UNTIL this weekend, the battle for the sand eel fisheries off the Firth of Forth had amounted to little more than skirmishing. However, Greenpeace scored a major success in the early hours of yesterday by sending in swimming protesters and successfully stopping a UK-registered industrial fishing boat from ``hoovering'' up sand eels and other small fish in the environmentally sensitive area of the Wee Bankie.

The Fleetwood-based industrial fishing boat Omega B, faced with Greenpeace protesters in the water and an oil boom approaching its bows, decided on a tactical retreat - lifting its nets and leaving the fishing grounds.

By yesterday afternoon, the Greenpeace vessel was engaged in a more violent scrap with five Danish vessels - two boats being used to protect the three engaged in fishing - with grappling hooks and other implements being employed.

Last year, industrial fishermen took 40,000 tonnes of sand eels off the Wee Bankie - this year, Greenpeace estimates the fishermen have taken a few hundred at most, although the season still has a number of weeks to run.

With the Greenpeace boat, the MV Sirius, standing guard on the Wee Bankie, the flotilla of boats that would normally take between 40,000 and 100,000 tonnes from this area have until recently been concentrating on less sensitive fishing grounds around Dogger Bank and East of the Long Forties. However, they appear to be returning.

Speculation is growing that they may have caught all the sand eels they can at other grounds, and with fears mounting that another industrial fishing ground off Denmark is about to be closed, the industrial fishermen may have decided that they can avoid the Wee Bankie no longer.

``They are getting a bit desperate - they want to catch as many sand eels as they can. It now appears they are turning up in larger numbers,'' said a Greenpeace spokesman.

Greenpeace may yet again find itself in its familiar David and Goliath role. On the one side are up to 40 industrial fishing boats - the bulk of them Danish, a reported seven Scottish and one English - with highly sophisticated tracking equipment, computers and satellite positioning systems. Some of these boats can take up to 1200 tonnes of sand eels and by-catch in their fine nets at one go, others average around 450 tonnes.

Facing them is the MV Sirius, backed by Greenpeace's powerful public relations machinery, and the undoubted weight of public opinion.

Local fishermen whose livelihoods are dependent upon the seas continuing to yield catches of ``table'' fish like cod, haddock and whiting, are opposed to the ``hoovering'' operations of the other fishermen which threaten to wipe out the small fish at the bottom of the marine food web.

Chris Rose, Greenpeace's UK campaigns director, claims that the vast majority of small boats fishing off the East Coast now fly a yellow Greenpeace flag supporting them in their sand eel campaign.

Conservation organisations such as the RSPB and the World Wide Fund for Nature fear for the future of the seabirds such as puffins and guillemots which colonise the nearby Isle of May - without sand eels to feed upon, how will they survive? Other wildlife are also believed to be vulnerable if sand eel stocks are destroyed, including the minke whales and dolphins that swim off the East coast and feed on sand eels.

Even the British Government appears to believe that sand eel fisheries require greater protection from over-fishing.

Fisheries Minister Tony Baldry has voiced Government concerns about industrial fishing and called for controls to be introduced. Last year, the Environment Secretary John Gummer told the North Sea Conference on the Sea that industrial fishing was the crucial issue it should be focusing upon.

However, no measures have been implemented to introduce quotas in this area of fishing to date, and Greenpeace is critical of the UK Government for failing to push its demands at EU Council of Ministers meetings. The environmentalists claim the Government could use permissive EU legislation which would allow it to impose controls which go further than current agreements, provided they follow the spirit of existing measures.

If, indeed, the British Government is serious about the threat to sand eel fisheries, then is it possible that Greenpeace is actually doing its work for it by policing the most sensitive marine areas? The Government's fishery protection vessels cannot stop the Danes, or indeed, our own industrial fishery boats, for they are doing nothing illegal. They may, however, be called upon to protect these boats in a confrontation at sea.

Multi-national companies appear to be one step ahead of the Government. Concerned about the possible backlash from a general public opposed to the use of fish-oils (derived from sand eels) being used in biscuits, margarines and other products, Unilever became the first to announce a boycott of fish-oils, followed by Tesco.

Unilever also said it was also concerned about the prospect of an over-fished North Sea and the threat of extinction of many of our fish stocks. That is the crucial issue underlining this particular war - how the EU plans to deal with fish stocks which are under serious threat. The sand eel battle may yet become the opening shot of a much bigger conflict.