Thesis
Regionally contrasting movement behaviour of sub-adult whale sharks in Indonesia
Masters by Research, Murdoch University
2022
Abstract
Movement studies on filter-feeding megafauna have revealed movement and behavioural plasticity in response to the variation of prey availability in different habitats, information that is needed to create a specific and effective conservation measures for species affected by anthropogenic activities such as tourism and fisheries. Over the past decade, year-round aggregations of juvenile whale shark have been documented across Indonesia. Understanding their behaviour in these developmental habitats and across the complex and diverse marine habitat of the archipelago is important for the country’s conservation effort for the species of high value from tourism is of particular importance for the world’s largest shark and ray fishing nation. Here we use multi-sensor tags to reconstruct the movement paths and locomotor kinematics of juvenile whale sharks in Saleh Bay and four in Cenderawasih Bay, Indonesia to compare how their movement and behaviour would differ in 3 differing regions, namely coastal Cenderawasih Bay (CBC), oceanic Cenderawasih Bay (CBO), and coastal Saleh Bay (SBC). These regions have different environmental conditions, as well as different exposure to bagan lift net fisheries and tourism. We describe a novel meso-pelagic foraging behaviour in SBC. Similar deep-water foraging has been stipulated previously, but this study is the first to describe its kinematics in detail. Statistical comparison of diel behavioural patterns through GAMMs reveals varying foraging specialization in relation to the presumed different prey availability by time of day and depth in each region. Some specialization is thought to be driven by habituation through provisioning from the passive presence of bagan fisheries, and tourism-driven active feeding. This information will allow conservation managers in Indonesia to assess the current management measure to protection and tourism of the species, as well as to design an effective site-specific conservation strategy that would allow the growing whale shark tourism in both sites to thrive sustainably. As the long-term impact of the habituation unclear, this study could serve as a baseline on future assessment on how the bagan fisheries and tourism affect the shark’s behaviour.
Details
- Title
- Regionally contrasting movement behaviour of sub-adult whale sharks in Indonesia
- Authors/Creators
- Abraham B Sianipar
- Contributors
- Adrian Gleiss (Supervisor) - Murdoch University, Centre for Molecular Medicine and Innovative TherapeuticsMark Meekan (Supervisor) - Australian Institute of Marine ScienceMark V Erdmann (Supervisor)Neil Loneragan (Supervisor) - Murdoch University, Centre for Sustainable Aquatic Ecosystems
- Awarding Institution
- Murdoch University; Masters by Research
- Identifiers
- 991005599068707891
- Murdoch Affiliation
- Harry Butler Institute
- Resource Type
- Thesis
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