Survey Reveals Decline in Native Fish Species in Periyar Tiger Reserve

by Fishery News

The first detailed survey of aquatic fauna and odonates (dragonflies and damselflies) conducted by the forest department in the Periyar Tiger Reserve (PTR) from May 16 to 19 has shown a decline in native fish species. This is due to an increase in the population of exotic species like catfish.
The survey identified 56 different fish species, the highest number recorded in PTR since 1940. Among these, seven potential new species were found in the reserve’s tributaries, though further molecular studies are needed to confirm if they are new species or subspecies.
PTR’s water bodies host 30% of all fish species found in Kerala. The survey found nine fish species that are unique to the reserve, but one of these species was not observed during this survey. Four exotic fish species were identified: the African Catfish, Common Carp, Mozambique Tilapia, and Nile Tilapia.
Assistant Field Director PJ Shuhaib noted a decrease in the population of native fish, which has led to fewer cormorants and darters in the lake. This decline is linked to the invasion of exotic species, especially after floods in 1986 and 2018 introduced catfish into the lake. To combat this, the forest department has eradicated about 2,780 catfish over the past two years and is working with local fishermen to control exotic species.
The survey also recorded 120 species of odonates, surpassing the previous record of 116 species. This is the highest number recorded in any protected area in Kerala, making up 63% of Kerala’s and 55% of the Western Ghats’ odonate diversity. These species are indicators of good air and water quality.
The forest department plans to continue studying and managing the aquatic ecosystem to support native species and further investigate the newly found fish species. The survey was coordinated by Periyar East Division Deputy Director Patil Suyog Subhash Rao and led by experts including Sethu Parvathy, S Kalesh, and Rajeev Raghavan.

You may also like

Leave a Comment

This website uses cookies to improve your experience. We'll assume you're ok with this, but you can opt-out if you wish. Accept Read More

Shares