KOCHI: Mud banks (Chaakara in Malayalam) are a remarkable phenomenon that can make astonishing changes in the physical and bio-spheres of Kerala.
The observation was made by scientists attending the ‘National workshop on mud banks of Kerala: Status, issues and societal concerns’, organised here by the Council of Scientific and Industrial Research (CSIR)-National Institute of Oceanography, Regional Centre. The workshop, which concluded the other day, also recommended more scientific studies into the mud bank phenomenon.
“Observations that chemical reactions during Chaakara will help in preventing global warming are noteworthy and merits more studies. Scientists and common people should co-operate with each other. Researches and findings of scientific studies should be passed on to the public for the betterment of the society,” said Earth Commission chairman M Rajeevan Nair.
He said the National Geographic Department had launched a deep ocean mission and all oceanography scientists should extend their support to the project.
Mud banks are a specialised oceanographic phenomenon of calm, turbid waters with high biological production. It occurs along certain parts of the Kerala coast during the summer monsoon season, when adjoining coastal regions experience high wave activity. The mud banks of Kerala have socio-economic relevance as they support livelihoods of fishermen, besides protecting the beaches from erosion. They are usually formed during June-July and sometimes get extended till August.
The scientists further said an abrupt reduction in methane concentrations was noted during the mud bank period in comparison to the pre-mud bank period. Accordingly, shifts in the presence of methanogenic and methanotropic bacteria, before and after the development of mud banks, invoke further study to establish the role of bacteria in mud banks in trapping the greenhouse gases.
In 2014, the CSIR had initiated a multi-disciplinary study in collaboration with the Central Marine Fisheries Research Institute, involving meteorology, physics, chemistry, biology, geology and fishery aspects. The study had ruled out several theories like the ‘subterranean flow theory’ of mud bank formation.
“The formation of Alappuzha mud banks is caused by the activation of resident fluid mud located at the adjacent offshore (10-20m) regions by energetic waves, reinforced by upwelling. Presence of fluid muddy layer at the bottom attenuates the waves resulting in the formation of calm mud banks,” said the study.
According to it, the chemical characteristics of mud banks were found to be unique. “It was found that absorption of cations by phosphorus-rich montmorillonite in mud bank sediments was responsible for the sustenance of mud banks,” it said.