Coastal Processes: Cabrillo Beach, CA

Salinas de San Pedro

First, a little history.  The Port of LA is one of the most important ports in the world, moving 190 metric tons annually.  The port was established 100 years ago, in 1907.  The harbor was visited by Portuguese explorer Juan Rodriguez Cabrillo in 1542.  At that time it was a marshland, and in 1771, the Spanish explorers established missions at San Juan Capistrano and San Gabriel.   

Since then, development along the coast has destroyed nearly all of the coastal ecosystems in the area. According to the Southern California Coastal Water Research Project1, the Southern California bight supported 19,591 hectares of estuarine habitats. Since 1850, about 48% of these areas have been lost, with the vegetated wetlands = aka saltmarshes) suffering the most. Saltmarshes are an important part of the coastal ecosystem. First, they are a filter for sediments entering the ocean. Lagoons, marshes, and other quiet water environments are also low energy environments, so sediements are deposited easily. This limits the amount of sediment entering into the coastal waters and keeps tidal and kelp ecosystems clear and sediment-free. The shallow, quiet waters are also the perfect location for the young of many fish and invertibrate species to spend their youth, protected from larger predators due to the reduced water depth, amount of silt in the water, and numerous plant species. Finally, estuarine habitats provide a place for birds to rest, and to find shelter, food, and water.

image source2

The Salinas de San Pedro Saltmarsh was created in 1985 by the Port of Los Angeles. Located in Cabrillo Beach Park, it restores a part of the marsh enviroment lost during the last century of development. In addition to numerous native plant species surounding it, the marsh is home to many bird species, such as blackcrowned night-herons, willets, great blue herons, snowy egrets = all year round inhabitants), sandpipers, killdeer and grebes = migratory visitors). Aquatic species include worms, clams, crabs, and other invertibrates, in addition to small fish. During high tide corbina, sharks and stingrays can be found.3

Mouse over the image below to see what the saltmarsh looks like at high and low tides. Photo taken on Saturday, April 8, 2017.

Saltmarsh at high and low tide


1. Stein, Eric D., Kristen Cayce, Micha Salomon, Danielle Liza Bram, Danielle De Mello, Robin Grossinger, and Shawna Dark. Wetlands of the Southern California Coast: Historical Extent and Change Over Time. Tech. no. 826. Vol. 826. Costa Mesa: Southern California Coastal Water Research Project, 2014. Web =

2. "The History of Bolsa Chica." The History of Bolsa Chica. Web. 15 May 2016. <>.

3. "Coastal Park." Cabrillo Marine Aquarium. Web. 15 May 2016. <>.