Pelagic shark fisheries along the west coast of the United States and Baja California, Mexico

Abstract

Fisheries targeting elasmobranch resources have experienced a dramatic growth during the past two decades. World-wide elasmobranch landings exceed 600 000 metric tons (mt) annually and have clearly made a significant impact on portions of that resource. In the eastern north Pacific catches of common thresher, shortfin mako and blue sharks may exceed 15 000 mt annually. Nearly 90% of all sharks taken within this area are immature. Like most sharks, these pelagics have low rates of increase which make them quite vulnerable to modern day fishing pressure. Clearly, the removal of large segments of juveniles from any population has the potential to decrease the adult population to unsustainable levels. The ability of populations to recover from over-exploitation depends not only on initial stock size, natural mortality, and migration rates, but also upon reducing total fishing mortality. Regulations enacted by special interest groups benefiting only one segment of the resource users, combined with the lack of biological information, have slowed progress towards achieving rational management.