Over three decades, a team of researchers from NYU Abu Dhabi’s Arabian Center for Climate and Environmental Sciences (ACCESS) studied the evolution of dissolved oxygen in the Arabian Gulf and discovered a significant decline in oxygen concentrations as well as the expansion of the seasonal near-bottom hypoxic zone (lower oxygen levels near the bottom of the Gulf in certain seasons). The researchers conclude that changes in local climate are altering the physical and biogeochemical environment of the Gulf, potentially affecting the region’s ecosystems and fisheries.
The researchers used a sophisticated ocean model to simulate hypoxia near the sea bottom from 1982 to 2010, in the paper titled “Recent expansion and intensification of hypoxia in the Arabian Gulf and its drivers,” which was published in the journal Frontiers in Marine Science. The findings revealed an expansion and intensification of hypoxia in the central Gulf, as well as an extension of the hypoxic season.
The dynamics of hypoxia in the Gulf remain largely unknown due to a lack of observations in the area. This is the first study to model the Gulf’s biogeochemistry. It’s also the first time researchers have looked into the causes of large-scale hypoxia in the Gulf, as well as its seasonal and long-term variability.
The growth and intensification of hypoxia in the Gulf has the potential to change its biogeochemistry and marine ecosystems in a variety of ways. Hypoxia can cause fish mortality, a loss of marine biodiversity, and distribution shifts as fish migrate to avoid hypoxia. This can change the community structure of reef ecosystems and make the Gulf coral reefs more vulnerable to ongoing warming and climate change.
“Oxygen is a necessary molecule for the survival of the area’s marine organisms and fish populations. Our team discovered that the seasonal hypoxic zone in the Arabian Gulf has increased by more than 50% since the 1980s, and it now lasts several months longer each year than it did several decades ago “ACCESS senior research scientist ZouhairLachkar is the lead author.
John Burt, Associate Professor of Biology at NYUAD and co-author of the report, added, “The spread and intensification of low-oxygen waters in the central Gulf poses a growing threat to regional fisheries, with this hypoxic zone steadily expanding towards the UAE’s offshore fishing grounds. We will continue to study the evolution of this phenomenon and will collaborate with relevant government agencies to assess this risk as climate change puts additional strain on our marine systems.”