North Temperate Lakes LTER: Fish Species Richness 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. Species richness for a lake is the number of fish species caught in that lake during the annual fish sampling. Hybrids captured are only included in the richness value if neither of the two hybridized species are caught in the lake that year. Fish identified only to genus or higher taxonomic level are not included if any fish identified to species within that genus or higher taxonomic level are caught. E.g., Unidentified Chub would be only included in the richness value if no other chub is caught in that lake that year. Sampling Frequency: annually. Number of sites: 11 Note that 2020 data does not exist due to insufficient sampling. In 2021, sampling in Fish Lake was suspended due to significant lake level changes. Data is missing for the two bogs in 2022. Please consult NTL's website for information on experimental lake manipulations and the DNR's website for management activities

本数据集为基于渔获数据衍生的专业数据集。本数据集按年度采集，旨在追踪11个主要湖泊的鱼类群落组成，涵盖湖泊包括：Allequash湖、Big Muskellunge湖、Crystal湖、Sparkling湖、Trout湖、27-02号沼泽湖[Crystal Bog，即水晶沼泽湖]、12-15号沼泽湖[Trout Bog，即鳟鱼沼泽湖]、Mendota湖、Monona湖、Wingra湖及Fish湖。其中，Monona湖、Wingra湖与Fish湖的采样工作始于1995年，其余湖泊的采样则于1981年启动。每个湖泊设置6个沿岸带采样点位，采用围网、小型鱼类陷阱、螯虾陷阱及兜网（fyke nets）开展采样；同时搭载船载电捕鱼系统，完成3条沿岸样带的采样作业。此外，于每个湖泊的最深点位布设垂直悬挂刺网，采集2份远洋带样本；另以双三层刺网（trammel net）在每个湖泊的2个点位跨越温跃层进行采样。需特别说明：仅在沼泽湖部署兜网与小型鱼类陷阱。本次采样的测量参数包含：所有渔获鱼类的物种鉴定结果与体长数据，以及部分个体的体重与鳞片样本。衍生数据集涵盖按物种、湖泊及年份划分的物种丰富度、单位捕捞努力量渔获量（catch per unit effort）与体长分布。其中，某一湖泊的物种丰富度定义为该湖泊在年度鱼类采样中捕获的鱼类物种总数。仅当某一杂交组合的两个亲本物种均未在当年该湖泊中被捕获时，捕获的杂交个体方可计入物种丰富度数值。若某一属或更高分类阶元内存在已鉴定至物种水平的鱼类被捕获，则仅鉴定至属或更高分类阶元的鱼类样本不计入丰富度统计。例如，若当年该湖泊未捕获其他雅罗鱼（Chub）类物种，则未鉴定的雅罗鱼方可计入物种丰富度。采样频率：年度采样。采样点位总数：11个。需注意以下数据缺失情况：2020年无有效采样数据；2021年，Fish湖因湖水位发生显著变化，采样工作暂停；2022年两个沼泽湖的采样数据缺失。有关湖泊实验调控的详细信息，请查阅NTL官方网站；有关湖区管理活动的内容，请咨询DNR官方网站。