Eliminating ‘pest’ Knife Fish from Laguna Lake

by Mirzi Angela Encelan

Knives are useful in the kitchen. However, there are knife-like fishes in our lakes which are more harmful than helpful.

Knife fish, specifically the carnivorous Clown Knife Fish (Chitala ornata), is currently abundant in the country’s biggest lake, Laguna de Bay.

It has razor sharp teeth, bony tongue, and equally sharp gill can cut through fish meat as if it was truly a knife. There are two types of knife fishes; one eats planktons and the other eats regular sized fishes.

The Clown Knife Fish grows about 100 cm (1m) and 5 kg (11lb) in the wild but if it is farm-produced it will grow no longer than 20-50 cm. A mature clown knife fish takes about 7 to 10 dark spots in the underside of their body. Although it may sound like a great fish, it is harming its new home. Clown knife fishes are not originally from the Philippines. They are ornamental fishes from Vietnam, Thailand, Cambodia, and Laos.

‘Introduced to the lake in 2009…’

Emiliana Casbadillo, the officer-in-charge in the provincial fisheries office of Bureau of Fisheries and Aquatic Resources IV-A (BFAR IV-A) said that knife fishes only started to spread in the Laguna lake at a fast rate when it was accidentally introduced to the lake during a flood back in September 26, 2009 when typhoon Ondoy delivered a record 448.5mm of rain that fell in Metro Manila.

In Vietnam, said Casbadillo, clown knife fishes are delicacies but here in the Philippines they are known as pests that preys on our local fisher folks’ source of income which are our local fishes like milkfish (bangus), tilapia, etc. and also some of our indigenous fishes such as catfish (kanduli) and silver perch (ayungin).

BFAR IV-A feared that the knife fish will outnumber our local fishes in the lake and as an answer to this BFAR together with other local government units (LGUs) worked towards the knife fish collection program.

However, the knife fish collection program may come to a stop due to the issuance of the fishing ban.

lio Managat, the president of FARMC-Sto. Domingo, receives all the knife fish that his co-fishermen gets. The knife fishes from the Mandaragat are collected by the BFAR-Los Baños and after each collection the fishermen gets P10.00 per knife fish that they surrendered.

‘Fishing ban’

On September 21, 2016, there was a consultation for a rapid rehabilitation plan. This was followed by the non-issuance of fishing permits from the Laguna Lake Development Authority (LLDA) specifically for the fish pen and fish pen operators in Laguna de Bay. Then a final warning was given to the operators last December 2016, and finally, the actual dismantling of fishcages and fishpens this happened January.

Casbadillo said that the Department of Environment and Natural Resources (DENR) secretary Gina Lopez disclosed that the whole 90,000 hectares of Laguna Lake will be under the strict rehabilitation but the timeline is yet to be discussed by the authorities.

According to the Board Resolution no. 518, series of 2017, a one (1) year moratorium on the operation of all fishpens, fishcages, and other aquaculture structures within the Laguna de Bay will be implemented. This means that no new stocking of fingerlings on any existing fish pens should be allowed and this is already in effect.

But fishermen will be able to harvest their fishpens until March 2017. After their harvest the fishermen are instructed to tear down their own fishing equipment.

With the fishing ban, fishermen from Laguna de Bay will lose their source of income, but according to the Board Resolution released and also to Ma’am Casbadillo, these fishermen will be given alternative livelihoods.

However, Ma’am Casbadillo said that plans should not come from them without the approval of the end-users, which are the fishermen, they should give the authorities suggestions or resolutions for them to construct an appropriate alternative livelihood program.

Right now, the country has a total of 1.5M registered fishermen in BFAR’s program FishR (Fish Registration). But, even if the registration process, according to Casbadillo, is fast and easy there are is still a big number of fishermen who practice illegal fishing. And this is one of the purposes of the fishing ban—to eliminate illegal fishers and stop them from operating.

If the first purpose is administered it will contribute to the last two goals; second, to distribute the resources equally, and third (2) to let the lake breathe. Fishermen who abuses the lake by taking undeveloped fish, uses illegal fishing tactics, etc., harm not only the lake but also their fellow fishermen.

