60,000 Km2 Dead Zone In Bay Of Bengal The Cherry On Top Of Collapsing Fish Stocks
EDIT
The Mergui archipelago on the Thai-Myanmar border is one of the more secluded parts of the Bay. In the late 19th century an English fisheries officer described this area as being “literally alive with fish”1. Today the archipelago’s sparsely populated islands remain pristinely beautiful while some of its underwater landscapes present scenes of utter devastation. Fish stocks have been decimated by methods that include cyanide poisoning. The region was once famous for its coral reefs; these have been ravaged by dynamite-fishing and climate-change induced bleaching.
Yet the exploitation of these waters continues without check. At night specially equipped, long-armed boats materialise around the islands and shine high-powered green lights into the water to attract plankton and the squid that follow in their wake. After nightfall, a glow that is bright enough to be visible from outer space12 hangs above the archipelago, like a miasmic fog. These squid boats, some of which are probably crewed by men who have been trafficked like slaves13, help to make Thailand the world’s largest exporter of squid – at least for the time being.
At the same time the bay’s ecosystems are also being disrupted by other environmental pressures. Several large rivers empty into the bay, carrying vast tides of untreated sewage, plastic, industrial waste and effluent from the agriculture and aquaculture industries14. The impact of this pollution could be catastrophic. The high load of organic pollutants, coupled with the diminution of the fish that keep them in control, could lead to massive plankton blooms, further reducing the water’s oxygen content.
Last month a multinational team of scientists reported an alarming finding – a very large “dead zone” has appeared in the bay. Apart from sulphur-oxidising bacteria and marine worms, few creatures can live in these oxygen-depleted waters15. This zone already spans some 60,000 sq km and appears to be growing16. The dead zone of the Bay of Bengal is now at a point where a further reduction in its oxygen content could have the effect of stripping the water of nitrogen, a key nutrient. This transition could be triggered either by accretions of pollution or by changes in the monsoons, a predicted effect of global warming.
EDIT
https://www.theguardian.com/environment/2017/jan/31/bay-bengal-depleted-fish-stocks-pollution-climate-change-migration
