Fish assemblage and habitat use in North Carolina and Virginia waters during the annual Cooperative Winter Tagging Cruise, 1988-2013

Abstract

Long-term ecological research can be valuable in understanding ecosystem function and species requirements, allowing managers to better regulate and enforce strategies for continued use of the resource, commercially and recreationally. My project focuses on the examination of trawl data from the Cooperative Winter Tagging Cruise (CWTC), a long-term effort off the North Carolina and Virginia coasts that has collected data on many important fish species since 1988. The data collected from this effort had not been fully entered in a database or utilized by researchers. The goal of my project was to develop habitat parameters and examine the relationships and trends between and among an assemblage of fish taxa, and their habitats within and across the time series 1988-2013. Hard copies of the data from the CWTC were transcribed into a single electronic database for analysis, and a suite of hypotheses testable with the data in their current state were developed. Using GIS, a study area was delineated, and trawl tows from the CWTC mapped. Habitat parameters were developed from data recorded during the CWTC efforts; additional parameter models were created in GIS from publicly available USGS data. Eight taxa were chosen for my analysis, based on consistency of records and ecologic and economic importance. These taxa were assessed with regard to their distributions within the study area and eight habitat parameters that describe the physical influences on their environment. My study describes the habitats used by these eight taxa and trends in the co-occurrence and north-south distributions of the taxa. This information is intended to aid in understanding the taxa life history and ecology - to fill existing data gaps in the overwintering requirements, encourage researchers to fully utilize available data and prompt new testable hypotheses using this platform, and provide management agencies with more comprehensive data to regulate and conserve existing resources.