KOCHI: A study on Yellow Catfish found in Periyar river which was published in the February issue of the Journal of Threatened Taxa, has brought out grim facts about the state of our inland fishing industry and the over-exploitation of the species.
The study was jointly carried out by the University of Kerala, Cochin University of Science and Technology, St Albert’s College, Kochi, and Durrel Institute of Conservation and Ecology, UK.
The Yellow Catfish, locally known as Manjakoori, is among the species which gets frequently targeted by the traditional fishermen operating in the waters of Periyar river.
Apart form being a gourmet, the fish is also becoming increasingly popular in the international aquarium pet trade for its vibrant yellow colour.
However, the popularity of the fish seems to have a detrimental effect on its population.
One of the key issues brought out by the report was that the due to over fishing and absence of the right management practices, the fish were often caught even before they start reproducing.
For Horabagrus brychysoma (Yellow Catfish) to start reproducing, it got to be of size between 176.7 mm and 196 mm.
However, the river is populated by fish of size between 112 to 340 mm.
Since, there is no selective fishing, the fishermen often end up catching a mix of mature and immature fish, thereby, threatening sustainability.
“The fact that immature fish are also being caught indicates that recruitment fishing is taking place, damaging the reproductive potential and reducing the spawning stock of the species.
Capture of small fish before they mature and breed is also known to lead to a reduction in fisher productivity and profit,” the study observes.
The study also reveals that the exploitation rate, an index used to assess if the stock is overfished, at 0.82 is far higher than the acceptable rate of 0.5744.
The study recommends that a size-limit should be set for the fish meant for fishing.
Letting the fish cross its first reproductive size can help in balancing the fish population.
It also recommends closed seasons similar to the trawling ban in Kerala’s marine waters.
A closed season from May to August should be put in place in the riverine system as these are the spawning months for Catfish, which can be found also in other major rivers of Kerala.
Another key recommendation is an organized effort of involving fishermen communities in the management practices
A DIP IN NUMBERS
■ A study on Yellow Catfish has brought out grim facts about the state of our inland fishing industry and the over-exploitation of the species
■ Locally known as ‘Manjakoori,’ the species is frequently targeted by the traditional fishermen operating in the Periyar river
■ The popularity of the fish seems to have a detrimental effect on its population ■ One of the main reason is that the Horabagrus brychysoma (Yellow Catfish) are often caught even before they start reproducing