In a study conducted by Dr. Michelle Grace Paraso of the UPLB College of Veterinary Medicine, carp was found to have a potential use as a biomarker in detecting the level of pollutants in the country’s water resources. The study evaluated carp as fish biomarker in determining the contamination of Laguna de Bay in four sites at Sta. Cruz and Paete, Laguna (East Bay) and Taguig City and Muntinlupa City (West Bay). Paraso found that majority of the male carps in study site have shrunken testes compared with that of the normal male carp. Shrunken testes of a male carp indicate that the fish has been feminized. Such feminization shows that the carp was exposed to certain type of pollutant known as estrogen, among others.

Carp an indicator of water pollution. (2016, September 23). Manila Times, p. B8.