The study, published in, challenges current scientific models which argue that by 2050, coral reef fish could shrink by 14-39 percent in size due to increasing temperatures under climate change.

The researchers from NYU Abu Dhabi, the Hawaii Institute of Marine Biology and The University of Manchester, identified how coral reef fish living in the Arabian Gulf - the warmest waters on earth - have adapted to survive extreme temperatures.

It was led by John Burt, co-principal Investigator at at NYU Abu Dhabi and Jacob Johansen, Associate Research  Professor at the  Hawaii Institute of Marine Biology.

Though they studied two kinds of fish the findings are likely to be relevant to other species.

Professor Holly Shiels was also on the team, along with her PhD students Dan Ripley and Grace Vaughan.

She said: “The Arabian/Persian Gulf is a window to future ocean conditions and working together with colleagues in the region we have used this natural laboratory to provide new insight into impact of rising water temperatures on fish.

“Our study offers hope for some marine species in a continuously warming world.”

According to the researchers, adaptations in both metabolism and swimming abilities helped the fish to survive extreme conditions in the Arabian Gulf.

The warming of our oceans is anticipated to drastically affect marine life and the fishing industry, potentially upsetting entire ecosystems and economic structures reliant on these habitats.

However, the study’s findings challenge the prevailing view that oxygen supply limitations in larger fishes are the main reason for smaller fish in warmer waters – known as the “shrinking fish phenomenon.”

The researchers instead argue the decrease in fish size and their survival in increasingly warm oceans might be more closely related to an imbalance between how much energy fish species can obtain and how much they need to sustain themselves.

The researchers compared two species of fish, the Blackspot snapper and the Arabian monocle bream, surviving under the elevated temperatures within the Arabian Gulf to those of similar age living in the cooler, more benign conditions in the nearby Gulf of Oman.

They determined the qualities reef fish in the Arabian Gulf have that enable them to survive there, where typical summer water temperatures are comparable to worst-case ocean warming projections for many tropical coral reefs globally by 2100.

John Burt said: “The hottest coral reefs in the world are an ideal natural laboratory to explore the future impact of rising water temperatures on fishes.

“Our findings indicate that some fish species are more resilient to climate change than previously understood and help explain why smaller individuals are evolutionarily favored at high temperatures.

This has significant implications for our understanding of the future of marine biodiversity in a continuously warming world.”

• “Causes and consequences of ocean warming on fish size reductions on the world’s hottest coral reefs” is published in the journal

University of Manchester scientists are at the forefront of the fight to protect cold water fish from the effects of crude oil spills from offshore oil rigs.

Dr Holly Shiels and PhD student Martins Ainerua are working off the coast of Norway with Dr Elin Sørhus of the Norwegian Institute of Marine Research to understand how the oil impacts on hearts of cod and halibut.

As the heart is the first organ to develop in fish larvae its good heath is crucial for survival of the animals into adulthood, say the team.

Two projects – known as ‘Eggtox’ - and ‘PW(produced water)exposed’, could provide vital information for oil companies who want to construct rigs in parts of the North Sea which are known to be key spawning grounds for these important fisheries.

The team also hope to understand the mechanisms of crude oil toxicity on the electrical and contractile properties of the fish heart.

They have been working in the electrophysiology lab at Austevoll station on the South West coast of Norway, investigating how various oil components affect the electrical activity of the juvenile cod and halibut hearts.

Dr Shiels said: “We know from disastrous crude oil spills like DeepWater Horizon, that components of oil negatively affects hearts of larval and juvenile fish.

"But it is possible the Produced Water used in oil drilling – which is released even in the absence of a spill - may impact fish stocks.

“And this is especially a worry in areas where drilling occurs in spawning grounds as the eggs and tiny larvae are unprotected.

“That is why are studying the impact of a single component of crude oil on the heart, and two of its metabolic derivatives.

“This is important work. A thorough understanding of cardiotoxicity will improve ecological risk assessments and environmental health monitoring.”