 |title=Irrawaddy Dolphins Disappearing from the Mekong |last=Pandawutiyanon |first=Wiwat |year=2005 |work=Mekong Currents |publisher=IPS Asia-Pacific/Probe Media Foundation |archive-url=https://web.archive.org/web/20100905023243/http://www.newsmekong.org/irrawaddy_dolphins_disappearing_from_the_mekong_0 |archive-date=2010-09-05 |access-date=2008-12-31}}</ref> The [[Si Phan Don]] Wetlands Project encouraged river communities to set aside conservation zones and establish laws to regulate how and when fish are caught.<ref name="Cranmer">{{cite book |last=Cranmer |first=Jeff |author2=Steven Martin |author3=Kirby Coxon |title=The Rough Guide to Laos |publisher=Rough Guides |year=2002 |page=[https://archive.org/details/laos0000cran/page/309 309] |chapter=The Far South |isbn=978-1-85828-905-2 |chapter-url=https://books.google.com/books?id=qSTQdorOvr0C&q=%22irrawaddy+dolphin%22+laos+protect++-com&pg=PA309 |url=https://archive.org/details/laos0000cran/page/309}}</ref>


Ultimately, these measures were unsuccessful. In early 2022, a 110kg 25 year old male dolphin was found dead on an island in the Si Phan Don called Koh La Ngo. It measured 2.6m in length and was the last Irrawaddy dolphin in Laos.<ref name=":2" />
Ultimately, these measures were unsuccessful. In early 2022, a 110&nbsp;kg 25-year-old male dolphin was found dead on an island in the Si Phan Don called Koh La Ngo. It measured 2.6m in length and was the last Irrawaddy dolphin in Laos.<ref name=":2" />


==== Myanmar ====
==== Myanmar ====
Myanmar's Department of Fisheries took charge in December 2005, and instituted a protected region in a {{convert|74|km|mi|abbr=on|adj=on}} segment of the Ayeyarwady River between [[Mingun]] and [[Kyaukmyaung (Sagaing)|Kyaukmyaung]].<ref name=":0" /> Protective measures in the area include mandatory release of entangled dolphins, prohibition of the catching or killing of dolphins and trade in whole or parts of them, and the prohibition of electrofishing and gillnets more than {{convert|300|ft|m|disp=flip}} long, or spaced less than {{convert|600|ft|m|disp=flip}} apart.<ref name=CMS/> [[Mercury poisoning]] and habitat loss from [[Gold mining#Dredging|gold-mining dredging]] operations in the river have been eliminated.<ref name="SD">{{cite news|url=https://www.sciencedaily.com/releases/2006/06/060623100318.htm|title=Site Of Human-dolphin Partnership Becomes Protected Area|date=2006-06-23|work=Science Daily|publisher=ScienceDaily LLC|pages=Science News|access-date=2008-12-30}}</ref>
Myanmar's Department of Fisheries took charge in December 2005 and instituted a protected region in a {{convert|74|km|mi|abbr=on|adj=on}} segment of the Ayeyarwady River between [[Mingun]] and [[Kyaukmyaung (Sagaing)|Kyaukmyaung]].<ref name=":0" /> Protective measures in the area include mandatory release of entangled dolphins, prohibition of the catching or killing of dolphins and trade in whole or parts of them, and the prohibition of electrofishing and gillnets more than {{convert|300|ft|m|disp=flip}} long, or spaced less than {{convert|600|ft|m|disp=flip}} apart.<ref name=CMS/> [[Mercury poisoning]] and habitat loss from [[Gold mining#Dredging|gold-mining dredging]] operations in the river have been eliminated.<ref name="SD">{{cite news |url=https://www.sciencedaily.com/releases/2006/06/060623100318.htm |title=Site Of Human-dolphin Partnership Becomes Protected Area |date=2006-06-23 |work=Science Daily |publisher=ScienceDaily LLC |pages=Science News |access-date=2008-12-30}}</ref>


