Report warns of rising tide of sewage

A rising tide of sewage is threatening the health of humans and wildlife living in and around many of the world's seas and oceans, according to a report by the United Nations environment programme (UNEP) released today.

In many developing countries, it is estimated that between 80% and 90% of sewage entering coastal zones is raw and untreated, the state of the marine environment report says.

This is putting at risk marine wildlife, the health of the local population and industries including fishing and tourism.

The reasons for the rise in sewage pollution are inadequate treatment infrastructure and waste handling facilities together with rising coastal populations, the report says. Almost 40% of the world's population live on the fringes of the coast, although this area covers just 7% of the land.

UNEP says it would cost an estimated $56bn (£30bn) a year more to address the waste water problem, suggesting countries could ask the biggest polluters to help fund the work.

"In the past we thought the ocean could be our sewage treatment plant," UNEP's executive director, Achim Steiner, told a news conference in The Hague.

"This sewage is not just something that goes into the sea and the sea does it for us anymore."

The report says progress has been made in reducing oil pollution and the discharge of toxic waste into the world's oceans, but the problems of litter and pollution by nutrients from the land are getting worse.

The number of coastal "dead zones" has doubled every decade since 1960, with the rise linked to an increased presence of nitrogen and phosphorus, it says.

These nutrients, which come from agricultural fertilisers running off the land, from manure, sewage and fossil fuels, have led to "over-enrichment" in some areas, which can lead to the death of wild and farmed fish, and endanger seagrass beds and coral reefs.

Nitrogen leaching into the marine environment from rivers is expected to rise globally by 14% by 2030 when compared with the mid 1990s.

The problem was once largely confined to developed countries but is now spreading to developing nations, the report says, with rivers running through Cambodia, China, Malaysia, Thailand and Vietnam now delivering nitrogen to the waters above the Sunda Shelf.

"An estimated 80% of marine pollution originates from the land, and this could rise significantly by 2050 if, as expected, coastal populations double in just over 40 years' time and action to combat pollution is not accelerated," Mr Steiner said.

He added: "We have a long way to go politically, technically and financially if we are to hand over healthy and productive seas and oceans to the next generation."

The report's findings will be presented at a meeting in Beijing between October 16-20, which will review the progress of a global plan to protect oceans from land-based activities.

Date: 2014-12-29; view: 886