Kanjirakode karimeen, with its rich and rare texture, is considered the most delicious variety of pearl stain. Harvested from the Kanjirakode stream of Ashtamudi, it is in a different league compared to ordinary or farmed types.
But anglers are now struggling to get a good catch as the fish population and size have plummeted over the years. “We used to have pretty big ones, not palm-sized fish like this. It is usually served whole due to its solid size, but not anymore,” says fisherman Joykutty, pointing to his catch.
The story is no different for many inland fishermen who depend on Ashtamudi and Vembanad for their livelihoods, especially after the Charru mussel, an invasive bivalve species, began colonizing the creeks.
Alteration of the estuarine ecosystem poses a serious threat to pearl patch habitats, resulting in a steady decline in yield. As studies show a decrease in the average size of commercially valuable fish, cage farming units and fish sanctuaries set up by the Department of Fisheries are also affected.
Although the pearlspot is a species that guards hatchlings and exhibits parental care, it cannot protect the eggs of the thick-shelled bivalve.
“Since the bivalve feeds on eggs and hatchlings, there will be a natural decline in the population. We have been observing this for some time,” says K. Suhair, deputy director of the Department of Fisheries.
Farmers engaged in cage farming also struggle because they are unable to control mussel fouling. “The mussels continue to cover the cages and it takes a lot of extra effort to clean the units. The small size and the low yield cause us a lot of difficulty in marketing the fish,” explains Basil, a fish farmer. The charru mussel also impacts the endemic clam stock by leaving no space for the larvae to settle in, affecting the livelihoods of fishermen engaged in shellfish fishing in Ashtamudi and Vemband.
Ashtamudi Fish Count 2022. conducted jointly by the Department of Fisheries, Ashoka Trust for Research in Ecology and the Environment (ATREE) and the Department of Aquatic Biology and Fisheries, University of Kerala, over the past month recorded a widespread mussel invasion and a decline in average pearlspot size.
“It’s a huge challenge because it can have long-term implications. The situation is serious and we have asked the authorities to carry out a detailed study so that we can look for options to save the situation,” adds Mr. Suhair.