Their numbers are dwindling due to increased human activity

Dugong, the sea-grass eating marine mammal found in the Gulf of Mannar and the Palk Bay, is under threat from increased human activity.

The Gulf of Mannar Marine National Park proposes to undertake a study to assess the population of these sea creatures, according to Deepak S.Bilgi, Wild Life Warden.

The study, to be conducted by Tuticorin based Suganthi Devadason Marine Research Institute, would be completed during this financial year, after which an action plan and measures for Dugong conservation would be launched, he told The Hindu.

As Dugongs feed on sea grass, the sea grass beds in the Palk Bay and the Gulf of Mannar region will also be assessed. The study will be conducted through the Tamil Nadu Bio-Diversity conservation and Greening Project (TBGP), and is aimed at determining the distribution, population and migratory pattern of Dugong.

“We will launch the study shortly and complete it by the end of this financial year,” Mr Bilgi said, adding a study conducted in 2007 had revealed that the region had over 150 Dugong. “The Dugong population is the highest in the Gulf of Mannar region compared to other parts of the country,” he said.

He added that their distribution was high in sea-grass bed areas.

Following the study, the Forest department plans to promote awareness among fisherfolk of the need to conserve the species and its habitat.

A similar exercise would be conducted in the case of sea turtles.

Mr Bilgi said the TREE foundation had identified nesting areas and enlisted local fishermen to help conserve the sea turtle population.

The study launched in April indicated that the eggs laid by sea turtles were either eaten by stray dogs or collected by fishermen for consumption, he said.

Methodology

A questionnaire-based survey will be conducted in the coastal villages of Palk Bay and the Gulf of Mannar to understand the present status of the Dugong population. Interviews will be conducted with a minimum of 10-15 active fishermen in each village, according to sources.

The respondents would be drawn from among experienced and knowledgeable people connected with fisheries. The questionnaire in Tamil will focus mainly on the historical and present occurrence of the Dugong, the threats, use, and local attitudes toward its conservation.

For sea-grass assessment, a preliminary visual survey will be carried out to identify the location and extent of sea-grass meadows in the Gulf of Mannar between Pamban and Tuticorin, covering 140 km. In the Palk Bay, the assessment will be carried out along a 130-km stretch between Pamban and Athiramapattinan.

The Palk Bay and Gulf of Mannar area will be demarcated, using GPS coordinates, into several separate sites. The focus areas will be the sea-grass species density, shoot density and sea grass biomass. Land-based as well as fishery-related threats to the Dugong habitat will be assessed.

Since sea-grass beds in both the Gulf of Mannar and the Palk Bay are important in terms of livelihood to traditional fisherfolk, the social-ecological system prevailing in this biodiversity-rich and productive coastal region will be documented and considered one of the key components in the preparation of the Dugong conservation action plan.