7 days with no shark drumlines off Ballina, Evans Head
Rough and dangerous seas have prevented contractors from deploying SMART drumlines off our coast for the past seven days.
The drumlines are part of the state government’s shark mitigation strategy.
Up to 35 of them are usually deployed every day at locations off Ballina and Evans Head, including beaches such as Lennox Headland, Boulder, Sharpes, Angels, Shelly, Lighthouse, South Ballina, Airforce, Evans Head, Main, Shark Bay and Joggly Point.
The SMART drumlines are located around 500m offshore in 8 to 15m of water.
They intercept and catch target sharks in an effort to reduce the chances of an interaction with water users.
But actually getting the drumlines in the water is all dependent on the weather and ocean conditions.
For the past seven days, NSW Shark Smart has advised the drumlines have not been put out.
A warning issued by the Bureau of Meteorology for the Byron coast explains that surf and swell conditions are expected to be hazardous.
People have been urged to stay out of the water and avoid activities such as rocking fishing and boating.
In fact, bad weather has hindered the effectiveness of North Coast SMART drumlines for many days this month.
Drumlines have only been deployed for five days off Ballina so far in February, and six days at Evans Head.
On February 16, when drumlines were in the water, the Department of Primary Industries Fisheries advised a 2m tiger shark was tagged and released at Seven Mile Beach, Lennox Head.
How do they work?
According to the DPI’s Shark Smart website, SMART drumlines consist of an anchor, two buoys and a satellite-linked GPS communications unit attached to a hook baited with one sea mullet.
A triggering magnet is attached to the communications unit.
When a shark takes the bait and puts pressure on the line, the magnet is released alerting the boat crew and DPI scientists that there is an animal on the line.
The team must respond within 30 minutes to tag and release the shark.
Drumlines are collected at the end of each day and are not left overnight.
‘Target sharks’ are white, bull and tiger sharks as they are the species mainly involved in shark bites in NSW.
Data shows sharks that are tagged and relocated move away from the coast for an average of 74 days before they are again detected by a listening station.
Post-release, the distance of the shark from the tagged location to the location of the listening station was an average of 165km.
“This provides us with confidence that SMART drumlines are effective in removing the immediate risk to beach users at that beach and other nearby beaches for several months,” the DPI states.