Hooking mortality of reef fishes in the snapper-grouper commercial fishery of the southeast United States

UNCW Author/Contributor (non-UNCW co-authors, if there are any, appear on document)
David V. Guccione Jr. (Creator)
Institution
The University of North Carolina Wilmington (UNCW )
Web Site: http://library.uncw.edu/
Advisor
Ileana Clavijo

Abstract: A widely used management regulation in the grouper-snapper fishery of the Southeast United States is the use of minimum size limits. This approach assumes that under the size limit fish caught and returned experience minimal post-release mortality. However visible signs of decompression injury due to the expansion of gas within the swim bladder when fish are hooked and reeled quickly to the surface suggest potential mortality. Mortality rates of fishes that are caught and released are unknown. This study examined mortality rates and decompression injury in below or just legal sized red porgy (Pagrus pagrus), vermilion snapper (Rhomboplites aurorubens), red grouper (Epinephelus morio) and scamp grouper (Mycteroperca phenax) caught on hook and line then caged and returned to the water. The major objective was to determine mortality of these fishes on release. Secondary objectives were to look at the relationships between depth and mortality and size and mortality. The project was done in federal marine waters offshore of North Carolina in 1999 and 2000 in depths ranging from 33.6 – 54.8 m. Mean mortality rates were conservatively estimated as 33% for E. morio, 39.5% for M. phenax, 30.35% for R. aurorubens, and 42.9% for P. pagrus. There were positive trends between depth and mortality in P. pagrus and M. phenax and depth caught was a significant factor in the mortality for R. aurorubens. Length was found to have a marginally significant positive correlation with mortality in P. pagrus. These results cast doubts on the use of size limits as an effective management tool for the snapper/grouper fishery. Various species-specific regulations and techniques are discussed as well as an ecosystem-based approach as an alternative to size limits for management of the snapper-grouper complex.

Additional Information

Publication
Thesis
A Thesis Submitted to the University of North Carolina Wilmington in Partial Fulfilment Of the Requirements for the Degree of Master of Science
Language: English
Date: 2009
Keywords
Fishery management--United States, Fishes--Mortality, Groupers--Mortality, Red snapper--Mortality
Subjects
Red snapper -- Mortality
Groupers -- Mortality
Fishes -- Mortality
Fishery management -- United States

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