Seawater carbonate chemistry and kelp densities and coral coverages at three study locations and photosynthesis and calcification of corals measured in the laboratory

• Main Authors: Agostini, