CAMEO: Comparative Approaches to Predicting the Consequences of an Impending Re-Invasion: Top Predator Effects on Californian Near-Shore Fisheries

University Of California-Santa Cruz, Santa Cruz CA

Investigators

Abstract

This project will compare the structure and dynamics of central and southern Californian nearshore ecosystems by parameterizing and analyzing the performance of three approaches for modeling these areas. The goals are to develop analytical tools to facilitate ecosystem-based decision making and management, and to forecast how marine reserves and the impending re-invasion of sea otters to southern Californian waters will affect the region's fisheries. The investigators will synthesize and leverage an array of preexisting data from spatially-extensive, long-term monitoring efforts. Along with a time series on the range, density, and feeding habits of sea otters, community data from a network of MPAs and reference sites of known age will provide the large-scale observational experiments needed to disentangle the effects of sea otters and MPAs on the structure and dynamics of California's nearshore ecosystems and their fisheries. The results will be incorporated into three different approaches: 1) EcoPath with EcoSim, 2) Metabolic scaling theory, and 3) Loop Analysis. These models range in data requirements, ease of application, and assumptions, and they vary greatly in the extent to which they simplify biology's complexity. By employing multiple modeling approaches, one can compare predictions for how the effects of MPAs and the impending re-invasion of sea otters will affect the productivity, dynamics, and resilience of these important communities. The data synthesis, analyses, and modeling efforts will provide ecosystem-based information to facilitate management decisions that will be needed in dealing with the impending conflict between the government's protection and supported re-establishment of a federally threatened species, and the preservation and governance of numerous fisheries. The comparisons will advance our understanding of ecosystem processes in central and southern CA kelp forests, including the interaction between bottom-up and top-down processes, and how these are influenced by geographic variation in key structural and functional attributes. On a more practical level, this work will result in 1) a set of analytical tools and effective and transferable ecosystem-based indicators to assess the status, thresholds and resiliency of nearshore temperate reef ecosystems; and 2) a collection of ecosystem-based predictions of short- and long-term community dynamics, including resiliency to environmental change and to commercially and recreationally valued kelp forest fisheries. These products will inform the design of monitoring and evaluation programs for MPAs, and will be especially useful for fisheries managers by helping them predict and accommodate the impacts of the re-invasion of sea otters into southern CA kelp forests. The project will also fulfill educational objectives through the training of 3 postdocs and 1 (Hispanic) graduate student in the development and application of ecosystem models and indicators. Postdocs will receive training in how to convene and run workshops, and to communicate scientific findings to resource managers and policymakers. Finally, the work will lead to the development of a collaborative partnership between academic researchers, NOAA fisheries scientists and USGS ecologists.