Dead fish could attract predators
The recent discovery of scores of dead fish in the vicinity of Durban’s uShaka/South Beach has raised concern that careless dumping of undersize fish and by-catches might attract sharks to nearby bathing beaches.
Spear fishermen Carl Stow and Selwyn Rautenbach found dead, undersized shad lying on the sea bed near the backline last week.
How the fish died remained a mystery, but fish researchers speculated that these might have been discarded by seine netters or ski-boat fishermen.
Durban spear fisherman Rory O’Connor said he was concerned that the presence of dead fish or fish blood so close to the shore could attract sharks and predator species to nearby bathing beaches.
He was also concerned that the presence of large shoals of fish struggling to escape from seine nets could also lure sharks.
Sean Fennessy, a senior scientist at the Oceanographic Research Institute, said: “Any dead fish thrown into the sea, be it in the form of angling bait, or in the form of seine net discards, could potentially attract sharks, but given the scale of the seine netting operation, and the nature of the discards (small fish), I would assess the risk as very low.
“It would be very difficult to quantify the risk posed by the seine netters relative to other shark-attracting factors such as bait angling, fresh water cues from the Mgeni river and Durban harbour etc,” he said.
Asked whether by-catch was dumped on a regular basis in the uShaka/Vetch’s Pier area, Fennessy said: “Generally, small fish or those that cannot be sold are discarded, and although this happens regularly, there are no estimates of how much is discarded or how often; the netters are only required to submit records of retained catch to the Department of Fisheries.
“There has been virtually no on-site monitoring of the seine net fishery since the institute did a year-long study on it in the early 1990s. Anecdotal reports are that the frequency of netting has increased in the past year or so, with the use of a motorised boat to deploy the net, so the incidence of discarding could have increased.
“However, it is my understanding that the netting permit will in future preclude the use of a motorised boat, which means that the netters will again only be able to operate in calm seas, which will minimise the discarding further.”
KwaZulu-Natal Sharks Board spokesman Mike Anderson-Reade said the presence of whole, dead fish was not as problematic as the blood and intestines of gutted fish.
“However, we don’t condone the dumping or gutting of dead fish anywhere near bathing beaches.”
Morgan Subramunien, a spokesman for the Durban Seine Netters group, said dolphins had been feasting on large shoals of shad around Limestone Reef this week, but members of his group were only allowed to keep four shad each for personal consumption.
“We do get some by-catch species – but we don’t just dump them. If necessary, we cut the nets and let them go.”
But Durban paddle-ski fisherman Johnny Vassilaros said he remained sceptical that seine netters were operating within the law.
“I believe this most indiscriminate method of fishing has outlived its purpose and it’s high time the authorities banned it outright. Instead, they are now accommodating their application to operate at night and have now acquired a motorised craft instead of using the old rowing boat.”