Researchers at the Mubadala Arabian Centre for Climate and Environmental Sciences (Mubadala ACCESS) at NYU Abu Dhabi have made groundbreaking discoveries about how reef fish in the Arabian Gulf, the world’s hottest sea, adapt to extreme temperature fluctuations. This region provides a unique setting for studying climate change impacts due to its highly variable thermal conditions. The study revealed that fish in the Arabian Gulf have a higher tolerance to temperature changes compared to those in more stable coral reef environments, such as the Gulf of Oman. However, despite this adaptability, the Arabian Gulf has fewer fish species overall, indicating that only certain species can withstand rising global temperatures.
The research team, led by Dr. Grace Vaughan, postdoctoral associate Daniel Ripley, and professor of Biology John Burt, compared fish from the harsh Arabian Gulf environment with those in the more temperate Gulf of Oman. They found that the fish in the Arabian Gulf showed a slight increase in temperature tolerance. However, the overall biodiversity in the Arabian Gulf is lower, suggesting that while some species can adapt to environmental variability, the difference in thermal tolerance between the two regions was minimal.
A key part of the research tested the “plastic floors and concrete ceilings” hypothesis, which suggests that fish can adjust their physiological rates, such as metabolism and heart rate, to adapt to warmer climates. By comparing the metabolic rates of three reef fish species in both regions, the team found no significant difference, indicating that this principle does not hold for tropical fish dealing with shifting temperature variability.
The findings highlight that while some coral reef fish in the Arabian Gulf show slight adaptability to increasing temperatures, many do not. This suggests that as global temperatures rise, fish biodiversity is likely to decline in many ecosystems. The research emphasizes the need to further investigate existing theories of thermal tolerance across different environments to better predict the long-term impacts of climate change.
The team’s findings were published in the paper “Narrow Margins: Aerobic Performance and Temperature Tolerance of Coral Reef Fishes Facing Extreme Thermal Variability” in the journal Global Change Biology. The study underscores the importance of understanding how marine ecosystems will respond to climate change, particularly in regions like the Arabian Gulf, where extreme conditions already pose significant challenges.
