In a pilot project towards assessing the prevalence of microplastics, a growing threat to the marine environment, National Institute of Ocean Technology (NIOT) has recently launched a survey in four different locations of the ocean, including near Chennai.
Microplastics, one of the major pollutants affecting marine environment, comprise particles that are less than 5 mm in size. A team of scientists has lifted water samples near coastal areas and deep sea locations off Chennai, Godavari river mouth, Mahanadi river mouth off Odisha and Ganga river mouth, West Bengal. Microplastics ingested by aquatic organisms may affect humans when they consume fish.
The project to study marine debris and microplastics is being jointly executed along with National Centre for Coastal Research (NCCR). M.A. Atmanand, director, NIOT, said the study is a first step towards understanding microplastics that are barely visible and preventing them from reaching the sea. The pilot study that would analyse the samples would help identifying possible sources from where microplastics reach the ocean. Scientists at the NCCR noted that accumulated plastics in waterways finally drained into sea. M.V. Ramanamurthy, director, NCCR, said that, in Chennai, plastic waste was found to be getting into sea through waterways like Cooum, Adyar and Kosasthalaiyar rivers. The study would help identify what kinds of plastics are in the ocean and ways of reaching the ocean, including surface current.
The 20-day survey was undertaken in various locations in Bay of Bengal last month. Samples were lifted from deep sea locations between Chennai and Andaman. R. Venkatesan, Scientist G, NIOT, said the water samples were lifting from depth varying between 40 m and 200 m to find the level of microplastics pollution. Ships too would drop waste in the seas and the currents would wash them near the shores.
“The plastic material that are exposed to sunlight for long would get disintegrated. These materials may either remain of surface, between water column or reach the seabed and remain forever. We are planning to develop a tool to survey a larger extent of ocean and also prepare a methodology to reduce marine debris from reaching oceans,” he said.
The samples would be filtered and sediments would be screened to determine the presence of microplastics and come up with remedial measures, he added.