Logo image
Divergent field metabolic rates highlight the challenges of increasing temperatures and energy limitation in aquatic ectotherms
Journal article   Peer reviewed

Divergent field metabolic rates highlight the challenges of increasing temperatures and energy limitation in aquatic ectotherms

K.O. Lear, D.L. Morgan, J.M. Whitty, N.M. Whitney, E.E. Byrnes, S.J. Beatty and A.C. Gleiss
Oecologia
2020
url
Link to Published Version *Subscription may be requiredView

Abstract

Environments where extreme temperatures and low productivity occur introduce energetically challenging circumstances that may be exacerbated by climate change. Despite the strong link between metabolism and temperature in ectotherms, there is a paucity of data regarding how the metabolic ecology of species affects growth and fitness under such circumstances. Here, we integrated data describing field metabolic rates and body condition of two sympatric species of ectotherms with divergent lifestyles, the benthic freshwater (or largetooth) sawfish (Pristis pristis) and the epipelagic bull shark (Carcharhinus leucas) occurring in the Fitzroy River, Western Australia, to test the implications of their differing metabolic ecologies for vulnerability to rising temperatures. Over a temperature range of 18–34 °C, sawfish had lower field metabolic rates (63–187 mg O2 kg−0.86 h−1) and lower temperature sensitivity of metabolic rates [activation energy (EA) = 0.35 eV] than bull sharks (187–506 mg O2 kg−0.86 h−1; EA = 0.48 eV). Both species lost body mass throughout the dry season, although bull sharks significantly more (0.17% mass loss day−1) than sawfish (0.07% mass loss day−1). Subsequent bioenergetics modelling showed that under future climate change scenarios, both species would reach potentially lethal levels of mass loss during dry season periods before the end of the century. These results suggest that ectotherms with low metabolic rates may be better suited to extreme environmental conditions, and that even small increases in temperature due to climate change could have substantial impacts on the ability of ectotherms to grow and survive in harsh conditions, including high temperatures and energy-limiting circumstances.

Details

UN Sustainable Development Goals (SDGs)

This output has contributed to the advancement of the following goals:

#14 Life Below Water
#15 Life on Land

Source: InCites

Metrics

InCites Highlights

These are selected metrics from InCites Benchmarking & Analytics tool, related to this output

Collaboration types
International collaboration
Citation topics
3 Agriculture, Environment & Ecology
3.2 Marine Biology
3.2.92 Fisheries Ecology
Web Of Science research areas
Ecology
ESI research areas
Environment/Ecology
Logo image