Sea-life switch in shifting oceans
Another study has reinforced the point that warming oceans will cause profound changes for marine species.
New research shows the global distribution of marine life is set to shift.
“A rapidly warming climate will cause many species to expand into new regions, causing impact on native species in those areas,” says Professor John Pandolfi, from the ARC Centre of Excellence for Coral Reef Studies.
He was part of an international research team that modelled the impacts of a changing climate on almost 13,000 marine species, more than 12 times as many species as previously studied.
“Some species will have much more restricted ranges, particularly those around the tropics, and these species are more likely to face extinction.”
Professor Pandolfi said global patterns of species richness would change significantly, with considerable regional variability.
Above all, the study showed the broad geographic effects of climate change.
“This study gave us hope that species have the potential to track and follow changing climates,” Professor Pandolfi said.
“But it also gave us significant cause for concern, particularly in the tropics, where strong biodiversity losses are predicted.
“This is especially worrying, and highly important for Australia’s coral reefs.
“Other studies have shown high extinction risk for plant and animal life in tropical regions, where localised human impacts – in addition to climate change – have resulted in substantial degradation.”
To model the projected impact of climate change on marine biodiversity, the researchers used climate-velocity trajectories; a measurement combining the rate and direction of movement of ocean temperature bands over time, together with information about thermal tolerance and habitat preference.
The analysis provides the simplest expectation for the future distribution of marine life, and shows recurring patterns of high rates of species invasion and local extinctions.
“New combinations of resident and migrant species will present unprecedented challenges for conservation planning,” Professor Pandolfi said.
“Countries will need to coordinate their conservation efforts to have any real chance of combating the potentially severe biodiversity losses that a changing climate might impose.”
Fellow researcher Dr David Schoeman said the model suggested there could be time to prevent significant climate-related extinctions outside of the tropics.
“Results under a scenario in which we start actively mitigating climate change over the next few decades indicates substantially fewer extinctions than the results from a business-as-usual scenario,” Dr Schoeman said.
But, he said, “the immense development of novel biotic assemblages” could be more worrying.
“We have little idea how these new combinations of species in ocean systems around the world will affect ecosystem services, like fisheries,” Dr Schoeman said.
“We should be prioritising ecological research aimed specifically at addressing this question.”
The paper - Climate velocity and the future of global redistribution of marine biodiversity - will be published in the journal Nature Climate Change.