Epibenthic biomass and environmental predictor variables for the Scotian Shelf and Gulf of Maine (Atlantic Canada)
Description
An assessment of the impacts of mobile bottom-contacting gears (otter trawls, scallop drags and hydraulic clam dredges) on eight previously identified epibenthic communities (Murillo et al. 2024), in the waters off Nova Scotia, Canada (Scotian Shelf and Gulf of Maine), using risk-based indicators of Relative Benthic Status (RBS) (ICES 2024) required biomass data for each sampling station and environmental variables for the entire study area (assessed within 3 km x 3 km grid cells established using a NAD 1983 UTM Zone 20°N coordinate system) as input to a GLMM model. Indices of both existing biomass relative to carrying capacity of the whole epibenthic community (RBStot) and that of the 10% most sensitive fauna (RBSsen) were quantified and mapped, facilitating evaluation of gear-impacts on the benthos. Here we provide the input data for the biomass of 99 invertebrate species and 6 environmental predictor variables. Further information on how the variables were derived can be found in Hiddink et al. (2026). Briefly, biomass of the trawl-vulnerable fraction of the epibenthos was recorded at 240 stations during the 2017 Fisheries and Oceans Canada Maritimes Ecosystem Research Vessel bottom-trawl survey and used by Murillo et al. (2024) in their analyses of presence/absence data to identify benthic communities on the Scotian Shelf and in the Gulf of Maine. Here we present the biomass data collected from that same survey. Some of the invertebrate catch (typically the Hydrozoa, most bryozoans, many sponges and some soft corals) was only sorted into its higher taxon before being weighed at sea. If, during subsequent examination, more than one lower taxon was found in such a collection, the recorded wet-weight was divided equally amongst the taxa found. The biomass (kg) and associated information on trawl set location is provided. Predictor variables included depth (m), seabed slope (°), bottom temperature (°C), bottom salinity, bottom current speed (m s-1) and sediment grain size (mm) averaged for each of the 18,652, 3 km x 3 km grid cells in the bioregion are provided in a separate file. References: Hiddink, J.G., van Denderen, D., Murillo, F.J., and Kenchington, E. 2026. Assessment of the impacts of mobile bottom-contacting fishing gears on epibenthic communities of the Scotian Shelf and Gulf of Maine (Atlantic Canada). Can. J. Fish. Aquat. Sci. (submitted). ICES. 2024. Technical Guidelines for assessing fishing impact from mobile bottom-contacting fishing gears. Version No. 01. ICES Guidelines and Policies - Technical Guidelines. 31 pp. doi: 10.17895/ices.pub.27301944. Murillo, F.J., Weigel, B., Clark, D., and Kenchington, E. 2024. Hierarchical modelling of epibenthic communities on the Scotian Shelf and Gulf of Maine (Atlantic Canada) in support of conservation planning. Can. J. Fish. Aquat. Sci. 81: 1752–1772. doi: 10.1139/cjfas-2023-0326.
Files
Institutions
- Bedford Institute of OceanographyNova Scotia, Dartmouth
- Fisheries and Oceans CanadaOntario, Ottawa