Realm: Freshwater
Climate: Temperate
Biome: Small Lake Ecosystems
Central latitude: 46.100000
Central longitude: -89.700000
Duration: 4 years, from 1987 to 2020

1492 records

29 distinct species

Across the time series Amnicola limosus is the most frequently occurring species

Methods

Freshwater snails were sampled in ten lakes in Vilas County, Wisconsin, USA during summer sampling events in 1987, 2002, 2011, and 2020. Snails were sampled at locations historically sampled for crayfish (n = 24 or 36 sites per lake) between late June and early August. Snails were sampled at randomly assigned depths of either 0.75 m, ½ of Secchi depth, or ¾ of Secchi depth. While the same absolute depths were used in 1987 and 2002 based on 1987 Secchi values, depths in 2011 and 2020 were determined using year-specific Secchi values. Most sampling depths in 2011 and 2020 varied only slightly from the 1987 and 2002 values, but in two lakes the change in sampling depth was greater than one meter due to larger shifts in water clarity. The greatest changes in sampling depth (2.7 m in Papoose Lake and 1.5 m in Little John Lake) occurred at the ¾ Secchi depth sites, whereas the ½ Secchi depth sites were less affected by the change in water clarity in these two lakes. Snails were sampled using methods and equipment designed for each habitat type present in the study lakes (soft substrates, macrophytes, and cobble). For soft substrates such as sand and muck (flocculent sediment or sediment rich in organic material), a cylindrical polyvinyl chloride (PVC) sediment corer (0.018 m2) was used to take a 5 cm sediment core. For sites with soft substrates where macrophytes were present, the authors used a modified PVC sampler of the same size but with two hinged PVC halves, and a net made of 1-mm mesh attached to the top. The two halves of the PVC sampler were carefully closed around macrophytes growing at the surface the mesh net was zippered around taller macrophytes before pushing the corer into the sediment to collect a 5 cm core. Collecting the macrophyte material along with the sediment allowed sampling of any snails on the macrophytes along with those in the sediment. At the waters surface, all cores from soft substrates were sieved (with 1 mm mesh) to remove fine sediments and large particles and picked through macrophyte material for snails. Finally, for cobble habitats, a ring (0.1 or 0.5 m2) was placed on the substrate at each site to define a sampling area. In 1987 and 2002, the 0.1 m2 ring was used for sites with a high density of snails, and the 0.5 m2 ring was used for sites with a low density of snails. In 2011 and 2020, the 0.5 m2 ring was used at all sites. The surface layer of rocks within the sampling ring was gently collected and the rocks were briefly brought to the surface, where attached material was scraped into a collection pan and funneled through a 1 mm mesh sieve to gather snails. Snails collected using all sampling methods were stored in 70% ethanol for later identification. In the lab, snails were picked from all samples and identified to species or genus (for Physella sp.) according to Burch (1989) and Johnson et al. (2013), with revisions for Lymnaeidae (Hubendick 1951) and Planorbidae (Hubendick and Rees 1955). Snail abundance was calculated as density to account for differences between the sediment corers and the rings in area sampled. Snail samples from 1987 were lost in a laboratory flood, but specimens from 2002 and 2011 are vouchered at the Notre Dame Museum of Biodiversity in Notre Dame, Indiana, USA. Specimens from 2020 are vouchered at the Illinois Natural History Survey Mollusk Collection at the University of Illinois in Champaign, Illinois, USA. In 2020, the authors were not able to sample snails using SCUBA due to limitations from the COVID-19 pandemic, and therefore excluded a small portion of deeper sites (approximately 13% of total sites) that could not be sampled accurately and safely while snorkeling. In addition, because of a few lost samples, data from previous sampling years were not always available for each site. Consequently, the dataset only includes sites with data in all four sampling years (n = 208 sites/year). Only snails which were alive at the time of sampling were included (i.e., not empty shells). Curators note: DepthElevation used in this study is for sampling depth, not the elevation for each lake.

Citation(s)

@Dataset{BioTIME_cit431, Study_id = {701}, Citation_id = {431}, Author = {Szydlowski, Daniel K. and Elgin, Ashley K. and Lodge, David M. and Tiemann, Jeremy S. and Larson, Eric R.}, Publisher = {Environmental Data Initiative.}, Title = {Aquatic macrophyte, snail, and crayfish abundance and richness data for ten lakes in Vilas County, WI, USA, 1987-2020 ver 3.}, Year = {2022}, Doi = {10.6073/pasta/f10681ca29a9a69e9597bcd77a06fbe5}, Url = {doi.org/10.6073/pasta/f10681ca29a9a69e9597bcd77a06fbe5}, Language = {English}, Version = {3} }