Spatial and temporal variability in growth, mortality, and recruitment potential of postsettlement red drum, Sciaenops ocellatus, in a subtropical estuary Academic Article uri icon


  • Patterns of growth and mortality were examined for postsettlement red drum, Sciaenops ocellatus, inhabiting seagrass meadows in the Aransas Estuary, Texas. Age and growth rates of larvae and early juveniles were estimated in 1994 and 1995 by using daily increments in otoliths. Otolith-derived estimates of age indicated that individuals spend approximately 20 d in the pelagic environment before entering demersal habitats (i.e. before settlement). Instantaneous growth coefficients (g) of red drum ranged from 0.049 (4.8%/d) in 1994 to 0.051 (5.0%/d) in 1995. Site-specific differences in growth were also examined and a significant site effect was detected in 1994; however, no site effect was observed in 1995. Interannual and cohort-specific (10-d cohorts) mortality rates were estimated from declines in log(e) abundance (abundance-at-age plots), and results indicated that mortality during the early postsettlement period was substantial. Instantaneous mortality coefficients (Z) were similar between years (0.134 [12.5%/d] in 1994; 0.139 [13.0%/d] in 1995), and no significant interannual effect was observed. Conversely, cohort-specific mortality rates ranged widely (0.106-0.265 [10.1-23.3%/d]) and losses were lowest for midseason cohorts. Recruitment potential (G:Z ratio) was highest for midseason cohorts (1.30-1.56) and lowest for early and late-season cohorts (<1). Although G:Z ratios varied over spatial and temporal scales, ratios were >1 in 1994 and 1995, suggesting that both year classes experienced favorable nursery conditions.

published proceedings


author list (cited authors)

  • Rooker, J. R., Holt, S. A., Holt, G. J., & Fuiman, L. A.

complete list of authors

  • Rooker, JR||Holt, SA||Holt, GJ||Fuiman, LA

publication date

  • July 1999