Intertidal clam settlement in Washington state, USA

This dataset addresses the settlement rates of two non-native intertidal clam species at 8 beaches in Washington state, USA from May to September 2016-2017. Clam species were manila (Ruditapes philippinarum) and eastern soft-shell (Mya arenaria). Settlement was measured at mean tide level on shore every 2-4 weeks in mesh bags (1.5 mm mesh, 10x12 mm) filled with round gravel or crushed shell. Clams were counted that were caught on 250 micron sieve (large settlers) and, in 2016, on 150 micron mesh (small settlers). Also, in June 2017, densities of juvenile clams <20mm were measured at mean tidal elevation at each beach in five samples of 900 cm^2, 5 cm depth. Archived files include site locations and the date, site, position along transect at mean tide level, and counts of each clam species and size class. Data were used to test for spatio-temporal variation in settlement, to relate settlement timing and magnitude to local temperature and salinity, and to relate juvenile densities to settlement the previous year.本数据集聚焦2016-2017年5月至9月期间，美国华盛顿州8处海滩的两种非本土潮间带蛤蜊物种的稚贝附着率。所涉蛤蜊物种为马尼拉蛤（Ruditapes philippinarum）与东软壳蛤（Mya arenaria）。稚贝附着率的采样流程如下：在各海滩的平均潮位带滩涂，每2至4周布设装填有圆砾或碎壳的网袋（网孔孔径1.5 mm，袋体尺寸10×12 mm）开展采样。捕获的稚贝通过250微米筛网完成计数（对应大规格稚贝）；2016年还额外通过150微米网筛对小规格稚贝进行计数。2017年6月，研究人员在每处海滩的平均潮位高程区域，采集5组面积为900 cm²、采样深度5 cm的沉积物样本，以此测量体长小于20 mm的幼年蛤蜊种群密度。存档文件涵盖采样点位置信息、采样日期、样点标识、平均潮位带样线的采样点位坐标，以及各蛤蜊物种与规格类群的个体计数数据。本数据集被用于检验稚贝附着过程的时空变异特征，探究附着时间与规模与当地水温、盐度的关联，同时分析幼年蛤蜊种群密度与前一年附着量的相关性。