Climate change and its impacts on Bay of Bengal

Climate change and its impacts on Bay of Bengal: Recently, a multinational study revealed that both unusually strong and weak Indian Summer Monsoons over the past 22,000 years have significantly reduced marine productivity in the Bay of Bengal.

• Why Bay of Bengal matters: A crucial region for global fisheries and local food security.

o Though it covers less than 1% of the world’s ocean area, it contributes nearly 8% to global fishery production.

o Millions living along its coasts depend on its nutrient-rich waters for protein and livelihoods.

o The productivity of these waters, driven by plankton growth, forms the foundation of the marine food web.

• Study Methodology: Researchers analyzed fossilized shells of foraminifera, microscopic marine organisms that store environmental data.

o Fossils were extracted from seafloor sediments aboard the JOIDES Resolution ship, part of the International Ocean Discovery Program (IODP).

o By examining chemical and biological indicators, past monsoon patterns, ocean temperatures, and productivity were reconstructed.

• Major Findings: Strong monsoons block nutrient mixing, starving plankton, while weak monsoons limit nutrient upwelling, both reducing plankton-based food supply by up to 50%.

o Historical periods like Heinrich Stadial 1 and Early Holocene saw sharp declines in productivity due to these extremes.