Catch alert drumline trial

Locations

Capricorn Coast (Yeppoon) region: Started in September 2021

• Mulambin Beach
• Tanby Point
• Fisherman Beach
• Emu Park Beach

Mackay region: Starting in 2024:

• Blacks Beach
• Eimeo Beach
• Bucasia Beach

Cairns region: Starting in 2024:

• Ellis Beach
• Buchans Point
• Palm Cove
• Clifton Beach

Design

SMART drumlines (developed at Reunion Island and trialled in New South Wales and Western Australia) are a type of catch alert drumline.

The catch alert drumline trial is conducted according to the permit issued by the Great Barrier Reef Marine Park Authority.

A traditional drumline is a baited fishing hook suspended from a large plastic float anchored to the seabed. Traditional drumlines are baited and deployed 24 hours a day. In the Great Barrier Reef Marine Park, they are checked daily by contractors on servicing days. The hooks are temporarily de-baited and rendered ineffective on non-servicing days.

Catch alert drumlines also use a baited fishing hook suspended from a large plastic float anchored to the seabed. A catch alert unit is attached which uses satellite technology to send a notification to a contractor when an animal is caught.

Traditional drumlines and catch alert drumlines use baited hooks to target and catch potentially dangerous sharks, aiming to reduce the risk to people in the water at popular beaches. They are well beyond the surf zone, well away from beach users. Traditional drumlines and catch alert drumlines are set to intercept sharks travelling the coast and the minimal bait used is insufficient to attract sharks to the area.

Captured animals

If an alert is received, the contractor will attend to the captured animal as soon as possible.

Bull, tiger and white sharks captured on catch alert drumlines or modified traditional drumlines are tagged and released away from the site of capture, when possible and safe to do so.

Acoustic tracking tags provide data on shark movements. As tagged sharks travel along the Queensland coastline, the tag ‘pings’ on an array of underwater receivers. This helps scientists map where and when sharks travel.

All other shark species and other animals are released alive, whenever possible and safe to do so.

About the trial

We began our trial of catch alert drumlines in September 2021 at 4 beaches on the Capricorn Coast, within the Great Barrier Reef Marine Park.

This trial is part of the Queensland Government’s investment in trials of alternative shark mitigation technology to determine what may be suitable for Queensland coastal conditions.

We would like to acknowledge the assistance of the NSW Department of Primary Industries (DPI) in supplying equipment for the duration of the trial, and for providing technical and scientific advice as a member of the project team.

Catch alert drumlines are trialled at locations where drumlines have been in place for many years. Modified traditional drumlines and catch alert drumlines will be alternated at trial beaches. The order of modified traditional drumlines and catch alert drumlines will be reversed periodically. This approach enables the project team to compare and report on catch rates of the 2 drumline types.

Overall the same number of traditional drumlines and catch alert drumlines will remain in place at each beach.

Both drumline types used in the trial areas are modified to use circle hooks with wire trace, whereas traditional drumlines used in the program use J hook and chain trace.

A contractor is responsible for monitoring and maintaining the catch alert drumlines by:

• deploying and baiting the catch alert drumlines early in the morning on servicing days
• monitoring for alerts from the GPS communication units throughout the day
• attending to the captured animal as soon as possible, preferably within 1 hour if an alert is received
• removing the catch alert drumline unit and hook each evening (or earlier in the day if sea conditions are forecast to become unsafe).

Aims

• Compare catches of potentially dangerous sharks and other marine animals on modified traditional and catch alert drumlines.
• Compare the rates of survival, at point of release, of marine animals captured on modified traditional and catch alert drumlines.
• Consider trial results to determine whether catch alert drumlines are suitable for long term use in Queensland coastal conditions.

Monitoring and evaluation

The first phase of the trial ran between 24 January 2022 and 23 January 2023 at 4 beaches in the Capricorn Coast region.

The evaluation report on the trial found:

• A total of 99 animals were caught on the 11 modified traditional drumlines and 66 animals on the 11 catch alert drumlines during the trial.
• Three species comprised approximately 85% of the total catch:
  • bull whalers (n=70)
  • pigeye whalers (n=51)
  • tiger sharks (n=19).
• More sharks were caught on modified traditional drumlines than catch alert drumlines, however a significant number of these were caught at night, and at dawn and dusk, when catch alert drumlines were not deployed.
• Catches of target shark species were more likely during the summer months, when sea surface temperatures were highest (higher than 25°C), irrespective of drumline type.
• The 2 most common species caught on both drumline types were bull whalers and pigeye whalers.
• Survival of sharks was substantially higher on catch alert drumlines than modified traditional drumlines, due to the reduced time the animals spent hooked (mean response time of contractors was 33 minutes), and survival increased with size.
• Tiger shark survival was high on both drumline types; however, more data is needed for a robust statistical analysis.
• Overall, catch alert drumlines increased the survival (at the point of release) of target and non-target species.
• All non-target species caught on catch alert drumlines (12 animals from 9 species) were released alive.

Outcomes

Based on the results of the first phase, the catch alert drumline trial is:

• extended to June 2025
• expanded to Cairns and Mackay.

Outside of catch alert drumline trial locations, traditional drumlines will remain in place at Queensland beaches.

The trial will continue to be monitored and outcomes will inform future government decisions on whether catch alert drumlines are suitable for long term use in Queensland conditions.