DOI: 10.5061/dryad.zgmsbccd8
title: Data and code from: Thermal niche and habitat use by co-occurring lake trout (Salvelinus namaycush) and brook trout (S. fontinalis) in stratified lakes

description: Realized thermal niche and habitat use are two conceptualizations of fish
 habitat based on organismal performance or lake-specific ecology,
 respectively. Both habitat types were compared for lake trout (Salvelinus
 namaycush) and brook trout (S. fontinalis) co-occurring in four large
 (&gt; 500 ha) oligotrophic lakes. Lakes were partitioned into two
 morphological categories based on possession of a central or non-central
 deep basin with corresponding differences in adjoining shelf areas. Lake
 asymmetry in basin location has been shown to strongly influence food web
 connections based on isolation of basins from shelf areas. Generally,
 overlap between both habitat types occurred in several comparisons with
 lake trout, suggesting that thermal habitat is a reasonable proxy for
 habitat use boundaries though not a full replacement for insights gained
 from habitat use models. For brook trout, overlap was not as consistent,
 especially for lakes with non-central basins. In central basin lakes,
 there were closer proximity between the two species and overlap in both
 thermal niche and habitat use models. There was very limited overlap of
 either habitat type in lakes with non-central basins. Further, there were
 no shared areas of interspecific overlap between thermal niche and habitat
 use in non-central basins pointing to additional complexity governing
 habitat partitioning between lake trout and brook trout in these types of
 lakes. The shelf area effect on spatial structure of habitat, and likely
 food web connections, can occur in lakes regardless of basin centrality so
 long as shelf areas are large. In this lake set, lakes were sufficiently
 large to observe this phenomenon.
description: Data are from one-hour set duration benthic gill-netting depth
 stratified randomized netting surveys conducted in four large lakes in
 Algonquin Provincial Park using standard North American large-mesh
 gillnets. Surveys were conducted during periods of thermal stratification
 (July-August) in the daytime. Each site was sampled at least three times
 during a survey.  Lake volumes for hypsographic data
 were derived from digital bathymetric surveys conducted by Harkness Lab
 staff. ArcGIS software was used to calculate lake volume at 1 metre
 resolution from the digital bathymetry rasters. Temperature and DO
 profiles were collected mid-basin in each lake during the netting
 surveys. 
description: Data and code to replicate the occupancy and overlap analysis and
 figures are provided in .Rdata files and can be opened in the R
 Statistical computing language. Analysis code is provided as .R scripts
 and is commented.  .R files can be opened in any R editor, but are best
 viewed in RStudio. .Rdata files can be opened in any instance of R. Files
 are provided in a compressed file containing all files to replicate the
 analysis found in the paper. To recreate the
 hypsographic figure lake volume data is provided in a .csv file and lake
 outlines and contours in a .gpkg file. Both of these can be opened in code
 provided in a .R file which can be used in R or RStudio.