Tagging studies on the Shortfin Mako Shark (Isurus oxyrinchus) in the Western North Atlantic

Abstract

Results of an ongoing Cooperative Shark Tagging Program conducted by the National Marine Fisheries Service (USA) are described. In all, 2459 shortfin mako sharks (Isurus oxyrinchus) were tagged off the Atlantic coast of North America and in the Gulf of Mexico in the 28-year period between 1962 and 1989. The sharks were tagged by volunteer fishers, scientists aboard research vessels, and US Foreign Fisheries Observers on foreign vessels fishing in US waters. Altogether, 231 recaptures (9.4% of releases) of these tagged sharks have been reported by fishers from 16 countries. The maximum time at liberty is 8.2 years, and the maximum straight-line distance between tag and recapture localities is 2452 nautical miles. One tag was recovered from the European side of the Mid-Atlantic Ridge. Mako shark distribution and migratory patterns in relation to water temperature are discussed for the western North Atlantic.