==== Philippines ====
==== Philippines ====
In 2000, Malampaya Sound was proclaimed a protected seascape. This is the lowest possible prioritization given to a protected area.<ref name="SmithBD"/> Malampaya Sound Ecological Studies Project was initiated by the WWF. With technical support provided by the project, the municipality of [[Taytay, Palawan|Taytay]] and the Malampaya park management developed fishery policies to minimize the threats to the Irrawaddy dolphin from bycatch capture. Gear studies and gear modification to conserve the dolphin species were implemented. The project was completed in 2007.<ref name="WWF-P">{{cite web |url=http://www.wwf.org.ph/about.php?pg=wwd&sub1=00004 |title=Malampaya Sound Ecological Studies Project |website=WWF Philippines |date=2008-07-07 |archive-url=https://web.archive.org/web/20131029210510/http://www.wwf.org.ph/about.php?pg=wwd&sub1=00004 |archive-date=2013-10-29 |access-date=2008-12-31}}</ref>
In 2000, Malampaya Sound was proclaimed a protected seascape. This is the lowest possible prioritization given to a protected area.<ref name="SmithBD"/> The Malampaya Sound Ecological Studies Project was initiated by the WWF. With technical support provided by the project, the municipality of [[Taytay, Palawan|Taytay]] and the Malampaya park management developed fishery policies to minimize the threats to the Irrawaddy dolphin from bycatch capture. Gear studies and gear modification to conserve the dolphin species were implemented. The project was completed in 2007.<ref name="WWF-P">{{cite web |url=http://www.wwf.org.ph/about.php?pg=wwd&sub1=00004 |title=Malampaya Sound Ecological Studies Project |website=WWF Philippines |date=2008-07-07 |archive-url=https://web.archive.org/web/20131029210510/http://www.wwf.org.ph/about.php?pg=wwd&sub1=00004 |archive-date=2013-10-29 |access-date=2008-12-31}}</ref>
In 2007, the [[Coral Triangle]] Initiative, a new multilateral partnership to help safeguard the marine and coastal resources of the Coral Triangle, including the Irrawaddy dolphin subpopulation in Malampaya Sound, was launched.<ref>{{cite press release |author=Philippine information Agency |date=2008-06-22 |title=PGMA to push for sustainable management of Coral Triangle |url=http://www.gov.ph/news/?i=21252 |publisher=Republic of the Philippines |access-date=2008-12-31}}{{cbignore}}</ref><ref>{{cite web |url=http://www.coralcoe.org.au/events/ctiworkshop/papers/13%20Threatened%20Spp.doc |title=Incorporating information about marine species of conservation concern and their habitats into a network of MPAs for the Coral Triangle region (Draft) |last1=Hamann |first1=Mark |last2=Heupel |first2=Michelle |last3=Lukoschek |first3=Vimoksalehi |last4=Marsh |first4=Helene |date=2008-05-11 |website=ARC Centre of Excellence for Coral Reef Studies |format=DOC |archive-url=https://web.archive.org/web/20091001212310/http://www.coralcoe.org.au/events/ctiworkshop/papers/13%20Threatened%20Spp.doc |archive-date=2009-10-01}}</ref> In 2006, a new population was discovered in [[Guimaras]] island in the Visayas. In 2015, another new population was discovered in [[Bago, Negros Occidental|Bago]] and [[Pulupandan]] in [[Negros Occidental]], part of Negros island in the Visayas.<ref>{{cite web|url=http://www.gmanetwork.com/news/news/regions/200345/rare-dolphins-make-negros-coastal-waters-their-home/story/|title=Rare dolphins make Negros coastal waters their home|website=gmanetwork.com|date=6 September 2010 }}</ref> The doplphins are locally known in the Visayas as ''lumba-lumba''.<ref>{{cite news |title=P187-B Visayas mega-bridge threatens endangered Irrawaddy dolphins |url=https://verafiles.org/articles/p187-b-visayas-mega-bridge-threatens-endangered-irrawaddy-dolphins |access-date=18 February 2025 |work=Vera Files |date=14 October 2024}}</ref><ref>{{cite web |title=Lumba |url=https://www.earthisland-ap.org/publications/lumba2019 |publisher=Earth Island Institute Asia-Pacific |access-date=18 February 2025}}</ref>
In 2007, the [[Coral Triangle]] Initiative, a new multilateral partnership to help safeguard the marine and coastal resources of the Coral Triangle, including the Irrawaddy dolphin subpopulation in Malampaya Sound, was launched.<ref>{{cite press release |author=Philippine information Agency |date=2008-06-22 |title=PGMA to push for sustainable management of Coral Triangle |url=http://www.gov.ph/news/?i=21252 |publisher=Republic of the Philippines |access-date=2008-12-31}}{{cbignore}}</ref><ref>{{cite web |url=http://www.coralcoe.org.au/events/ctiworkshop/papers/13%20Threatened%20Spp.doc |title=Incorporating information about marine species of conservation concern and their habitats into a network of MPAs for the Coral Triangle region (Draft) |last1=Hamann |first1=Mark |last2=Heupel |first2=Michelle |last3=Lukoschek |first3=Vimoksalehi |last4=Marsh |first4=Helene |date=2008-05-11 |website=ARC Centre of Excellence for Coral Reef Studies |format=DOC |archive-url=https://web.archive.org/web/20091001212310/http://www.coralcoe.org.au/events/ctiworkshop/papers/13%20Threatened%20Spp.doc |archive-date=2009-10-01}}</ref> In 2006, a new population was discovered in [[Guimaras]] Island in the Visayas. In 2015, another new population was discovered in [[Bago, Negros Occidental|Bago]] and [[Pulupandan]] in [[Negros Occidental]], part of Negros island in the Visayas.<ref>{{cite web|url=http://www.gmanetwork.com/news/news/regions/200345/rare-dolphins-make-negros-coastal-waters-their-home/story/|title=Rare dolphins make Negros coastal waters their home|website=gmanetwork.com|date=6 September 2010 }}</ref> The dolphins are locally known in the Visayas as ''lumba-lumba''.<ref>{{cite news |title=P187-B Visayas mega-bridge threatens endangered Irrawaddy dolphins |url=https://verafiles.org/articles/p187-b-visayas-mega-bridge-threatens-endangered-irrawaddy-dolphins |access-date=18 February 2025 |work=Vera Files |date=14 October 2024}}</ref><ref>{{cite web |title=Lumba |url=https://www.earthisland-ap.org/publications/lumba2019 |publisher=Earth Island Institute Asia-Pacific |access-date=18 February 2025}}</ref>
[[File:Irrawaddy Dolphin.jpg|thumb|Irrawaddy dolphin on [[Mekong River]] at [[Kratié Province|Kratié]], [[Cambodia]]]]
[[File:Irrawaddy Dolphin.jpg|thumb|Irrawaddy dolphin on [[Mekong River]] at [[Kratié Province|Kratié]], [[Cambodia]]]]


