Global warming resulting in climate change impacts the oceans and seas. As the planet warms up, up to 93 percent of the extra heat is absorbed by the oceans. While excessive evaporation and resulting precipitation leads to extreme weather events, it also affects the fish that live in it. Simply put, when the water becomes excessively warm, fish move away. When the excessive warmth of the waters changes the Ph value of the water and makes it more acidic, the fish again will not survive.
Though no waters are immune to the ravages of climate change, the Gulf of Maine, a dent in the coastline from Cape Cod to Nova Scotia, best illustrates the problem. The gulf, where fishermen have for centuries sought lobster, cod and other species that thrived in its cold waters, is now warming faster than 99 percent of the world's oceans, scientists have said. The warming waters, in the gulf and elsewhere, have caused other valuable species, such as clams, to migrate to deeper or more northern waters.
Others, such as lobsters, have largely abandoned the once-lucrative waters off the southern New England states of Connecticut and Rhode Island. The number of adult lobsters in New England south of Cape Cod slid to about 10 million in 2013, according to a report issued last year by an interstate regulatory board. It was about 50 million in the late 1990s. The lobster catch in the region sank to about 3.3 million pounds in 2013, from a peak of about 22 million in 1997.
A long coast line, with over 3,200 fishing villages, India’s fishing industry is equally vulnerable to climate change issues. Except, unlike in the US, no impact studies have been carried out. One of the few papers on the subject is by Dr. Kripa, Principal Scientist, Central Marine Fisheries Research Institute (CMFRI), Kochi.
According to her, oil sardines, a low-priced staple sustenance and nutritional food for millions and with a total value of Rs 350 crore and an annual production of 3.8 lakh tonnes, prefer sea temperatures lower than 28°C. They are now moving away from their traditional waters, because the temperature is higher.
The Indian Mackerel, worth another Rs 350 crore and an annual production of 1.4 lakh tonnes, is generally seen in surface and sub-surface waters. Conventionally caught by surface drift nets by artisanal fishermen, in recent years, the fish is increasingly getting caught in bottom trawl nets operated by large mechanised boats at about 50 m depth, because the fish is descending into deeper waters to avoid warmer surface waters. Changes in the presence of zoo plankton, with larger presence of macro zooplankton and diminishing of micro zoo plankton because of acidification of the waters, is also affecting fish.
The lives of the fishermen and their families are also being affected because of eroding coast lines reducing landing sites for their boats, extreme weather robbing them of days at sea, and flooding of their homes because of rising sea levels and excessive rainfall. With more than 100 million people living along the country’s 7,510 km coastline, their vulnerability to climate change is still not attended to with the rigour the issue deserves, a situation that the government better change in a hurry.
