Inventory of Rocky Intertidal Resources in Southern Santa Barbara and Orange Counties

INVENTORY OF ROCKY INTERTIDAL RESOURCES IN SOUTHERN SANTA BARBARA, VENTURA AND LOS ANGELES COUNTIES

Principal Investigator: Richard Ambrose (UCLA)

Project Summary

The southern California coast possesses an exceptional diversity of valuable rocky intertidal resources. In addition, these rocky intertidal resources are heavily utilized, with large human populations concentrated on the coastlines of San Diego, Orange and Los Angeles Counties. Knowledge of the status and trends in rocky intertidal resources over a wide region is essential for understanding how oil and gas development might affect these important resources. Oil and gas activities, especially the tankering of oil along the California coast, raise the possibility of an oil spill or other impact to coastal resources. Population monitoring of coastal biota can provide indispensable information on the effects of an oil spill as already demonstrated for the recent spill at Vandenburg AFB. This research project continues a long-term monitoring study begun 10 years ago. This baseline information is essential for (1) scientific studies investigating the short- and long-term effects of an oil spill, and (2) natural resource damage assessment. In addition, the monitoring studies will yield important data on population dynamics on a local and regional scale, which could be utilized for more effective resource management as well as provide fundamental ecological knowledge about the dynamics of the systems.

Major factors contributing to the richness of coastal marine life in central and southern California include their location along the boundary of two major biogeographic provinces (cold-temperate Oregonian and warm-temperate California), their high diversity of habitat types, and their exposure to varying local oceanographic conditions. In addition, these rocky intertidal resources are heavily utilized, with large human populations concentrated on the coastlines of San Diego, Orange and Los Angeles Counties. Significant activities related to the production of oil and gas occur along this same stretch of coastline, and offshore extraction, transport of oil and decommissioning of platforms may lead to oil spills or other impacts to coastal resources. Monitoring of coastal biota in central and southern California provides baseline information in case an event such as a spill damages these resources. This baseline information is essential for effective resource management or understanding anthropogenic effects (such as an oil spill), as well as provide fundamental ecological knowledge about the dynamics of the system.

This study addresses the need to continue the inventory of the coastal ecological resources of southern Santa Barbara, Ventura and Los Angeles Counties. (inventories are also being done in San Luis Obispo, northern Santa Barbara, and Orange Counties). In 2005, the inventory will be entering its 15th year. During this period, it has been funded by MMS, CMI, the California Coastal Commission and the County of Santa Barbara. All of these agencies recognized the value of the inventory as the primary source of information for determining the impacts of (mainly) oil spills. Indeed the 1997 oil spill at Vandenburg Air Force Base in northern SB County reinforces the contention that such disturbances are inevitable and that long-term baseline information is essential for determining their biological impacts. For that spill, the only source of baseline information that could be used to assess damages to biological communities came from our shoreline inventory. Moreover, we were able to estimate the biologic effect of the spill only because our sampling program has been running long enough to determine the sort of biological changes resulting from natural disturbances like ENSO events. Only long term and ongoing inventories allow such separation of natural from anthropogenic disturbances.

Summarized results for selected species are available to the public at: www.marine.gov