A team of researchers has identified unexpected ways in which coral reef fish that live in the warmest waters on earth, in the Arabian Gulf, have adapted to survive extreme temperatures.
Led by co-principal investigator at the Mubadala Arabian Center for Climate and Environmental Sciences (ACCESS) at NYU Abu Dhabi John Burt and Associate Research Professor, Hawaii Institute of Marine Biology Jacob Johansen, the team discovered adaptations in both metabolism and swimming ability that help fish survive the conditions of the Arabian Gulf. Surprisingly, these fish did not follow leading theoretical predictions, which expected that the maximum size of fish would need to be reduced due to limitations in metabolic oxygen supply. Instead, these fish showed the ability to maintain an efficient oxygen supply to optimize performance even at high temperatures.
The warming of our oceans is expected to drastically impact marine life and the fishing industry, potentially disrupting entire ecosystems and economic structures that depend on these habitats. Current scientific models predict that coral reef fish could shrink by 14 to 39 percent in size by 2050 due to rising temperatures caused by climate change. The study’s findings challenge the prevailing view that limitations in oxygen supply in larger fish are the main reason for smaller fish in warmer waters – the so-called ‘fish shrinkage’ phenomenon. The observed species did not follow this pattern, suggesting that other factors are also at play. The study proposes a new theory that the decline in fish size and their survival in increasingly warmer oceans may be more closely linked to an imbalance between the amount of energy fish species can obtain and how much they need to sustain themselves.
In the article entitled “Impacts of ocean warming on fish size reductions on the world’s hottest coral reefs”, published in the journal Nature communicationthe researchers compared two fish species, Lutjanus ehrenbergii And Scolopsis ghanam, survive in the higher temperatures in the Arabian Gulf than people of similar age living in the cooler, milder conditions in the nearby Gulf of Oman. Specifically, the researchers wanted to determine what traits reef fish in the Arabian Gulf have that allow them to survive there, where typical summer water temperatures are comparable to the worst-case ocean warming predicted for many tropical coral reefs worldwide by 2100.
“The world’s hottest coral reefs are an ideal natural laboratory to investigate the future impact of rising water temperatures on fish. Our findings indicate that some fish species may be more resilient to climate change than previously thought and help explain why smaller individuals are evolutionarily favored at high temperatures. temperatures,” Burt said. “This has significant implications for our understanding of the future of marine biodiversity in a continuously warming world.”
