Context: A recent study has found that both strong and weak monsoons can influence (disrupt) marine productivity in the Bay of Bengal. This can pose serious ecological and livelihood challenges.
Relevance of the Topic: Prelims: Impacts of Climate Change.
Major Highlights of the Study
The researchers reconstructed the past 22,000 years of monsoon history by comparing ancient patterns (chemical signatures and fossil records) with modern ocean data and climate model projections.
- Extreme monsoon conditions (abnormally strong or weak monsoons) cause major disruptions in ocean mixing. They interfere with the vertical movement of nutrient-rich waters from the deep ocean to the surface.
- Consequences: This can lead to a 50% reduction in food for marine life (like planktons) in the surface waters. This will directly result in decline in the growth of plankton, and thus, impact the entire aquatic food chain.
Significance and Impacts on the Bay of Bengal:
- Significance: Despite covering less than 1% of the world’s ocean area, the Bay of Bengal accounts for 8% of global fishery production. Its nutrient-rich coastal waters are vital to the densely populated communities along its shores, many of whom rely heavily on fisheries for food and income.
- Impacts: If ocean productivity declines, it will powerfully affect the ecosystem, ultimately reducing fish stocks. This in turn will threaten food security for coastal communities and risk their livelihoods.
The study is significant given that several climate models warn of significant disruption to the monsoon, under the impact of human-caused global warming.