SMART (Shark-Management-Alert-in-Real-Time) drumlines are a key feature of the NSW Government's shark bite mitigation measures.
The state-of the art technology differs greatly from the operation of traditional drumlines as they are not designed or operated to kill sharks.
SMART drumlines comprise of an anchor and rope, two buoys, and a satellite-linked communications unit which is attached to a trace and baited hook. SMART drumlines are deployed approximately 500 metres offshore away from swimmers and surfers to allow sharks to be intercepted beyond the surf zone. When a shark is hooked, the pressure on the line triggers the communications unit which alerts DPI scientists or contractors via phone call, email and text message to the presence of an animal on the line. The team then responds immediately to the SMART drumline alert to manage the animal.
Target sharks caught on the SMART drumline are relocated approximately 1km offshore, and any bycatch can be released alive immediately. Intercepting and catching sharks as they travel along our coastline reduces the chances of an interaction with water users. Their relocation by the response team and natural reaction to move offshore after release also provides a non-lethal method of removing sharks further away from an area in the short to medium term.
SMART drumlines are also an important research tool to better understand the movements and distribution of sharks. Sharks caught on SMART drumlines can be tagged and released. DPI can then provide alerts to the community via our network of 21 VR4G listening stations when they are close to shore. Once the shark is tagged, they are released approximately 1km offshore. Recent tracks from tagged sharks shows that they often head further offshore immediately after release (for the first 24-48 h), so in addition to minimising any threat of an interaction with water users, having them move offshore after release further enhances the utility of SMART drumlines as a non-lethal bather protection tool.
SMART drumlines have been in use extensively on the NSW North Coast and as required at other coastal locations since December 2015. Up to 35 SMART drumlines are deployed daily between Evans Head and Lennox Head (weather and ocean conditions permitting).
Ten SMART Drumlines were also trialled at each of the following locations:
These locations were chosen using historical data and recent aerial surveillance data. There are 25 SMART drumlines retained by DPI for research.
Tagged sharks will be tracked by NSW DPI scientists, who will monitor their movements to gain a better understanding of their movement patterns. When a tagged shark swims past our network of 21 VR4G acoustic listening stations, it is broadcast automatically via the DPI SharkSmart Twitter account @NSWSharkSmart and also on the SharkSmart app (itunes.apple.com). This program provides vital information about sharks and helps to improve our understanding of the behaviour and movements of the population of white, bull and tiger sharks that live on the east coast of Australia.
Our DPI Shark Tagging Team is having promising success tagging White, Tiger and Bull sharks using SMART drumline technology while it is also proving effective in catching target species with minimal bycatch and mortality. The initial trials of these SMART drumlines demonstrated their ability to capture sharks and trigger the system with instant alerts.
They have proven to be four-times more effective than mesh nets on the North Coast during our six month trial earlier this year with minimal bycatch of non-target animals.
DPI will continue its research to fine tune this gear for use in Australian conditions. This involves testing different gears (hooks, trace lengths and trace material), bait types to maximise catch rates of target shark species only, and videoing the activity of animals around SMART drumlines before and after capture using underwater cameras.