==== Thailand ====
==== Thailand ====
In 2002, the Marine and Coastal Resources Department was assigned to protect rare aquatic animals such as dolphins, whales, and turtles in Thai territorial waters. To protect the dolphins, patrol vessels ensure boats stay at least {{convert|30|m|ft|abbr=on}} away from dolphins and no chasing of or running through schools of dolphins occurs. Many fishermen on the [[Bang Pakong River]], [[Prachinburi Province]], have been persuaded by authorities to stop [[shrimp fishing]] in a certain area and 30 to 40 fishing boats have been modified so they can offer dolphin sightseeing tours.<ref>{{cite news |last=Svasti |first=Pichaya |date=2007-03-24 |title=The Irrawaddy dolphin; It's an uphill struggle, but Thailand is trying to protect its marine wildlife |newspaper=Bangkok Post |via=Factiva |quote=It wasn't until 2002 that the Marine and Coastal Resources Department was assigned to protect rare aquatic animals such as dolphins, whales and turtles in Thai territorial waters. To protect the dolphins, patrol vessels will ensure that boats stay at least 30 metres away from dolphins and that there is no chasing of or running through schools of dolphins ... Thanks to persuasion by the authorities, many fishermen on the Bang Pakong have agreed to stop using the phong phang, and 30 to 40 fishing boats have been modified so they can offer dolphin sightseeing tours ... But shrimp boats from other provinces are still fishing the Bang Pakong."}}</ref>
In 2002, the Marine and Coastal Resources Department was assigned to protect rare aquatic animals such as dolphins, whales, and turtles in Thai territorial waters. To protect the dolphins, patrol vessels ensure boats stay at least {{convert|30|m|ft|abbr=on}} away from dolphins and no chasing of or running through schools of dolphins occurs. Many fishermen on the [[Bang Pakong River]], Prachinburi Province, have been persuaded by authorities to stop [[shrimp fishing]] in a certain area, and 30 to 40 fishing boats have been modified so they can offer dolphin sightseeing tours.<ref>{{cite news |last=Svasti |first=Pichaya |date=2007-03-24 |title=The Irrawaddy dolphin; It's an uphill struggle, but Thailand is trying to protect its marine wildlife |newspaper=Bangkok Post |via=Factiva |quote=It wasn't until 2002 that the Marine and Coastal Resources Department was assigned to protect rare aquatic animals such as dolphins, whales and turtles in Thai territorial waters. To protect the dolphins, patrol vessels will ensure that boats stay at least 30 metres away from dolphins and that there is no chasing of or running through schools of dolphins ... Thanks to persuasion by the authorities, many fishermen on the Bang Pakong have agreed to stop using the phong phang, and 30 to 40 fishing boats have been modified so they can offer dolphin sightseeing tours ... But shrimp boats from other provinces are still fishing the Bang Pakong."}}</ref> A total of 65 Irrawaddy dolphins have been found dead along the coast of [[Trat Province]] in the past three years.<ref>{{cite news |title=65 dolphins found dead in three years |url=http://bangkokpost.newspaperdirect.com/epaper/viewer.aspx |url-access=subscription |work=Bangkok Post |access-date=2014-01-24 |via=NewspaperDirect}}</ref> The local fishing industry is blamed for the deaths of the dolphins.<ref>{{cite news |title=Fishery blamed for dolphin deaths |url=http://www.bangkokpost.com/archive/65-dolphins-found-dead-in-three-years/337361 |url-access=subscription |work=Bangkok Post |date=2013-02-23 |access-date=2014-01-24}}</ref> In January 2013, over a dozen dead Irrawaddy dolphins were found on the coast of Thailand. These dolphins were said to be dead because of a lack of oxygen. Dolphins are mammals, and unlike other animals that live in the sea, they must come to the surface for air. Many of the dolphins are found dead in the water, and others were washed ashore, said to have been dead for a few days. Also, in the first week of February 2013, as many as four Irrawaddy dolphins were found dead.<ref>{{cite news |last=Tumcharoen |first=Surasak |date=2013-02-07 |title=Dozen Irrawaddy dolphins found dead off Thailand's eastern coast |url=http://news.xinhuanet.com/english/sci/2013-02/07/c_132158097.htm |newspaper=Xinhuanet |agency=Xinhua News Agency |access-date=2015-10-29 |archive-url=https://web.archive.org/web/20130211084746/http://news.xinhuanet.com/english/sci/2013-02/07/c_132158097.htm |archive-date=2013-02-11}}</ref> The Natural Resources and Environment Ministry is studying artificial breeding options in 2022 to try to save the last herd of Irrawaddy dolphins in Songkhla Lake, which is on the verge of extinction after only 14 were found in the most recent survey.<ref>{{cite news |title=Artificial Breeding Eyed To Boost Dolphin Population In Songkhla Lake |url=https://www.nationthailand.com/in-focus/40015358 |website=The Nation |access-date=2022-05-14}}</ref> They also intend to list dolphins as a [[Reserved wild animals of Thailand|protected species]], Thailand's highest level of animal protection.<ref>{{cite news |title=Thailand adds Irrawaddy dolphins to 'reserved' list as extinction beckons |url=https://www.nationthailand.com/in-focus/40015559 |website=The Nation |access-date=2022-05-14}}</ref>
A total of 65 Irrawaddy dolphins has been found dead along the coast of [[Trat Province]] in the past three years.<ref>{{cite news |title=65 dolphins found dead in three years |url=http://bangkokpost.newspaperdirect.com/epaper/viewer.aspx |url-access=subscription |work=Bangkok Post |access-date=2014-01-24 |via=NewspaperDirect}}</ref> The local fishing industry is blamed for the deaths of the dolphins.<ref>{{cite news |title=Fishery blamed for dolphin deaths |url=http://www.bangkokpost.com/archive/65-dolphins-found-dead-in-three-years/337361 |url-access=subscription |work=Bangkok Post |date=2013-02-23 |access-date=2014-01-24}}</ref> In January 2013, over a dozen dead Irrawaddy dolphins were found on the coast of Thailand. These dolphins were said to be dead because of a lack of oxygen. Dolphins are mammals, and unlike other animals that live in the sea, they must come to the surface for air. Many of the dolphins are found dead in the water, and others were washed ashore, said to have been dead for a few days. Also, in the first week of February 2013, as many as four Irrawaddy dolphins were found dead.<ref>{{cite news |last=Tumcharoen |first=Surasak |date=2013-02-07 |title=Dozen Irrawaddy dolphins found dead off Thailand's eastern coast |url=http://news.xinhuanet.com/english/sci/2013-02/07/c_132158097.htm |newspaper=Xinhuanet |agency=Xinhua News Agency |access-date=2015-10-29 |url-status=dead |archive-url=https://web.archive.org/web/20130211084746/http://news.xinhuanet.com/english/sci/2013-02/07/c_132158097.htm |archive-date=2013-02-11 }}</ref> The Natural Resources and Environment Ministry is studying artificial breeding options in 2022 to try to save the last herd of Irrawaddy dolphins in Songkhla Lake, which is on the verge of extinction after only 14 were found in the most recent survey.<ref>{{cite news |title=Artificial Breeding Eyed To Boost Dolphin Population In Songkhla Lake |url=https://www.nationthailand.com/in-focus/40015358|website=The Nation |access-date=2022-05-14}}</ref> They also intend to list dolphins as a [[Reserved wild animals of Thailand|protected species]], Thailand's highest level of animal protection.<ref>{{cite news |title=Thailand adds Irrawaddy dolphins to 'reserved' list as extinction beckons |url=https://www.nationthailand.com/in-focus/40015559|website=The Nation |access-date=2022-05-14}}</ref>


==== Malaysia ====
==== Malaysia ====
In 2008, the Department of Forestry and Sarawak Forestry Cooperative in Sarawak established a protected area for Irrawaddy dolphins in Santubong and Damai (Kuching Wetland).<ref name=CMS/> Furthermore, they plan to establish more beaches in Miri as protected areas for them. The protection measures in the area include prohibition of catching or killing of dolphins and trade in whole or parts of them, and prohibiting the use of gillnets. The government may also start small- and medium-scale research of this species at [[Universiti Malaysia Sarawak|Sarawak Malaysia University]] with sponsorship from Sarawak Shell.
In 2008, the Department of Forestry and Sarawak Forestry Cooperative in Sarawak established a protected area for Irrawaddy dolphins in Santubong and Damai (Kuching Wetland).<ref name=CMS/> Furthermore, they plan to establish more beaches in Miri as protected areas for them. The protection measures in the area include prohibition of catching or killing dolphins and trade in whole or parts of them, and prohibiting the use of gillnets. The government may also start small- and medium-scale research of this species at [[Universiti Malaysia Sarawak|Sarawak Malaysia University]] with sponsorship from Sarawak Shell.


