The influence of temperature on cohort-specific growth, survival, and recruitment of striped bass, Morone saxatilis, larvae in Chesapeake Bay

• Published in: Fishery bulletin (Washington, D.C.) Vol. 93; no. 2; pp. 315 - 332
• Main Authors: Rutherford, E S, Houde, ED
• Format: Journal Article
• Language: English
• Published: 1995
• Subjects: Brackish; Morone saxatilis; ANW, USA, Chesapeake Bay; USA, Maryland
• ISSN: 0090-0656

Factors that affect survival and growth of larvae and influence recruitment variability of striped bass, Morone saxatilis, were investigated in the Potomac River and Upper Chesapeake Bay from 1987 to 1989. Ages and growth rates of larvae hatched within 3-day periods (cohorts) were estimated from otolith daily increments. Cohort-specific mortality rates were estimated from declines in cohort abundances over time. Temperature strongly affected larval cohort dynamics and potential to recruit. Storm fronts caused water temperature to drop near to or below 12 degree C, resulting in episodic mortalities of eggs and newly hatched larvae. Cohort-specific growth rates of larvae were variable, ranging from 0.11 to 0.46 mm/d in the Potomac and from 0.18 to 0.36 mm/d in the Upper Bay, and were positively correlated with mean water temperatures. Cohort instantaneous mortalities (d super(-1)) also ranged widely, from Z = 0.05 to 0.92 in the Potomac and from Z = 0.02 to 0.28 in the Upper Bay, but were not correlated with temperature, growth rate, or other measured variables. The medians of cohort G/Z ratios (ratios of weight-specific growth rate to instantaneous mortality rate) and productions of 8.0-mm standard length larvae in each year were positively correlated with juvenile recruitment indices. Larval productions at 8.0 mm also were positively correlated with mean water temperatures because temperature strongly affected larval growth and because of the strong selection for survival of cohorts hatched later in the spawning seasons when water temperatures were consistently > 17 degree C.