Mumbai: Fishery experts have raised concerns with the state regarding the unusual sighting of jellyfish at the Sindhudurg coast and triggerfish in the waters of the west coast. They have sought extensive research on the matter stating that it could lead to the loss of the native and big fish at the affected sites.

The local fishermen from the Sindhudurg district approached the Central Marine Fisheries Research Institute (CMFRI) regarding the occurrence of jellyfish in large numbers since last 15 days in the waters of Vengurla taluka.

Experts examining this phenomenon stated that two species of jellyfish have been observed: Chrysoara and Cephea.

“This is a rare occurrence when jellyfish are seen in such large quantity in five to 10 metres of depth in water. The jellyfish are getting trapped in the nets rather than small fish, which has also hampered the fishing activities for the community,” said Swapnil Tandel, former senior researcher at CMFRI.

When Mr Tandel visited the site a fortnight ago, he stated that the fishing yield included 20 per cent of mackerel against 80 per cent of jellyfish in the net.

“Jellyfish feed on small fish eggs and fish larvae, which could strict the growth of fishes in that area. As such, the big commercial fishes that feed on small fishes would also leave the area due to the absence of food,” Mr Tandel added.

Meanwhile, the recent occurrence of triggerfish, also known as Odonus Niger, in bulk on the Maharashtra coasts has led to decline in commercial fish in Mumbai, as per experts.

“Triggerfish have also been witnessed in bulk across Mumbai’s and Palghar’s water. While the phenomenon started becoming regular since last October, it is occurring now in abundance. It started from Malvani region and is now moving northwards in the state. This could be due to the change in water currents,” said Ajay Nakhwa, a scientist at the CMFRI.

The institute has been gathering data from fishing communities of different areas to determine the exact cause of mass occurrence of the triggerfish.