Fall 2019 crab population monitoring: mid-marsh and creek bank abundance based on crab hole counts at GCE marsh, monitoring sites 1-10

This data set is the Fall 2019 estimate of crab densities at the GCE-LTER marsh sites used for population monitoring. Crab abundance was determined by counting the number of crab holes within a 625 cm^2 quadrat and converting the counts to number per square meter. Counts were made in the mid-marsh and creek bank zones (n = 4 per zone) at GCE sites 1 through 10. Note that this census method does not differentiate which species made a particular hole and therefore only estimates total burrowing crab abundance, potentially including species Uca pugnax, Uca minax, Uca pugilator, Armases cinereum, Eurytium limosum and Sesarma reticulatum. Crab holes that are not actively maintained are quickly covered by tidal activity and other sediment disturbances, therefore plugged holes were assumed to be unoccupied and excluded from the counts.本数据集系2019年秋季针对用于种群监测的GCE-LTER沼泽样地所开展的蟹类密度估算成果。蟹类丰度通过统计625平方厘米样方内的蟹洞数量，并将计数结果换算为每平方米的个体数得以确定。调查工作在GCE 1至10号样地的沼泽中部与溪岸带展开，每个区域设置4个重复样方（n=4 per zone）。需注意，本次普查方法无法区分单个蟹洞的归属物种，因此仅能估算穴居蟹类的总丰度，潜在涵盖的物种包括Uca pugnax、Uca minax、Uca pugilator、Armases cinereum、Eurytium limosum及Sesarma reticulatum。未被持续维护的蟹洞会快速被潮汐活动及其他沉积物扰动覆盖，因此本研究将堵塞的蟹洞视作空置状态，排除在统计范围之外。