Improving Stock Definitions and Understanding of Stock Boundaries for North Pacific Albacore

Contributors: Kathleen G. O’Malley, Felix Vaux, John R. Hyde, Sandra Bohn

Organizations: State Fisheries Genomics Lab, Coastal Oregon Marine Experiment Station, Department of Fisheries and Wildlife, Hatfield Marine Science Center, Oregon State University, Newport, OR • NOAA Fisheries, Southwest Fisheries Science Center, La Jolla, CA

Summary: Though much work has been done to understand stock structure of albacore globally [1], research in the Pacific Ocean has been coarse in nature and has raised a number of questions. For example, tagging data have shown no movement of albacore across the equator and yet previous genetic data have shown a surprisingly poor ability to discriminate between the currently managed North and South Pacific stocks [1,2]. These genetic results suggest that some fish migrate between the two oceans and interbreed on the spawning grounds. On a more local scale, tagging studies have shown that the migratory behavior of juvenile albacore varies regionally and seasonally with limited mixing between the northern and southern fishery areas in the Northeast Pacific [3]. However, it is uncertain whether the two migratory groups represent two genetically distinct stocks or fish from the same stock that exhibit different foraging behaviors.

The overall goal of our research was to generate genomic data to help resolve some of these uncertainties and provide more definitive results regarding stock boundaries of albacore tuna in the North Pacific. This collaborative effort involved researchers from Oregon State University, NOAA’s Southwest Fisheries Science Center, the Pacific Community (SPC) Pacific Marine Specimen Tissue Bank and partners from the American Fishermen’s Research Foundation (now ARF) and the Western Fishboat Owner’s Association.