Sand dunes are present on shorelines across the globe where fine sediment is transported landward by a combination of wind and waves, and stabilised with dune vegetation. NT BUZZ finds out about the proposal to have Goa’s first sand dune park and the need to save nature’s first line of defence – the sand dunes
SHERAS FERNANDES | NT BUZZ
The coast of Goa is abundant in sand dunes but we are seldom aware about the need to protect them from degradation. While it cannot be ignored that some sand dunes are intact along some beaches in Goa, most of them have been invaded and trampled by human involvement and developmental activities. This is now posing a threat to the existing sand dunes. If things go as planned and the government approves the proposal, Goa will have India’s first sand dune park.
Sand dunes across the globe act as nature’s first line of defence facing the mighty oceans. “During the monsoon the waves are driven by winds and at times waves overshoot the beach. It is a dune that stops the waves from advancing inland,” says former scientist at National Institute of Oceanography (NIO), Goa, Antonio Mascarenhas adding that the beach does not belong to the land and is the property of the sea. “That is where the sea ends and the waves come down to zero at the foot of a dune. A sandy beach is also known as the intertidal zone and is the playing field of the ocean,” says Mascarenhas adding “Higher the sand dune, greater is nature’s defence.”
Mascarenhas revels that the beaches that get eroded in monsoon have a unique feature of getting replenished in the month of September. However, this isn’t happening because of the shacks along the shore. “From Baga to Sinquerim the dune field is occupied by shacks but there are quite a few dunes. In Agonda there are just a few dunes left but the entire stretch in Palolem is gone. The sand dunes in the central part of Goa are still in a good shape,” says Mascarenhas.
Goa has four sites that are notified areas and are protected by law as they are turtle nesting sites. “In Goa – Mandrem, Morjim, Galjibag and Talpona are protected by law and hence can be ideal for sand dune parks,” says Mascarenhas. There is no need for budget allotment or funds to have a sand dune park. “All you need to do is leave the place alone and let the winds and waves take over. If we identify any alien vegetation we will terminate it and replace with native vegetation,” says Mascarenhas.
It is the dune vegetation that prevents the sand from venturing further inwards, the vegetation holds the sand carried by the wind and hence we have bigger sand dunes at some places. “A dune should be covered with frontal vegetation such as ipomoea creepers,” says secretary of Botanical Society of Goa, Miguel Braganza. The Botanical Society of Goa has even published a report on the sand dune vegetation in the State. In Goa we find Ipomoea Pes-caprae, Spinifex littoreus, Merrill, Cyperus arenarius, Saccharum spontaneum, Sporobolus virginicus, Dactyloctenium aegyptium wild, Eragrostis unioloides, Clerodendrum-inerme, Pedalium murex L, Physalis minima, Triumfetta rhomboidea, Vitex trifolia L, Calotropis gigantean, Casuarina equisetifolia, Anacarduium oxydentrum, Cocos nucifera L, Calotropis gigantean, amongst others. The most common of which are Spinifex and Ipomoea.
Mascarenhas points that coconut and Casuarina trees shouldn’t be the frontal vegetation. “The frontal vegetation should comprise of spinifex or ipomea creepers, the mid dunes should have smaller bushes, and the back dunes should be coconut trees and casuarinas,” says Mascarenhas.
He adds that Goa has five wildlife sanctuaries, a national park, a bird sanctuary, a coral reef at Grande Island but is missing a sand dune park. “The sand dune park could serve as a natural laboratory. Students can visit these parks and understand what a sand dune is, the vegetation there and the need to have sand dunes,” says Mascarenhas adding that in this way we can achieve coastal stability.