Beneath the surface: the overlooked subtidal reef‐building oysters of the east coast of Australia

Molecular and morphological evidence has reshaped our understanding of oyster diversity, distributions and phylogeny, revealing widespread misidentifications and undescribed species. On Australia's east coast the Sydney rock oyster, Saccostrea glomerata , traditionally thought to be reef‐building both intertidally and subtidally, is likely a predominantly intertidal species. Examination of museum specimens and historical literature indicates that subtidal S. glomerata identifications are likely incorrect and instead represent multiple species, all with reef‐building capacity. Broadly, clarifying species identities and distributions by tidal zone and depth will be an essential first step for guiding subtidal oyster reef restoration in tropical and subtropical areas. Given this re‐interpretation, the threatened status of S. glomerata reefs should be re‐assessed to reflect their true, predominantly intertidal distribution.