Ecology of early stage yellowtail flounder (Limanda ferruginea) on the New York Bight continental shelf: Responses to anthropogenic and climate-induced change.

摘要

The goal of this dissertation was to investigate the settlement ecology of a commercially important/poorly studied species (yellowtail flounder, Limanda ferruginea) within an ecosystem where knowledge of the scales of variation is known. The New York Bight continental shelf functions as a highly productive nursery ground for over 30 species of groundfish. For specific guilds (i.e. flatfish), the generation of settlement variability is carried out over a complicated hierarchy of scales, each with its own associated suite of biological and physical processes. In a previous study, a simple, hierarchical framework classified L. ferruginea settlement as a large-scale process driven by interannual variations in water temperature and hydrography. The dissertation presented herein continues to explore this hypothesis (and related questions) using information gleaned from a variety of sources, including: archived databases, field collections, otolith microstructure analysis, and experimental manipulations. First, long-term data sets, as well as more recent field-oriented studies, were used to examine the hypothesized link between large-scale, atmosphere-ocean forcing and L. ferruginea recruitment in the Mid-Atlantic region. Second, patterns of settlement timing, size-at-settlement and pelagic/early benthic growth were evaluated for an exceptional and below-average year class during two contrasting environmental regimes. Finally, an experimental manipulation was undertaken to examine the influence of a large-scale fishing disturbance, relative to natural variability, and its impact on juvenile nursery habitat.