Invasive Species Found In San Francisco Bay
Four new non-native aquatic species have taken up residence in San Francisco Bay, according to the 2011 Invasive Species Report by the California Department of Fish and Game (DFG). These organisms include:
- Caprella simia, a Caprellid, or "skeleton" shrimp, which was first discovered in California's Long Beach Harbor in 2000. C. simia is a Japanese species, probably introduced by fouling or ballast water and considered likely to spread north. It is now widespread in San Francisco Bay.
- Nicolea sp. A Harris, an undescribed polychaete worm, was first found in California in 2000 in San Diego Bay and Los Angeles/Long Beach Harbor. Possible vectors include ballast water and fouling on ships or recreational boats.
- Grateloupia lanceolata, a red alga native to Japan and Korea, has been found for the first time in the Port of Oakland and in Richardson Bay. This species was previously found at Santa Catalina Island, Port Hueneme and Moss Landing. It has been working its way up the coast.
- The collection of Amphibalanus eburneus (ivory barnacle) from Richmond and San Francisco marinas confirmed new distribution records for the San Francisco Bay. Although one specimen had been collected from a ship's hull around 1938, no other occurrences were documented in the Bay during the intervening time. More recent California observations of this North Atlantic native had been limited to Colorado Lagoon (Long Beach) and Huntington Harbor.
These four species were previously found only in other parts of the coast.
DFG's Marine Invasive Species Program (MISP) conducts biological surveys to monitor California coastal and estuarine waters to determine the level of invasion by non-native aquatic species (NAS). The triennial report covers July 2008 through June 2011 and describes results of field surveys for NAS in the San Francisco Bay Area, as part of long-term monitoring efforts of its ports, harbors, estuaries and the outer coast.
MISP, housed in DFG's Office of Spill Prevention and Response, employs a variety of programs with partners to gather report data. Programs include:
- A survey of 50 sites in 2010 and molecular analysis of NAS in the Bay.
- A two-year pilot program to detect NAS using a "next-generation" sequencing process to analyze the DNA extracted from samples collected from artificial settling plates.
- A collaborative study with Smithsonian Environmental Research Center (SERC) to examine the transfer mechanisms (vectors) likely responsible for marine introductions to the state.
- An MISP-funded genetic study of the difficult-to-identify "Breadcrumb" sponges by Moss Landing Marine Laboratories Genomics Lab.
MISP monitors coastal and estuarine waters of California for new introductions of NAS that could have been transported into state waters in ballast or as hull-fouling. Research with SERC shows that of the 290 invasive aquatic species (excluding fish and vascular plants) with established populations in western North America, 81 percent were first recorded in California. Of the 257 established in California, 61 percent were first recorded in San Francisco Bay and 57 percent are known from multiple estuaries, suggesting secondary spread. Ballast water and hulls of ocean-going ships remain the primary mechanisms responsible for bringing species to California in recent years.
Non-native species affect the structure and function of ecosystems through declines of native and commercial fisheries, parasite interactions with native species and humans, and physical habitat alteration. They can compete with native species; approximately 42 percent of the species on the federal threatened or endangered species lists are at risk primarily because of predation, parasitism and competition from non-native species. Approximately 40 percent of the species forced to extinction in aquatic ecosystems are due to biological invaders.