View source for Castro Rocks

{{short description|Rocks in the San Francisco Bay, California}}
[[File:Castro Rocks from the water.jpg|thumb|Castro Rocks with harbor seals]]
The '''Castro Rocks''' are several rocks in [[Richmond, California]], protruding from the waters in [[San Francisco Bay]] between [[Castro Point]] and [[Red Rock Island]]. The rocks lie almost directly under the [[Richmond-San Rafael Bridge]] ([[Interstate 580 (California)|I-580]]).<ref name="topomap">[http://www.topoquest.com/map.asp?lat=37.93235&lon=-122.41732&datum=nad83&u=4&layer=DRG25&size=m&s=24 Topographic map], TopoQuest, retrieved July 6, 2008</ref>

==Name==
[[File:Don_Víctor_Castro.jpg|thumb|upright|The Castro Rocks are named after Don [[Víctor Castro (landowner)|Víctor Castro]], a [[Californio]] ranchero and politician.]]
The rocks are named after [[Don Víctor Castro]], a local rancho-era land owner.{{citation needed|date=October 2013}} They are shown as "Castro Rocks" on an 1850 survey map of the [[San Francisco Bay area]] made by [[Cadwalader Ringgold]].<ref name="survey1850">{{cite web
 |url         = https://www.davidrumsey.com/luna/servlet/detail/RUMSEY~8~1~24355~890046?id=1-1-24355-890046&name=General+chart,+San+Francisco+Bay#
 |title       = General Chart embracing Surveys of the Farallones Entrance to the Bay of San Francisco, Bays of San Francisco and San Pablo, Straits of Carquines and Suisun Bay, and the Sacramento and San Joaquin Rivers, to the Cities of Sacramento and San Joaquin, California
 |last1       = Ringgold
 |first1      = Cadwalader
 |last2       = Stuart
 |first2      = Fred D.
 |last3       = Everett
 |first3      = Chas.
 |last4       = Harrison
 |website     = David Rumsey Map Collection
 |publisher   = San Francisco Common Council
 |date        = 1850
 |access-date = 25 February 2021
 |quote       = 
}}</ref>

==Harbor seals==
Castro Rocks are the home of many [[harbor seal]]s,<ref name="tag">[http://userwww.sfsu.edu/~halmark/tagging.htm Tagging program] {{webarchive|url=https://web.archive.org/web/20070909185737/http://userwww.sfsu.edu/~halmark/tagging.htm |date=2007-09-09 }}, SFSU, retrieved August 1, 2007</ref> which lie on them to rest and sunbathe. The rocks are the largest harbor seal rookery in the northern San Francisco Bay and the second largest in the Bay Area itself.<ref name="rocks">[http://userwww.sfsu.edu/~halmark/castro.htm SFSU] {{webarchive|url=https://web.archive.org/web/20070906204647/http://userwww.sfsu.edu/~halmark/castro.htm |date=2007-09-06 }}, Castro Rocks page, retrieved August 1, 2007</ref> There are also sometimes sea lions on the rocks.<ref name="noaa2">[http://www.publicaffairs.noaa.gov/releases99/feb99/noaa99r109.html NOAA Seeks Comments On A Proposed Reauthorization For California Department Of Transportation To Harass Seals During Bridge Reconstruction] {{Webarchive|url=https://web.archive.org/web/20080212011001/http://www.publicaffairs.noaa.gov/releases99/feb99/noaa99r109.html |date=2008-02-12 }}, NOAA Press Release, February 12, 1999, retrieved August 4, 2007</ref> The rock's Harbor Seals also frequent [[Mowry Slough]], [[Brooks Island Regional Preserve|Brooks Island]], [[Yerba Buena Island]], and [[Mare Island]].<ref name="radiotag">[http://userwww.sfsu.edu/~halmark/vhfmap.htm vhfmapweb.jpg] {{webarchive |url=https://web.archive.org/web/20070911212146/http://userwww.sfsu.edu/~halmark/vhfmap.htm |date=September 11, 2007 }}, Radio tagging map, San Francisco State University, February 2004, retrieved August 4, 2007</ref>

The seals at this location have high levels of toxic pollutants including the [[DDT]], [[Polychlorinated biphenyl|PCBs]], [[PBDE]]s, [[PFOS]], [[PFOA]], and [[mercury (element)|mercury]].<ref name="chems">[http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2007/10/19/MN11SRS7D.DTL Harbor seals may help determine effect on humans of eating toxic fish], by Jane Kay, ''[[San Francisco Chronicle]]'', 19-10-2009, access date 19-02-2009</ref>

==References==
{{reflist|2}}

==External links==
*[https://web.archive.org/web/20070906204647/http://userwww.sfsu.edu/~halmark/castro.htm Castro Rocks page]
*[https://web.archive.org/web/20070909185737/http://userwww.sfsu.edu/~halmark/tagging.htm SFSU Tagging] - Photos

{{coord|37.932817|-122.416963|region:US-CA_type:isle_source:wikimapia| display=title}}

{{Bodies of water in Richmond, California}}
{{Islands of the San Francisco Bay Area|state=autocollapse}}
{{San Francisco Bay watershed|state=autocollapse}}

[[Category:Geography of Richmond, California]]
[[Category:Islands of Contra Costa County, California]]
[[Category:Islands of San Francisco Bay]]
[[Category:Islands of Northern California]]
[[Category:Landforms of Contra Costa County, California]]
[[Category:Rock formations of California]]