Work

Assessing the current and projected distributions of temperate sharks and rays in southeastern Australia

Year: 2025

Type: article

Abstract: Elasmobranchs, including sharks and rays, face significant threats with a quarter of the global population at risk of extinction. In southeastern Australia, climate change (and in particular rising ocean temperatures) poses a significant threat. However, our understanding of how climate change will affect elasmobranch populations, and the effectiveness of marine protected areas (MPAs) in safeguarding them, remains limited, especially in temperate regions. This study aimed to address these gaps by modelling how environmental factors influence elasmobranch distribution and abundance in temperate waters off the Victorian coastline in Australia, and quantified the degree to which areas of high abundance and richness were contained within MPA boundaries. Data from 1,048 baited remote underwater video stations (BRUVS) were combined with six layers representing oceanographic variables and seafloor habitat. Models generated were then projected using two climate change scenarios to identify future change. The protective capacity of Victorian MPAs was then assessed by identifying the extent of habitat suitable for elasmobranchs contained within each MPA, both now, and under future predictions. Sea surface temperature and mean wave orbital velocity were identified as key drivers of current elasmobranch abundance and distribution, but the importance varied between taxa studied. MPAs were found to offer varying degrees of protection under each environmental scenario, however, MPA effectiveness was predicted to increase under moderate to extreme climate scenarios, respectively. This research provides insights for the conservation and management of temperate elasmobranch species in the face of environmental threats.

Source: Regional Studies in Marine Science

DOI: 10.1016/j.rsma.2025.104418

Authors: Louisa G. Graf, Oliver Dalby, Sasha Whitmarsh, Daniel Ierodiaconou, Mary A. Young

Institution: Deakin University

Language: English

Topic: Ichthyology and Marine Biology

Subfield: Nature and Landscape Conservation

Field: Environmental Science

Domain: Physical Sciences

SDGs: Life below water, Life on land, Climate action

Open Access status: hybrid

Estimated APC paid: $3,030