For decades, the fishermen of the southern Philippines have been going to sea for a few days, catching one or two tuna fish and living off the sales for a month.

As the catch rose to match surging demand, the Philippines became the world’s fourth-largest tuna producer.

Six of the country’s eight tuna canneries are now at General Santos City, on the southern tip of the archipelago, and the government built a $56 million fish port at its natural harbor.
Purse seiner boats, which use huge nets that scoop up fish by the score, were increasingly used.

But last year, for the first time, the catch dwindled.

“It’s only now that the tuna do not bite, not like in previous years,” said Carlos Puno, captain of a boat that came back from a 32-day trip with only 48 fish, one-sixth the capacity of its hold.

Speaking as workers hauled away the fish, each weighing at least 50kg, a despondent Puno said he has been fishing in waters about 1,000km to the southeast, near the island of Papua.
Being away for so long also means that the catch is not as fresh as it could be, despite the huge slabs of ice on board, and consequently will fetch lower prices.

“I have lost money this time,” he said, referring to fuel and other costs of keeping his boat and crew at sea.

“I had some good trips last year, but this was bad. I had to come back because provisions were running out.”

As late as 10 years ago, fishermen rarely needed to venture more than two or three days out to fill their hold.

No-one in General Santos, known as the Philippines’ tuna capital, disputes that fish are harder to find, but estimates of how much the catch has dwindled, and the causes, are varied.
Domingo Teng, who owns one of the biggest fishing fleets in General Santos, estimates the 2007 catch was about five per cent less than the 400,000 tonnes in 2006, possibly due to global warming.

“The habitation of tuna is in water of 27-29 degrees Centigrade,” he explains. ‘When the weather gets warmer, they go deeper and are more difficult to catch, Puno exlained.
“That is one of the reasons we suspect has contributed to the lower catch because the water is getting warmer and warmer.”

But John Heitz, a former US Peace Corps volunteer who classifies fish at the port, said the drop in the catch could be as high as 50 per cent and he squarely blamed over-fishing.

“People are selling their boats because they cannot find fish,” he said, speaking after a day that began at dawn, poking a classifier’s stick into each tuna, drawing out a sliver of meat and inspecting it for color.

The highest grade fish, especially the big-eye tuna, have pale pink flesh, and are treated carefully.

With time of the essence, they are immediately packed and flown to Japan or the United States to be used as sashimi, but these are rare.

Most of the catch, largely yellow-fin or skipjack tuna, is used in cooking, processing into frozen products or in the canneries.