Patrick J. Harris

Age, growth, and temporal change in size at age of the vermilion snapper from the South Atlantic Bight

Abstract Sectioned sagittal otoliths were used to determine ages of vermilion snapper Rhomboplites aurorubens collected from the South Atlantic Bight (SAB) by trawl, trap, and hook-and-line gear during 1979–1993. Annulus formation, validated by marginal increment analysis of ages 1–8, occurred from June to August, the peak spawning period for vermilion snapper. Ages ranged from 0 to 12 years for each sex. No significant difference was found for size at age between males and females. The von Bertalanffy growth equation for vermilion snapper taken during 1979–1981 was TL t = 562{1 – exp[–0.202(t + 0.117)]}, where TL t = total length (mm) at age and t = age in years. The length–weight relationship was w = 2.147 × 10−5 TL2.899, where w = whole fish weight in grams. Weighted mean back-calculated lengths at age, compared by analysis of variance for five 3-year periods, declined from 1979–1981 through 1982–1984 to 1985–1987. but did not change significantly during 1985–1993. The temporal decrease in size at age ...

Age, Growth, and Reproduction of Greater Amberjack off the Southeastern U.S. Atlantic Coast

Abstract The greater amberjack Seriola dumerili is a pelagic, epibenthic species that is widely distributed in the Atlantic, Pacific, and Indian oceans. Life history samples from a total of 2,729 greater amberjacks were collected between 2000 and 2004 by personnel of the Marine Resource Monitoring Assessment and Prediction program and National Marine Fisheries Service port agents from recreational fisherman and in commercial fish houses from Cape Lookout, North Carolina, to Key West, Florida. Ages were estimated using thin transverse otolith sections from 1,996 specimens; sex and reproductive state were assigned to 2,517 fish based on histological preparations of gonadal tissues. Ages of greater amberjacks sampled ranged from 1 to 13 years; these data were described with a von Bertalanffy growth equation fitted to all aged specimens: Lt = 1,241.5 × [1 − e −0.28(t+1.56)]. Sexual dimorphism was evident; females were larger at age than males. Size at 50% maturity was 644 mm fork length (FL) for males and 733...

Age, growth, and reproductive biology of blueline tilefish along the southeastern coast of the United States, 1982-1999

Abstract The blueline tilefish Caulolatilus microps is a long-lived, slow-growing deepwater demersal species patchily distributed along the outer continental shelf of North America from Cape Lookout, North Carolina, to Campeche Bank, Mexico. Commercial landings of blueline tilefish for the southeastern United States peaked in 1983 at 530 metric tons (mt), fell to 31 mt by 1985, and exceeded 100 mt only once between 1986 and 1999. We collected blueline tilefish off North Carolina and South Carolina (approximately 32°N to 33°N) during 1982–1987 and 1996– 1999 with fishery-independent gear, and whole tilefish were sampled from commercial catches during 1996–1998. Specimens were assigned an age from counts of increments on a transverse section of the left sagitta. Sex and reproductive state of all individuals were determined from histological sections of the gonad. The mean size of males was significantly larger than that of females (583 versus 537 mm total length), and the mean lengths of males and females d...

Indications of Continued Overexploitation of Speckled Hind Along the Atlantic Coast of the Southeastern United States

Abstract From 1977 to 2007, speckled hind Epinephelus drummondhayi were sampled along the Atlantic coast of the southeastern United States from North Carolina to central Florida. In total, 1,365 speckled hind were obtained from two sources (fishery-independent survey and commercial catches). The ages of specimens were estimated from increment counts on transverse sections of sagittal otoliths. Sex and reproductive state of specimens were determined by histological examination of gonads. Age of collected speckled hind ranged from 1 to 35 years, and total length (TL) ranged from 164 to 973 mm. The TL and age ranges were 169–730 mm and 1–13 years, respectively, for females; 366–730 mm and 2–13 years for mature females; 451–718 mm and 3–7 years for transitional individuals; and 500–930 mm and 4–35 years for males. There were several indications that the speckled hind population off the U.S. Atlantic coast continues to be overexploited despite a trip limit of 1 fish/vessel, which was established in 1994. The i...

The role of trap cameras in catch per unit effort calculations for species of the South Atlantic Bight snapper-grouper complex

Abstract Since 1990, 35 mm cameras have been mounted on Caribbean chevron traps used to sample reef fish in the South Atlantic Bight. These cameras were developed to photograph the habitat type associated with the trap. In instances where traps were recovered with no catch, the photograph was checked to determine if the trap had landed on sponge coral habitats, ledges, and rocky outcrops, commonly referred to as live bottom. If it had, the trap was considered a valid sample and incorporated into catch per unit effort (CPUE) calculations. This method of calculating CPUE was compared with that previously used in which all traps with zero catches were excluded from analyses, and a new method where all traps set were considered valid samples. Using a single factor ANOVA, no significant differences were found between CPUEs calculated using the three methods for the five most abundant species sampled. While trap cameras were useful in identifying live bottom habitat for sample sites where no historic bottom type data were available, they did not significantly impact the results of CPUE analyses when traps were set in the vicinity of previously identified sponge coral habitats.

Characterization of King Mackerel and Spanish Mackerel Bycatches of South Carolina Shrimp Trawlers

Abstract Juvenile king mackerel Scomberomorus cavalla and Spanish mackerel S. maculatus are caught by commercial shrimp trawlers in South Carolina. Our study documented the extent and duration of this bycatch during the commercial shrimp trawling season in South Carolina waters. Sampling was conducted onboard commercial shrimp vessels based in McClellanville, South Carolina, during 1991 and on vessels based in McClellanville, Charleston, and Beaufort in 1992. Eight vessels and 137 trawl tows (mean tow duration, 2.88 h) were sampled; 81 king and 257 Spanish mackerel were collected. The mean annual sample catch per unit effort (CPUE) of king mackerel was 0.244 fish/h; adjusted for trawl footrope length in meters, the mean annual total CPUE was 0.038 fish/(h·m). King mackerel were found in only 21% of the tow samples, and peak catches occurred in October 1991 and September 1992. The mean annual sample CPUE for Spanish mackerel was 0.701 fish/h, and the mean annual total CPUE was 0.109 fish/(h·m). Spanish mac...

Fishery-Independent Recruitment Indices for King and Spanish Mackerels

Abstract We investigated whether the abundance of age-0 mackerels in a fishery-independent trawl survey could be used to predict abundance at age 1 for king mackerel Scomberomorus cavalla and Spanish mackerel S. maculatus. After deletion of inappropriate length-classes and partitioning by season, depth, and stratum, subsets of the data set were compared to landings data and stock assessment results from the National Marine Fisheries Service. Total landings of age-1 Spanish mackerel were closely predicted (r 2 = 0.91) by catch per unit effort (CPUE) of age-0 fish 11–28 cm in fork length (FL) in samples taken by the Southeast Area Monitoring and Assessment Program-South Atlantic (SEAMAP-SA) during fall from shallow strata in the coastal waters of Georgia and South Carolina (latitudes 30°44′–33°12′N; SEAMAP-SA odd strata 31–49). The best predictor (r 2 = 0.72) for age-1 king mackerel was CPUE of age-0 fish 9–30 cm FL in SEAMAP-SAs fall samples from shallow strata in the coastal waters of South Carolina and ...