The environmental activist group Greenpeace dropped dozens of boulders into the Kattegatt, the strait between Sweden and Denmark, on Monday. The boulders, Greenpeace hopes, will protect the area from the effects of "bottom trawling," a method of fishing that rakes the seabed with nets.

Greenpeace was "threatening necessary cooperation," Sweden's agriculture and fisheries minister, Eskil Erlandsson, wrote in an editorial in Swedish daily Dagens Nyheter over the weekend. He called the actions confrontational and unilateral and said the organization's undertaking was unnecessary seeing as marine protection is already on the EU's agenda.

Greenpeace sank the boulders, weighing between half a ton and three tons (1,100 lbs to 6,600 lbs), in "Natura 2000" zones in the Fladen and Lilla Middelgrund areas, about 20 kilometers (12 miles) off Sweden's southwest coast. Natura 2000 is a network of nature areas around Europe that are protected by European Union legislation.

Putting pressure on the presidency

Sweden, which now holds the six-month EU presidency, said that while it wanted to protect marine life, the waters were not a spawning area for popular species like cod.

"The Swedish government needs to fulfill its commitment to protect the area and put a permanent ban on fishing in Fladen and Lilla Middelgrund," Greenpeace ocean campaigner Isadora Wronski said in a statement issued by the activist.

Under the EU Common Fisheries Policy (CFP) members can ban their own vessels from an area as well as those of another nation, by bilateral agreement, but they cannot issue a general fishing ban on a site.

Greenpeace urged the Swedish EU presidency to reform the CFP to enable member states to impose tougher conservation measures on protected marine areas.

Magnus Kindbom, a political adviser at Sweden's fisheries ministry, told news agency AFP that the action threatened agreements with neighboring Denmark on fishing bans in larger, more sensitive fishing areas between their coasts.

Battling trawlers

Greenpeace say the area in question is the only one off Sweden known to hold maerl beds, formed from slow-growing algae, and bubble reefs made of lime deposit, and is vulnerable to bottom trawling.

The environmentalists say that before the Kattegat's fish stocks collapsed, it held important feeding grounds for fish and a spawning ground for herring. It is an important winter feeding ground for many seabirds and is covered with kelp forests teeming with marine life.

Last year, Greenpeace sunk 320 boulders in the Sylt Outer Reef off the northern coast of Germany, another Natura 2000 site, which was being damaged by bottom trawling. The boulders have since prevented trawlers from fishing the reef. Greenpeace says the boulders have already been colonized by a wealth of marine life.

sjt/Reuters/AP
Editor: Nancy Isenson