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.
Estuaries playa key role in the juvenlle stage of gag (Myeteroperca microlepis). The use of estuarine habitats by juvenlle gag has been examined in temperate estuaries, which are at the northern limits of the range of this species, but the importance of subtropical estuaries during fue early life history of this species has not heen studied extensively. Gag were collected in subtropical Charlotte Harbor, Florida, during routine monthiy sampling from January 1996 to Decemher 2002. Juvenlle gag were collected using a 21.3-m seine, a 183-m haul seine, and a 183-m purse seine. A total of 738 individuals ranging from 30 to 489 rom standard length (SL) were collected in 4,480 samples. Most gag (96%) were probably young-of-the-year « 288 rom SL). The majority of juveniles were collected in polyhatine Gasparilla and Pine Island sounds from April to December, with a few larger individuals captured year-round. The observed period of gag settlement was similar to thet reported in other subtropical and temperate estuaries, but gag in Charlotte Harbor remained in fue estuary longer and egressed at a larger size 1han did gag in other estuaries. Relative abundance of juvenile gag within Charlotte Harbor was greatest on shallow seagrass shoals but was also high along flinging mangrove shorelines, which is a habitat not previously reported for gag.
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