SAURABH JOSHI MUMBAI
The already polluted seas in Mumbai took a further beating after collision between cargo ships MSC Chitra and MV Khalijia in August 2010 and more recently after cargo vessel MV Rak sunk 20 nautical miles of Mumb
ai coast and started spewing oil. Citing the danger on marine ecology, the authorities turned to the traditional way of spraying Oil Slick Dispersants ( OSD) to contain the slick, however, environmentalists claim that its usage added to the pollution levels since dispersants are chemicals that also add to destruction of environment.
According to the Coast Guard authorities, over 3000 litres of OSDs have been sprayed to control the spreading layer of oil that has been leaking from sunken MV Rak. The condition was similar after the two ships had collided only a year ago off the Mumbai coast. Dr. Rakesh Kumar, an environment expert said, ” In case of such adverse situations, spraying OSDs is the most viable option to control the spill from spreading. However, it is important to assess the place where OSDs are being sprayed.” Experts stated that there are various species and vegetation under the water that get hampered due to presence of OSDs, which are high on phosphorous. The dispersants have been used to contain the oil spill for second consecutive year, which is cause of a concern.
The fishermen donalt39t go to sea during monsoons, since its the only time fish breed during the year. However, using OSDs to counter oil spillage from spreading to a larger area, adds to the higher levels of pollution in the sea, resulting in destruction of marine flora and fauna.
Dr. C S Purshottaman, Principal Scientist, Central Institute of Fisheries Education said, ” The OSDs are of various types and have composition similar to that of detergents, which act as binding agents to pollutants.
The abnormally high level of any types of pollutants affects the abnormality in growth of alt39 phytoplankton,alt39 which are microscopic plant- like organisms that form the base of the marine food web.” The growth of the Phytoplankton depends on availability of carbon dioxide, sunlight, and nutrients. But when pollutants like oil or dispersants cover the water surface, it hinders the passage of sunlight and thereby disturbs the natural process of growth and overall affects the whole cycle, leading to a long- term damage.
Environmentalists slam use of chemical dispersant sprays