But the main outcome of the UN talks was agreement to hold more talks. Frustrated environmental groups said it was one more example of nations doing too little too late. The global marine catch has soared almost five-fold in post-war years but peaked at 86 million tons in 1989 and fell in the following two years. Preliminary indications are that in 1992 the catch rose a little but had not returned to the 1989 peak.
The UN Food and Agriculture Organisation says most of the well- known marine fish stocks are being exploited at or far beyond limits of sustainability. Much of this increase has come from the development of deep-sea fleets working grounds thousands of miles from their home ports in Japan, Korea, the United States, Russia, Spain, Portugal and several other countries. One stock after another has collapsed from over-fishing and each time the fleets move on, sometimes having to settle for a smaller, less valuable alternative.
The global industry, with more than 1 million medium to large boats, has become unprofitable: the FAO said it had costs of dollars 124bn ( pounds 82bn) and revenues of only dollars 70bn in 1990. Much of the shortfall was being covered by state subsidies.
The New York conference, which ended yesterday, focused on the problem of straddling and highly migratory fish stocks - those species crossing the dotted lines on maps which delineate the 200-mile exclusive fishing zones which coastal nations have awarded themselves. It is now universally accepted that countries can claim and police these limits even though the convention which enshrines them, the UN Law of the Sea, has not yet come into force. But unfortunately fish don't recognise them.
And beyond the limits these fish are preyed on by the distant-water fleets. This has produced international tension, although outright hostilities so far have been confined to clashes on the high seas between fishing boats of different nationalities and the occasional gunboat.
There has been bad feeling for years between Canada and the EC nations, especially Spain and Portugal, over fishing off Newfoundland. The Canadians blame the EC fleet, fishing just outside the 200-mile zone, for the collapse in cod stocks.
Chile says it is considering a unilateral extension of its zone beyond 200 miles to protect its fisheries; Iceland has also talked about it. The New York conference aimed to promote co-operation between nations so that they need not resort to such drastic measures.
The answer is seen to be regional fishing organisations in which nations exploiting each particluar fishing ground meet regularly. They would agree on an allocation of catches between themselves which sustained stocks at an optimum level, taking scientific advice and agreeing to abide by it.
Such groupings already exist: the North Atlantic Fisheries Organisation is meant to control fishing off the Grand Banks outside Canada's 200- mile zone. But as far as Canada is concerned it has dismally failed to protect stocks from over-exploitation.
One issue still to be resolved is whether such organisations should be based on loose, non-legally binding guidelines or a legal convention. Nations which feel victimised, like Canada, want the latter, while the deep- sea fishing fleet countries want something as loose as possible.
They are deeply unhappy about the promotion of such regional organisations because they fear they will exclude new members. The nature of deep-sea fishing in post-war years has been to over-exploit one area and then move on. Regional organisations could make that more difficult.
The conference also touched on the issue of fleets operating under flags of convenience. Spanish and Portugese boats have been buying the flags of Belize, Honduras, Panama and sundry other countries to flout international fisheries agreements. Here hopes of law and order on the high seas rest on a proposed convention which would force the flag-of-convenience states to make their fishing fleets abide by fisheries rules. But that would only happen if those states chose to ratify the convention.
There will be further talks in March and August next year and, it is hoped, resolutions at the UN General Assembly later on. But the only real answer is for nations to reduce their deep-sea fleets. Professor John Beddington, of the Renewable Resources Assessment Group at Imperial College, London, said: 'Worldwide over-exploitation of major fish stocks is likely to continue until nations cut the over-capacity.'