Thesis
Optimising SMART drumlines to reduce the risk of shark bites on people while minimising deleterious impacts on marine fauna
Southern Cross University
Doctor of Philosophy (PhD), Southern Cross University
2022
DOI:
https://doi.org/10.25918/thesis.286
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Abstract
Despite increasing global numbers of shark bites around popular coastal locations, shark bite management strategies have been largely unaltered since the 1930s. Common methods like mesh nets and traditional drumlines are indiscriminate in what they catch and, therefore, can negatively impact populations of non-threatening bycatch. In contrast, Shark-Bite- Management-in-Real-Time (SMART) drumlines facilitate effective shark-bite management without significant shark mortality. My thesis explores the use of SMART drumlines to reduce the risk of shark bites to people. To do this, data were collected over 18 months throughout the field program associated with the New South Wales (NSW) Shark Management Strategy implemented in 2016 over ~ 990 km of coast between Ulladulla and Lennox Head, NSW, Australia. A total of 500 animals were caught on the SMART drumlines, 70.0 % of which were shark species associated with most bites worldwide, and therefore the target species for my research. These target species were white (298), bull (9, Carcharhinus leucas), and tiger (43, Galeocerdo cuvier) sharks. The remaining 30 % mostly comprised of non-target shark species (144), and 5.4 % were threatened species; greynurse sharks (26, Carcharias taurus) and a loggerhead turtle (Caretta caretta). Juvenile and sub- adult white sharks experienced minimal acute physiological stress responses following capture. Video observations revealed > 18,000 animals from 7 classes and 28 families in close vicinity to SMART drumlines. Schooling bait fish (Carangidae and Clupeidae/Engraulidae) accounted for most of the abundance, with endangered or protected species comprising < 1 % of observed fauna. Overall, my research revealed that SMART drumlines successfully targeted the shark species most often associated with bites on people and resulted in low bycatch and minimal mortality of non-threatening species. Additionally, capture by SMART drumlines had minimal acute physiological impacts on the threatened population of white sharks. In conclusion, my thesis highlights the potential for SMART drumlines to provide critical research data needed to build evidence-based shark bite management strategies while offering utility to selectively target, catch, and relocate the shark species most often implicated in bites on people with relatively low associated environmental impacts.
Details
- Title
- Optimising SMART drumlines to reduce the risk of shark bites on people while minimising deleterious impacts on marine fauna
- Creators
- Rick Tate
- Contributors
- Brendan Kelaher (Supervisor) - Southern Cross UniversityPaul Allan Butcher (Supervisor) - Southern Cross UniversityStephen D A Smith (Supervisor) - Southern Cross University
- Awarding Institution
- Southern Cross University; Doctor of Philosophy (PhD)
- Theses
- Doctor of Philosophy (PhD), Southern Cross University
- Publisher
- Southern Cross University
- Number of pages
- xix, 108
- Identifiers
- 991013127813802368
- Copyright
- © RD Tate 2022
- Academic Unit
- Faculty of Science and Engineering
- Resource Type
- Thesis