Panaji: A bumper crop this year has assured an occasional plate of tasty tisreo (clams) at the dinner table. The bivalves appearance after many years has warmed the cockles of the consumers hearts, but hundreds of raiders waiting to reap a harvest may spell bad news for a few years.
Between a familiar pattern of abundance and scarcity, Goa’s shellfish species are tottering on the brink, also, due to unscientific exploitation.
Pollution caused by mining, waste disposal and other factors is being blamed for it. But overexploitation is hardly being noticed as one of the critical factors.
“The bumper crop is due to an undisturbed reproductive cycle, as many activities have stopped. But when too many persons exploit it and even take the brood stock, they destroy the habitat,” Baban Ingole, retired chief scientist, biological oceanography, NIO, Goa said.
* Goa’s inland shellfish catch in 2019 was: crabs 317 tonnes, back water clams 8, false clams 78, oysters 86 and mussels 96 tonnes.
* Goa has more than 100 molluscan species, including 50 bivalves.
* Shellfish, especially clams needs clean and conducive environment for breeding in sensitive stages
* Window pane oysters are unique but highly endangered bivalves, now found mostly in Chicalim bay
The sensitive shellfish has its own breeding dynamics. “Clams, for instance, take about one year to reach a mature stage of 2cms,” Ingole said.
Quiet and clean waters provide create a better ecosystem for their breeding. “Clams as also other shellfish require conducive environment during the delicate settlement stages,” Shamila Monteiro, director of fisheries department.
Near Chicalim’s Vareg island, a plentiful clam crop island has delighted the villagers and local biodiversity management committee (BMC). But recently, a large crowd of 500 persons entered the site, unmindful of any sustainable practices. “They must have taken away huge quantities of tisreo and even small ones, driven by commercial or other interests,” Cyril Fernandes, a BMC member said.
Further upstream, Quelossim villagers recently found the unique cyclindrical chuddio, a fresh water mussel, after many years. “But they are in small quantities, ” Lopinho Xavier, local chairman local BMC said.
Chapora river stretch was another hotspot of shellfish, especially xinanneo (green mussels) and khube (big-sized clams). “A few years ago, we consumed shellfish like a staple food and rice like a side dish. Our catch was sent to markets in Goa, but now there is hardly anything,” says a Siolim resident.
But despite intensive harvesting then, fishermen largely blame pollution due to water sports and other activities.
Mud flats of River Sal in Betul also accounted for a sizeable shellfish production. “Tisreo are in small quantities now. Xinanneo were aplenty but a fishermen may hardly find a few dozen of them,” Sudhakar Joshi, former sarpanch said.
In Chicalim, the local BMC has mooted a unique model of shellfish conservation. While lockdown proved useful to halt clam collectors, the committee is considering an option of keeping Vareg site closed or allow only a few local stakeholders.
Traditional fishers of yore were grounded in nature and ensured sustainable practices. “After many years, nature has tried to reinvent itself. This critical restoration of a destroyed habitat should not be disturbed,” Fernandes said.
Sustainable practices are inevitable to maintain fish production. “The fisher folk should harvest prudently and keep some shellfish as brood stock in the interest of their own livelihood and ecosystem,” the fisheries director said.
Ingole says assessment of carrying capacity is needed, though availability of data is a hurdle. “An area of the plot, may be about one-tenth, could be marked as “no take zone” and preserved completely. This will provide the seed next year,” he said.