==== Vietnam ====
==== Vietnam ====
In 2012 in Vietnam, a group of scientists took in four Irrawaddy dolphins and provided them with medical care to see how they would survive. However, they found this to be the first case they saw of Irrawaddy dolphins having bacterial infections. The bacterial infection, [[chorioamnionitis]], is common in many marine animals, but when these few dolphins were taken in, the scientists discovered this same bacterial infection for the first time in this group of dolphins. This disease mostly affects animals that are pregnant because the infection occurs through the umbilical cord and goes into the maternal bloodstream. One of the dolphins <!-- the scientists in Vietnam --> was pregnant and before her death was found circling around the bottom of the pool and was found dead early the next morning. This bacterial infection affects many organs in the body of the animal.<ref>{{cite journal |last1=Yu |first1=Jin Hai |last2=Xia |first2=Zhao Fei |title=Bacterial infection in an Irrawaddy dolphin (Orcaella brevirostris) |journal=Journal of Zoo and Wildlife Medicine |date=2013 |volume=44 |issue=1 |pages=156–158 |doi=10.1638/1042-7260-44.1.156 |pmid=23505717 |s2cid=22163089 }}</ref>
In 2012 in Vietnam, a group of scientists took in four Irrawaddy dolphins and provided them with medical care to see how they would survive. However, they found this to be the first case they saw of Irrawaddy dolphins having bacterial infections. The bacterial infection, [[chorioamnionitis]], is common in many marine animals, but when these few dolphins were taken in, the scientists discovered this same bacterial infection for the first time in this group of dolphins. This disease mostly affects animals that are pregnant because the infection occurs through the umbilical cord and goes into the maternal bloodstream. One of the dolphins was pregnant, and before her death, she was found circling the bottom of the pool and was found dead early the next morning. This bacterial infection affects many organs in the body of the animal.<ref>{{cite journal |last1=Yu |first1=Jin Hai |last2=Xia |first2=Zhao Fei |title=Bacterial infection in an Irrawaddy dolphin (Orcaella brevirostris) |journal=Journal of Zoo and Wildlife Medicine |year=2013 |volume=44 |issue=1 |pages=156–158 |doi=10.1638/1042-7260-44.1.156 |pmid=23505717 |s2cid=22163089}}</ref>


==See also==
==See also==

Latest revision as of 15:04, 17 December 2025

Template:Short description Template:Use Indian English Template:Speciesbox

The Irrawaddy dolphin (Orcaella brevirostris) is a euryhaline species of oceanic dolphin found in scattered subpopulations near sea coasts and in estuaries and rivers in parts of the Bay of Bengal and Southeast Asia. It closely resembles the Australian snubfin dolphin (of the same genus, Orcaella), which was not described as a separate species until 2005. It has a slate blue to a slate gray color. Although found in much of the riverine and marine zones of South and Southeast Asia, the only concentrated lagoon populations are found in Chilika Lake in Odisha, India, and Songkhla Lake in southern Thailand.[1]

Taxonomy

Script error: No such module "Multiple image". One of the earliest recorded descriptions of the Irrawaddy dolphin was by Sir Richard Owen in 1866, based on a specimen found in 1852 in the harbour of Visakhapatnam on the east coast of India.[2] It is one of two species in its genus. It has sometimes been listed variously in a family containing just itself and in the Monodontidae and Delphinidae. Widespread agreement now exists to list it in the family Delphinidae.

Etymology

The species' name, brevirostris, is from the Latin meaning "short beaked".Script error: No such module "Unsubst".

Description

File:Orcaella brevirostris 1878.jpg
1878 illustration

The Irrawaddy dolphin's colour is grey to dark slate blue, paler underneath, without a distinctive pattern. The dorsal fin is small and rounded behind the middle of the back. The forehead is high and rounded; the beak is lacking. The front of its snout is blunt. The flippers are broad and rounded. The finless porpoise (Neophocaena phocaenoides) is similar and has no back fin; the humpback dolphin (Sousa chinensis) is larger and has a longer beak and a larger dorsal fin.[2] It ranges in weight from Script error: No such module "convert". with a length of Script error: No such module "convert". at full maturity.[3][4] The maximum recorded length is Script error: No such module "convert". of a male in Thailand.[5]

The Irrawaddy dolphin is similar to the beluga in appearance, though most closely related to the killer whale. It has a large melon and a blunt, rounded head, and the beak is indistinct. Its dorsal fin, located about two-thirds posterior along the back, is short, blunt, and triangular.[4] Dorsal fin shapes differ from one Irrawaddy dolphin to another.[4] The flippers are long and broad.[6] These dolphins are usually two-toned, with the back and sides being gray to bluish-gray and the belly lighter.[6] Unlike any other dolphin, the Irrawaddy's U-shaped blowhole is on the left of the midline and opens towards the front of the dolphin.[6] Its short beak appears very different from those of other dolphins, and its mouth is known for having 12-19 peg-like teeth on each side of the jaws.[6]

Behaviour

File:DKoehl Irrawaddi Dolphin jumping.jpg
Closeup of an Irrawaddy dolphin jumping in the Mekong River

