How Monsoon Shifts Due to Climate Change Threaten Bay of Bengal Fisheries?

Extreme changes in India’s summer monsoon could significantly affect the Bay of Bengal’s ability to support the region’s food supply, according to a study published in the journal Nature Geoscience.

Although the Bay of Bengal covers less than 1% of the global ocean, it accounts for about 8% of the world’s fishery production, providing food and income to coastal communities that heavily rely on marine resources.

"Millions of people living along the Bay of Bengal rely on the sea for protein, particularly from fisheries," Yair Rosenthal, a Distinguished Professor at Rutgers University and co-author of the study, told phys.org.

"The productivity of these waters—the ability of the ocean to support plankton growth—is the foundation of the marine food web. If ocean productivity declines, it will powerfully affect the ecosystem, ultimately reducing fish stocks and threatening food security for coastal communities," added Rosenthal.

Rising Sea Temperatures Impact Fisheries

To understand how the Indian summer monsoon and ocean productivity have changed over time, scientists studied the fossil shells of foraminifera—tiny single-celled plankton that live in the ocean and build calcium carbonate shells. These shells preserve environmental data, acting as natural recorders of past ocean and climate conditions.

"By analysing their chemistry and tracking the abundance of certain types that thrive in productive waters, we reconstructed long-term changes in rainfall, ocean temperatures and marine life in the Bay of Bengal," geoscientist Kaustubh Thirumalai, an assistant professor at the University of Arizona and lead author of the study told phys.org.

“Together, these chemical signals helped us understand how the monsoon and ocean conditions responded to global climate changes over the past 22,000 years," added Thirumalai.

A study published in PubMed revealed that an increase in sea surface temperature by 4  degrees Celsius could result in a 5% decrease in fisheries productivity.

This would lead to a projected loss of $1.7 billion in GDP per capita by 2050. The loss of low-cost fisheries would negatively impact the poorer coastal population since they strongly depend upon these fisheries as a source of protein.

As reported by The Guardian, with 200 million people living along the Bay’s coasts, the compounded effects of flawed policy, economic over-exploitation, unsustainable forms of waste management and climate change can have serious implications for the region.