North Temperate Lakes LTER: Zooplankton - Trout Lake Area 1982 - current

Zooplankton samples are collected from the seven primary northern lakes (Allequash, Big Muskellunge, Crystal, Sparkling, and Trout lakes and bog lakes 27-02 [Crystal Bog], and 12-15 [Trout Bog]) at two to nine depths using a 2 m long Schindler Patalas trap (53um mesh) and with vertical tows (1 m above the bottom of the lake to the surface) using a Wisconsin net (80um mesh). Zooplankton samples are preserved in buffered formalin (up until the year 2000) or 80% ethanol (2001 onwards) and archived. Data are summed over sex and stage and integrated volumetrically over the water column to provide a lake-wide estimate of organisms per liter for each species. A minimum of 5 samples per lake-year are identified and counted. Sampling Frequency: fortnightly during ice-free season - every 6 weeks during ice-covered season. Number of sites: 7

浮游动物 (Zooplankton) 样本采集自7个主要北部湖泊，包括Allequash湖、Big Muskellunge湖、Crystal湖、Sparkling湖、Trout湖，以及编号27-02的沼泽湖 (Crystal Bog，水晶沼泽) 与编号12-15的沼泽湖 (Trout Bog，鳟鱼沼泽)；采样采用两种方案：其一为使用2米长的辛德勒-帕塔拉斯捕集器 (Schindler Patalas trap，53 μm网目) 在2至9个水层深度采集样本，其二为采用威斯康星网 (Wisconsin net，80 μm网目) 开展垂直拖网采样，采样范围为湖底上方1米至水面。样本保存策略分为两个阶段：2000年以前采用缓冲福尔马林固定，2001年起改用80%乙醇固定，所有采集样本均完成归档留存。数据处理环节，研究人员按性别与发育阶段对样本进行汇总，并对全水柱进行体积积分，以此得到各物种在全湖尺度下的每升生物体数量估算值。每个湖年周期内至少需鉴定并计数5份样本。采样频率为：无冰期每两周采样一次，冰封期每6周采样一次。本次采样共设置7个位点。