: Use of fish aggregating devices has devastating effect on stocks of cuttlefish through “recruitment overfishing”.
A recently-released study by scientists from the Central Marine Fisheries Research Institute on the impact of FADs on Pharoh cuttlefish showed that the annual spawning stock biomass (SSB) came down from 17,862 tonnes in 2008 to 1,467 tonnes in 2013. The number of recruits, fishes reaching the fishable age, dwindled from 93.2 million in 2008 to 35.6 million in 2013 in the study area.
Pharoh cuttlefish (Sepia pharaonis) is the most abundant of the cuttlefish varieties.
FADs are floating or moored structures meant to attract or aid aggregation of fish to help easy fishing. There are permanent FADs and temporary ones from season-to-season.
FADs are now being made more and more out of synthetic non-degrading materials in place of traditional materials like matted coconut fronds. Concerns have been raised also about the impact of these materials on the marine environment.
A CMFRI scientist said that FADs are widely used off the Malabar coast and that the Institute had recommended the practice be banned. Karnataka has issued an ordinance banning the use of FADs.
The study, conducted off the coast of Karnataka, revealed that the biological qualities of the cuttlefishes from free schools, caught through commercial fishing operations, and those near FADs differed. Those from the free schools were found to be maturing, immature, spawning and spent individuals. However, the aggregating devices brought together larger spawning cuttlefish.
Earlier studies have revealed that cuttlefish and squid deposit eggs amid artificial reefs along the southern coast of India, pointed out the Policy Guidance on Cuttle Fishery Using Fish Aggregating Devices, released in May this year by the Central Institute.
The CMFRI scientists found that only gravid animals were involved in FAD-assisted fishery, which showed that “spawning cuttlefish population is vulnerable” to fishing linked to FADs. The study said that catching spawners with high reproductive capacity led to “recruitment overfishing”.
The study, which called for sustainable management, said: “Recent increase in export demand for cuttlefishes has resulted in a renewed interest in extensive and unregulated use of FADs…”
The number of recruits, fishes reaching the fishable age, dwindled from 93.2 million in 2008 to 35.6 million in 2013 in the study area.
