Dugongs, mermaids of the sea

by Vardhan Patankar and Elrika D’souza

 

Blubbery, yet curvaceous, with a body like that of a woman and a tail like that of a fish. This is exactly what they were once mistaken for, according to folklore. They are said to have lured sailors, giving rise to the myth of mermaids.

Much better understood today, dugongs are found in warm Indo-Pacific waters, they can live up to 70 years and much like humans, reach sexual maturity between 10 and 17 years. They belong to an order of animals called Sirenians, the manatees being the others in this order. Their nearest relatives on land are the elephants, and like them, dugongs also have beautiful tusks, though they are exposed only in older individuals.

In India, dugongs have been sighted around the Lakshadweep islands (over 100 years ago) and the Gulf of Kutch along the west coast and the Gulf of Mannar and Palk Bay region, and the Andaman and Nicobar Islands. In most of these areas their sightings are rare and from the Lakshadweep islands they are locally extinct. In other areas, only a few individuals survive in the wild and the information available is mainly from mortality and stranding records.

Though they are large in size weighing upto 400 kilograms their primary diet is seagrass. They consume almost 30-40 kg of seagrass daily. Studies in the Andaman and Nicobar islands show that they feed on specific seagrass which are small and easy to digest even through their availability is low as compared to other types of seagrasses. Today, dugongs are not referred to as mermaids; rather they are unflatteringly locally referred to as sea-pigs. The thickest part of its body is the back, where there is the most blubber. The animal protects themselves from predators, such as sharks, by simply turning their backs on them.

They may be able to flee from sharks in the water, but they can’t flee from poachers. Their sluggish behaviour makes them easy to trap them and their need to surface every 5-6 minutes to breathe adds to their vulnerability. Targeted hunting, entanglements in fishing nets and high-speed boat traffic have wreaked havoc on wild populations. Adult females and young ones are highly susceptible with the former unfailingly following the latter and vice-versa when either is trapped or looped and pulled alongside a boat.

Dugongs give birth to a single calf once every five to seven years and young ones depend on the mother for a year and a half. The population growth is thus very low making it difficult to re-establish or propagate when the population dips to extremely low levels.

Today, dugongs are listed as vulnerable to extinction by the International Union for Conservation of Nature. The Indian Wildlife Protection Act has given them the highest level of legal protection. Yet dugong hunting continues in some parts, and their habitats are continuously degrading due to manmade destruction and climate change.

In the present day and the future, we hope that these the beauty, rarity and posterity of the animal are reasons good enough to conserve the species.

 

Photo credit: Vardhan Patankar