Kothamangalam: A study on the fish wealth in Periyar is in progress in Thattekkad Bird Sanctuary. The one-year-long study has completed four months. The decline in indigenous fish in rivers will affect the ecosystem of water birds. This is the key reason for conducting an authentic study on the fish wealth in Periyar. The main food of local and migratory birds is fish. The migratory birds arrive in the place mostly from October to April.

The study is conducted by Dr. Raju Thomas, the head of the zoology department of Thiruvalla Marthoma College and research fellows under the supervision of ornithologist Dr. R. Sugathan. The current study intends to find out whether any changes have occurred to 57 species of fish found in a study held 15 years ago. Some of the migratory birds feed on only fish. So their number is likely to decline, if there is no sufficient fish in the river.

The part of Periyar from Idukki to Bhoothathankettu is subject to the study. There are also plans to set up a fish museum in connection with the bird sanctuary. Dr. Sugathan said that authentic data which helps further studies on fish will be available in the museum. The Federation for Fisheries Development (Fish fed) puts foreign species of fish in Periyar often, which is suspected to have adverse effects on the indigenous fish wealth in the river. The study also considers this issue.