Adelaide University researchers have found that some estuarine fishes that live in habitats with highly variable temperatures can withstand the warmer ocean conditions expected to result from climate change.
The study, published in Global Change Biology , shows estuarine fishes’ resilience to these extreme conditions is genetically determined.
“Climatic extremes are increasing in frequency, intensity, and duration across Earth’s biomes as a consequence of anthropogenic climate change,” said project leader Professor Ivan Nagelkerken, from Adelaide University’s School of Biological Sciences.
“In aquatic systems, climatic extremes can rapidly restructure communities, disrupt ecosystem functioning, and compromise ecosystem services, including fisheries productivity.
“Our study examined the resilience of three economically important estuarine species, which we found to be ‘thermal generalists’ with a genetic ability to withstand extreme conditions.”
The study, performed by Dr Angus Mitchell, focused on yellowfin bream, sand whiting and tarwhine due to the species’ important role in the fisheries industry.
“Yellowfin bream and sand whiting are among the most commonly caught inshore species by recreational and commercial fishers on the east coast,” Dr Mitchell said.
“They’re what people target to take home, so understanding whether they can cope with warming estuaries matters directly for the fisheries that coastal communities depend on.”
While these fishes are primed for extreme conditions, many marine habitats are already experiencing changes in species distribution due to climate change.
"We’re already seeing tropical species push further south as waters warm, reshuffling which fish support local fisheries,” Professor Nagelkerken said.
“Our results suggest estuarine species with broad thermal tolerance may hold their ground, but that won’t extend to species with narrower limits such as coral reef fishes.”
Professor Nagelkerken said these results provide hope for the future but he highlighted that many other species are more sensitive to climate change.
“Many estuaries are increasingly subject to other types of human pressures, such as pollution and overfishing,” he said.
“Hence, we need to manage our estuaries well to sustain the fisheries species that are set to be more resilient to a future climate.”