PHL waters being taken over by invasive fish听
By Bront毛 H. Lacsamana 听
Over the last decade, fisherfolk operating in freshwater lakes and rivers have noticed a shift in the contents of their catch, according to environmental group Best Alternatives.听听
Native fish like听biya听(gobies),听ayungin听(silver perch),听martiniko听(climbing perch), and听ulang听(freshwater shrimp)听have grown scarcer while species alien to the Philippines such as knifefish from Indochina, blackchin tilapia from Africa, janitor fish from the Americas, and cream dory from other parts of Asia, have multiplied in inland waters.听听
鈥淥ur native fish are dying a slow, silent death because they鈥檙e quietly being eaten by invasive fish every minute, every second. It鈥檚 happening now,鈥 said Gregory Paul 鈥淕regg鈥 H. Yan, founder of the Best Alternatives campaign, in an interview with听大象传媒.听听
He shared that fisherfolk along Marikina River observed an abundance of Nile tilapia, janitor fish, knifefish, and blackchin tilapia (dubbed Gloria or Arroyo due to the black moles on their faces) after heavy rains this July.听听
(When it rains, ponds, lakes, and other bodies of water in areas like Rizal and Laguna overflow, allowing fish to escape into the Marikina and Pasig rivers. Fisherfolk, knowing this, go there while water levels are elevated.)听听
Only the听kanduli, a type of brackish water catfish,听remained plentiful among the numerous native species that used to roam the river.听听
鈥淭hey said there’s regularly a lot of听kanduli, but that鈥檚 almost the only native species left,鈥 he said. 鈥淪till, they鈥檙e just happy to have a catch because, when you get a 20-kilogram cream dory,听siyempre听tingin听nila听biyaya听(of course they see it as a blessing).鈥澨听
ALIENS EVERYWHERE
In 2011, two years after Typhoon Ondoy, fisherfolk in the Laguna Lake area reported an alarming presence of the ornamental knifefish in the lake, which was traced back to their possible escape from aquaculture ponds during the typhoon. BFAR, after conducting surveys, declared it an infestation of invasive alien species (IAS) in the lake.听听
鈥淏y 2012, nearly half of fishermen in the area were affected by this, with knifefish comprising a large chunk of their catch,鈥 said Romualdo M. Pol, officer-in-charge at BFAR鈥檚 National Inland Fisheries Technology Center (NIFTC), told听大象传媒.听
He added that NIFTC analyzed the gut contents of the knifefish, finding that around 32% were small fish heads and tails and about 29% were scales and eyes of听kanduli, meaning the lake鈥檚 native species were indeed being eaten by the IAS. The sad part was, knifefish weren鈥檛 appealing to fish markets and were often released back into waters, where they would continue their reign of terror.听听
The worst-case scenario, according to Mr. Yan of Best Alternatives, is similar to what happened to Lake Victoria in Africa, where the Nile perch was introduced to the lake to boost productivity, eventually听. There鈥檚 also a local example, unfortunately 鈥 Lake Lanao in December 2020 saw 15 of the 17 freshwater fish听endemic听to the lake听.听听
To combat extinction of species in Laguna Lake, BFAR-NIFTC enacted multiple initiatives, from the development of a prototype electro-fishing gadget to stop eggs from hatching to a buy-back scheme that mobilizes fisherfolk to catch knifefish for at least P20 per kilo until they are consumed to depletion, said Mr. Pol.听听听
He added that the catch is usually processed into fishmeal feed for farm animals as well as value added products like hotdog,听fishball,听kikiam, and听siomai,听which they also teach affected fisherfolk to do through livelihood programs. During the pandemic, these have unfortunately been hindered by restrictions.听听听
Fisherfolk also caught much less, unable to go out in lockdowns, resulting in a drop to around 900,000 knifefish caught in 2020 from 1.9M in 2019, reported Mr. Pol.听听
Meanwhile, the听听(BASIL) program, launched by BFAR in 2017, has been working on propagating native freshwater species like听biya,听ayungin,听martiniko,听ulang,听and听kanduli听to replace the invasive ones being retrieved.听听
In addition to collaborating with the Department of Science and Technology (DOST) and University of the Philippines Los Banos (UPLB) for studies on the population dynamics and control assessment of knifefish in Laguna Lake, BFAR-NIFTC said that they鈥檝e been sharing their native species repopulation methods and technologies to a network of regional government hatcheries, to replicate their pilot efforts nationwide.听听
SUSTAINABLE BUT EXPENSIVE
Best Alternatives, meanwhile, has put forward transitioning into the farming of local fish species 鈥 a long-term objective they鈥檙e looking into with European research firm VB Consultancy.听听听
鈥淲e鈥檙e trying to convince government and businesses that instead of farming invasive tilapia and cream dory, we should invest in the farming of high-value local fish species like听ludong听(which is expensive at P5,000 per kilo). It鈥檚 a type of mullet, a very common fish, just like how the听maliputo听and听tawilis听in Taal Lake are really nothing more than freshwater sardines, which can be marketed well,鈥 said Mr. Yan.听听
He cited their advantages: being better adapted to local conditions, resilient to diseases in this part of the world, and profitable for fish farmers who can earn up to P5,000 per kilo of听ludong听compared to at least P15 per kilo for knifefish and about P80 for tilapia.听听
Mr. Pol of BFAR-NIFTC echoed this sentiment, adding that culturing these fishes in aquaculture facilities could eventually lead to more affordable prices once the population grows, since large听ayungin听currently reach up to P600 a kilo.听听听
鈥淚f we embrace the technologies now, there鈥檚 potential for profit, locally and in export markets. Most people have this idea that, to be sustainable, you have to let go of profitability. That鈥檚 not true. You can be profitable by farming the right species听and听you can bring back native fish in the country,鈥 said Mr. Yan.听听
