LLDA: Spread of knife fish an opportunity, not crisis

In an attempt to assuage public worries over the presence of knife fish in Laguna de Bay, the head of the Laguna Lake Development Authority (LLDA) says it will be exploring the good potentials of the ornamental and exotic fish.

Neric Acosta, President Benigno Aquino III’s adviser for environmental protection and LLDA chief, would not even describe the proliferation of the fish as alarming and invasive.

Recent field surveys done by the LLDA in the east side of the lake showed that fishermen were getting 20-30 percent of knife fish in a ton of their catch. In Santa Cruz River in Laguna, a hook-and-line fisherman was able to catch a knife fish, which would indicate that it can swim upstream.

“We can turn a potential crisis into an opportunity,” Acosta said, referring to the complaints of ordinary fishermen that  their earnings had declined due to the presence of the knife fish.

Most knife fish species come from Southeast Asia, specifically in Thailand, Borneo in Malaysia, India and Sumatra in Indonesia.

According to the LLDA, the silvery gray fish found in the Laguna Lake could be from the Chitala ornata family.

Its aesthetic similarity with the popular “arowana” makes the knife fish a popular ornamental fish. The Bureau of Fisheries and Aquatic Resources (BFAR), however, has claimed that the knife fish is carnivorous and will compete with natural fish in the lake.

The knife fish may have found their way into the lake in at least two ways, the LLDA said in a statement. It mentioned “escaping from an ornamental fish farm or aquarium and deliberate release into waterways of hobbyists who wanted to get rid of them.”

Acosta said the widespread flood spawned by Tropical Storm “Ondoy” in 2009 could have led to the proliferation of the fish in Laguna Lake. It was only this year that fishermen felt its presence, but Acosta said it had not yet reached an alarming volume.

“The problem is the familiarity issue. On a wider scale, the people are not familiar with this fish. They don’t know that knife fish is safe to eat and has a lot of uses. That’s why it is cheaper in the market,” Acosta said.

Knife fish can be sold for only P30 a kilo in the market while bangus or tilapia costs about P100, he said.

Acosta could only find what good benefits to be derived from knife fish. Compared to the more popular “janitor fish,” he said, the knife fish has actually more commercial value.

While ornamental in nature, the knife fish is actually edible, he said. It can be braised or broiled and can be sautéed in curry or soy sauce, he added.

In Thailand, he said, a steamed knife fish with curry is a famous recipe while in Laos, a popular paste is made from finely chopped knife fish. He also cited the BFAR’s suggestion that the knife fish can be processed into the popular street food “fish balls,” which can be exported to other countries.

Like the janitor fish, the knife fish is being considered a component for liquid soil fertilizer, Acosta said.

The fishermen’s group Pamalakaya, however, said the LLDA suggestions were lame, pointing out that losses from the income of fisherfolks were not just 20 to 30 percent as the the government agency claimed.

“The knife fish even prey on bangus, tilapia, big head carps and other fishery species in the lake for food, resulting in 90 percent income loss and fishery production to small, medium and corporate fishpen operators in Laguna Lake,” said Fernando Hicap, Pamalakaya chair.

Instead of just fishing them out of the water, the left-leaning group urged the LLDA to allow the entry of saltwater from the Manila Bay into the lake through the Napindan Hydraulic Control Structure to eliminate the presence of knife fish and other species in the 90,000-hectare lake.

The saltwater can do the cleansing, it said, but the government had been preventing its entry so it could change and tap bay water for the use of water concessionaires.

At least 61 municipalities and cities in six provinces, including Metro Manila, are part of the Laguna de Bay region.