Activists claim it's the 10th humpback dolphin to be found dead this year.

Concern over rising levels of water pollution has once again gripped Mumbai after a dead dolphin washed ashore Manori beach on Monday. While a toxicology report stating the cause of death is yet to be released, experts are concerned over the increasing number of such incidents in India's maximum city.Animal activists claim it's the 10th humpback dolphin, a protected species, to be found dead this year."One of our wildlife experts reached the location and identified the body as an Indo Pacific Humpback dolphin which is a very rare and threatened species under the International Olympic Committee guidelines and Wildlife Protection Act," Dr Madhurita Gupta, President of Myvets Charitable Trust & Research Centre, told NDTV.This June, 42-foot-long blue whale was washed ashore near Alibag in Raigad district of Maharashtra. Some people even took pictures standing on the animal. Environmentalists insist rising sea pollution, ingestion of plastic and possibly even poaching in the deep seas could have led to these mysterious deaths.Dr Anish Andheria from the Wildlife Conservation Trust says, "Oceans are getting polluted in a grave manner and there is no regulation on what matter can go into the sea. Apart from fecal matter there is a large amount of industrial and toxic waste that goes into the sea. These are not banned in India but this should be regulated as it seriously impacts the marine life."Sources in the Maharashtra Pollution Control Board (MPCB) have ruled out death due to water pollution claiming that reports of tests on dead dolphins in the past doesn't point to pollution as a cause of these deaths. But experts say without a toxicology test it's impossible to conclude why they died. They claim the MPCB has not conducted these.This time, however, samples have been taken for toxicology tests and animal activists hope it will throw some light as to what's causing large marine animals to die off Mumbai's coast.