North Temperate Lakes LTER: Fish Lengths and Weights 1981 - current

Data are collected annually to enable us to track the fish assemblages of eleven primary lakes (Allequash, Big Muskellunge, Crystal, Sparkling, Trout, bog lakes 27-02 [Crystal Bog] and 12-15 [Trout Bog], Mendota, Monona, Wingra and Fish). Sampling on Lakes Monona, Wingra, and Fish started in 1995; sampling on other lakes started in 1981. Sampling is done at six littoral zone sites per lake with seine, minnow or crayfish traps, and fyke nets; a boat-mounted electrofishing system samples four littoral transects. Vertically hung gill nets are used to obtain two pelagic samples per lake from the deepest point. A trammel net samples across the thermocline at two sites per lake. In the bog lakes only fyke nets and minnow traps are deployed. Parameters measured include species-level identification and lengths for all fish caught, and weight and scale samples from a subset. Dominant species vary from lake to lake. Perch, rockbass, and bluegill are common, with walleye, large and smallmouth bass, northern pike and muskellunge as major piscivores. Cisco have been present in the pelagic waters of four lakes, and an exotic species, rainbow smelt, is present in two. The bog lakes contain mudminnows. The only sampling done in 2020 were a single gill-netting replicate in Sparkling, Crystal, and Trout lakes. Sampling in Fish Lake was suspended in 2021 due to significant lake level changes. Sampling Frequency: annually Number of sites: 11. Please consult NTL's website for information on experimental lake manipulations and the DNR's website for management activities

本数据集按年度采集数据，旨在追踪11处主要湖泊的鱼类群落（fish assemblages）组成，涵盖的湖泊包括Allequash湖、Big Muskellunge湖、Crystal湖、Sparkling湖、Trout湖、27-02号沼泽湖[Crystal Bog]、12-15号沼泽湖[Trout Bog]、Mendota湖、Monona湖、Wingra湖及Fish湖。Monona湖、Wingra湖与Fish湖的采样作业始于1995年，其余湖泊的采样则于1981年启动。每个湖泊设置6处沿岸带（littoral zone）采样点位，采用围网（seine）、小鱼笼（minnow traps）、螯虾笼（crayfish traps）及渔笼网（fyke nets）开展采样作业；同时使用船载电捕鱼系统（boat-mounted electrofishing system）对4条沿岸样带进行采样。此外，在每个湖泊的最深点位布设垂直悬挂的刺网，采集2份远洋带（pelagic zone）样本；在每个湖泊的2处点位布设三重刺网（trammel net），采集跨越温跃层（thermocline）的样本。仅在沼泽湖中布设渔笼网与小鱼笼进行采样。本次采集的测量参数包括所有捕获鱼类的物种鉴定结果与体长数据，以及部分样本的体重与鳞片样品。各湖泊的优势物种存在差异：鲈鱼（perch）、岩鲈（rockbass）与蓝鳃太阳鱼（bluegill）较为常见，大眼梭鲈（walleye）、大口黑鲈、小口黑鲈、北美狗鱼（northern pike）及巨狗鱼（muskellunge）为主要的食鱼性鱼类。西鲱（Cisco）曾在4处湖泊的远洋水域被记录；另有外来物种彩虹胡瓜鱼（rainbow smelt）分布于2处湖泊。沼泽湖中则存在泥鲦（mudminnows）。2020年仅在Sparkling湖、Crystal湖及Trout湖开展了1次重复刺网采样作业。2021年因湖泊水位发生显著变化，Fish湖的采样工作暂停。采样频率：年度采样。采样点位总数：11处。有关湖泊实验调控的相关信息，请参阅NTL官网；有关管理活动的详情，请参阅DNR官网。