That's according to a major international study, recently publicised nationally following a report published in the journal Science. Records for coastal zones in Europe, North America and Australia have shown sharp declines in yields, say the researchers.
Project leader Boris Worm, of Canada's Dalhousie University, told BBC News: 'What we're highlighting is that there is a finite number of stocks; we have gone through one third, and we are going to get through the rest.'
Europe's North Sea was highlighted as being at particular risk of following Canada's Grand Banks into apparently terminal decline, unless measures are taken to impose fishing limitations or total bans in certain sea areas.
Boris Worm lamented a reluctance among European governments to act. 'You have scientific consensus and nothing moves,' he said. 'It's a sad example - and what happened in Canada should be such a warning, because now it's collapsed it's not coming back.'
Biodiversity is a big issue, with bottom-trawling, for instance, capable of doing great harm. 'Marine life is a bit like a house of cards,' said Worm. 'All parts of it are integral to the structure; if you remove parts, particularly at the bottom, it's detrimental to everything on top and threatens the whole structure.'
Factors such as pollution and the effects of global warming come into play. Even so, the research implies, targeting fisheries yields would do much to alleviate pressure on marine species. |
