Seismic activity: Indian scientists investigate unusual changes to the sea near Kerala

September 17, 2011 – INDIA - With a foul smell emanating from the sea in some parts of Kerala in the last few days, scientists have said there was no cause for anxiety but are divided on the reasons behind the phenomenon. Some scientists have attributed this to the large mass of marine algae killed by lowering of salinity owing to influx of fresh water from rivers and run-off but another state-based researcher disagrees with it and said the phenomenon was due to seismic factors. A team of researchers from Kerala University, which studied the phenomenon reported from coastal areas off Kollam and Thiruvananthapuram had held the foul smell was attributable to the bacterial decay of a possible algal bloom. They said they reached the conclusion based on examination of various parameters like the colour of the sea, salinity, temperature, pH nutrients, plankton, microbes and fish mortality. However, Dr. Sainudeen Pattazhy, Associate Professor of Zoology in SN College Kollam, said the stench was linked to seismic phenomena like tremors of moderate intensity that had been experienced in several districts of Kerala and other states recently. Even though parameters like salinity and temperature were within the optimum levels, there was no chance of occurrence of algal blooming, massive death and decay of algae. If algal blooming occurred, a thick scum would develop on the sea surface, which had not happened, Dr. Pattazhy told PTI. Anoxic conditions during the night, changes in water quality, pollution, upwelling, nutrient discharges, run-off from the land during the south west monsoon were all natural process but no foul smell had been felt, Dr Pattazhy said. “If massive death of plankton was due to lowering of salinity, then why did it not affect the fish fauna and other animals? No mortality of fish and other animals were observed during this period,” Dr. Pattazhy, also president of Kerala Environmental Researchers Association, said. Stench event and “red rain” were observed in 2000, 2001 and 2011 in Kerala. These events were preceded by low intensity tremors in several districts of Kerala, massive collapse of wells and land slips, he said. The fundamental cause of stench from sea was attributable to geological changes under sea, he said. The December 12, 2000 quake and the lesser intensive tremors that occurred in 2001 were causing several perceivable changes in the earth as well as the atmosphere. The epicentre was stated to be in Meenachil Taluk in Kottayam district, he said. When ‘fault’ occurred under sea, hydrogen sulphide and other inert gases would escape from the sea surface, which was the reason for the foul smell and this had no connection with algal blooming, salinity and nutrient variations, he said. At times, following the emission of gases from under the sea, molten lava would ooze to the sea surface. Some fisherman had recently reported that they had seen oozing of black fluid from the bottom to the surface of sea, he said. –The Hindu