THIRUVANANTHAPURAM: Research divers armed with underwater cameras have revealed how a toxic combination of increased development activity and pollution is killing marine ecosystems off the Thiruvananthapuram coast.
Underwater photographs and video footage reveal devastated mussel colonies and barren reefs - once thriving with life forms - along a seven-kilometre stretch covering Kovalam, Vizhinjam and Mulloor. The independent survey was conducted by Valiyathura-based research group Friends of Marine Life (FML)
on February 5 as a follow-up to a data collection 'dive' held in January 2016. Prime suspects for the marine mayhem, apparently, are the dredging underway for the Vizhinjam seaport and indiscriminate dumping of city waste in the sea.
"There are 33 near-inshore underwater reefs along the 7-km stretch. It is also the main mussel zone in this part of the coast. Ten to 12 reefs, mostly in Vizhinjam and Mulloor, are already under mud now. Some are visible above the bed in Kovalam. But the shocking thing is all the rocky reefs have become empty of life forms," researcher and FML convener Robert Panipilla said.
Mussels are 'bivalve' molluscs which feed on water-based nutrients by keeping their halves open. Dredging activity in the region for the port has
agitated the sea-bed and caused sediments to smother the colonies clinging to the reefs.
"Once silt settles inside their shell, the mussels die off. When you run your hand on the rocky reefs now, only dirt rises," Panipilla said. Footage taken by the FML diving team show empty mussel shells lying in heaps on the seabed. And this, in an underwater locale where life flourished once.
In 2014-15, an eight-month study undertaken by FML on behalf of the Kerala State Biodiversity Board (KSBB) had thrown light on the abundance of reef-centred life forms in the region.
They included 40 types of seaweed, 70 varieties of sponges, corals, 230 types of sea worms, 500 types of molluscs (shell fish) and 48 unidentified organisms.