An array of corals, including a new species called Dipsastraea favus that resembles a human head, was spotted in the seabed along a 3km stretch from Thumba to Puthenthope off the city's coast. The species are usually found near Lakshadweep, the Andaman and Nicobar Islands, Seychelles, south of Sri Lanka and Southeast Asia.Divers from Friends of Marine Life (FML) and Scuba Cochin discovered a dense area of corals at a depth of 22m while surveying the seabed as part of a project to create a people's marine biodiversity registry in association with Kerala University. The seabed features laterite formations and is rich in marine life, including corals.The discovery is significant, as Centre is planning underwater mining off Kollam. The presence of a variety of marine life close to the shore shows that such undersea excavations will disturb the marine environment and impactthe availability of fish catch. When diving at a location 22m deep in the sea, shown by fish fisherman Thadeose from St Andrews, divers of FML encountered an astonishing sight of coral patches. FML, which has been capturing images of the seabed off the coast of Thiruvananthapuram for over a decade, has never seen such a dense area of coral patches," said FML chief coordinator Robert Panipilla.We could see a solid seafloor formed by layers of laterite for the 3km stretch. There are corals of the species Dipsastraea favus in the region. This has not been reported in Kerala. Patches of coral species like Dendrophyllia and Tubastrea are abundant. There are also various types of organisms, some anchored to the floor and others swimming freely in water," he said.The discovery shows that the seabed off Thiruvananthapuram shore is rich in marine biodiversity, which needs to be mapped,he added.Marine habitat mapping is necessary to record sightings and protect marine life from the impacts of mining and other activities, said experts.Marine habitat mapping will help us understand the physical characteristics of the seabed and also the marine biological community present underwater," said Panipilla. Govt should have coastal and marine planning so that the fishing community will not be adversely affected when large-scale projects are formulated in connection with the sea, he added .