Communication is carried out with clicks, creaks, and buzzes at a dominant frequency of about 60  kilohertz, which is thought to be used for echolocation. Bony fish (including catfish) and fish eggs, cephalopods (such as squid, octopus, and cuttlefish), and crustaceans are taken as food.[7] Observations of captive animals indicate food may be taken into the mouth by suction. Irrawaddy dolphins are capable of squirting streams of water that can reach up to Script error: No such module "convert".; this distinct behaviour has been known for herding fish into a general area for hunting.[8] They do this sometimes while spyhopping and during feeding, apparently to expel water ingested during fish capture or possibly to herd fish. Some Irrawaddy dolphins kept in captivity have been trained to do spyhopping on command. The Irrawaddy dolphin is a slow swimmer, but swimming speeds of Script error: No such module "convert". were reported when dolphins were being chased in a boat.[9] In a year, females can sometimes swim as fast as an average of Script error: No such module "convert"., and males can swim up to an average of Script error: No such module "convert"..[10]Template:Rp

Most Irrawaddy dolphins are shy of boats, not known to bow-ride, and generally dive when alarmed. They are relatively slow-moving but can sometimes be seen spyhopping and rolling to one side while waving a flipper and occasionally breaching. They are generally found in groups of 2-3 animals, though sometimes as many as 25 individuals have been known to congregate in deep pools. Groups of fewer than six individuals are most common, but sometimes up to 15 dolphins are seen together.[9][11] Traveling and staying in groups not only enables Irrawaddy dolphins to hunt, but it also creates and maintains social bonds and allows copulation to occur.[12] There are a few groups of dolphins in Brunei Bay seen near the mouths of the Temburong and Aloh Besar rivers, which are tame and gather around fishermen's boats that catch fish during the fishing season from around December to February.[13]

It surfaces in a rolling fashion and lifts its tail fluke clear of the water only for a deep dive. Deep dive times range from 30 to 150 seconds to 12 minutes. When 277 group dives were timed (time of disappearance of the last dolphin in the group to the emergence of the first dolphin in the group) in Laos, the mean duration was 115.3  seconds with a range of 19  seconds to 7.18  minutes.[5]

Interspecific competition has been observed when Irrawaddy dolphins were forced inshore and excluded by more specialized dolphins. When captive humpback dolphins (Sousa chinensis) and Irrawaddy dolphins were held together, reportedly the Irrawaddy dolphins were frequently chased and confined to a small portion of the tank by the dominant humpbacks. In Chilika Lake, local fishers say when Irrawaddy dolphins and bottlenose dolphins meet in the outer channel, the former get frightened and are forced to return toward the lake.[2]

Mating

A female or male dolphin will attempt to pursue a mate for about a few minutes. They intertwine, facing their bellies together, and begin to copulate for 40 seconds. Once copulation has occurred, the dolphins will break away from each other and set off in different directions.[12]

Reproduction

Script error: No such module "Labelled list hatnote".

File:Orcaella foetus.jpg
1878 illustration of a foetus in the uterus
File:Irrawaddy Dolphin Sundarban West Bengal August 2019.jpg
Mother with calf from Sundarban, Bangladesh

These dolphins are thought to reach sexual maturity at seven to nine years. In the Northern Hemisphere, mating is reported from December to June. Its gestation period is 14 months; cows give birth to a single calf every two to three years. Length is about Script error: No such module "convert". at birth. Birth weight is about Script error: No such module "convert".. Weaning is after two years. Lifespan is about 30 years.

Feeding

There are plenty of food items that this dolphin feeds upon. They include fish, crustaceans, and cephalopods. During foraging periods, herds of about 7 dolphins will circle around prey and trap their victim. These prey entrapments occur slightly below the water surface level.[12]

Distribution and habitat

File:DSC 0764f.jpg
Irrawaddy Dolphin in Chilika Lake, Odisha

The Irrawaddy dolphin is an oceanic dolphin that lives in brackish water near coasts, river mouths, and estuaries. It has established subpopulations in freshwater rivers, including the Ganges and the Mekong, as well as the Ayeyarwady River, from which it takes its name. Its range extends from the Bay of Bengal to New Guinea and the Philippines, although it does not appear to venture offshore. It is often seen in estuaries and bays of Borneo, with sightings from Sandakan in Sabah to most parts of Brunei and Sarawak,[14]Template:Rp and another specimen was collected at Mahakam River in East Kalimantan.[15] Its presence in Chinese, Taiwanese, and Hong Kong waters has been questioned, as the reported sightings have been considered unreliable.[16]

It has been extinct in Laos since 2022.[27]

Interaction with humans

Irrawaddy dolphins have a mutualistic relationship of co-operative fishing with traditional fishers. Fishers in India recall when they would call out to the dolphins by tapping a wooden key, also known as a lahai kway,[28] against the sides of their boats, asking the Irrawaddys to drive fish into their nets.[29] In Burma, in the upper reaches of the Ayeyarwady River, Irrawaddy dolphins drive fish towards fishers using cast nets in response to acoustic signals from them. The fishermen attempt to gain the attention of the dolphins through various efforts such as using a cone-shaped wooden stick to drum the side of their canoes, striking their paddles to the surface of the water, jingling their nets, or making calls that sound turkey-like. A pod of dolphins that agrees to work alongside the fisherman will entrap a school of fish in a semicircle, guiding them towards the boat.[30] In return, the dolphins are rewarded with some of the fishers' bycatch.[31] Historically, Irrawaddy River fishers claimed particular dolphins were associated with individual fishing villages and chased fish into their nets. An 1879 report indicated legal claims were frequently brought into native courts by fishers to recover a share of the fish from the nets of a rival fisher that the plaintiff's dolphin was claimed to have helped fill.[5]

Folk stories

Laotians and Cambodians have a common belief that the Irrawaddy dolphins are reincarnations of their ancestors. Some even claim that the dolphins have saved drowning villagers and protected people from attacks by crocodiles. Their beliefs and experiences have led the people of Laos and Cambodia to live peacefully alongside one another for ages.[32] The West Kalimantan people have a similar story where the dolphins were naughty children who ate a pot of rice reserved for the shaman, but their mouths scalded, and they jumped into the water to cool themselves, and later transformed into these dolphins.[10]Template:Rp

Buddhist Khmer and Vietnamese fishermen have regarded the Orcaella as a sacred animal. If caught in fishing nets, they release the dolphin from the rest of the catch. In contrast, Muslim Khmer fishermen kill them for food. This has led to the dolphin becoming reputed to recognize the local languages of the area and approaching areas of the Khmer Muslim community with caution.[33]