For example, they take more than the maximum size allowed for a fishpen which decreases the chances of another fisher folk of catching anything. And the last purpose, said Casbadillo, is to recreate Sampaloc Lake’s ecotourism project in San Pablo City, Laguna.

‘Programs to eliminate knife fish’

Knife fishes weren’t originally from our country’s waters, and there are theories as to why it is now in our lake. According to Casbadillo and to Julio T. Managat, a fisherman from Sto. Domingo, Bay, Laguna, there are two theories; during the typhoon Ondoy back in 2009 the flood washed the fish from a hobbyist’s aquaculture structure into Laguna Lake; and that there are irresponsible owners that after playing with the ornamental fish (at least here in the Philippines, knife fish is an ornamental fish) and threw it in the lake, little did that owner know that the fish adapted to the environment and propagated.

In a survey conducted by the BFAR IV-A in the areas where the fishermen lived in which they asked fishermen to rank the fishes they caught in a day knife fish is in no. 1 spot, followed by bangus and tilapia. It became alarming since the clown knife fish is a carnivore it can wipe all the other fishes in the lake, such as milkfish (bangus), tilapia, catfish (kanduli), silver perch (ayungin), shrimps, sea shells etc.

It is evident because during the Forum on the Containment of Knifefish Infestation in Laguna de Bay on June 14, 2013 in Taguig City, there is a data on the analysis of the clown knife fish gut content which showed remnants of heads/tails of small fishes (32.29%); scales and eggs of other fishes (29.41%); shrimps (17.65%); and shells (17.65 %).

With this problem, BFAR together with LLDA, DENR, Department of Science and Technology (DOST), University of the Philippines—Los Baños (UPLB), Technical Education and Skills Development Authority (TESDA), Department of Public Works and Highways (DPWH), and Department of Social Welfare and Development (DSWD) created a technical working group to find solutions to the problem.

BFAR released 10M pesos in their first attempt to eliminate knife fishes in Laguna de Bay. A total of Php 100,000 was given to the LGUs such near the Laguna de Bay to buy the collected knife fish for Php10 per kilo from their local fisher folks. DSWD also gave some cash.

‘Electro Fishing Gadget’

However, there is a problem in collecting: knife fishes destroy ordinary nets using their tongues and the shape of their bodies. That’s why TESDA helped create a special device for catching knife fishes called Electro Fishing Gadget. This gadget has a Fisheries Administrative Order (FAO) that it will be solely used for catching knife fish.

Ordinary nets can be ruined by knife fishes using their teeth, tongue, and body shape

After the successful collection of knife fishes another problem was raised: what will they do to the boats and boats of knife fishes?

When BFAR IV-A analyzed the knife fish, Casbadillo said, “Maganda pa naman ‘yung flesh niya, wala pang heavy metals although nandito na sila [naninirahan],” (Despite these knife fishes living in Laguna de Bay, its flesh has no heavy metals and is still good). Their solution was value-adding, they created plans and machines for food-processing.

Knife fishes can be turned into: hotdogs, nuggets, burger patties, noodles, sausages, siomai, kikiam, embutido, and fish balls. BFAR IV-A handled the livelihood project in Marikina where there was a workshop on how to process knife fish. They discovered that the fishbones of the knife fish are high in protein by the crude protein measurement that is an essential ingredient for feeds.

Casbadillo said that the ranking of knife fish in the numbers of fishes in the Laguna Lake became lower. There are times it is in number 2, and most of the time it is in number 4. With this development in diminishing the number of knife fishes in Laguna Lake, how will the authorities keep this up without the local fisher folks since they are not allowed to fish?

According to Managat, the president of FARMC of Brgy. Sto. Domingo, Bay, Laguna, “Tatanggalin jan yun mga fishcage tapos tulad nung sa ibang bansa, papatayin yung lahat ng mga isda sa lawa, ‘yun yung alam ko” (From what I know, they will rehabilitate the lake by removing the fishcages and kill every single fish in the lake, just like in other countries).

As of now, the BFAR IV-A are still brainstorming about the continuation of the knife fish collection project in accordance with the fishing ban.

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