Habitat use, growth, and mortality of post-settlement lane snapper ( Lutjanus synagris) on natural banks in the northwestern Gulf of Mexico

Abstract

Three low-relief banks in the northwestern Gulf of Mexico were evaluated as nursery habitat of lane snapper ( Lutjanus synagris). Trawl surveys were conducted in three habitat types (inshore mud, shell ridge, offshore mud) to quantify lane snapper distribution and abundance. Heald Bank and Sabine Bank were trawled in 2003 while Freeport Rocks was trawled in 2000 (Freeport A) and 2004 (Freeport B). Density of lane snapper varied among banks and years sampled: Sabine Bank (20.8 ± 2.8 ind ha −1), Heald Bank (1.1 ± 0.4 ind ha −1), Freeport A (12.7 ± 2.3 ind ha −1), and Freeport B (3.0 ± 1.0 ind ha −1). Habitat-specific differences in density were observed, although patterns were not consistent among banks. Otolith microstructure analysis indicated that post-settlement lane snapper ranged in age from 21 to 66 d, with hatch dates from 1 May to 31 August. Growth rates varied from 0.90 mm d −1 at Heald Bank to 1.27 mm d −1 at Sabine Bank, and habitat-specific differences in growth were negligible. Mortality of post-settlement lane snapper ranged from 15.2% d −1 at Sabine Bank to 9.2% d −1 at Freeport A. Our findings indicate that Heald Bank, Sabine Bank, and Freeport Rocks all serve as settlement habitat of lane snapper, which appear to be capable of successful settlement across a variety of habitats.