Threats

File:BD-fishermen.jpg
Fishermen with fishnets in Bangladesh

Irrawaddy dolphins are more susceptible to human conflict than most other dolphins that live farther out in the ocean. Drowning in gillnets is the main threat to them throughout their range. Between 1995 and 2001, 38 deaths were reported, and 74% died as a result of entanglement in gillnets with large mesh sizes.[34] The majority of reported dolphin deaths in all subpopulations are due to accidental capture and drowning in gillnets and dragnets, and in the Philippines, bottom-set crab nets. In Burma, electrofishing, gold mining, and dam building are also serious and continuing threats. Though most fishers are sympathetic to the dolphins' plight, abandoning their traditional livelihood is difficult for them.[15]

Another identified threat towards the Irrawaddy dolphins was noise pollution from high-speed vessels. This caused the dolphins to dive significantly longer than usual. The Irrawaddy dolphins always changed directions when they encountered these large vessels.[34]

In recent years, Laotians and Cambodians developed techniques of using explosives for fishing. The government of Laos has made the use of such tactics illegal, but few regulations have been made in neighboring Cambodia, where explosives are sold in local markets and the practice of using fishnets has been abandoned. The practice of using explosives instead has become very popular and led to a steady decline of populations of fish, and especially the dolphins swimming in the area. Although Laotians may not use explosives, they do use nylon gillnets, which pose another large threat to the survival of the Irrawaddy. Some dolphins accidentally become entangled in the net. Poor fishermen refuse to cut and destroy their nets because it would result in too great an economic loss to save one Irrawaddy dolphin.[32]

In Laos, a dam across the Mekong River is planned. This could threaten the existence of the endangered Irrawaddy dolphins in downstream Cambodia. Laos's government decision is to forge the dam upstream of the core habitat of the Irrawaddy dolphins. This could precipitate the extinction of this specific species in the Mekong River. The dam builders propose to use explosives to dig out the tons of rock. This will create strong sound waves that could kill the Irrawaddy dolphins due to their highly sensitive hearing structures.Script error: No such module "Unsubst".

In several Asian countries, Irrawaddy dolphins have been captured and trained to perform in public aquaria. Their charismatic appearance and unique behaviors, including spitting water, spyhopping, and fluke-slapping, make them very popular for shows in dolphinariums. The commercial motivation for using this dolphin species is high because it can live in freshwater tanks, and the high cost of marine aquarium systems is avoided. The region within and near the species' range has developed economically; theme parks, casinos, and other entertainment venues that include dolphin shows have increased.

In 2002, there were more than 80 dolphinariums in at least nine Asian countries.[35]

Collateral deaths of dolphins due to blast fishing were once common in Vietnam and Thailand. In the past, the most direct threat was killing them for their oil.

The IUCN lists five of the seven subpopulations as endangered, primarily due to drowning in fish nets.[15] For example, the Malampaya population, first discovered and described in 1986, at the time consisted of 77 individuals. Due to anthropogenic activities, this number dwindled to 47 dolphins in 2007,[36] which further dwindled to 35 by 2013.[37] In the Mahakam River in Borneo, 73% of dolphin deaths are related to entanglement in gillnets, due to heavy fishing and boat traffic.[38]

Tourism

The Irrawaddy dolphins in Asia are increasingly threatened by tourist activity, such as large numbers of boats circulating the areas in which they live. The development of tours and boats has put a large strain on the dolphins.[39]

Disease

Cutaneous nodules were found to be present in various vulnerable populations of Irrawaddy dolphins. A more precise estimate of the affected dolphins is six populations. Although the definite fate of this emergent disease is unknown, the species is at risk.[40]

Conservation

File:Stamp of Indonesia - 1996 - Colnect 253526 - Irrawaddy Dolphin Orcaella brevirostris.jpeg
Irrawaddy dolphin on a 1996 Indonesian stamp

The Irrawaddy dolphin's proximity to developing communities makes the effort for conservation difficult.[41] Entanglement in fishnets and degradation of habitats are the main threats to Irrawaddy dolphins. Conservation efforts are being made at international and national levels to alleviate these threats.

International efforts

Protection from international trade is provided by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Enforcement, though, is the responsibility of individual countries.[15] While some international trade for dolphinarium animals may have occurred, this is unlikely to have ever been a major threat to the species.

Some Irrawaddy dolphin populations are classified by the IUCN as critically endangered in Cambodia, Vietnam (Mekong River sub-population), Indonesia (Mahakam River sub-population, Borneo), Myanmar (Ayeyarwady/Irrawaddy River sub-population), the Philippines (Malampaya Sound sub-population), and Thailand (Songkhla Lake sub-population). Irrawaddy dolphins in general, however, are IUCN listed as an endangered species, which applies throughout their whole range.[15] In 2004, CITES transferred the Irrawaddy dolphin from Appendix II to Appendix I, which forbids all commercial trade in species that are threatened with extinction.[42]

The UNEP-CMS Action Plan for the Conservation of Freshwater Populations of Irrawaddy dolphins notes that multiple-use protected areas will play a key role in conserving freshwater populations. Protected areas in fresh water could be a particularly effective conservation tool and can facilitate management, due to the fidelity of the species to relatively circumscribed areas. The Action Plan provides details on strategies for mitigating by-catch, including:

-establishing core conservation areas where gillnetting is banned or severely restricted
-promoting net attendance rules and providing training on the safe release of entangled dolphins
-initiating programs to compensate fishers for damage caused to their nets by entangled dolphins that are safely released
-providing alternative or diversified employment options for gillnet fishers
-encouraging the use of fishing gear that does not harm dolphins, by altering or establishing fee structures for fishing permits to make gillnetting more expensive while decreasing the fees for nondestructive gear
-experimenting with acoustical deterrents and reflective nets.[43]

The Irrawaddy dolphin is listed on both Appendix I and Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals (CMS).[44] It is listed on Appendix I[44] as this species has been categorized as being in danger of extinction throughout all or a significant proportion of their range, and CMS Parties strive towards strictly protecting these animals, conserving or restoring the places where they live, mitigating obstacles to migration, and controlling other factors that might endanger them, as well as on Appendix II[44] as it has an unfavourable conservation status or would benefit significantly from international co-operation organized by tailored agreements.[45]

The species is also covered by the Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region (MoU).[46]

