Thermal habitat fragmentation in stratified lakes induces resource waves that brook charr track across seasons

The spatial configuration of thermal habitats constrains the thermoregulatory performance of ectotherms. Thermal landscapes also vary through time, which is particularly relevant in seasonal environments such as temperate lakes. Indeed, elevated temperatures in the epilimnion of dimictic lakes during summer could substantially reduce the use of this habitat by cold-stenothermic fish during the stratified period. The main objective of this study was to evaluate whether thermal habitat fragmentation in stratified lakes modulates accessibility to resources that brook charr, Salvelinus fontinalis, which is a mobile consumer, can track across seasons. More specifically, we hypothesize that reduced access to the littoral habitat during summer enhances foraging opportunities in this habitat during winter. We used an automatic acoustic telemetry system offering full coverage of the lake to continuously record brook charr locations across seasons, and we estimated zoobenthos abundances in the li..., The study was carried out in Lake Ledoux (46° 38’ N, 73° 15’ W), Mastigouche Wildlife Reserve, Québec, Canada, from 2016 to 2018. Lake Ledoux is a typical small oligotrophic temperate zone lake with respect to surface area (11.9 ha), mean depth (5.5 m), maximum depth (18.0 m), and general physicochemical characteristics (Gignac-Brassard et al. 2023, Magnan 1988). Brook charr is the only fish species in the lake, and sport fishing is rigorously controlled by the Québec Government (Bourke et al. 1996). The lake was closed to fishing during the three years of the study, but illegal fishing was observed in Lake Ledoux (M. Pépino, personal observation; see details in Supplement 1).
We deployed acoustic telemetry positioning arrays to continuously follow brook charr movements and habitat use at fine spatiotemporal scales (<1 min, <5 m resolution) using two different VEMCO Positioning Systems (VPS). From 5 to 7 July 2016, we deployed 10 receivers (VR2Tx-069k-111-BAT; VEMCO Inc., Halifax,..., , # Thermal habitat fragmentation in stratified lakes induces resource waves that brook charr track across seasons

[https://doi.org/10.5061/dryad.x69p8czr4](https://doi.org/10.5061/dryad.x69p8czr4)

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We have submitted lake temperature profile data (**Water_Temperature_Data.csv**), benthos count data (**Benthos_Count_Data.csv**), brook charr position data from the VR2 (**FishVUE.csv**) or HR2 (**FishHRtot.csv**) positioning systems, and GIS lake data for lake contour (**ledoux_line.shp**), lake bathymetry (**ledoux_bathy.shp** or **ledoux_raster.tif**) or benthos stations (**ledoux_benthos.shp**) in a .zip file (**Lake_Data.zip**).

## Descriptions

### **Water\_Temperature\_Data**

* *Temp*: Temperature (°C)
* *Depth*: Depth (m)
* *DateUTC*: Time in universal time zone (yyyy-mm-dd hh:mm:ss)
* *DateEDT*: Time in Eastern/Canada time zone (yyyy-mm-dd hh:mm:ss)
* *Set*: Interger from the first (1) to the last (5) download of the temperature data
* *Day*: Date (yyyy-mm-dd)

##...