nature
Saving the Dolphins

This endangered mammal has found a new habitat at Harike wetland, near Amritsar. To ensure its survival, firm steps need to be taken to curb poaching, writes R.K. Luna

A recent news report stated that dolphins have been sighted at the Harike wetland in Punjab. While the sighting of these aquatic mammals at Harike which is traditionally not known as a dolphin habitat, has delighted wildlife conservationists and biologists, they are worried how and when these animals have come to stay at Harike and why were they not detected earlier during various ecological surveys held earlier.

Also it needs to be seen whether the dolphins will be able to survive and proliferate in the Harike waters. According to Dr Sandeep Bahera and Asgar Nawab, the animals have migrated from the Indus river. The Indus river dolphins have historically confined themselves to the lower Indus river basin and the Satluj, Beas, Ravi, Chenab and Jhelum tributaries.

Around 965 of Indus river dolphins are presently found between Guddu and Sukkur barrages constructed over the Indus river system over a stretch of 1000 km. Withdrawal of water from the river systems, construction of numerous dams and barrages have been responsible for the reduction of habitat and fragmentation of the dolphin population. After Partition, the river flows in Ravi, Satluj, Beas and Chenab have reduced drastically. However, considering the devastating floods of 1988 in Satluj, Beas and Ravi rivers, there is a every possibility that a family of Indus river dolphins distracted and retreated to Harike waters via Satluj river, when floodgates of Harike barrage were opened. The river tract distance between the tributaries of the Indus and Harike is hardly 250 km via river course which the dolphins can cover within a fortnight.

Dolphins have a streamlined fusiform body adapted for fast swimming. In Harike they have been seen covering a linear distance of 20-25 km everyday. The theory is further supported by the fact that when Indus was a free-flowing river, the Indus River Dolphin used to migrate upstream into the smaller tributaries during the monsoon. Reports from Pakistan suggest that Indus river dolphins often swim through regulator gates into the irrigation canals where they get trapped and have to be rescued to safer places.

The reason that why "smiling" dolphins were not detected earlier lies in the fact that Indus river dolphins unlike marine dolphins are not a very acrobatic species and avoid all types of boats. They also leave and re-enter the water very quickly and it can be difficult to actually sight the animal. The usual time between surfacing is only 30 and 45 seconds when they breathe through their slot-like blowholes. Only when in danger it will risk coming out of water before diving back down head first, with a large splash of its tail. Else, they are shy creatures, especially in a new habitat.

The family of Indus river dolphins at Harike comprises one female (cow), two males (bulls) and three siblings (calves). The reported mature dolphins are about 90 to 100 kg and the younger ones half of that. Since dolphins become reproductive at a young age of 6-10 years, the birth of calves could have taken place in Harike waters after the migration. The present generation may be of 1988-98. This is surely the first generation of dolphins at Harike. This is a matter of great rejoicing, as the already endangered species has found a new habitat at Harike.

According to WWF (World Wide Fund for Nature) experts, Harike is a suitable habitat for regeneration and preservation of dolphins. Spread over 148 sq km of which 73 sq km constitutes a wetland enclosing shallow, marshy tracts that serve a feeding and wading habitats for a variety of wild animals. The wetland is the convergence point for Satluj and Beas. Harike has also emerged as a fine waterfowl habitat, wherein more than 210 avian species have been recorded at one time or another. Twenty-six fish species are found in Harike waters with high density in some areas. Given the habitat with abundant food, water and protection, Harike barrage alone can sustain 160 dolphins safely.

Soon after conversion to wildlife sanctuary in 1982, the Harike lake acquired the status of Ramsar wetland of international importance in 1990. Harike supports not only migratory and domestic birds, animals, and fishes, but also supports rare, vulnerable and endangered fauna species which include the testudine turtle, and the smooth Indian otter both of which are listed in the Red list of IUCN (International Union for Conservation of Nature).

Besides supporting birds and animals, the wetland is serving another important role in maintaining the hydrological balance in the catchment of Satluj and Beas river systems. Intensive agriculture in the catchment area with the excessive use of pesticides and chemical fertilisers, flushing of sewage and industrial effluents in the rivers have deteriorated the quality of water in the lake. Monitoring of water quality in the Satluj by the Punjab Pollution Control Board over the years has indicated the presence of higher concentration of heavy metals, pesticides and coliform bacteria.

For the dolphins to survive, government must curb illegal activities of poaching and fishing in the wetland, must declare the dolphins territory as a protected area, stop the movement of cattle and increase the patrolling of wildlife guards to curb illegal activities. Measures to stop contamination of waters with plastics, pesticides, heavy metals and other agricultural and industrial pollutants that do not disintegrate rapidly in the environment have to checked in the catchment area of Harike.

As the Indus river dolphins need sufficiently deep water all the times to play and feed, consistent water flow in the Beas and Satluj has to be maintained by regulating the river flow and storage in the barrage. Out of the 40 species of dolphins found in the world, only one species i.e. Ganges river dolphin is found in India, that too with a small population in the Ganga, Brahmputra and Meghana in India. If concrete conservation strategies including the habitat management, are not undertaken, the species may go extinct. As the top animal in the river food chain, saving the dolphin would mean conservation of water, maintain the river health as well as of land and human beings.

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