Blue Crab Densities in a Landscape Context on the Virginia Coast, Summer 2019

Table 1 Crab Data : Blue crab ( Callinectes sapidus ) abundance was sampled at twenty-four sites in Spider Crab Bay, Cobb Bay, and South Bay (comprising two large seagrass meadows: "South Bay" for the northern portion and "Ship Shoal" for the southern portion) as part of a study to evaluate the drivers of blue crab spatial patterns across restored seagrass meadows in the coastal bays of Virginia, USA. The four meadows are representative of seagrass meadows in the region that have recovered after experiencing large declines due to wasting disease and storms (Orth et al., 2006). Each meadow contained six fixed sampling sites. Each captured crab's morphological and demographic characteristics were evaluated; as such, data are presented at the individual level. Table 2 Landscape Data: Landscape measurements were taken for twenty-four sites in Spider Crab Bay, Cobb Bay, and South Bay (comprising two large seagrass meadows: "South Bay" for the northern portion and "Ship Shoal" for the southern portion) as part of a study to evaluate the drivers of blue crab spatial patterns across restored seagrass meadows in the coastal bays of Virginia, USA. The four meadows are representative of seagrass meadows in the region that have recovered after experiencing large declines due to wasting disease and storms (Orth et al. 2006). Each meadow contained six fixed sampling sites. All landscape measurements were made using QGIS 3.14.0 (QGIS.org 2020). Seagrass landscape measurements were calculated using maps developed from aerial imagery by Orth et al. (2019). Oyster reefs polygons were mapped by Ross and Luckenbach (2009). Salt marsh polygons were mapped by Berman et al. (2011) and modified based on imagery from Planet Team (2019). Mean seagrass shoot density measurements were based on a VCR-wide 2019 sampling effort led by McGlathery (2018).表1 蓝蟹数据集：本研究旨在评估美国弗吉尼亚州沿海海湾恢复海草床的蓝蟹（Callinectes sapidus）空间格局驱动因子，于蜘蛛蟹湾、科布湾及南湾（该区域包含两片大型海草床：北部片区为“南湾”海草床，南部片区为“船滩”海草床）的24个采样点开展了蓝蟹丰度采样工作。这4片海草床代表了该区域因枯萎病与风暴遭遇大规模退化后得以恢复的海草床群落（Orth等，2006）。每片海草床均设有6个固定采样点。研究人员对每只捕获蓝蟹的形态学与种群统计学特征进行了测定，因此本数据集以个体为单位呈现相关数据。表2 景观数据集：本数据集隶属于上述美国弗吉尼亚州沿海海湾恢复海草床蓝蟹空间格局驱动因子评估研究，在蜘蛛蟹湾、科布湾及南湾的24个采样点开展了景观特征测定，该区域包含两片大型海草床：北部片区为“南湾”海草床，南部片区为“船滩”海草床。这4片海草床代表了该区域因枯萎病与风暴遭遇大规模退化后得以恢复的海草床群落（Orth等，2006）。每片海草床均设有6个固定采样点。所有景观特征测定均通过QGIS 3.14.0（QGIS.org，2020）完成。海草床景观特征数据基于Orth等（2019）通过航空影像生成的地图计算得到。牡蛎礁多边形矢量图层由Ross与Luckenbach（2009）绘制。盐沼多边形矢量图层由Berman等（2011）绘制，并基于Planet Team（2019）提供的影像进行了修正。海草茎枝平均密度数据基于2019年由McGlathery主导的VCR沿线采样工作所得（McGlathery，2018）。