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 2m long Schindler Patalas trap (53um mesh) and with vertical tows using a Wisconsin net (20cm diameter, 80um mesh). Zooplankton samples are preserved in buffered formalin (until 2001) or 95% ethanol (2001 onwards). Subsamples of the individual Schindler trap samples are combined to create a hypsometrically pooled sample which is counted for copepods, cladocerans, and rotifers. Data are summed over sex and stage to provide a lake-wide estimate of organisms per liter for each species. A minimum of 5 samples per lake-year are counted. The data set also contains length measurements for copepods and cladocerans. The Wisconsin net sample and the pooled sample are archived in the UW Zoology museum. Each year one complete set of Schindler Patalas depth samples collected in August is also archived. From 1981 to August 1986 - used a 0.5m high Schindler Patalas trap. Sampling Frequency: every two weeks during ice-free season, every 5 weeks during ice-cover. Number of sites: 7

本数据集的浮游动物样本采集自7处北部主要湖泊，包括Allequash湖、Big Muskellunge湖、Crystal湖、Sparkling湖、Trout湖，以及沼泽湖27-02号[水晶沼泽(Crystal Bog)]、12-15号[鳟鱼沼泽(Trout Bog)]。采样时采用长2m的辛德勒-帕塔拉斯捕集器(Schindler Patalas trap)（网目尺寸53μm）在2至9个深度层采集样本，同时使用威斯康星网(Wisconsin net)（网口直径20cm，网目尺寸80μm）开展垂直拖网采样。所有浮游动物样本采用缓冲福尔马林固定（2001年之前），2001年起改用95%乙醇保存。将各辛德勒-帕塔拉斯捕集器样本的子样合并，制备得到高程加权混合样本(hypsometrically pooled sample)，并对该样本中的桡足类、枝角类及轮虫进行计数。按性别与发育阶段对计数数据进行汇总，从而得到各物种的全湖每升水体个体数量估计值。每个湖泊每年至少需计数5份样本。本数据集还包含桡足类与枝角类的体长测量数据。威斯康星网采集的样本与上述混合样本均存档于威斯康星大学动物学博物馆(UW Zoology Museum)。每年8月采集的全套辛德勒-帕塔拉斯捕集器深度分层样本也会一并存档。1981年至1986年8月期间，使用的采样设备为高度0.5m的辛德勒-帕塔拉斯捕集器(Schindler Patalas trap)。采样频率：无冰期每两周采样一次，冰封期每五周采样一次。采样点位总数：7处。