By Mayabhushan Nagvenkar, IANS,
Panaji : If fish is on your food menu during a Goa visit this year, you are in for competition.
Swarms of toxic jellyfish have suddenly surfaced in Goa’s inland waters, preying on small fish and fish larvae, especially in the Mandovi river off Panaji, and experts say the phenomenon can further deplete the state’s falling fish haul this year.
According to National Institute of Oceanography (NIO) scientist Baban Ingole, increasing pollution in the river water and permanent parking for vessels in the river could have given rise to the jellyfish phenomenon, which does not bode well for fish lovers of the human kind.
“What happens is that both the jellyfish and the big fish prey on the same diet — which is smaller fish and fish larvae. So if you have jellyfish consuming the prey of the larger fish, the latter will also disappear because of food shortage,” Ingole told IANS.
Ingole claims that the breed of jellyfish, which has suddenly surfaced in huge numbers in the waters off Goa, needs to be studied because it is a relatively new phenomenon and can impact marine life.
“This thing has to be studied. Suddenly, there are lots of reports of these jellyfish surfacing. We used to have another kind of jellyfish in Goa, but these seem different,” Ingole said.
Jellyfish are bulbous, soft and gelatinous creatures with highly toxic tentacles. The predatory fish uses the tentacles to inject venom into their victims before consuming them.
The jellyfish phenomenon was first noticed in Goa a few weeks ago, when huge quantities of them were getting caught in fishing nets cast by trawlers and other smaller fishing craft.
According to Ingole, one of the reasons why the jellyfish may be prospering in waters off Panaji is because of the constant parking of vessels in the river, providing the fish with an ideal environment for habitat.
“The non-moving vessels provide a good and safe environment for the jellyfish,” Ingole said.
The scientist is one of the first marine experts to claim that Goa can head for a fish famine, because of overkill in the waters surrounding the state and a shortened fishing ban during the breeding season.
The causes are natural, such as climate change and decreased dissolved oxygen (in the seas), as well as manmade, such as over-fishing and increased level of pollutants, Ingole said.
He said popular fish such as mackerel, sardines and prawn would be the first to exit the marine habitat off the state, which is flanked by the Arabian Sea to the west.
A recent Goa government report on fishing also confirmed overkill of fish.
“With the total fish production in the state crossing the maximum sustainable yield, there is a need to restrict fishing efforts in coastal waters of the state,” the report said.
(Mayabhushan Nagvenkar can be contacted at [email protected])