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.芬迪湾主要扇贝渔场的年度夏季调查采用分层随机设计（stratified-random designs）。所用采样装备为带4个“桶体”的迪格比扇贝拖网（Digby scallop drag），每个桶体内侧宽度为760毫米，网袋由74毫米钢丝环通过橡胶垫圈连接制成。本数据集涵盖迪格比、勒彻浅滩与格兰德马南共3个扇贝渔场，其中1997年完成采样的站位共190个，2007-2008年完成采样的站位共213个。调查记录了68个底栖无脊椎动物类群的存在/缺失状态，包含43个独立物种、20个属级类群以及5个高阶类群，隶属于9个动物门。针对每个类群，研究人员基于其与环境驱动因子的潜在关联程度，选取7项生物学性状（每项性状均对应若干状态模态），并采用模糊编码（fuzzy coding）方法，依据已有文献为每个类群对各性状状态模态的亲和性赋予0至3的分值，且需为类群成体阶段的所有相关性状状态模态分配非零分值。由此生成的类群×性状模态矩阵涵盖68个类群与27个性状模态，同时附带所有采样站位的元数据。此外，本数据集还量化了14项与底栖表栖动物相关的环境变量，涵盖海底沉积物与水柱两大维度。其中，海底水深、平均粒径、平均有效波高、平均海底切应力、海底上方1米处的均方根潮流流速以及组合平均波流切速度，均取自Li等人（2015）为芬迪湾构建的沉积物输运模型。表层与底层的平均流速、盐度、温度，以及最大混合层深度和海底切应力，均取自贝德福德海洋研究所北大西洋模型（Bedford Institute of Oceanography North Atlantic Model, BNAM），相关参数详见Wang等人（2018）的研究。在分析不同调查区域的群落差异时，采用1990-2015年的BNAM年均值；而探究时间变化趋势时，则分别采用1997年与2007年的年度BNAM数值。附件电子表格中的变量命名规则遵循Li等人（2015）与Wang等人（2018）的规范。相关数据的时空分析结果详见Staniforth等人（2023）的研究。本数据集附带的电子表格中包含所有环境变量的实测值，同时提供了各变量的插值曲面。