An assessment of the feeding success of young-of-the-year winter flounder (Pseudopleuronectes americanus) near a municipal pier in the Hudson River Estuary, USA

We examined feeding success of young-of-the-year winter flounder (Pseudople uronectes americanus Walbaum) (20-50 mm TL) around a large, municipal pier in the Hudson River estuary, USA. Replicate, 3-h feeding experiments were c onducted using benthic cages (0.64 m(2)) deployed under, at the edge, and o utside of the pier during late spring and early summer in 1998 and 1999. Si gnificantly more winter flounder caged under piers had empty stomachs ((x) over bar = 71.9%) than at the edge or in open water ((x) over bar = 29.2% a nd. 14.4%, respectively). Feeding intensity was significantly higher outsid e of the pier ((x) over bar = 0.40%) than the edge or under the pier ((x) o ver bar = 0.19% and 0.03%, respectively). Simultaneous with feeding experim ents, benthic core samples were collected adjacent to cages. Variability wa s high, but abundances of prey were consistently higher under the pier ((x) over bar = 200.14 +/- 113.3 SD in 1998; 335 +/- 290.2 in 1999) than at the edge ((x) over bar = 126.6 +/- 50.2 in 1998; 70.8 +/- 68.5 in 1999) or in open water ((x) over bar = 53.4 +/- 16.1 in 1998; 123.8 +/- 193.9 in 1999). No significant differences in prey biomass were determined, suggesting tha t small, numerous prey were available under the pier and fewer, larger taxa were present at the edge and outside. Data indicate that feeding is suppre ssed among young-of-the-year winter flounder caged under piers in spite of sufficient prey available. Based on these and other experiments we submit t hat areas under piers are not suitable long-term habitats for juvenile fish because they interfere with normal feeding activities.