The countries bordering the Arabian Gulf are the world’s largest users of desalination technologies to meet their freshwater needs. But will the increased use of desalination technologies in combination with climate change affect Gulf-wide salinity in the coming decades?

As the Gulf region is home to the biggest desalination plant complexes in the world and 45% of global freshwater desalination production, it is important to consider the long-term effects of this industry.

In the paper titled Long-term, basin-scale salinity impacts from desalination in the Arabian/Persian Gulf, published in Scientific Reports, researchers from NYU Abu Dhabi’s Arabian Center for Climate and Environmental Sciences (ACCESS) and Water Research Center stated that growing desalination would result in increasing amounts of hypersaline (high-salt) brine being released into the Gulf. 

A key finding was that any increase in salinity would drive a corresponding increase in the flux through the Hormuz strait, resulting in a more rapid renewal of the Gulf waters. As a consequence, even in extreme-case scenarios, basin-scale salinity increases are not projected to exceed a level that will have a significant impact on the Gulf’s marine life, such as flora and fauna, as these levels of salinity increase are well within the natural range of variability that organisms in the Gulf are already exposed to. 

The occurrence of hypoxia, low or depleted oxygen levels in a body of water, appear to pose a larger threat to marine life in the deepest part of the Gulf and the shallow reefs, but these conditions are unrelated to desalination brine discharge.

POSSIBLE FUTURE EFFECTS OF CLIMATE CHANGE

While other modeling studies have attempted to estimate the increase of salinity at basin-wide scales due to desalination, this is the first model to consider the possible future effects of climate change. 

“Our team’s research provides valuable, new insights into the impacts of this critical industry for the Gulf region,” said Francesco Paparella, Principal Investigator at the NYUAD Arabian Center for Climate and Environmental Sciences. “We have developed a reliable model that has allowed us to predict changes in salinity over the next few decades, advancing the ability of our team and the greater scientific community to determine ways to protect our ecosystems better.”

The data gathered on the anticipated salinity levels in the Gulf coastal waters can guide the future study of the other effects of widespread desalination, such as the economic impacts of changes to the fishing industry

“The Gulf is a naturally extreme marine system, and we have been utilizing a growing fraction of its waters for desalination purposes. This raises concerns about whether this may have ecological consequences, particularly in this era of a rapidly changing climate,” said John Burt, Co-Principal Investigator at the NYUAD Water Research Center and the Arabian Center for Climate and Environmental Sciences.

“The results of this work show that salinity increases under even the worst-case climate projections and increased desalination in coming decades are likely to have only negligible impacts on salinity at the Gulf-wide scale, and well within the normal seasonal variation in salinity that organisms here are already exposed to. While we need further research on processes occurring at more localized scales around desalination plants, these results suggest that there is little cause for concern of salinity increases at the Gulf-wide scale,” added Burt.