Benthic Megafaunal Assemblages on Scallop Fishing Grounds in the Bay of Fundy (1997 and 2007)
The annual summer scallop surveys on the principal grounds in the Bay of Fundy follow stratified-random designs. The gear comprises a ‘Digby scallop drag’ with four ‘buckets’, each of 760 mm inside width, their bags being made of 74 mm steel-wire rings linked by rubber washers. A comparative data set of three scallop grounds (Digby, Lurcher Shoal and Grand Manan) was produced comprised of 190 stations sampled in 1997 and 213 from 2007–08. Presence/absence of a common suite of 68 benthic invertebrate taxa were recorded: 43 individual species, 20 additional genera and five higher taxa, all drawn from nine phyla. Each taxon was coded for each of seven biological traits (each with associated modalities), selected for their assumed relevance to environmental drivers. A score between 0 and 3 was assigned based on the literature for the taxon’s affinity to each modality, using ‘fuzzy coding’. Non-zero scores were assigned to as many modalities as required to represent the traits of the taxon’s adult stage. The resulting taxa x traits matrix, of 68 taxa by 27 modalities, is provided here along with the metadata for each station sampled. In addition, fourteen environmental variables, deemed relevant to benthic epifauna and representing both seabed sediments and the water column, were quantified for each survey station. Seabed depth, mean grain size, mean significant wave height, mean seabed shear stress, root mean square tidal current speed 1 m above the seabed and combined averaged wave-current shear velocity were each extracted from a sediment transport model for the Bay of Fundy prepared by Li et al. (2015). Mean values for current velocities, salinity and temperature for both surface and bottom layers, plus maximum mixed layer depth and bottom shear were each drawn from the Bedford Institute of Oceanography North Atlantic Model (BNAM: Wang et al., 2018). BNAM values averaged across 1990–2015 were used when examining faunal differences among survey areas, but explorations of temporal change used annual values for 1997 and 2007 individually. The variable nomenclature in the attached spreadsheet follows those of Li et al. (2015) and Wang et al. (2018). Results of the spatial and temporal analyses of these data are found in Staniforth et al. (2023). The values for each of the environmental variables are provided in the spreadsheet below. Their interpolated surfaces are also provided.