Survival of outplanted juvenile clams 2017

This spreadsheet shows numbers of recovered live and dead juvenile Manila clams outplanted at 4 field sites in the inside waters of Washington state over 2 months in the summer of 2017. Each replicate (e.g., A1) initially had 20 ‘large’ and 20 ‘small’ clams; avg size of large clams at the start of the experiment was 6.2 mm length, of small clams was 3.2 mm. Clams of both starting size classes were placed in windowscreen tubes filled with sediments at two elevations on the shore: 'high' at +1m MLLW, 'low' at +0.3m MLLW. Some tubes were 'open' to predators, others had a window-screen 'top' to exclude all predators. Some tubes had a mix of pebble and sand ('pebble'), others had crushed shell added to buffer porewater pH ('shell'). Each treatment combination was repeated 5 times (set A through E) along a 50m horizontal transect, but not all 5 tubes were recovered at all sites and elevations. Survival varied highly among sites and treatments, but not substantially between elevations. Tops tended to greatly increase survival, but not at all sites.

本电子表格展示了2017年夏季在华盛顿州内部水域的4个现场地点，在两个月内移植的存活和死亡幼年马尼拉蛤蜊的数量。每个重复样本（例如，A1）最初包含20个‘大型’和20个‘小型’蛤蜊；实验开始时，大型蛤蜊的平均尺寸为6.2毫米，小型蛤蜊为3.2毫米。两种起始尺寸等级的蛤蜊被放置在岸上两个高度的筛网管中填充了沉积物：‘高’位于+1米平均低潮水位（MLLW），‘低’位于+0.3米MLLW。一些管子是‘开放’的，供捕食者进入，而另一些则配备了窗口筛顶，以排除所有捕食者。一些管子含有砾石和沙子的混合物（‘砾石’），而另一些则在其中添加了破碎的贝壳以缓冲孔隙水的pH值（‘贝壳’）。每个处理组合沿50米水平横断面重复5次（从A组到E组），但在所有地点和高度并非所有5个管子都能被回收。存活率在地点和治疗方法之间差异很大，但在不同高度之间没有显著差异。顶部处理通常会极大地增加存活率，但并非在所有地点都如此。