Experts and fishermen offer different reasons
A veterinary team of Forest department on Tuesday conducted post mortem of four dolphins that were washed ashore in Punnaikayal shore on Monday.
Around 30 spotted dolphins (Stenella attenuate), which were stranded, were rescued by fishermen and pushed into the sea. Ten dolphins were dead. Of them, four were washed ashore. The post mortem was done by a team led by R. Sridhar, Professor, Department of Pathology, Veterinary College and Research Institute, Tirunelveli.
A. Sugumar, veterinary surgeon, said that three among the dead were female and each was about 6.9 feet in length and weighed about 150 kg to 200 kg. The male dolphin was about 9.5 feet in length and weighed about 225 kg.
The exact cause of death was not known. However, during the post mortem, samples were collected for tests. Carcasses were buried in the shore.
According to P.P. Manojkumar, scientist (in-charge), Thoothukudi Research Centre of Central Marine Fisheries and Research Institute, two of the dead dolphins were lactating.
These dolphins could have been disoriented due to rough weather or stranded while in search of prey. As the dolphins moved into shallow waters of Punnaikayal, the situation could have caused lack of oxygen and led to their death. Such species, which feed on small fishes, could be spotted in the Bay of Bengal.
Thennavan, a resident of Punnaikayal, blamed it on discharge of untreated industrial effluents into the sea. He urged the government to provide two rescue boats to the village committee to render assistance to fishermen.
K. Diraviyaraj, Assistant Professor, Suganthi Devadason Marine Research Institute, said similar dolphins called ‘Spinner Dolphin’ (Stenella longirostris) had been reported in the Gulf of Mannar. As many as 37 dolphins were stranded at Vellapatti near Thoothukudi on June 26, 1999. R. Amal Xavier, Joint Director of Fisheries, said that six dolphins were washed ashore at Siluvaipatti in 2000.