Braiding Indigenous oral histories and habitat mapping to understand urchin barrens in southern New South Wales

Context The sea urchin (Centrostephanus rodgersii) is linked to urchin barrens and potential kelp forest depletion along New South Wales (NSW) southern coast. Whereas previous studies employed scientific methods to evaluate barrens, Indigenous Traditional Knowledges offer valuable insights into urchin population dynamics. Aims This study aimed to ‘braid’ Traditional Knowledges with Western science to better understand urchin barrens in the region. Methods Yarning circles with Walbunja Traditional Owners were conducted alongside habitat mapping using image segmentation of remotely sensed imagery. Key results Traditional Knowledges highlighted long-term declines in culturally significant species, including snapper (Pagrus auratus), lobster (Jasus edwardsii), groper (Achoerodus viridis), abalone (Haliotis rubra) and cuttlefish (Sepia apama). Habitat mapping showed dynamic vegetation cover, although differentiating kelp from other vegetation posed challenges. Urchin barrens were present across all study sites as part of a habitat mosaic typical of NSW rocky reefs. Conclusions This research demonstrated the value of braiding Traditional Knowledges with Western methods to enhance understanding of kelp and urchin dynamics. Implications The results of the yarning circles suggest that utilising Aboriginal and Torres Strait Islander perspectives in future studies would improve ecological insights and inform sustainable marine management strategies. Further, the habitat mapping has highlighted the need for higher resolution aerial imagery.