National efforts

Several national efforts are resulting in the reduction of threats to local Irrawaddy dolphin subpopulations:

Bangladesh

File:Sundarbans.jpg
Satellite image of the Sundarbans

Portions of Irrawaddy dolphin habitat in the Sundarbans mangrove forest of Bangladesh are included within Script error: No such module "convert". of three wildlife sanctuaries, which are part of the Sunderbans World Heritage Site. The Wildlife Conservation Society is working with the Bangladesh Ministry of Environment and Forests to create protected areas for the 6000 remaining dolphins.[47][48]

Cambodia

Irrawaddy dolphins are fully protected as an endangered species under Cambodian fishery law.[49] In 2005, the World Wide Fund for Nature (WWF) established the Cambodian Mekong Dolphin Conservation Project with support from government and local communities. The aim is to support the survival of the remaining population through targeted conservation activities, research, and education.[50] In January 2012, the Cambodian Fisheries Administration, the Commission for Conservation and Development of Mekong River Dolphin Eco-tourism Zone, and WWF signed the Kratie Declaration on the Conservation of the Mekong River Irrawaddy Dolphin, an agreement binding them to work together, and setting out a roadmap for dolphin conservation in the Mekong River.[51] On 24 August 2012, the Cambodian government announced that a Script error: No such module "convert". stretch of the Mekong River from eastern Kratie province to the border with Laos has been designated as a limited fishing zone where using floating houses, fishing cages, and gill nets is disallowed, but simple fishing is allowed.[52] This area is patrolled by a network of river guards, specifically to protect dolphins. Between January and February 2006, a dozen Irrawaddy dolphins were found dead. Since the endangerment was evident, 66 guards have been posted along the Mekong River in Cambodia to protect these dolphins.[53]

File:Irrawaddy Dolphin at Sundarban National Park 27102012.jpg
Irrawaddy dolphin in the Sundarbans

India

The Irrawaddy dolphin (under the common name of snubfin dolphin, with the scientific name misspelled as Oreaella brevezastris) is included in the Indian Wildlife Protection Act,[54] Schedule I,[55] which bans their killing, transport, and sale of products.[47] A major restoration effort to open a new mouth between Chilika Lake and the Bay of Bengal in 2000 was successful in restoring the lake ecology and regulating the salinity gradient in the lake waters, which has resulted in increases in the population of Irrawaddy dolphins due to an increase of prey species of fish, prawns, and crabs.[56][57]

Indonesia

A conservation program, entitled Conservation Foundation for the Protection of Rare Aquatic Species of Indonesia, focused on protecting the Irrawaddy dolphin population and their habitat, the Mahakam River. The program not only educates and surveys the public, but also controls and monitors the dolphin population and their habitat. A prime example of this is the establishment of patrols in several villages.[58]

File:Utl album fb.jpg
Specimen in Kalimantan

Laos

The dolphins have been extinct in Laos since 2022. In the 1970s, many Irrawaddy dolphins were slaughtered for oil, and soon after, intensive fishing practices with explosives and gillnets began. The dolphins were protected in Cambodia and Laos, and explosive fishing and use of gillnets were restricted in many of the Irrawaddy dolphins' habitats.[20] Canadian conservationist Ian Baird set up the Lao Community Fisheries and Dolphin Protection Project to study the Irrawaddy dolphins in the Laotian part of the Mekong. Part of this project compensated fishers for the loss of nets damaged to free entangled dolphins. This project was expanded to include Cambodia after the majority of the dolphin population was determined to have been killed or migrated to Cambodia.[59] The Si Phan Don Wetlands Project encouraged river communities to set aside conservation zones and establish laws to regulate how and when fish are caught.[60]

Ultimately, these measures were unsuccessful. In early 2022, a 110 kg 25-year-old male dolphin was found dead on an island in the Si Phan Don called Koh La Ngo. It measured 2.6m in length and was the last Irrawaddy dolphin in Laos.[27]

Myanmar

Myanmar's Department of Fisheries took charge in December 2005 and instituted a protected region in a Script error: No such module "convert". segment of the Ayeyarwady River between Mingun and Kyaukmyaung.[30] Protective measures in the area include mandatory release of entangled dolphins, prohibition of the catching or killing of dolphins and trade in whole or parts of them, and the prohibition of electrofishing and gillnets more than Script error: No such module "convert". long, or spaced less than Script error: No such module "convert". apart.[47] Mercury poisoning and habitat loss from gold-mining dredging operations in the river have been eliminated.[61]

Philippines

In 2000, Malampaya Sound was proclaimed a protected seascape. This is the lowest possible prioritization given to a protected area.[43] The Malampaya Sound Ecological Studies Project was initiated by the WWF. With technical support provided by the project, the municipality of Taytay and the Malampaya park management developed fishery policies to minimize the threats to the Irrawaddy dolphin from bycatch capture. Gear studies and gear modification to conserve the dolphin species were implemented. The project was completed in 2007.[62] In 2007, the Coral Triangle Initiative, a new multilateral partnership to help safeguard the marine and coastal resources of the Coral Triangle, including the Irrawaddy dolphin subpopulation in Malampaya Sound, was launched.[63][64] In 2006, a new population was discovered in Guimaras Island in the Visayas. In 2015, another new population was discovered in Bago and Pulupandan in Negros Occidental, part of Negros island in the Visayas.[65] The dolphins are locally known in the Visayas as lumba-lumba.[66][67]

File:Irrawaddy Dolphin.jpg
Irrawaddy dolphin on Mekong River at Kratié, Cambodia

Thailand

In 2002, the Marine and Coastal Resources Department was assigned to protect rare aquatic animals such as dolphins, whales, and turtles in Thai territorial waters. To protect the dolphins, patrol vessels ensure boats stay at least Script error: No such module "convert". away from dolphins and no chasing of or running through schools of dolphins occurs. Many fishermen on the Bang Pakong River, Prachinburi Province, have been persuaded by authorities to stop shrimp fishing in a certain area, and 30 to 40 fishing boats have been modified so they can offer dolphin sightseeing tours.[68] A total of 65 Irrawaddy dolphins have been found dead along the coast of Trat Province in the past three years.[69] The local fishing industry is blamed for the deaths of the dolphins.[70] In January 2013, over a dozen dead Irrawaddy dolphins were found on the coast of Thailand. These dolphins were said to be dead because of a lack of oxygen. Dolphins are mammals, and unlike other animals that live in the sea, they must come to the surface for air. Many of the dolphins are found dead in the water, and others were washed ashore, said to have been dead for a few days. Also, in the first week of February 2013, as many as four Irrawaddy dolphins were found dead.[71] The Natural Resources and Environment Ministry is studying artificial breeding options in 2022 to try to save the last herd of Irrawaddy dolphins in Songkhla Lake, which is on the verge of extinction after only 14 were found in the most recent survey.[72] They also intend to list dolphins as a protected species, Thailand's highest level of animal protection.[73]

