Red Drum (Sciaenops ocellatus) are highly targeted recreationally in the Gulf of Mexico, and support a small commercial fishery in Mississippi. Despite their popularity, the stock is assessed using data limited approaches that necessitate accurate life history information. I estimated the year-specific and year-aggregated escapement rates for the Mississippi stock (years 2004 to 2015), which were sensitive to mortality estimation methods; year-aggregated estimates were 6.9 to 28.2 % depending on the method, but temporal patterns were consistent. I then addressed concerns with previously estimated life-history characteristics by describing the sex-specific growth and reproductive dynamics. The three-parameter von Bertalanffy growth function was the best candidate length-at-age model, with no significant difference in overall growth between sex-specific relationships, but females had a larger mean asymptotic length, and four candidate models showed significant sexual dimorphism. I described Red Drum as batch spawners, with 3.7 days between successive spawns during the spawning season (August and September). The age at 50% maturity was around age-3 y in both sexes, but spawning capability was not evident until around age-6 y. The carbon (delta C-13) and nitrogen (delta N-15) stable isotope composition of Red Drum muscle tissue was more enriched in carbon offshore and was significantly different with respect to reproductive phase. Mean and variance of delta N-15 and variance of delta C-13 was significantly different between fish < age-7 y and those older. When accounting for muscle turnover rates, this coincides with the age of spawning capability, indicating an ontogenetic migration at age-6 y.
","abstract_html":"<p>Red Drum (<em>Sciaenops ocellatus</em>) are highly targeted recreationally in the Gulf of Mexico, and support a small commercial fishery in Mississippi. Despite their popularity, the stock is assessed using data limited approaches that necessitate accurate life history information. I estimated the year-specific and year-aggregated escapement rates for the Mississippi stock (years 2004 to 2015), which were sensitive to mortality estimation methods; year-aggregated estimates were 6.9 to 28.2 % depending on the method, but temporal patterns were consistent. I then addressed concerns with previously estimated life-history characteristics by describing the sex-specific growth and reproductive dynamics. The three-parameter von Bertalanffy growth function was the best candidate length-at-age model, with no significant difference in overall growth between sex-specific relationships, but females had a larger mean asymptotic length, and four candidate models showed significant sexual dimorphism. I described Red Drum as batch spawners, with 3.7 days between successive spawns during the spawning season (August and September). The age at 50% maturity was around age-3 y in both sexes, but spawning capability was not evident until around age-6 y. The carbon (delta C-13) and nitrogen (delta N-15) stable isotope composition of Red Drum muscle tissue was more enriched in carbon offshore and was significantly different with respect to reproductive phase. Mean and variance of delta N-15 and variance of delta C-13 was significantly different between fish < age-7 y and those older. When accounting for muscle turnover rates, this coincides with the age of spawning capability, indicating an ontogenetic migration at age-6 y.</p>","abstract_has_math":false,"creators":["Bennetts, Corbin"],"institution":null,"degree_name":"Master of Science (MS)","degree_level":"Masters Thesis","degree_discipline":"Coastal Sciences, Gulf Coast Research Laboratory","degree_department":null,"school":null,"contributors":["Robert T. Leaf","Nancy J. Brown-Peterson","Kevin S. Dillon"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2018,"date_issued":"2018-05-01T07:00:00Z","date_published":"2018-05-01T07:00:00Z","updated_at":"2026-07-24T05:44:50Z","subjects":["age and growth","reproduction","stable isotope analysis","escapement rate","Marine Biology","Population Biology","Statistical Models"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://aquila.usm.edu/masters_theses/348","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Robert T. Leaf","Nancy J. Brown-Peterson","Kevin S. 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Despite their popularity, the stock is assessed using data limited approaches that necessitate accurate life history information. I estimated the year-specific and year-aggregated escapement rates for the Mississippi stock (years 2004 to 2015), which were sensitive to mortality estimation methods; year-aggregated estimates were 6.9 to 28.2 % depending on the method, but temporal patterns were consistent. I then addressed concerns with previously estimated life-history characteristics by describing the sex-specific growth and reproductive dynamics. The three-parameter von Bertalanffy growth function was the best candidate length-at-age model, with no significant difference in overall growth between sex-specific relationships, but females had a larger mean asymptotic length, and four candidate models showed significant sexual dimorphism. I described Red Drum as batch spawners, with 3.7 days between successive spawns during the spawning season (August and September). The age at 50% maturity was around age-3 y in both sexes, but spawning capability was not evident until around age-6 y. The carbon (delta C-13) and nitrogen (delta N-15) stable isotope composition of Red Drum muscle tissue was more enriched in carbon offshore and was significantly different with respect to reproductive phase. Mean and variance of delta N-15 and variance of delta C-13 was significantly different between fish < age-7 y and those older. When accounting for muscle turnover rates, this coincides with the age of spawning capability, indicating an ontogenetic migration at age-6 y.
"]},{"key":"dc:title","label":"Title","values":["Life-History Characteristics and Fishery Dynamics of Red Drum (Sciaenops ocellatus), in the North-Central Gulf of Mexico"]}]}],"canonical_facts":{"dc:contributor":["Robert T. Leaf","Nancy J. Brown-Peterson","Kevin S. Dillon"],"dc:creator":["Bennetts, Corbin"],"dc:date.available":["2018-03-28T07:00:00Z"],"dc:description.abstract":["Red Drum (Sciaenops ocellatus) are highly targeted recreationally in the Gulf of Mexico, and support a small commercial fishery in Mississippi. Despite their popularity, the stock is assessed using data limited approaches that necessitate accurate life history information. I estimated the year-specific and year-aggregated escapement rates for the Mississippi stock (years 2004 to 2015), which were sensitive to mortality estimation methods; year-aggregated estimates were 6.9 to 28.2 % depending on the method, but temporal patterns were consistent. I then addressed concerns with previously estimated life-history characteristics by describing the sex-specific growth and reproductive dynamics. The three-parameter von Bertalanffy growth function was the best candidate length-at-age model, with no significant difference in overall growth between sex-specific relationships, but females had a larger mean asymptotic length, and four candidate models showed significant sexual dimorphism. I described Red Drum as batch spawners, with 3.7 days between successive spawns during the spawning season (August and September). The age at 50% maturity was around age-3 y in both sexes, but spawning capability was not evident until around age-6 y. The carbon (delta C-13) and nitrogen (delta N-15) stable isotope composition of Red Drum muscle tissue was more enriched in carbon offshore and was significantly different with respect to reproductive phase. Mean and variance of delta N-15 and variance of delta C-13 was significantly different between fish < age-7 y and those older. When accounting for muscle turnover rates, this coincides with the age of spawning capability, indicating an ontogenetic migration at age-6 y.
"],"dc:identifier":["https://aquila.usm.edu/masters_theses/348"],"dc:subject":["age and growth","reproduction","stable isotope analysis","escapement rate","Marine Biology","Population Biology","Statistical Models"],"dc:title":["Life-History Characteristics and Fishery Dynamics of Red Drum (Sciaenops ocellatus), in the North-Central Gulf of Mexico"],"thesis:degree_discipline":["Coastal Sciences, Gulf Coast Research Laboratory"],"thesis:degree_level":["Masters Thesis"],"thesis:degree_name":["Master of Science (MS)"]},"updated_at":"2026-07-24T05:44:50Z"}