North Temperate Lakes LTER: Fish Abundance 1981 - current

This data set is a derived data set based on fish catch data. 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 three 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. Derived data sets include species richness, catch per unit effort, and size distribution by species, lake, and year. Protocol used to generate data: Day seines were only used in 1981 and have been eliminated from this data set to make sampling effort across years comparable. Number caught for each species is summed over repetitions of a gear within a lake and over depth. For information on fish stocking by the Wisconsin Department of Natural Resources in LTER lakes in Dane and Vilas counties, see https://dnr.wi.gov/fisheriesmanagement/Public/Summary/Index. Beach seining was discontinued after 2019. The only sampling done in 2020 were a single gill-netting sample in Sparkling, Crystal, and Trout lakes. Sampling in Fish Lake was missed in 2021 due to significant lake level changes. Data from the two bogs is missing in 2022. Sampling Frequency: annually. Number of sites: 11

本数据集为基于渔获数据构建的衍生数据集。研究团队按年度收集数据，用于追踪11处核心湖泊的鱼类群落组成，这11个湖泊分别为：阿勒夸什湖（Allequash）、大北美狗鱼湖（Big Muskellunge）、水晶湖（Crystal）、斯帕克林湖（Sparkling）、特劳特湖（Trout），以及两处泥炭湖27-02［水晶泥炭湖（Crystal Bog）］和12-15［特劳特泥炭湖（Trout Bog）］，另有门多塔湖（Mendota）、莫诺纳湖（Monona）、温格拉湖（Wingra）与菲什湖（Fish）。其中莫诺纳湖、温格拉湖与菲什湖的采样工作始于1995年，其余湖泊的采样自1981年启动。每个湖泊布设6处沿岸带采样位点，采用围网、幼鱼诱捕笼、螯虾诱捕笼及囊网（fyke nets）开展采样；同时依托船载电捕鱼系统对3条沿岸样带进行采样。研究人员在每个湖泊的最深点垂直悬挂刺网（gill nets），以获取2份远洋层采样样本；另布设三重刺网（trammel nets），在每个湖泊的2处温跃层跨点开展采样。仅在泥炭湖布设囊网与幼鱼诱捕笼。本次采集的测量参数包括所有渔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。衍生数据集包含物种丰富度、单位捕捞努力量渔获量（catch per unit effort），以及按物种、湖泊与年份划分的体长分布情况。数据生成规程如下：日间围网（day seines）仅在1981年使用，现已从本数据集中剔除，以保证不同年度间采样努力量的可比性。针对每个湖泊，将同一渔具的重复采样及不同深度的渔获量按物种进行求和。如需了解威斯康星州自然资源部对戴恩县与维拉斯县长期生态研究（Long-Term Ecological Research, LTER）湖泊的鱼类放养信息，请访问：https://dnr.wi.gov/fisheriesmanagement/Public/Summary/Index。2019年后停止沿岸滩涂围网采样。2020年仅在斯帕克林湖、水晶湖与特劳特湖开展了1次刺网采样。2021年因湖泊水位大幅变化，未对菲什湖开展采样。2022年两处泥炭湖的采样数据缺失。采样频率：每年1次；共覆盖11处采样站点。