The California Department of Fish and Game reports that four new non-native species have taken up residence in the San Francisco Bay.
The 2011 Invasive Species Report, released late last week, includes data about four species new to the San Francisco Bay. These organisms include:
• Caprella simia, a "skeleton" shrimp — a Japanese species, it was first discovered in California’s Long Beach Harbor in the year 2000. The shrimp is now widespread in the San Francisco Bay.
• Nicolea sp. A Harris — a polychaete worm first found in California in 2000 in the San Diego Bay and Los Angeles/Long Beach Harbor.
• Grateloupia lanceolata, a red algae native to Japan and Korea — found for the first time in the Port of Oakland and Richardson Bay. The species had already been documented at Santa Catalina Island, Port Hueneme and Moss Landing.
• Amphibalanus eburneus (ivory barnacle) was found in the Richmond and San Francisco marinas. Although one specimen was collected from a ship’s hull around 1938, no other occurrences had been documented in the Bay until this report.
Non-native aquatic species impact the structure and function of ecosystems and often compete with native species.
Approximately 42 percent of the species on the federal threatened or endangered species lists are at risk primarily because of competition from non-native species. Approximately 40 percent of the species forced to extinction in aquatic ecosystems are due to biological invaders.
The DFG Marine Invasive Species Program conducts biological surveys to monitor California coastal and estuary waters to determine the level of invasion by non-native aquatic species. The report covers the period between July 2008 and June 2011.
Research shows that of the 290 non-native aquatic species (excluding fish and vascular plants) with established populations in western North America, 81 percent were first recorded in California.
Ballast water and hulls of ocean-going ships remain the primary mechanisms responsible for bringing species to California in recent years.