An Index of Abundance for Coastal Species of Juvenile Sharksfrom the Northeast Gulf of Mexico

Carlson, John K.; Brusher, John H.

An Index of Abundance for Coastal Species of Juvenile Sharksfrom the Northeast Gulf of Mexico

1999

Carlson, John K. | Brusher, John H.

A fishery-independent assessment of juvenile coastal shark populations in U.S. waters of the northeast Gulf of Mexicowas conducted using two methods: gillnets and longlines. Surveys were conducted monthly during April–October in two fixed sampling areas from 1996 to 1998. The Atlantic sharpnose shark, Rhizoprionodon terraenovae, and the blacktip shark, Carcharhinus limbatus, were the most common species captured with either longlines or gillnets. An additional 14 shark species were captured, and juvenileindices of abundance were developed for 8 species with gillnets and 6 species of sharks with longlines. Trends in catch-per-unit-effort were found to vary depending on species. Length-frequency information revealed that the majority of sharks captured were juveniles. Given the direct relationship between stock and recruitment for sharks, continued monitoring of juvenile abundance will aid in determining the strength of the parental stock sizeand for predicting future population strength.

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