(Eagle News) — The International Union for Conservation of Nature (IUCN) has marked tawilis or “sardinella tawilis,” a freshwater sardine species found exclusively in the Philippines, particularly in Taal Lake, as an “endangered” species because of the alarming decrease in its population.
The IUCN included tawilis in its Red List of Threatened Species, saying this fish species is decreasing.
The international agency cited a study done in 2017 which found that over-fishing, pollution, habitat degradation,and competition with other species in Taal Lake had led to the decline in the tawilis population “by at least 50 percent.”
“Fishing effort using illegal gears which target this species in the lake is increasing… So it is inferred that the population has declined, which qualifies it for ‘Endangered’ criterion,” the research, cited by IUCN said.
“With an increase in effort, it is likely that the population is declining faster than the catch, and we therefore infer that the population has declined by at least 50 percent,” the study added.
IUCN said that three major threats to tawilis and fish diversity within Taal Lake which resulted in its continuing decline are “overexploitation, pollution, and competition and/or predation with introduced fishes.”
“[C]atches of this species have declined significantly since at least 1998, and it is estimated that harvest has declined by about 49% over the past 10 years,” the IUCN said.
The IUCN said that tawilis may face total extinction, if its population is not properly managed and protected.
The study which the international organization cited was conducted on February 28, 2017. It was published in 2018.
The Bureau of Fisheries and Aquatic Resources will be assessing Tawilis stocks and determine its spawning areas. It said that there will be a reserved area for the fish species in Taal Lake to protect it from overfishing.
Sardinella tawilis or bombon sardine, locally known as tawilis is a freshwater sardine found exclusively in Taal Lake in the Philippines. It is the only member of the genus Sardinella known to exist entirely in fresh water.