Credit: Sebastian Pena Lambarri/Unsplash
Credit: Sebastian Pena Lambarri/Unsplash

Fish are far more vulnerable to global warming than previously thought

Embargoed until: Publicly released:
Peer-reviewed: This work was reviewed and scrutinised by relevant independent experts.

A research review has found fish species around the world are at greater risk from climate change than previously realised. German scientists analysed published research on nearly 700 marine and freshwater fish species to understand which stages of the lifecycle were most impacted by increased water temperatures. Their findings suggest spawning fish and embryos are more vulnerable than adult fish, and a significant proportion of the fish species evaluated will not be able to exist in their current habitat if global warming continues unchecked. Their research challenges previous risk estimates which were based on information from adult fish alone.

Journal/conference: Science

Link to research (DOI): 10.1126/science.aaz3658

Organisation/s: Centre for Polar and Marine Research, Germany

Funder: Supported by the research project METAFISCH of the German Federal Ministry of Education and Research (BMBF grant FZK01LS1604A to H.-O.P. and F.T.D.) and by the Deutsche Forschungsgemeinschaft (Po 278/16-1 and -2) as part of the Research Unit Tersane (FO 2332). S.W. was funded through HIFMB based on the collaboration between the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, and the Carl von Ossietzky University Oldenburg, initially funded by the Ministry for Science and Culture of Lower Saxony and the Volkswagen Foundation through the Niedersächsisches Vorab grant program (grant ZN3285)

Media release

From: AAAS

Spawning Fish and Embryos Most Vulnerable to Climate’s Warming Waters
Spawning fish and embryos are far more vulnerable to Earth’s warming waters than fish in other life stages, according to a new study, which uniquely relates fish physiological tolerance to temperature across the lifecycles of nearly 700 fish species. The results reveal a critical bottleneck in the lifecycle of fish and suggest that many ecologically and economically important fish species are threatened by climate warming more than studies based on adult fish thermal tolerance alone have shown. Understanding an organism’s physiological limits to temperature changes can provide a window into how some species will likely respond to Earth’s changing climate. However, thermal tolerances often vary throughout an organism’s life. Thus, the vulnerability of a species to climate change hinges on its most temperature-sensitive life stages. But due to a lack of experimental data, large-scale climate risk assessments often simplify or fail to account for the effects of these thermal bottlenecks across the entire lifecycle of many major animal groups, including fish. Whether our current climate mitigation targets are sufficient enough to sustain healthy fish populations remains poorly understood. Flemming Dahlke and colleagues compiled published observational and experimental data to assess the life stage-specific thermal tolerances for 694 marine and freshwater fish from waters worldwide. Their large-scale meta-analysis found that spawning adults and embryos were much more susceptible to temperature changes than other life stages across fish species. Dahlke et al.’s findings suggest that, with unchecked warming, a significant proportion of the fish species they evaluated will not be able to exist in the current geographic range of their most vulnerable life stages within a century – a finding that stands in stark contrast when compared to the relatively low percentage of species estimated using only the thermal tolerance of adults. “The minute thermal safety margins of spawning fish and embryos in the tropics suggest that there are limited fish species on Earth that can tolerate warmer or less oxygenated habitats. Intensified efforts to stabilize global warming are warranted more than ever,” writes Jennifer Sunday in a related Perspective.

Attachments:

Note: Not all attachments are visible to the general public

News for:

International

Media contact details for this story are only visible to registered journalists.