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次级数据集。本数据按年度采集，用于追踪11处主要湖泊的鱼类群落组成，具体包括Allequash湖、Big Muskellunge湖、Crystal湖、Sparkling湖、Trout湖，以及两处泥炭湖27-02（Crystal Bog）与12-15（Trout Bog）、Mendota湖、Monona湖、Wingra湖与Fish湖。其中Monona湖、Wingra湖与Fish湖的采样工作始于1995年，其余湖泊的采样则始于1981年。 采样方式包括：使用围网（seine）、小型鱼类诱捕笼（minnow trap）、螯虾诱捕笼（crayfish trap）及定型网（fyke nets）对每处湖泊的6个沿岸带（littoral zone）采样点开展采集；依托船载电捕鱼系统（boat-mounted electrofishing system）对3条沿岸样带进行采样。此外，研究人员会在每处湖泊的最深点位布设垂直悬挂刺网（gill net），采集2份远洋带（pelagic zone）样本；并在每处湖泊的2个点位布设三重刺网（trammel net），跨越温跃层（thermocline）进行采样。仅在泥炭湖中布设定型网与小型鱼类诱捕笼开展采样。 本次采集记录的参数涵盖所有渔获鱼类的物种鉴定结果与体长数据，同时从部分样本中采集了体重与鳞片样品。衍生数据集包含物种丰富度（species richness）、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数据。其中，湖泊的物种丰富度指该湖泊在年度鱼类采样中捕获的鱼类物种总数。仅当某杂交个体的两个亲本物种均未在当年该湖泊中被捕获时，该杂交个体方可计入物种丰富度。若某一属或更高分类阶元下存在已鉴定至物种水平的鱼类被捕获，则仅鉴定至该属或更高阶元的鱼类样本不计入物种丰富度；例如，若当年该湖泊未捕获其他雅罗鱼（Chub）类物种，则未鉴定物种的雅罗鱼样本方可计入物种丰富度。 采样频率为年度采样。共设置11处采样点位。需注意：2020年因采样量不足，无有效数据；2021年Fish湖因水位发生显著变化，采样工作暂停；2022年两处泥炭湖的数据缺失。有关湖泊实验调控的详细信息，请参阅NTL官方网站；有关湖泊管理活动的内容，请咨询DNR官方网站。