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Data and Code for: Isotopic Niche Size of Coregonus artedi (sensu lato) Increases in the Presence of Mysis diluviana, Expanded Habitat Use and Phenotypic Diversity

Citation

Ridgway, Mark; Bell, Allan; Piette-Lauziere, Piette-Lauziere; Turgeon, Julie (2021), Data and Code for: Isotopic Niche Size of Coregonus artedi (sensu lato) Increases in the Presence of Mysis diluviana, Expanded Habitat Use and Phenotypic Diversity, Dryad, Dataset, https://doi.org/10.5061/dryad.5hqbzkh42

Abstract

Post-glacial colonization of lakes in Algonquin Park, Ontario, Canada resulted in food webs with cisco (Coregonus artedi sensu lato) and either Mysis diluviana or Chaoborus spp. as the dominant diel migrator. Mysis as prey, its diel movements and benthic occupancy, are hypothesized to be key elements of ecological opportunity for cisco diversity in the Laurentian Great Lakes.  If correct, the hypothesis strongly implies that lakes with Mysis would have greater trophic niche size and drive greater adaptive radiation of cisco forms relative to lakes without Mysis. The dichotomy in diel migrator in Algonquin Park lakes was an opportunity to assess the isotopic niche size of cisco (δ15N and δ13C) and determine if niche size expands with Mysis presence. We found the presence of Mysis is necessary to expand isotopic niche size in our study lakes. The use of habitats not typically associated with the ancestral form of cisco (e.g., benthic habitats) and phenotypic diversity (blackfin and cisco) also continue to expand niche size in Mysis-based food webs. Partial ecological speciation based on a large niche space appears to be present in one lake (Cauchon Lake) where use of alternative habitats is the only real difference in cisco. The presence of blackfin expands niche space in Cedar and Radiant Lakes. This was not matched in Hogan Lake where niche space was relatively smaller with similar forms. Possible reasons for this discrepancy may be related to the asymmetric basin of Hogan Lake and whether the two forms overlap during cool and cold-water periods of the annual temperature cycle. By comparing trophic niche size among lakes with and without Mysis we conclude that Mysis provides a key ecological opportunity for cisco diversity in our study lakes and likely more widely.

Methods

Lake surveys in Algonquin Provincial Park were conducted in lakes with and without Mysis diluviana, a glacial relict species signifying pro-glacial lake inundation over 10,000 years ago. Surveys were conducted with standardized gillnets following a depth stratified randomized design. Cisco muscle tissue was analyzed for trophic isotopes (δ15N and δ13C). Cisco were distinguished based on whether they were caught in pelagic nets (ancestral habitat) or bottom nets as well as based on morphogical variation. The datasets included here are summaries of the data in Figures in Ridgway et al (2020). This also includes the morphologial data from Piette-Lauziere et al (2019).

Usage Notes

The datasets and R code pertain to figures in Ridgway et al (2020). Data are in .csv files and data labels precede R code for each figure.

Funding

Great Lakes Fishery Commission

Ontario Ministry of Natural Resources and Forestry