Age and growth of red snapper, Lutjanus campechanus, from the southeastern United States

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

Abstract: This study investigated length and age relationships for a sample of red snapper, Lutjanus campechanus, from the South Atlantic between the years 1977 – 2006, a period of time that included 3 different management schemes for this species. Total lengths ranged from 197 to1,001 mm with a mean total length of 573 mm. Fractional ages of these fish ranged from 0.5 to 53.67 years with corresponding calendar ages ranging from 1 to 54 years. Von Bertalanffy models were derived using both observed lengths with fractional age and back-calculated lengths to the last annulus. There was no biological difference in theoretical growth between observed and back-calculated lengths. When back-calculating lengths from otolith radius taken along the transverse plane compared to along the sulcal groove, there was no difference in estimates between measurement axes. Mean length, mean age, mean length-at-age, and von Bertalanffy curves were used to test for differences in growth between geographical area, fishery type, and regulatory period. Regulatory periods consisted of the no regulation period (1977 – 1982), the FMP period (1983 – 1991) where a minimum size limit of 305 mm total length was instituted for red snapper, and the Amendment 4 period (1992 – 2006), where the minimum size limit was raised to 508 mm total length. No differences in growth were found between fish caught in the Carolinas (NC/SC/GA) and those caught in Florida or between fish caught in the recreational fishery as opposed to the commercial fishery. However, red snapper 2 – 5 years old were significantly larger at age in the Amendment 4 period than in the other two periods. This shows evidence for a size selective fishery due to the increase in size limits. Von Bertalanffy models, corrected for size limit effects, showed there was no difference in the growth pattern between areas, fisheries, or regulatory periods, therefore, one corrected von Bertalanffy model (Lt = 896 * (1 – e -0.25 (t + 0.16))) was used to represent growth for the entire South Atlantic red snapper population from 1977 to 2006.

Additional Information

Publication
Thesis
A Thesis Submitted to the University of North Carolina at Wilmington in Partial Fulfillment of the Requirement for the Degree of Masters of Science
Language: English
Date: 2009
Keywords
Fishery management, Red snapper--Growth, Red snapper--Mortality
Subjects
Red snapper -- Growth
Red snapper -- United States -- Southeastern
Red snapper -- Mortality
Fishery management