Communities and marine organizations around the world celebrate World Ocean Day on June 8 to raise awareness about the importance of the seas. Most Asian fishermen are not in a celebratory mood, however. Fish stocks are declining, climate change is creating havoc in the seas and the livelihood of poor fishing communities is under threat. Claudia Blume reports from Hong Kong.

"Too Many Fish in the Sea" was a popular American song in the 1960's.

If written today, the lyrics might be "Too Few Fish in the Sea". In all of the world's oceans, fish stocks have declined dramatically. In Asia, they have gone down by up to 30 percent in the past 25 years. Fishermen have to go farther out to sea than they used to and they return with fewer, smaller fish in their nets.

Stephen Hall, head of the WorldFish Center, a Malaysian research institute, says the main reason for the decline is over-fishing, which he calls the biggest threat to Asia's oceans.

"The main reason for over-fishing is quite simple, really," he said. "There are simply far too many boats and far too many people trying to make a living from the resource."

The effects of declining fish stocks on the region are enormous. Asia is not only the world's biggest producer of fish products, Asians also consume more seafood than anyone else in the world. It is an important part of most people's diets and accounts for about half of the protein intake in the region.

As people in Asia have become more affluent, the demand for fish has grown, and prices have gone up. Poor Asians find it harder and harder to afford fish. And individual fishermen find it increasingly difficult to make a living. Stephen Hall says many in the region live on less than a dollar a day.

"Even in Malaysia, which is a relatively wealthy country in the region, the average wage is only $34 a month per fisherman," he said. "So there is a real issue of providing alternative opportunity for fishers so that they can exit the fishery and reduce the pressure on fish stocks and ensure that those who do remain in the fishery have healthy fish stocks to harvest and supply to people who need them."

Some fishermen think that if fish stocks in their area are depleted, they can just go to the waters of another country. That does not work, however, as stocks are collapsing everywhere. Andy Cornish, director of conservation at the Hong Kong office of the WWF conservation group, predicts that the competition for seafood will lead to increasing conflict in the region.

"This is already happening with Indonesian boats sneaking down into northern Australian waters and even into the Great Barrier Reef to poach sharks," he said. "This has caused real friction between the Indonesian government and the Australian government."

Cornish says poor marine management is one reason for the decline of fish stocks in the region - for example in Hong Kong.

"There are no controls on fishing at the moment. You don't need a license to own a boat," added Cornish. "There are no catch limits, you can catch any species - any size. It's just a disaster out there."

The waters around Hong Kong are almost empty and 90 percent of the seafood consumed here is imported. People in this affluent city have a taste for rare - and expensive - delicacies. In Hong Kong's restaurants, many fish tanks are filled with live reef fish, which sell for as much as $200 a kilogram. Cornish says many have been caught on reefs in Southeast Asia, in countries that do not have sustainable fisheries management.

"Really this live reef food fish trade, which transports these fish to Hong Kong by sea and air, it really has been like a vacuum cleaner going through the reefs of the Asia Pacific," he said. "They move into a new area, within a few years they have cleaned out all these live, valuable fish, then they move on to another area."

Pollution in waters near the region's urban centers also hurts fish stocks. Another threat is climate change. Ocean waters are becoming warmer and more acidic, and sea levels are rising. All these changes threaten life in the oceans.

Over-fishing, pollution, climate change - will people in the region be able to eat fish in the future?

Stephen Hall thinks they probably will, but he says the fish will increasingly come from aquaculture - fish farms in the sea, lakes or ponds.

"The powerhouse of aquaculture in the world is Asia - Southeast Asia and China in particular. And over the coming years we will see that development grow further - there is no doubt about that in my mind," said Hall. "But the challenge is of course to do it in a way that is environmentally sustainable."

One bit of good news is that governments in the region are trying to address over-fishing. Hall says all over Asia, there are efforts to reduce the number of fishing boats. In the Indian state of Tamil Nadu, for example, mechanized boats and trawlers are banned from fishing for 45 days in coastal waters every year. Hall says the challenge is to help people who stop fishing find new livelihoods.