Affiliation:
1. Institute of Marine Ecology and Conservation, National Sun Yat‐sen University Kaohsiung Taiwan
2. Department of Fisheries and Oceans Bedford Institute of Oceanography Dartmouth Nova Scotia Canada
Abstract
AbstractSpatial scales are important for examining health of exploited fishery stocks and guiding management actions. However, information about the optimal spatial scale is still unclear for assessment of transit fisheries, such as elver fisheries of the American eel Anguilla rostrata. We applied a generalized depletion model to assess catch and effort data from three nearby rivers (within 50 km) to test the hypothesis that modeling on pooled and separate data from nearby rivers would give similar estimates of abundance and exploitation rate. Overall, pooling data from rivers within 50 km did not result in large differences (<20% in relative difference) in estimates of abundance and exploitation rate with close mean abundance estimates and similar temporal trends in abundance, exploitation rate, and relative escapement. Pooling nearby river systems can greatly reduce modeling effort, at the cost of ignoring fine‐scale variability in elver recruitment and having coarser spatial scale for the management. When only an index of annual recruitment and exploitation rate are of interest, pooling data may be practical from different locations up to 50 km.
Reference59 articles.
1. Natural mortality of blue rockfish, Sebastes mystinus, during their first year in nearshore benthic habitats;Adams P.B.;Fishery Bulletin,1996
2. What are the relative risks of mortality and injury for fish during downstream passage at hydroelectric dams in temperate regions? A systematic review
3. ASMFC. (2023)Atlantic States Marine Fisheries Commission American Eel Benchmark Stock Assessment and Peer Review Report.http://www.asmfc.org/uploads/file/64da82f5AmEelBenchmarkStockAssessment_PeerReviewReport_Aug2023.pdf
4. Barcelo V.(2021)National report‐Cuba. Fishing for American eel Anguilla rostrata. Prepared for: International Oceanographic Commission—United Nations Educational Scientific and Cultural Organisation (IOC‐UNESCO).