Malaysia

In 2008, the Department of Forestry and Sarawak Forestry Cooperative in Sarawak established a protected area for Irrawaddy dolphins in Santubong and Damai (Kuching Wetland).[47] Furthermore, they plan to establish more beaches in Miri as protected areas for them. The protection measures in the area include prohibition of catching or killing dolphins and trade in whole or parts of them, and prohibiting the use of gillnets. The government may also start small- and medium-scale research of this species at Sarawak Malaysia University with sponsorship from Sarawak Shell.

Vietnam

In 2012 in Vietnam, a group of scientists took in four Irrawaddy dolphins and provided them with medical care to see how they would survive. However, they found this to be the first case they saw of Irrawaddy dolphins having bacterial infections. The bacterial infection, chorioamnionitis, is common in many marine animals, but when these few dolphins were taken in, the scientists discovered this same bacterial infection for the first time in this group of dolphins. This disease mostly affects animals that are pregnant because the infection occurs through the umbilical cord and goes into the maternal bloodstream. One of the dolphins was pregnant, and before her death, she was found circling the bottom of the pool and was found dead early the next morning. This bacterial infection affects many organs in the body of the animal.[74]

See also

Script error: No such module "Portal".

References

<templatestyles src="Reflist/styles.css" />

  1. Script error: No such module "citation/CS1".
  2. a b c Script error: No such module "Citation/CS1".
  3. Script error: No such module "citation/CS1".
  4. a b c Script error: No such module "citation/CS1".
  5. a b c Script error: No such module "Citation/CS1".
  6. a b c d Script error: No such module "citation/CS1".
  7. Mark, Carwardine et al.. 2020. Handbook of Whales, Dolphins, and Porpoises of the World. Princeton University Press.
  8. "Irrawaddy Dolphins, Orcaella brevirostris ~ MarineBio.org." MarineBio Conservation Society. Retrieved 2014-10-20.
  9. a b Script error: No such module "citation/CS1".
  10. a b Script error: No such module "citation/CS1".
  11. Script error: No such module "citation/CS1".
  12. a b c Script error: No such module "Citation/CS1".
  13. Script error: No such module "Citation/CS1".
  14. Script error: No such module "Citation/CS1".
  15. a b c d e f Cite error: Script error: No such module "Namespace detect".Script error: No such module "Namespace detect".
  16. Script error: No such module "Citation/CS1".
  17. Script error: No such module "citation/CS1".
  18. Script error: No such module "Citation/CS1".
  19. Script error: No such module "citation/CS1".
  20. a b Script error: No such module "Citation/CS1".
  21. Script error: No such module "citation/CS1".
  22. Script error: No such module "citation/CS1".
  23. Script error: No such module "citation/CS1".
  24. Script error: No such module "citation/CS1".
  25. Script error: No such module "citation/CS1".
  26. Script error: No such module "citation/CS1".
  27. a b Script error: No such module "citation/CS1".
  28. Koss, Melissa. "Orcaella Brevirostris." Animaldiversity.umich.edu. Animal Diversity Web, n.d. Web. Retrieved 2014-10-19
  29. Script error: No such module "citation/CS1".
  30. a b Script error: No such module "Citation/CS1".
  31. Script error: No such module "citation/CS1".
  32. a b Script error: No such module "Citation/CS1".
  33. Script error: No such module "citation/CS1".
  34. a b Script error: No such module "Citation/CS1".
  35. Script error: No such module "citation/CS1".
  36. Script error: No such module "citation/CS1".
  37. Script error: No such module "citation/CS1".
  38. Kreb D, Budiono (2005). Conservation management of small core areas: key to survival of a Critically Endangered population of Irrawaddy river dolphins Orcaella brevirostris in Indonesia. Oryx 39: 178-188.
  39. Script error: No such module "citation/CS1".
  40. Script error: No such module "citation/CS1".
  41. Script error: No such module "Citation/CS1".
  42. Script error: No such module "citation/CS1".
  43. a b Script error: No such module "Citation/CS1".
  44. a b c Script error: No such module "citation/CS1".
  45. Script error: No such module "citation/CS1".
  46. Script error: No such module "citation/CS1".
  47. a b c d Script error: No such module "citation/CS1".
  48. Script error: No such module "citation/CS1".
  49. Script error: No such module "citation/CS1".
  50. Script error: No such module "citation/CS1".
  51. Script error: No such module "citation/CS1".
  52. Script error: No such module "citation/CS1".
  53. Script error: No such module "citation/CS1".
  54. Script error: No such module "citation/CS1".
  55. Script error: No such module "citation/CS1".
  56. Script error: No such module "citation/CS1".
  57. Script error: No such module "citation/CS1".
  58. Script error: No such module "citation/CS1".
  59. Script error: No such module "citation/CS1".
  60. Script error: No such module "citation/CS1".
  61. Script error: No such module "citation/CS1".
  62. Script error: No such module "citation/CS1".
  63. Script error: No such module "citation/CS1".Template:Cbignore
  64. Script error: No such module "citation/CS1".
  65. Script error: No such module "citation/CS1".
  66. Script error: No such module "citation/CS1".
  67. Script error: No such module "citation/CS1".
  68. Script error: No such module "citation/CS1".
  69. Script error: No such module "citation/CS1".
  70. Script error: No such module "citation/CS1".
  71. Script error: No such module "citation/CS1".
  72. Script error: No such module "citation/CS1".
  73. Script error: No such module "citation/CS1".
  74. Script error: No such module "Citation/CS1".

Script error: No such module "Check for unknown parameters".

Bibliography

External links

Script error: No such module "Navbox". Template:Taxonbar Template:Authority control