UNEP report links Climate Change with impacts on Natural Cleaning Mechanisms of the World’s Oceans

By: Anup Khastagir on February 23rd, 2008

MONACO, Feb 22 (BSS)-Climate Change is slowing down the ocean thermohaline circulation and continental shelf “flushing and cleaning” mechanisms increasing the risk of more pollution and making many productive fishing grounds as dead zones.

Ocean thermohaline circulation and flushing and cleaning mechanisms are crucial for coastal water quality and nutrient cycling, but the mechanism declined in more than 75 percent of the world fishing grounds.

It was told in a scientific report released by United Nations Environment Programme (UNEP) here today to mark the UNEP’s Governing Council/Global Ministerial Environment Forum meeting here.

Productive fishing grounds depend extensively upon sea currents for marinating life cycle patterns for sustainable production of fish and other marine life. But the water exchange mechanism, which periodically ‘flush and clean’ continental shelf areas, has been reduced largely in the oceans.

Christian Nellemann, leader of the study team of the report, at a press conference in the sideline of the UNEP GC/GEMF meeting released the report.

He said, in the backdrop of changing scenario, the intensity and frequency of coastal flushing mechanism would fall potentially particularly at lower to medium latitude over the next 100 years, which in turn would impact both nutrient and larval transport in the ocean and increase the risk of pollution and dead zones.

At least three quarters of the global key fishing grounds might become seriously be impacted by the changes in the ocean natural pumping system, he said.

UNEP scientists in collaboration with universities and institutes in Europe and the United States have conducted the study titled- In the Dead Water, for the first time on the state of world’s fishery resources.

UNEP Executive Director Achim Steiner, president of Global Environment Ministers Forum (GEMF) and environment minister of Costa Rica Roberto Dobles and senior officials of UNEP attended the press conference.

The UNEP report, first of its kind on the state of world’s fishery resources, said the number of dead zones (oxygen deficient areas) has been increased from 149 in 2003 to over 200 in 2006 in the global oceanic regions. The number might multiply in a few years due to increased release of urban and agricultural pollutants in the ocean.

Besides, assimilation of carbon dioxide in the water as well as atmosphere would make the seas more acidic and this would likely result in reduction in the area of cold water coral reefs and other shell-forming marine life including planktonic organisms.

Pointing out the rapid increase in coastal development, the report said increased loads of sediments and substances from deforestation, sewage and river run-off would greatly diminish the resilience of coral reef.

The effects of pollution were exacerbated by destruction of mangroves and other habitats due to rapid construction taking place on coast lines, the UNEP report said, adding, ‘as much as 91 percent of all temperate and tropical coasts would heavily be impacted by development by 2050.

The impact would be further compounded by sea level rise and increased frequency and intensity of storms that easily break down weakened and dead corals and would severely damage beaches and coastal lines, the report warned.

The report said over harvesting and advanced technology has increased the fishing capacity about 2.5 times higher every year. But the productive beds of fishery resources partly and extensively damaged in some areas.