The Wash, east coast of England, mussel survey (1983-1989)

The beds were surveyed on foot by 2 man teams, landed by dinghy. Total biomass was estimated by the product of: Total bed area x mean percentage mussel cover x mean biomass of mussels per square metre. The total bed area was estimated by plotting position fixes taken around the outer edge using bearing compasses or electronic navigators. Percentage cover of mussel mounds was estimated by 100m random zig-zag transects across the bed recording by 'clicker counters' the number of paces on and off mounds. At the end of each transect leg a weighed sample of mussels was taken using a 0.1 square metre quadrat and rake. The percentage of dead shell and other debris in the sample was estimated by eye. A minimum of 8 quadrat samples were retained from each bed to enable the estimates of debris to be calibrated. The mussels in these retained samples were measured to establish the size structure of mussels on the bed.

该数据集的调研工作通过两组人组成的团队进行，他们乘坐皮艇登陆。总生物量的估算是通过以下乘积得出的：总床面积乘以平均 mussel 覆盖率乘以每平方米 mussel 的平均生物量。总床面积是通过绘制围绕边缘的位置固定点来估算的，这些点使用罗盘或电子导航设备进行定位。通过在床面上进行100米随机的之字形横切线，并使用‘计数器’记录在 mussel 堆上下的步数，来估算 mussel 堆的覆盖率。在每个横切线段结束时，使用面积为0.1平方米的样方和耙子采集 mussel 样本进行称重。通过目测估算样本中死亡贝壳和其他杂质的百分比。从每个床面上保留至少8个样方样本，以便校准杂质的估算。这些保留样本中的 mussel 被测量以确定床面上 mussel 的大小结构。