Nekton (i.e., fish and large decapods) are an important component of coastal ecosystems, and knowledge of their density and assemblage structure can provide important insight into ecosystem dynamics. Here we present the results of field surveys of nekton in Zostera marina L. (eelgrass) beds and bare soft-sediment bottom on the Atlantic coast of Nova Scotia, Canada. These data will be used as input for a model to determine fish production derived from coastal habitats which is currently being developed. Visual snorkel and trawl transects were used to identify the nekton species present and their density (per m2). All captured fish were measured and age was determined using length-age information from the regional literature. Calibration ratios to account for different sampling gear and time of day indicated that snorkel transects underestimated densities relative to trawls, pelagic species were not sampled by trawls, and some species densities differed between night and day. Calibration ratios were applied to the data to correct for these differences. 22 species of nekton (5 large decapods, 17 fishes) were captured across both habitat types, and of these, nine hold commercial fishery status in the Canadian Maritimes. Although most species were captured in both habitats, densities were much higher in Z. marina. The captured nekton were mainly juveniles, although some older age classes were present. This report provides some of the first data of nekton assemblage structure and density in Z. marina and bare soft-sediment bottom for Atlantic Canada, and will be used in the future application of a model to determine nekton production derived from coastal habitats.
- Pages
- 46
- Published in
- Ottawa
