Fishing out data on Goa’s marine wealth

Goans’ love for fish is legendary and the tiny state’s marine assets are oceanic in scale, but little is known about fisheries scientists’ work of recording 600+ fish species.

The Arabian Sea, which lines Goa with a silvery band, ensures an abundance of fish in the state’s bays, estuaries, wetlands, and other waterbodies.

From the near shores and exotic patchy coral reefs of Grande Island to the brackish pools and freshwaters in the hinterlands, Goa’s aquatic ecosystem teems with rich fish diversity. This comprises scores of fin fishes, crustaceans, and molluscs — pelagic (relating to the open sea) and bottom-dwelling.

Traditional fisheries, shore seines, and dragnets on beaches, and gillnets, drift nets, and mechanised vessels in coastal waters haul in the catch.

Aquatic life’s deep pockets

Of the plethora on offer, a few fish species are popular. And yet, there is a fair choice for the locals and tourists craving seafood, be it the much-preferred fish curry, the traditional dish of kismur, or the mouthwatering rawa-fried slices of visvan or chonak.

The work of recording these fish species was initiated by the Zoological Survey of India. But the National Institute of Oceanography (NIO) carried out further pioneering work. In one study, the reputed fisheries scientist Baban Ingole noted more than 100 fish species and 55 species of shellfish in the Chicalim-Sancoale bay of the Zuari estuary.

When the ICAR-CCARI (Indian Council of Agricultural Research-Central Coastal Agricultural Research Institute) took the plunge in 2014 — scouring the Grande Island coral reefs, estuaries, and other waterbodies — the fish inventory grew longer to 646 species.

“When we started our work, we were excited about entering the turbid and unexplored ecosystems of rivers, estuaries, and ponds,” said G B Sreekanth, an ICAR fisheries scientist.

After learning fish names in Konkani, the exploration exercise began for Sreekanth and his teammate, Trivesh Mayekar. “We may not have touched half of Goa’s fish diversity yet, but with stakeholders’ help, especially the fisherfolk, our work will continue,” Sreekanth said.

Threats lie beneath

The overexploitation of fish resources, the pollution of the sea and waterbodies as well as the presence of invasive species are posing a threat to aquatic food, as some species are showing a decline.

Freshwater species like catfish, dhaddi, and inzulam have been delicacies on Goa’s fish platter for long. But some of them are seen less often in ponds and lakes. The same is the story in the estuaries.

“Increasing pollution and the overexploitation of riverine fish resources are putting pressure on biodiversity. We are not sure about the annual stocks and their reproductive capabilities,” Ingole said.

Invasive species such as African catfish and Mozambique tilapia are known to be outnumbering the local species. But no proper study has been done on this aspect.

“There is an urgent need to explore and conserve Goa’s freshwater ichthyofauna,” Mayekar said. “Unexplored regions, particularly the upper riverine systems and isolated inland aquatic habitats within the Western Ghats range likely harbour endemic and unclassified fish species, including small indigenous fishes and indigenous ornamental fishes.”