“Protecting native freshwater fishes is not only about preserving aquatic biodiversity. It is also about securing food, protecting livelihoods, and maintaining healthy freshwater ecosystems for future generations.”
Guest author:
- DR. MARK NELL C. CORPUZ, NAST PHL 2026 Outstanding Young Scientist, Institute of Fisheries and Aquatic Sciences, College of Agriculture and Fisheries, Bataan Peninsula State University (BPSU), Balanga, Bataan
Short link: https://wp.me/paaccn-10K0
BALANGA, Bataan — Many of the Philippines’ native freshwater fishes are quietly disappearing from rivers, lakes, and streams.
Once common in local markets and on the dining tables of Filipino families, several of these fishes are now becoming increasingly difficult to find because of habitat destruction, overfishing, pollution, and the spread of invasive fish species. A new scientific review highlights the urgent need to strengthen conservation efforts before these valuable aquatic resources are lost forever.
Recent studies examined some of the country’s most important native freshwater fishes, including ayungin, tawilis, ludong, native hito, biya, sinarapan, maliputo, and freshwater eels. These fishes are more than sources of food; they support the livelihoods of thousands of fisherfolks, contribute to local economies, and play essential roles in maintaining healthy freshwater ecosystems.
Unfortunately, several studies identified several major threats affecting these fishes. Rivers and lakes continue to be degraded by pollution, logging, land conversion, habitat alteration and poorly managed aquaculture. Excessive fishing pressure removes fish faster than populations can recover, while introduced species compete with or prey on native fishes.
For migratory fishes, structures that block rivers prevent them from reaching important breeding and feeding areas. Together, these pressures have degraded many freshwater ecosystems across the country.
Unfortunately, many of the abovementioned fishes have experienced sharp population declines over the past two decades. Ayungin or silver therapon, once abundant in Laguna de Bay and many inland waters, has experienced substantial declines due to overfishing, habitat loss, and invasive species.
Tawilis or bombon sardine, the world’s only freshwater sardine found exclusively in Taal Lake, is now listed as “Endangered” because of excessive fishing and lake degradation.
Ludong or lobed river mullet, a prized migratory fish from northern Luzon known for its exceptional market value, has become increasingly scarce as a result of illegal fishing and river disturbance.
Science-based management measures contribute to recovery of species
Native hito or catfish has also declined in the wild, largely displaced by introduced catfish species that now dominate commercial aquaculture.
Gobies locally known as biya, continue to support small-scale fisheries but have shown significant reductions in production over the past decade.
Likewise, sinarapan, recognized as the world’s smallest commercially harvested fish, now survives in only a few lakes in the Bicol Region after decades of declining catches.
Our maliputo, the freshwater form of the giant trevally in Taal Lake, depends on an open connection between the lake and Balayan Bay to complete its life cycle. Obstructions along this migration route, together with overfishing and habitat degradation, have contributed to its declining abundance.
Freshwater eels, locally known as igat or kasili, also undertake migrations between the ocean and Philippine rivers, making them highly vulnerable to river modification, pollution, and excessive harvesting of juvenile eels for export.
Despite these challenges, there are encouraging examples of conservation success. Closed fishing seasons have been introduced for several species, protected areas have been established in important habitats, and research institutions have successfully bred native fishes such as ayungin, native hito, and maliputo in hatcheries.
In Taal Lake, the removal of fish cages from the Pansipit River helped restore the natural migration route of several native fishes. These initiatives demonstrate that science-based management can contribute to species recovery when combined with effective implementation.
The conservation strategies must go beyond protecting individual fish species. Healthy rivers, lakes, wetlands, and watersheds are essential for sustaining fish and human populations. Stronger enforcement of fisheries regulations, restoration of degraded habitats, continuous scientific monitoring, and greater collaboration among government agencies, universities, LGUs, and coastal communities are needed to ensure long-term success. Conservation breeding programs should also support the recovery of wild populations while maintaining their natural genetic diversity.
Protecting native freshwater fishes is not only about preserving aquatic biodiversity. It is also about securing food, protecting livelihoods, and maintaining healthy freshwater ecosystems for future generations. By investing in science-based conservation today, the Philippines can ensure that these unique native fishes continue to thrive in our rivers and lakes, and remain an important part of our country’s natural heritage. (/)
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Editor’s Note:
Dr. Mark Nell C. Corpuz is an Associate Professor in Bataan Peninsula State University and a specialist in freshwater fish biodiversity and conservation. His research focuses on the ecology, conservation, and sustainable management of Philippine freshwater fishes, with particular emphasis on biodiversity assessment, river health, and evidence-based conservation strategies.