Marine life killed off by industrial waste 'dead zones': UN report

'Dead zones' in the world’s oceans and seas, areas starved of oxygen through the overuse of agricultural fertilizers and dumping of industrial waste, could threaten the survival of many marine animals and plants species, a UN report has claimed.

The United Nations Environment Programme's (UNEP) first Global Environment Outlook (GEO) Year Book 2003 highlighted 150 areas where artificially low oxygen levels can be closely linked with the use of synthetic fertilizers in agriculture – nitrogen is a main ingredient of these fertilizers.

Some of these 'dead zones' are relatively small, less than one square kilometre in size, whereas others are far larger at up to 70,000 square kilometres. 'Dead zones' have been found in Chesapeake Bay in the US, the Baltic Sea, the Kattegat Strait between Sweden and Denmark, the Scandinavian fjords, the Black Sea and the northern Adriatic Sea.

Inefficient and often excessive use of fertilizers, the discharge of untreated sewage and the ever-increasing emissions from vehicles and factories could produce irreversible effects on the world's underwater environment, according to UNEP Executive Director Klaus Toepfer.

The fertilizers trigger blooms of tiny marine organisms called phytoplankton, whose rapid growth and decomposition use up oxygen in seawater, the report said.

“Sometimes, the effects are mild. But sometimes they can be dramatic, with fish fleeing the ‘suffocating waters’ and creatures, like clams, lobsters, oysters, snails and other slow-moving, bottom-living creatures, dying en masse,” Mr Toepfer said.

More oxygen-starved areas may emerge in coastal waters off parts of Asia, Latin America and Africa as industrialisation and more intensive agriculture increase the discharge of nutrients, UNEP said.

As already flagged in 2000, the best-known area of depleted oxygen is in the Gulf of Mexico, caused by nutrients or fertilizers from the Mississippi River. Other zones have appeared off South America, China, Japan, southeast Australia and New Zealand.

The Year Book will be launched at this week’s Global Ministerial Environment Forum (GMEF) meeting in Jeju, Republic of Korea.

(gmcg)