Towards a fisheries ecosystem plan for the Northern California Current


Field, J.C., Francis, R.C., Strom, A. 2001. Towards a fisheries ecosystem plan for the Northern California Current. CalCOFI Report 42: 74-87.


Recently the congressionally established Ecosystem Principles Advisory Panel issued a report on how best to amend single-species management. A major recommendation was that fisheries management councils develop a fisheries ecosystem plan (FEP) for every ecosystem under their jurisdiction. This document would be an umbrella document containing detailed information on the structure and function of the ecosystem under consideration.

The U.S. portion of the northern California Current ecosystem (NCCE) may be an appropriate test case to develop some of the key elements of a draft FEP. Fishing pressure in the NCCE has been intense for decades, and the possibility of consequent large-scale ecosystem changes is large. Although fisheries science in this region has considerably advanced our understanding of the intricate linkages between fisheries production and large-scale oceanographic and atmospheric climate forcing, fisheries management efforts throughout the region may be insufficient for assessing the ecological impacts associated with fishing.

We use Ecopath models to assess the state of the NCCE in the 1960s during a cool regime with low exploitation rates and high rates of zooplankton production, and also in the 1990s during a warm regime characterized by low productivity, declining stocks, and intense exploitation. We compile population parameters and diet data for 34 species/species assemblages for both time periods to generate a food web of basic trophic interactions. These models are in agreement with the general consensus that this system has been functioning at lower levels of productivity since the 1977 regime shift. More work is needed to understand the status of many NCCE populations, but stock assessments and fisheries data suggest that the observed fluctuations in many harvested populations may be rapid, highly variable, and increasingly undesirable.