Journal article
Ocean warming increases residency at summering grounds for migrating bull sharks (Carcharhinus leucas)
Science of the Total Environment, Vol.992, pp.1-11
2025
PMID: 40570393
Abstract
Globally, climate change is driving warming ocean temperatures, increasing the frequency and severity of extreme temperature events and altering current systems. Consequently, distributions and movement patterns of marine species are shifting, causing changes to ecosystem functioning. Migration patterns of large-bodied species are also expected to be affected by climate change. However, contemporary evidence of such changes to the spatio-temporal dynamics of movement and residency in migratory marine predators is rare, consisting mainly of predictions of distributions under future climate change scenarios because long-term tracking/catch data is difficult to obtain. Here, we use passive acoustic telemetry data spanning 15 years (2009–2024), in combination with remotely sensed and in-situ temperature data, to investigate how shifts in climate influence residency duration and migration timing in migratory bull sharks (Carcharhinus leucas) on their temperate summering grounds. Our results show that sharks have delayed departure from their temperate summering grounds off Sydney, Australia by an average of 1 day per year over a 15-year period, while also for the first time recording arrival times in October rather than November, as previously published. As a result, sharks are increasing residency duration, shifting the timing of migrations back to tropical latitudes for the colder months. Bull sharks depart temperate summering grounds upon possible long-term exposures to temperatures of ∼19–20.5 °C and below. Increases in sea temperatures are likely reducing the species' exposure to this thermal limit. In concordance, we found an average warming of 0.67 °C based on remotely sensed sea-surface temperature data (1982–2024) and of 0.57 °C based on in situ data (2006–2024) at our study site. As bull sharks are high-trophic level predators and implicated in shark-human interactions, more time spent at temperate summering grounds has the potential to impact local ecosystems through intensified predation pressure, while increasing temporal overlap with people in estuarine and coastal areas.
Details
- Title
- Ocean warming increases residency at summering grounds for migrating bull sharks (Carcharhinus leucas)
- Authors
- Nicolas Lubitz (Corresponding Author) - James Cook UniversityPaul A Butcher - Southern Cross UniversityPatrick Vianello - Nelson Mandela UniversityAdam Barnett - Biopixel Oceans Foundation (Australia)Ross G Dwyer - University of the Sunshine Coast, Queensland, School of Science, Technology and EngineeringMarcus Sheaves - James Cook UniversityAmy F Smoothey - Sydney Institute of Marine Science
- Publication details
- Science of the Total Environment, Vol.992, pp.1-11
- Publisher
- Elsevier BV
- Date published
- 2025
- DOI
- 10.1016/j.scitotenv.2025.179966
- ISSN
- 1879-1026
- PMID
- 40570393
- Copyright note
- © 2025 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
- Data Availability
- All data used in this manuscript are publicly available. Shark tracking and receiver meta data can be obtained from the Integrated Marine Observing System Animal Tracking Facility at https://animaltracking.aodn.org.au/. Temperature data from the IMOS mooring can be obtained via the Remora R package or from https://imos.org.au/ directly via the Australian Ocean Data Network. Remotely sensed SST data from the OSTIA data set can be obtained from the Copernicus Marine Service under the Ocean Products tab https://marine.copernicus.eu/.
- Grant note
- Funding for this study was mainly provided by the New South Wales Government through the NSW Department of Primary Industries Bull shark tagging research program and NSW Shark Management Program with in-kind contributions and additional funding from the Department of Environment and Science, Queensland, The Department of Agriculture and Fisheries, Queensland, the Save Our Seas Foundation, and the Holsworth Wildlife Research Endowment Student Grant for bull shark work undertaken in Queensland.
- Organisation Unit
- School of Science, Technology and Engineering
- Language
- English
- Record Identifier
- 991140406102621
- Output Type
- Journal article
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