The Indian Ocean is an ecological desert in the works, warned scientists who sounded the alarm not just on overfishing but also on the pernicious effects of global warming.
Overfishing is not the sole cause for the lowered catch in the region – food sources for fish are increasingly becoming scarce because of global warming.
Warming in the Indian Ocean has been decreasing phytoplankton by up to 20 percent, revealed Roxy Mathew Koll, a scientist working at the Indian Institute of Tropical Meteorology. Along with other scientists, Koll put out related research in December.
Rising water temperatures appear to have been decreasing the number of phytoplankton – microscopic plants located at the base of the marine food chain serve as food for fish – for more than six decades now.
This scarcity of phytoplankton is feared to affect the whole food chain and likely turn the Indian Ocean into an “ecological desert,” according to Koll.
This situation will hound food security not just in the region but also international fish markets that get their supply from such countries.
Fifty-four-year-old Anslem Silva, for instance, has been fishing for 40 years from a harbor on the west coast of Sri Lanka. However, for about five years now, it has been tough for him to fill his boat.
“Where there were fish for decades, now there is very little. It is strange, but all of us have been noticing that.”
Waters in sections of the Indian Ocean have warmed over the past century by 1.2 degrees Celsius or 34.16 degrees Fahrenheit, leading to a slower integration of surface water and nutrient-dense deeper waters. This has barred nutrients from getting to plankton, which mostly find themselves in surface waters.
This vertical mixing, according to scientist Raghu Murtugudde of the University of Maryland, is a critical procedure to bring nutrients into upper zones that harbor sufficient light for photosynthesis.
According to data, phytoplankton amounts are also declining in regions that typically shelter large schools of fish, including areas near the coasts of Kenya and Somali.
There is already up to 30 percent decline in the western part of the Indian Ocean, which is among the most biologically sound regions and home to 20 percent of the tuna catch worldwide.
The researchers are not so optimistic as fish stocks will likely decline even further in the face of overfishing and warming of the oceans, bending under the pressure of increased greenhouse gases. Countries such as India, Sri Lanka, Bangladesh, and import partners United States and Europe could experience the negative blow.
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