It’s grass and it’s green, but you are not likely to find cattle grazing on it. Look for fish instead. Seagrass ‘wracks’ that have washed up on the Kovalam beach have piqued the interest of the local people and marine scientists alike, as the phenomenon is rather unfamiliar to the Kerala coast.
Seagrass grows entirely underwater and these marine plants are different from seaweeds. Wracks are loose seagrass patches that accumulate on beaches due to wave action.
A biodiversity team of the Department of Aquatic Biology and Fisheries, University of Kerala, has identified the wracks as belonging to two species; Oceana serrulata and Syringodium isoetifolium , the latter commonly called the ‘noodle seagrass.’
Unreported in Kerala
As both seagrass species have not been reported so far from the Kerala coast, the finding calls for a detailed underwater study, especially along its southern sections of the coast, said A. Biju Kumar, head, Department of Aquatic Biology and Fisheries.
Many merits
Seagrass beds or meadows along the continental shelf play a vital role in marine biodiversity and the overall productivity and health of coastal ecosystems. These submerged flowering plants, found in shallow marine waters usually, enhance water quality, absorb carbon dioxide and liberate oxygen. They also act as ‘nurseries’ and havens for a large number of fish species. “In the Indian coast they are the feeding grounds of the critically endangered sea cow (Dugong dugon),” Dr. Biju Kumar said.
Both the species found at Kovalam, categorised as of ‘Least Concern’ in the Red Data List, are reported from the Lakshadweep islands, Gulf of Mannar, and the Andaman and Nicobar islands.
The suggested possible biogeographic distribution of Oceana serrulata and Syringodium isoetifolium include the southern east and west coasts of India, and part of eastern and western Indian Ocean. Extreme currents, tides, and wave action may have carried them to Kovalam from the east coast of India. The possibility of separated patches from the seagrass afforestation areas in the Gulf of Mannar also cannot be ruled out, Dr. Biju Kumar said.
Recording seagrass beds
“Artificial reefs and geotubes deployed along the Kerala coast recently support the growth of seagrass. It would be interesting to record the possible seagrass beds along the Indian coast, as there are no records of seagrass beds in the region and they offer nature-based solutions for coastal protection,” he said.
