DOI: 10.5061/dryad.bk3j9kdq0
title: Data and code from: Brook trout thermal habitat selection in stratified lakes: diel patterns, body size, and the importance of thermal time

description: Thermal habitat selection is a key consideration when assessing the
 capacity of ectotherms to tolerate warming conditions during summer. We
 used high dimension acoustic arrays in three lakes to determine diel
 thermal habitat selection by free-ranging adult brook trout with
 surgically implanted acoustic tags (fork length range, 26.2–54.5 cm).
 Brook trout occupied a range of temperatures during lake stratification
 when warm surface waters and cold hypolimnetic waters were present. The
 overall mean occupied temperature was close to literature estimates of a
 single preferred temperature (15°C), but few individuals spent most of
 their time at this temperature. The preferred temperature range was
 13–17°C in each lake while &lt; 10°C and &gt; 20°C were avoided.
 Individual variation was extensive and closely associated with body size.
 Despite wide diel variation in patterns of thermal habitat selection,
 thermal time (degree-hours; °C-hrs) was consistent and inversely related
 to body size over a month. Large adult brook trout accumulated fewer
 degree-hours than smaller brook trout. The intercept of this relationship
 was close to their sublethal threshold as defined by physiological stress.
 We hypothesize that adult brook trout actively manage metabolic rate as a
 function of body size over periods greater than the diel cycle.
description: # Data and code from: Brook trout thermal habitat selection in stratified
 lakes: diel patterns, body size, and the importance of thermal time
 Dataset DOI: [10.5061/dryad.bk3j9kdq0](10.5061/dryad.bk3j9kdq0) ##
 Description of the data and file structure The data and files in this
 Dryad are those required to reproduce the analysis and figures in the
 associated manuscript. They consist of hourly mean temperature occupied by
 individual fish in the three study lakes, lake volumes categorized within
 thermal strata, and the R file uses to run the analysis and produce
 figures.  ### Files and variables #### File: lakevolumes.csv
 **Description:** proportional volumes of thermal habitat present in each
 study lake (as above) ##### Variables * lake: study lake (3 levels; Scott
 Lake, Stringer Lake, Welcome Lake) * zone: thermal habitat zone (5 levels;
 cold = &lt; 10°C, cool = 10-13°C, opt = 13-17°C, warm = 17-20°C, hot =
 &gt;20°C) * zone_tot: mean availability of thermal habitat zone
 (proportion of total lake volume) * zone_max: zone maximum proportion of
 lake volume calculated over study month * zone_min: zone minimum
 proportion of lake volume calculated over study month #### File:
 Clean_RScript.R **Description:** R Script to reproduce analyses and plots
 within manuscript #### File: BT_THS_hour_subset.csv **Description:** brook
 trout hourly temperatures interpolated from depths (VPS data) in Scott
 Lake, Stringer Lake, and Welcome Lake in Algonquin Provincial Park. #####
 Variables * lake: study lake (3 levels; Scott Lake, Stringer Lake, Welcome
 Lake) * fish: individual fish ID (55 levels; coded XX000 where XX is lake
 code, 000 is fish number specific to lake) * year: study year (2 levels;
 2009 for Scott and Stringer, 2014 for Welcome) * date: date of detection
 (yyyy-mm-dd) * FLEN: fork length (millimetres) * datetime: date and time
 of detection (yyyy-mm-dd hh:mm, Eastern Daylight Time) * month: detection
 month as numeric value (7 = July) * day: detection day (relative to month;
 1-31) * temp: interpolated temperature in °C * mean: overall mean occupied
 temperature (mean of all temps for individual fish) * hour: hour of
 detection (0-23) * time: detection time (hh:mm:ss) * period: detection
 time of day (4 levels; DT = daytime, EC = evening crepuscular, NT =
 nighttime, MC = morning crepuscular. See manuscript for definition of
 periods) ## Code/software R is required to read and run the script and
 notepad or equivalent is required to view the csv files.