The sea urchin Centrostephanus rodgersii is anecdotally associated with urchin barrens and depletion of kelp forests along the South Coast of NSW. Western science has been used to assess urchin density and barrens extent; however, Indigenous knowledges may provide crucial insights to the population dynamics of urchins to understand habitat dynamics beyond the temporal reach of Western science. The aim of this study was to ‘braid’ Traditional Knowledge with western science to gain a deeper understanding of urchin barrens along the NSW south coast. We facilitated a series of yarning circles with Walbunja Traditional Owners, analysing Western science datasets and conducting new remote sensing along key sites of southern NSW. Remote sensing confirmed that vegetation cover was temporally dynamic at all study sites, and this was confounded by difficulties differentiating kelp extent from other vegetation types. Urchin barrens were evident at all study sites, often as part of a mosaic of rocky reef habitat. Yarning circles provided knowledge of urchin dynamics over a longer period and established a consistent pattern of decline in culturally important species. This study demonstrates the benefits of applying an approach that braids oral Traditional Knowledge with observations of kelp and urchin extent from aerial photography.