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

Fisheries targeting elasmobranch resources have experienced a dramatic grow th during the past two decades. World-wide elasmobranch landings exceed 600 000 metric tons (mt) annually and have clearly made a significant impact o n portions of that resource. In the eastern north Pacific catches of common thresher, shortfin mako and blue sharks may exceed 15 000 mt annually. Nea rly 90% of all sharks taken within this area are immature. Like most sharks , these pelagics have low rates of increase which make them quite vulnerabl e to modem day fishing pressure. Clearly the removal of large segments of j uveniles from any population has the potential to decrease the adult popula tion to unsustainable levels. The ability of populations to recover from ov er-exploitation depends not only on initial stock size, natural mortality, and migration rates, but also upon reducing total fishing mortality. Regula tions enacted by special interest groups benefiting only one segment of the resource users, combined with the lack of biological information, have slo wed progress towards achieving rational management. (C) 1998 Elsevier Scien ce B.V, All rights reserved.