Spatial Redistribution of Fishing Effort: Identifying Drivers and Testing Model Predictions for Informing Expectations in Marine Spatial Planning

Do marine reserves reduce fishermen’s catches or simply displace where fish are caught? Is “spill-over” real and can it be documented from catch records? This project seeks to identify, test and quantify factors that have redistributed fishing effort (where fishing is occurring and how intensely) around the Northern Channel Islands since the region’s marine protected areas (MPAs) went into effect in 2003. In the project’s first year, researchers will mine data from existing socio-economic reports, developed by the environmental consulting firm Ecotrust, based on extensive interviews with local fishermen. This analysis will be used to formulate hypotheses about fishermen’s responses to the MPAs. Examples of the types of hypotheses that will be considered include: MPAs remove rather than redistribute fishing effort and MPAs induce fishermen to “fish the line” to take advantage of “spill-over” from no-fishing areas. In the second year, researchers will compile empirical data to test the hypotheses developed in the project’s first stage. This empirical data will be drawn from multiple datasets, including aerial monitoring of fishing vessel type and location, fish biodiversity, benthic habitat and kelp forest cover, weather conditions and other relevant spatial information across the islands, before and after the MPAs’ establishment. Findings will be used to develop models for forecasting potential impacts of other MPAs in redistributing fishing effort and/or changing the amount or quality of fish caught by fishermen. The team will share their results with marine scientists and managers at two local meetings, and their findings will also be presented at the five-year review of the North Central coast’s MPAs in 2015. Ecotrust, a partner on the project, will communicate the results with California fishermen.