Persian Gulf fish are surprisingly resistant to extreme heat

2 Jul. () –

Unexpected ways to survive extreme temperatures have been identified in coral reef fish that live in the warmest waters on Earth, in the Persian Gulf.

Surprisingly, these fish did not follow the main theoretical predictions, which expected the maximum size of fish to be reduced due to limitations in metabolic oxygen supply, according to a study by New York University in Abu Dhabi.

Instead, these fish They demonstrated an ability to maintain an efficient oxygen supply to boost performance even at high temperatures.

The warming of our oceans is expected to dramatically impact marine life and the fishing industry, potentially disrupting entire ecosystems and economic structures that depend on these habitats.

Current scientific models predict that by 2050, coral reef fish will could reduce their size by 14 to 39 percent due to rising temperatures caused by climate change.

The study’s findings challenge the prevailing view that oxygen supply limitations in larger fish are the main reason why fish are smaller in warmer waters, the so-called “fish shrinkage phenomenon”. The observed species did not follow this pattern, suggesting that other factors are also involved.

The study proposes a new theory that fish size decline and survival in warming oceans may be more closely linked to an imbalance between the amount of energy fish species can obtain and the amount they need to sustain themselves.

In the article, published in the magazine Nature Communications, The researchers compared two species of fish, Lutjanus ehrenbergii and Scolopsis ghanam, that survive the high temperatures of the Persian Gulf with others of similar age that live in the cooler, milder conditions of the nearby Gulf of Oman.

Specifically, the researchers set out to determine what qualities Persian Gulf reef fish have that allow them to survive there, where typical summer water temperatures are comparable to projections for ocean warming. in the worst case scenario for many tropical coral reefs worldwide by 2100.

“The world’s warmest coral reefs are an ideal natural laboratory to explore the future impact of rising water temperatures on fish. Our findings indicate that some fish species are more resilient to climate change than previously believed and help explain why smaller individuals are evolutionarily favored at high temperatures“explains co-author John Burt, co-principal investigator at the Mubadala Arab Center for Climate and Environmental Sciences (ACCESS) at New York University in Abu Dhabi.

“This has significant implications for our understanding of the future of marine biodiversity in a warming world,” he said.