Categories: Sports

Climate change affecting fish availability in Bay off Vizag

Visakhapatnam: Climate change with seas getting warmer is affecting the availability of fish, an aspect common fisherfolk of Visakhapatnam have realised over the past few years. Says Yellaji, a fisherman from Peddajalaripet, “The distance required for me to get a good catch of fish has increased from 10 nautical miles to 60–70 nautical miles. Rising ocean temperatures near the coasts are causing fish to migrate deeper offshore, intensifying the challenges for fisherfolk.”

Chief scientist V.V.S.S. Sharma of the National Institute of Oceanography (NIO), a prominent expert in the field, has attributed the fish availability to climate change and abnormal temperatures. “Significant increase in the intensity and duration of summer, coupled with untimely and insufficient rainfall, have led to environmental conditions, wherein conditions for marine life to thrive in the Indian Ocean are deteriorating,” Sharma observed.

He pointed out that waters of the Indian Ocean are warming more than all other seas. This is due to Indian Ocean not having direct contact with the North or the South poles, resulting in absence of cold water flowing from the poles. Additionally, Indian Ocean is surrounded by landmasses. As a result, it is exposed to higher levels of atmospheric pollution. About 30 per cent of the world’s population resides around the Indian Ocean.

The NIO chief scientist said, “Topography, population and pollution are contributing to endangering of living organisms within the Indian Ocean, particularly within the depths of 700 metres to 1,000 metres.”

According to the Central Institute of Fisheries Technology (CIFT), sea surface temperature typically ranges between 26–28 degrees Celsius, while the seabed temperature varies from 14–18 degrees Celsius. Oceanic movements, such as up-welling and down-welling, are common occurrences.

Fish exhibit increased activity in colder temperatures, as cold water promotes growth of phytoplankton, which is a vital food source for fish. Fish thus inhabit colder areas. Further, when oceanic conditions are colder, fish tend to ascend towards the surface, making them more susceptible to falling in fisherfolks’ nets.

Conversely, fish tend to remain in the deeper, cooler regions of the sea, when warmer surface temperatures prevail. The chances of a good catch thus fall, something that Yellaji of Peddajalaripet has realised.

Climate change is thus affecting the livelihood of common fishermen, who cannot proceed farther into the seas.

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