Applying the basin model: Assessing habitat suitability of young-of-the-year demersal fishes on the New York Bight continental shelf

The extent to which young-of-the-year (YOY) fish habitats become saturated with new recruits has remained relatively unevaluated for temperate, demersal, continental shelf fishes. MacCall's [1990. Dynamic Geography of Marine Fish Populations. Washington Sea Grant Program, University of Washington Press, Seattle, Washington] basin model was used as a framework for examining the dynamics of an assemblage of recently settled fishes in relation to available microhabitat on the New York Bight continental shelf (USA). For four abundant species (three flatfish, one merlucciid hake), density-specific patterns of microhabitat selection, spatial dispersion and overall cross-shelf habitat use were investigated using a research submersible over three cross-shelf transects during the late summer settlement season. Typically, recruits that saturated YOY habitats (>1 ind/m2) were randomly distributed within underwater transects and formed weak associations with specific microhabitats. At lower densities (<1 ind/m2), recruit spacing tended toward nonrandom (clumped/even) with increasing significant affinities for ecologically important substrates (i.e. Limanda ferruginea, sand wave crests/low shell hash). For Citharichthys arctifrons, clumping appeared to increase with complexity of the habitat. Several less-abundant species (i.e. Urophycis chuss, Tautogolabrus adspersus) formed tight associations with rare habitat features and may consequently encounter the greatest bottleneck for space during the benthic/pelagic transition. Although restricted by the scale of observation, these results begin to elucidate the mechanisms by which habitat quality and quantity moderate recruitment on the continental shelf.