Seawater carbonate chemistry and coverage of turf algae, other macroalgae and corals

• Main Authors: Harvey, Ben P, Allen, Ro, Agostini, Sylvain, Hoffmann, L J, Kon, Koetsu, Summerfield, Tina C, Wada, Shigeki, Hall-Spencer, Jason M
• Format: Dataset
• Language: English
• Published: PANGAEA 2021
• Subjects: Alkalinity; total; standard deviation; Aragonite saturation state; Benthos; Bicarbonate ion; Calcite saturation state; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Calculated using seacarb after Orr et al. (2018); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; CO2 vent; Coast and continental shelf; Community composition and diversity; Coverage; Distance; Entire community; EXP; Experiment; Field experiment; Figure; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Fugacity of carbon dioxide in seawater; North Pacific; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.930799; https://doi.org/10.1594/PANGAEA.930799

Human activities are rapidly changing the structure and function of coastal marine ecosystems. Large-scale replacement of kelp forests and coral reefs with turf algal mats is resulting in homogenous habitats that have less ecological and human value. Ocean acidification has strong potential to substantially favour turf algae growth, which led us to examine the mechanisms that stabilise turf algal states. Here we show that ocean acidification promotes turf algae over corals and macroalgae, mediating new habitat conditions that create stabilising feedback loops (altered physicochemical environment and microbial community, and an inhibition of recruitment) capable of locking turf systems in place. Such feedbacks help explain why degraded coastal habitats persist after being initially pushed past the tipping point by global and local anthropogenic stressors. An understanding of the mechanisms that stabilise degraded coastal habitats can be incorporated into adaptive management to better protect the contribution of coastal systems to human wellbeing.