Phytoplankton samples from the seven northern Wisconsin LTER lakes in the Trout Lake area (Allequash, Big Muskellunge, Crystal, Sparkling, and Trout lakes and bog lakes 27-02 [Crystal Bog], and 12-15 [Trout Bog]) are collected six times per year at the deep hole sampling station at the same time as our other limnological sampling is conducted. We use a peristaltic pump and tubing, collecting a separate sample from the epilimnion, metalimnion and hypolimnion for most of the lakes. For 27-2 Bog Lake, which is only 2m deep, we collect one 0-2m composite sample. The samples are preserved with Lugols iodine solution. We create a single hypsometrically pooled composite sample per lake from subsamples of the strata samples. The pooled samples are sent to PhycoTech, Inc., a private lab specializing in phytoplankton analysis, to be made into permanent slide mounts. The slide mounts, 3 slides per sample, are archived at the University of Wisconsin - Madison Zoology Museum Phytoplankton are identified to species using an inverted microscope (Utermohl technique) and are reported as natural unit (i.e., colonies, filaments, or single cells) densities per mL, cell densities per mL, and algal biovolume densities per mL. Multiple entries for the same species on the same date may be due to different variants or vegetative states - (e.g., colonial or attached vs. free cell.) Biovolumes for individual cells of each species are determined during the counting procedure by obtaining cell measurements needed to calculate volumes for geometric solids (e.g., cylinders, spheres, truncated cones) corresponding to actual cell shapes. Biovolume concentrations are then computed by mulitplying the average cell biovolume by the cell densities in the water sample. Note that one million cubicMicrometers of biovolume PerMilliliter of water are equal to a biovolume concentration of one cubicMillimeterPerMilliliter. Assuming a cell density equal to water, a cubicMillimeterPerMilliliter of biovolume converts to a biomass concentration of one milligramPerLiter. Sampling Frequency: 6 samples per year Number of sites: 7
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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
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- Award ID(s):
- 2025982
- PAR ID:
- 10493160
- Publisher / Repository:
- Environmental Data Initiative
- Date Published:
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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