Assessing Habitat Quality of Mount Hope Bay and Narragansett Bay Using Growth, RNA:DNA, and Feeding Habits of Caged Juvenile Winter Flounder (Pseudopleuronectes americanus Walbaum)

Abstract

Abstract Somatic growth rates, RNA:DNA, and feeding habits of juvenile Pseudopleuronectes americanus (Winter Flounder) were used to asses small-scale spatio-temporal variations in the habitat quality of Mount Hope Bay and Narragan-sett Bay, RI. Three successive caging experiments (14–16 d each) were conducted with flounder (initial size = 25–35 mm total length) in June and July 2003 in shallow water habitats (<1 m) of Spar Island, Common Fence Point, and Hog Island; the first two sites were located in Mount Hope Bay, and the latter in Narragansett Bay. The average growth rate of flounder ranged between 0.51 and 0.95 mm d−1 and was inversely related with increased incidences of hypoxic conditions (i.e., amount of time dissolved oxygen was ≤ 4.0 mg L−1). RNA:DNA, a surrogate measure of growth and feeding condition, corroborated somatic growth trends, and therefore exhibited similar spatio-temporal variability. In contrast to somatic growth, however, water temperature was the most important factor affecting ...