The Baltic Sea Action Summit opened here on Wednesday with leaders expected to make commitments to saving one of the world's most polluted seas.

"It is clear that we need cooperation of all the countries in the region to work together to solve the environmental problems of the Baltic Sea," Finnish President Tarja Halonen said in her opening speech.

"The Baltic Sea is a route for travel and trade, but decades of exploitation and sheer irresponsibility have taken their toll on its vulnerable eco-system. It is clear that something has to be done quickly," she said.

Seven foreign heads of state or government are joining Halonen in the meeting, including Russian Prime Minister Vladimir Putin, who will arrive at noon, and leaders from Sweden, Latvia, Lithuania, Estonia, Norway and Denmark.

Some 350 people from business circles and non-governmental organizations are also taking part in the summit, which aims to bring together parties from all sectors in a bid for concerted action to save the sea.

The need for action has been recognized by all of the Baltic countries. In November 2007, the countries bordering the sea adopted in Cracow, Poland, the Baltic Sea Action Plan, which identifies the actions needed to restore the status of the Baltic Sea. The European Union has recently adopted the Strategy for the Baltic Sea Region.

"We want to give our support to these decisions and actions," the Finnish president said.

The Baltic is one of the most polluted seas in the world, with an average depth of just 59 meters. Its catchment area is home to some 90 million people from 14 industrialized countries.

The sea has been choking on emissions for several decades, with large parts of the sea bottom showing no signs of life. The list of potential threats to the Baltic Sea is uncomfortably long, including eutrophication, high toxin levels, and heavy sea traffic and related risks.

A particular threat is the growing volume of oil transports, the annual volume of which is expected to grow from the present 150 million tons to 250 million tons by 2015.