Abstract

In 2006, the Dauphin Island Sea Lab (DISL) began conducting bottom longline surveys along the north central Gulf of Mexico. The data gathered from these surveys are used to make ecological connections between organisms and their environment, as well as inform stock assessment models and the resulting management decisions. While DISL has caught and gathered data on thousands of fish since beginning the program, the gear available on the vessels did not allow for accurate measurements on large species that could not be safely boated. While encounters with these large fish provide valuable catch and effort data, our inability to boat them precludes precise measurements and maturity status determinations. To address these limitations, in 2010 the DISL developed a low-cost landing cradle to safely lift large fish-es onto the deck of the boat. The implementation of this cradle has resulted in accurate length measurements of an addi-tional 74 large coastal sharks across 8 species. The addition of a spring scale in 2013 has provided weight data for 14 large sharks that would otherwise have gone unweighed. Our preliminary results demonstrate how the integration of a landing cradle into longline surveys provides researchers a safe platform for accurately inserting intramuscular tags, getting precise (mm) length measurements, taking blood and tissue samples, and getting proper sex and sexual maturity information. Given current harvest restrictions (for example, closure of the commercial fishery for Sandbar shark Carcharhinus plumbeus), the landing sling is an additional tool researchers can employ to gather increasingly important life history data for shark populations recovering from overexploitation.

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