Agence France-Presse in Hanoi – Updated on Apr 12, 2008
The food security of millions of people is at risk because overfishing, climate change and pollution are inflicting massive damage on the world’s oceans, marine scientists have warned.
The two-thirds of the planet covered by seas provided one-fifth of the world’s protein – but 75 per cent of fish stocks were now fully exploited or depleted, a Hanoi conference that ended yesterday was told.
Warming seas were bleaching corals, feeding algal blooms and changing ocean currents that affected the weather, and rising sea levels could in future threaten coastal areas from Bangladesh to New York, experts said.
“People think the ocean is a place apart,” World Ocean Observatory head Peter Neill said. “In fact, it’s the thing that connects us – through trade, transportation, natural systems, weather patterns and everything we depend on for survival.”
Marine ecosystems and food security were key concerns at the Global Conference on Oceans, Coasts, and Islands, an international meeting of hundreds of experts from governments, environmental groups and universities.
“There is a race to fish, but in wild-capture fisheries right now we can catch no more,” said Steven Murawski, fisheries chief science adviser at the US National Oceanic and Atmospheric Administration.
“We catch 100 million metric tonnes per year, and that’s been very flat globally. Our only hope is if we conserve and rebuild stocks,” he said, adding that sustainable aquaculture could help make up the shortfall.
The plunder was risking long-term sustainability with “too many fishing boats taking too many fish and not allowing the stocks to regenerate”, Conservation International’s Frazer McGilvray said.
“Once the oceans are gone, we’re gone. The oceans sustain the planet.”
The world had already seen the effects of overfishing, experts said. North Atlantic cod fisheries collapsed in the 1990s, and anchovies previously disappeared off Chile, herring off Iceland and sardines off California.
Sixty-four per cent of ocean areas fall outside national jurisdictions, making it difficult to reach international consensus or to stop illegal fishing – a growing concern as hi-tech ships scour the high seas.
“It’s the Wild West. It’s a very small number of boats, but the technology allows them to take enormous amounts of fish,” Mr Neill said.
“They take only the high commercial product and they throw the bycatch overboard. The waste is extraordinary.”
Marine life was also being harmed by climate change, Mr Murawski said. “We’ve seen that fish populations go up and down with variations in the climate,” he said. “Increasingly, we are starting to see long-term change affect the productivity, the distributions, the migrations.”
The trend was speeding up, he said. “Our forecasts are wrong. The melt-off is much faster than has been forecast in the models.”
Meanwhile, land-based pollution put heavy strain on oceans, the UN Environment Programme’s Ellik Adler said.
“Rivers of untreated sewage, factories, refineries, oil industry discharge their effluent into the marine environment, and this causes huge damage,” he said. “Marine pollution has no political borders.”
There were few easy fixes, experts said, but one initiative now being considered was setting up a global network of marine protected areas.
“You’ve got to get agreements between countries,” said consultant Sue Wells, who has worked in coastal East Africa. “Some developed countries have already closed some areas, and most coastal countries are now considering it.”
Satellites could monitor no-catch areas, she said, while inspiration could come from South Pacific fishing communities.
“They have taboo areas, coral reef sanctuaries, where fish would be saved for bad weather periods or major festivals and feast,” she said. “They know if they leave an area and don’t fish there, they’ll have much better stocks.”
It was a view that had been lost in modern times, she said, where the common view was “if I don’t go and fish it, someone else will”.