Red Snapper: Ecology and Fisheries in the U.S. Gulf of Mexico

Patterns of Habitat Use by Newly Settled Red Snapper in the Northwestern Gulf of Mexico

Bert W. Geary, Joseph J. Mikulas, Jr., Jay R. Rooker, André M. Landry, Jr., and Timothy M. Dellapenna

doi: https://doi.org/10.47886/9781888569971.ch3

Abstract.—Trawl surveys were conducted to measure patterns of habitat use by newly settled red snapper Lutjanus campechanus at three natural banks on the inner continental shelf of Texas. Digital side-scan sonar and multibeam bathymetric data were used to define inshore (mud), ridge (shell), and offshore (mud) habitats for Freeport Rocks, Heald Bank, and Sabine Bank. Otter trawls were conducted July through September in 2003 (Heald Bank, Sabine Bank) and in 2004 (Freeport Rocks) during the settlement period of red snapper. Freeport Rocks had markedly higher densities of red snapper (91 ha^⁻1) in 2004 than Heald Bank (6 ha^⁻1) or Sabine Bank (<1 ha^⁻1) in 2003. A significant habitat effect was observed at Heald Bank and densities were higher at offshore mud habitats; no habitat effect was detected for Freeport Rocks or Sabine Bank. Growth rates varied from 0.86 mm‧d^⁻1 at Sabine Bank up to 1.12 mm‧d^⁻1 at Freeport Rocks, and rates were higher on inshore and offshore mud than ridge habitats. Otolith-based estimates of age indicated that settlers were first detected at 22–28 d and the majority of individuals were 30–60 d. Hatch dates peaked from early June to early July in both 2003 and 2004. Results from this study indicate that both shell and inshore and offshore mud habitats associated with these natural banks serve as settlement habitat of red snapper, and all three habitats have the potential to function as nursery areas of this species.