Stephen C. Turner1, Clay E. Porch1, Victor R. Restrepo2 and Gerald P. Scott1
1 National Marine Fisheries ServiceABSTRACT
Southeast Fisheries Science Center, Miami Laboratory
75 Virginia Beach Drive
Miami, Florida 33149 USA2 Division of Marine Biology and Fisheries
Cooperative Unit for Fisheries Education and Research
University of Miami, Rosenstiel School of Marine and Atmospheric Science
4600 Rickenbacker Causeway
Miami, Florida 33149 USA
Examples of interactions among Atlantic bluefin tuna fisheries are reviewed. Analyses of the impact of reductions in historical catches of small bluefin tuna in the western Atlantic were conducted under a hypothesis of a western Atlantic resource negligibly affected by mixing with bluefin from the eastern component of the resource. The analyses indicated that abundances of larger bluefin and, presumably, catch rates in associated fisheries for that size range would have increased. Analyses conducted under one set of hypotheses about mixing behaviour and mixing rates between eastern (including the Mediterranean Sea) and western components of the resource investigated the impacts of alternative levels of fishing in each area on projected abundances. Different catch levels of the more abundant eastern component were shown to impact the western component, while different catch levels for the western area showed no impact on the eastern component.
