Fisheries Abundance Cycles in Ecosystem and Economic Management of California Fish and Invertebrate Resources

Abstract

It is important for fishery scientists and ecosystem-based fishery managers to recognize that there may be apparent persistence in an ecosystem followed by ecosystem changes corresponding to different ecological states and different levels of fisheries Output; revenues paid to California fishers have varied more than fivefold in inflation adjusted dollars during the 75-year period of our study. Empirical orthogonal 41 function (EOF) analysis of California commercial fish landings from 1928 to 2002 defines a two-dimensional ecological space and the position of indicator species within it. This ecological space appears related to more easily monitored physical environmental processes that can be used to determine the persistence and probable temporal variability in species and ecological states. Observation of ecological changes in limited take marine reserves, file first step in ecosystem-based fishery management, is needed to reveal the proportion of ecosystem cycling that is dependent on exploitation. Future ecosystem-based fishery management may use Individual Transferable Quota shares that confer to fishers a user right to a percentage share of the Total Allowable Catch of fish. This management structure within the ecosystem-based management framework will require a high level of knowledge about ecosystem changes, fishery changes, and the resulting changes in the economic and social environment of the fishery. It is likely that the concepts of ecological space and ecological change presented here will be useful in assessing the population size and Total Allowable Catch of particular species and the importance of these species in sustaining a productive ecosystem for consumptive use and increasingly important nonconsumptive users.