Growth Rates of Juvenile Winter Flounder under Varying Environmental Conditions

• Published in: Transactions of the American Fisheries Society (1900) Vol. 132; no. 2; pp. 335 - 345
• Main Authors: Meise, C. J., Johnson, D. L., Stehlik, L. L., Manderson, J., Shaheen, P.
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Taylor & Francis Group 01-03-2003; American Fisheries Society
• Subjects: Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Brackish; Exploitation and management of natural biological resources (hunting, fishing and exploited populations survey, etc.); Freshwater; Fundamental and applied biological sciences. Psychology; Marine; Pleuronectes americanus; United States; North America; New Jersey; America; USA, New Jersey, Navesink R; ANW, USA, New Jersey, Sandy Hook Bay; Temperature; Growth rate; Estuaries; Environmental factor; Spatial variation; Young animal; Salinity; Marine environment; Aquatic environment; Vertebrata; Seasonal variation; Pisces; Development; Stream; Metamorphosis; Food supply
• ISSN: 0002-8487; 1548-8659
• DOI: 10.1577/1548-8659(2003)132<0335:GROJWF>2.0.CO;2

Fluctuations in juvenile winter flounder growth have been attributed to large‐scale fluctuations in temperature, mesoscale fluctuations in salinity, and smaller‐scale factors such as prey abundances. This study examines individual growth rates determined through otolith increment counts of free‐living juvenile winter flounder during the 2000 settlement period (April 11–July 7) in Navesink River–Sandy Hook Bay estuary in New Jersey. The fish grew at highly variable rates (mean = 1.02, range = 0.25–1.91 mm/d) and did not demonstrate localized differences in growth. In addition, growth rates determined by changes in length of fish from two local areas (river and bay) were compared in the laboratory. Growth in these fish was highly variable, did not differ with location, but did decline significantly during the settlement period in the river (mean = 0.17 mm/d, range = 0.00–0.54 mm/d) and bay (mean = 0.27 mm/d, range = 0.02–0.61 mm/d). The laboratory observations supported field results of no significant differences between river and bay growth rates. General additive models were used on estuarywide field growth rates to examine their relationship with environmental variables. We found a significant positive linear relationship between growth and average water temperature and negative relationships between growth and temperature range and salinity. Food abundance showed the only curvilinear relationship with growth rate, indicating lower growth at food levels below 50 individuals/m2. Long‐term sampling was conducted to examine the effects of these early growth conditions on fall survivors. Through this sampling, it was revealed that winter flounder continued to metamorphose late into the season (July–August). By spawning over several months and having many offspring with variable growth rates, winter flounder may increase the probability of some members surviving the innate variability of a temperate estuary.