The polluted Baltic Sea has the potential to become a pilot area for the use of liquefied natural gas as an alternative shipping fuel, Norse Prime Minister Jens Stoltenberg says.

Stoltenberg, speaking last week at the Baltic Sea Summit in St. Petersburg, said Norway supports EU efforts to reduce emissions of nitrogen oxides by ship traffic in the Baltic, which is heavily polluted by nitrogen and phosphorus, causing oxygen-depleting algae, murky waters and dead seabeds.

In November, the European Union adopted the International Maritime Organization's call to implement strict limits on the sulfur content of marine fuels, especially those used in the Baltic and North seas, beginning in 2015.

Meanwhile, the IMO is also working on new lower levels for nitrogen oxide and particulate matter on the Baltic.

Supporters of the move say switching ship engines from diesel to LNG propulsion virtually eliminates emissions of sulfur and particulates and effectively reduces nitrous oxide emissions about 80 percent.

But the implementation of the goals is dependent on ships' capacity to be retrofitted for LNG propulsion and the development of a good distribution network of refueling stations at Baltic seaports. The ports will need to make large-scale investments in storage and ship refueling capacities requiring expertise in cryogenic techniques.

The European Commission has announced plans to help fund the installation of LNG refueling stations in all 139 maritime and inland ports on the Trans European Core Network by 2020 to meet new requirements to reduce air pollution.

Stoltenberg said Norway is fully on board with the LNG development idea, touting not only its promise to clean up the Baltic but also to trigger economic development.

"Norway supports technological solutions to meet the new requirements for the maritime industry in the Baltic Sea," he said. "One of the most promising alternatives is the use of LNG as fuel for ships.

"The Baltic Sea region has strong and innovative maritime industries and traditions. And the distances in the Baltic Sea are ideal for short sea shipping. Therefore, we believe that the Baltic Sea has the potential to become a pilot area for the use of LNG in Europe."

Stoltenberg's comments came Thursday during an environmental summit in St. Petersburg called in part to strengthen international cooperation on tackling the chronic environmental woes of the Baltic, which is plagued by nitrates from ship engine emissions and phosphates from sewage and agricultural waste runoff.

Environmentalists say the pollution is causing the "eutrophication" of the Baltic Sea, though which algae blooms deplete oxygen from the water, triggering fish die-offs and creating a 25,000-square-mile-wide "dead zone."

The push for the conversion to LNG fuels is being coordinated by the Baltic Ports Organization, based in Gdynia, Poland, which has initiated an "LNG in Baltic Sea Ports" project as a response to the IMO's decision to establish the new sulfur content limits in marine fuels sailing in the Baltic, the North Sea and the English Channel.

The main aim of the program, co-financed by the European Union's TEN-T Multi Annual Program, is to establish LNG bunker filling infrastructure at seven Baltic seaports -- Aarhus, Copenhagen-Malmo, Helsingborg, Helsinki, Stockholm, Tallinn and Turku.

The plans took a hit earlier this year, however, when the battle over the European Union's 2014-20 budget resulted in significant reductions for transportation infrastructure projects, which were reduced from a proposed $42 billion to $30 billion.