Local conditions drive interpopulation variation in field-based critical thermal maximum of brook trout

Conservation Physiology, Journal Year: 2024, Volume and Issue: 12(1)

Published: Jan. 1, 2024

Individual- and population-level responses to thermal change will be pivotal for species' resilience adaptive climate change. Thermal tolerance of ectotherms has been extensively studied under laboratory conditions, but comparatively few studies have assessed intra- interpopulation variation natural conditions or in situ. We measured field critical maximum (CTmax) brook trout (Salvelinus fontinalis) populations at twenty sites across Ontario, Canada, assess their situ examine potential factors underlying intraspecific performance. modelled CTmax as a function acclimation using short-term stream temperature data variation, used full-season temperatures calculate safety margins (TSM) each population. ranged between 27.41 30.46°C periods 4 40 days were strong predictors site CTmax, aligning closely with lab-based studies. Seasonal profiles varied substantially among sites, mean 30-day accounting 66% the among-site CTmax. TSMs 0.51 15.51°C reflected differences regimes. Streams watersheds more urban agricultural development had lowest addition those that fed by lake surface water. This work emphasizes importance locally based conservation management practices act below population level, local beyond partly responsible thus dictate resiliency

Language: Английский

Microgeographic variation in demography and thermal regimes stabilize regional abundance of a widespread freshwater fish

Ecological Applications, Journal Year: 2023, Volume and Issue: 34(2)

Published: Dec. 10, 2023

Abstract Predicting the persistence of species under climate change is an increasingly important objective in ecological research and management. However, biotic abiotic heterogeneity can drive asynchrony population responses at small spatial scales, complicating species‐level assessments. For widely distributed consisting many fragmented populations, such as brook trout ( Salvelinus fontinalis ), understanding drivers dynamics improve predictions range‐wide impacts. We analyzed demographic time series from mark–recapture surveys 11 natural populations eastern Canada over 13 years to examine extent, drivers, consequences fine‐scale variation. The focal were genetically differentiated, occupied a area (~25 km 2 ) with few human impacts, experienced similar conditions. Recruitment was highly asynchronous, weakly related variables showed population‐specific relationships other processes, generating diverse dynamics. In contrast, individual growth mostly synchronized among driven by shared positive relationship stream temperature. Outputs models unrelated four five hypothesized (recruitment, growth, reproductive success, phylogenetic distance), but variation groundwater inputs strongly influenced temperature regimes stock–recruitment relationships. Finally, generated portfolio effect that stabilized regional abundance. Our results demonstrated demographics habitat diversity microgeographic scales play significant role moderating change. Moreover, we suggest absence activities within study streams preserved contributed abundance, while eased monitoring increased likelihood detecting asynchrony. Therefore, anthropogenic degradation, landscape context, scale must be considered when developing management strategies monitor maintain are diverse, stable, resilient

Language: Английский

Temporal Variability in Effective Size (N̂e$$ {\hat{N}}_e $$) Identifies Potential Sources of Discrepancies Between Mark Recapture and Close Kin Mark Recapture Estimates of Population Abundance

Molecular Ecology Resources, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 24, 2024

ABSTRACT Although efforts to estimate effective population size, census size and their ratio in wild populations are expanding, few empirical studies investigate interannual changes these parameters. Hence, we do not know how repeatable or representative many estimates may be. Answering this question requires of long‐term dynamics. Here took advantage a rich dataset seven brook trout ( Salvelinus fontinalis ) populations, 5 consecutive years 5400 individuals genotyped at 33 microsatellites examine variation ratio. We first estimated the annual number breeders b using aged 1+. then adjusted two life history traits, obtain subsequently, following Waples et al. (2013). was for 2014 2019. Census by mark recapture double‐pass electrofishing () (years 2014–2018) as well Close Kin Mark Recapture approach 2015–2017). Within (ratio maximum minimum ranged from 1.6‐fold 58‐fold. Over all 7 median around 5‐fold. These results reflect important variance reproductive success more generally varied between (median) factor 2.7 with range 2 4.3. Thus, nearly twice much did size. Our therefore suggest that, least small like those examined present study, any single is unlikely be At 3–4 required an contemporary truly representative. compared . For five abundance based on were indistinguishable close kin (). The discordant exhibited extremely low ratios largest (58‐fold 35.4‐fold respectively). that sampling effort streams have been insufficient properly capture genetic diversity entire sampled population. study further validates CKMR method estimating it demonstrates knowledge temporal can used identify potential sources discrepancies

Language: Английский