Carbonate production and erosion on temperate reefs: overlooked but globally relevantBiogeochemical Cycling

Albert Pessarrodona^1,2,3, Oceane Attlan¹, Karen Filbee-Dexter^1,4, Thomas Wernberg^1,4

¹University of Western Australia, Australia - ²Conservation International, USA - ³International Blue Carbon Institute, Singapore - ⁴Institute of Marine Research, Flødevigen Research Station, Norway

Calcifying organisms underpin key geo-ecological functions on shallow reefs worldwide, where they produce sediments, support reef accretion and create habitat structure. These functions strongly depend on the carbonate budget: the balance between calcium carbonate production and erosion. While carbonate budgets are well characterized for tropical coral reefs, they remain much less well understood for temperate reefs. This talk will share the findings of a research program dedicated to understanding the global magnitude and spatio-temporal variation of carbonate budgets on temperate reefs. Studies on Australia’s Great Southern Reef suggest that temperate reef carbonate production could be comparable to tropical systems renowned for their high carbonate production such as the Great Barrier Reef. Moreover, temporal surveys across 116 reefs in Western Australia indicate that carbonate production may be increasing, as these processes are increasingly shaped by tropical-affinity species such as corals and parrotfishes. The talk will finish by discussing insights from a global collaborative study on temperate reef carbonate production, which reveals consistent latitudinal patterns in temperate carbonate reef production and highlights its relevance as an important but overlooked function.