Castro Rocks are several rocks in Richmond, California

Richmond, California

Richmond is a city in western Contra Costa County, California, United States. The city was incorporated on August 7, 1905. It is located in the East Bay, part of the San Francisco Bay Area. It is a residential inner suburb of San Francisco, as well as the site of heavy industry, which has been...

 protruding from the waters San Francisco Bay

San Francisco Bay

San Francisco Bay is a shallow, productive estuary through which water draining from approximately forty percent of California, flowing in the Sacramento and San Joaquin rivers from the Sierra Nevada mountains, enters the Pacific Ocean...

 between Castro Point

Castro Point

Castro Point is a cape in western Richmond, California, United States.-History:Castro Point was once the east shore landing for the Richmond-San Rafael Car and Passenger Ferry that crossed the San Pablo Bay. It was also the western terminal for the East Shore and Suburban Railway connecting trains...

 and Red Rock Island

Red Rock Island

Red Rock Island is an uninhabited, island in the San Francisco Bay located just south of the Richmond – San Rafael Bridge. The property is the only privately owned island in San Francisco Bay. The boundaries of three counties – San Francisco, Marin and Contra Costa – converge on this high rock...

.The rocks lie almost directly under the Richmond-San Rafael Bridge

Richmond-San Rafael Bridge

The Richmond – San Rafael Bridge is the northernmost of the east–west crossings of the San Francisco Bay in California, USA, connecting Richmond on the east to San Rafael on the west end...

 (Interstate 580

Interstate 580

Interstate 580 is the designation for several Interstate Highways in the United States, all of which are related to Interstate 80:*Interstate 580 , a connector in the San Francisco Bay Area to Interstate 5...

).

Castro Rocks are the home of many harbor seals and who lie on them to rest and sunbathe. The rocks are named after Don Victór Castro a local rancho-era land owner. The rocks are the largest harbor seal rookery in the northern San Francisco Bay and the second largest in the Bay Area itself. There are also sometimes sea lions on the rocks. The rock's Harbor Seals also frequent Mowry Slough

Mowry Slough

Mowry Slough is a slough in Don Edwards San Francisco Bay National Wildlife Refuge and is the primary breeding ground for San Francisco Bay Harbor Seals. It is situated amongst salt marshes and salt evaporation ponds in the city of Fremont....

, Brooks Island, Yerba Buena Island

Yerba Buena Island

Yerba Buena Island sits in the San Francisco Bay between San Francisco and Oakland, California. The Yerba Buena Tunnel runs through its center and connects the western and eastern spans of the San Francisco-Oakland Bay Bridge. It has had several other names over the decades: Sea Bird Island, Wood...

, and Mare Island

Mare Island

Mare Island is a peninsula in the United States alongside the city of Vallejo, California, about northeast of San Francisco. The Napa River forms its eastern side as it enters the Carquinez Strait juncture with the east side of San Pablo Bay. Mare Island is considered a peninsula because no full...

.

The seals at this location have high levels of toxic pollutants including the DDT

DDT

DDT is one of the most well-known synthetic insecticides. It is a chemical with a long, unique, and controversial history....

, PCBs

Polychlorinated biphenyl

Polychlorinated biphenyls are a class of organic compounds with 2 to 10 chlorine atoms attached to biphenyl, which is a molecule composed of two benzene rings. The chemical formula for PCBs is C12H10-xClx...

, PBDE

PBDE

Polybrominated diphenyl ethers or PBDE, are organobromine compounds that are used as flame retardants. Like other brominated flame retardants, PBDEs have been used in a wide array of products, including building materials, electronics, furnishings, motor vehicles, airplanes, plastics,...

s, PFOS, PFOA, and mercury

Mercury (element)

Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...

.

External links

• Castro Rocks page
• SFSU Tagging - Photos