A recent study revealed that the effect of rising temperature on the water bodies and organisms is increasing and may lead to big extents. According to the study, the statistics show that there has been significant fall in the number of fishes in river and ocean waters since five years. Hence, fishermen are finding difficult to catch fishes for the living.
Sri Lankan fishermen have been catching fish for decades from the popular harbor on Sri Lanka’s west coast, Negombo. Fisherman complains that they are spending out more and more time in the high seas with the catch falling continuously from past five years. Most of the fishermen go far to 100 to 150 kilometers from the shore to catch fishes. But still they are unable to fill their boats.
The catch has been dwindling posting a livelihood crisis. When asked fishermen about the reasons of the catch fall, they said “Overfishing might have impacted the population but it can’t affect this much. There is something else that is hampering the growth of the population of fishes.“
Roxy Mathew Koll, a scientist at the Centre for Climate Change Research at the ‘Indian Institute of Tropical Meteorology’ in Pune said that rapid warming of the Indian Ocean has led to up to 20% fall in the phytoplankton population in the ocean. Phytoplankton is a major contributor of oxygen on the planet.
Phytoplankton is a microscopic plant that plays an important role in food chain cycle as fishes eat them as their food. Reduction in the amount of phytoplankton means lesser food available for fishes which further may cascade through the food chain, potentially turning this biologically productive region into an ecological desert.
Study authors explained that ground water is nutrient rich and surface water mixes with groundwater to receive necessary nutrients. Hotter surface temperature leads to improper mixing. Since planktons grow in surface water, there has been nutrient deficit which has led to the population decline. Researchers have warned that strict steps are required to control the catastrophic condition.