This study investigates the global impacts of marine heatwaves (MHWs) on coastal foundation species (macroalgae, seagrass, corals). Analysis of 1322 shallow coastal areas across 85 marine ecoregions reveals that intense summer MHWs significantly contribute to the decline of these species, particularly at their warm-range edges. Several ecoregions show resilience, suggesting factors like cumulative MHW intensity, temperature, and location within a species' range mediate impacts. The loss of foundation species threatens biodiversity, ecological function, and ecosystem services.

Kathryn E. Smith, Margot Aubin, Michael T. Burrows, Karen Filbee-Dexter, Alistair J. Hobday, Neil J. Holbrook, Nathan G. King, Pippa J. Moore, Alex Sen Gupta, Mads Thomsen, Thomas Wernberg, Edward Wilson, Dan A. Smale