Tagged shark nets

Researchers test new “eco-friendly” shark barriers

eNCA reports that researchers from Stellenbosch University are performing a test trial of a new “eco-friendly” shark barrier near Dyer Island off the coast of Gansbaai, SA.

The Sharksafe Barrier System consists of connected rigid pipes that span from the ocean floor to the surface. The system is designed to resemble kelp and emits a “magnetic barrier,” which will deter sharks from attempting to swim through the artificial barrier, according to the team who developed the system.

Unlike “traditional” shark nets that indiscriminately kill various forms of marine life, the Sharksafe Barrier System is designed to serve as a physical barrier to merely deter sharks from passing through. The system will span from shoreline to shoreline, as well as from the sea floor to the surface, to create an all-encompassing barrier, unlike traditional nets.

In addition to researchers from Stellenbosch University, PhD candidate Craig O’Connell (University of Massachusetts Dartmouth) and renown diver and white shark conservationist Mike Rutzen have collaborated on the project, which has been under development since 2011. The team plans to finish testing the barrier within the next month before submitting requests for permission to use the barriers at Cape Town’s Muizenberg and Fish Hoek beaches.

Swimming banned in Scottburgh after 14 tiger sharks netted

South Africa’s The Mercury reports that swimming has been banned indefinitely after 14 tiger sharks (Galeocerdo cuvier) were found in shark nets off Scottburgh on the south coast of KwaZulu-Natal, yesterday. The nets have been temporarily removed, which prompted the swimming ban.

Nine of the netted sharks were tagged and released alive. Dissection of the dead sharks revealed large amounts of whale blubber in the sharks’ stomach. It is believed the sharks were attracted to the area by a whale carcass. An apparent “slick” is also present in the area, as a result of the presence of the whale carcass.

The swimming ban is expected to remain in place until the slick dissipates, and the shark nets are replaced.

Western Australia rules out culling of great white sharks

great white shark
Western Australia officials have ruled out the culling of white sharks.

The Australian is reporting that Fisheries Minister Norman Moore has ruled out any cull of white sharks (Carcharodon carcharias) in response to three fatal shark attacks in Western Australia. Instead a newly formed response unit will look examine the effectiveness of shark nets, correlations between weather conditions and shark attacks, and whether or not protection laws have resulted in an increase in the number of the species.

Moore said that his department is trying to balance protecting the species and providing as much information about the probability of shark attacks when they go swimming. Additionally, the response unit will assess the effectiveness of the SMS shark alert system.

“The Conversation” feature on Australia’s shark nets

The Conversation has an interesting article on the history of shark nets in Australia. The article, written by Christopher Neff, focuses primarily on the use of shark nets in the waters of New South Wales and gives a bit of history about how the nets first came to be. Neff also touches on the politics associated with the nets and the effectiveness of them in protecting humans from shark attacks.

Neff questions the effectiveness of shark nets noting that from 1937-2008 of the recorded shark attacks in New South Wales, 63% of them occurred at beaches using shark nets. He also points out that only one fatal attack has occurred at a netted beach in the state, but cautions that associating low fatality rates with the nets might be questionable, as there was a three year period in which the nets were removed and no fatalities were reported.

While the Neff certainly seems to lean in the direction of opposing the nets he admits that the issue of Australia’s shark nets is not a simple matter. Neff stresses the need for public safety measures and points out that the consequences from shark attacks can be “terrible.” However, he notes that public dialog and education are necessary to move away from outdated tactics that are leaving Australia behind.

You can check Neff’s full article at The Conversation.

Queensland shark nets to be fitted with alarms for whales

Shark nets in Queensland will be fitted with “pingers” designed to alert migrating whales to the presence of shark nets, according to the Sydney Morning Herald. The move marks an attempt to help prevent whales from becoming entangled in the nets. In 2009, six whales were trapped in the shark nets, which have stirred up controversy in the past. All six of the whales trapped last year were successfully freed.

The shark nets are already equipped with pingers designed to alert dolphins. The whale pingers will a “longer and louder noise” as compared to the dolphin pingers, according to Primary Industries Minister Tim Mulherin, who went on to note that the pingers are designed only to alert the whales of the presence of the nets not to scare them away.

Multiple prototypes will be fitted to the nets this week as a test run. The goal is to have the alarms on all the shark nets by August when younger whales are more likely to come in close proximity to the nets.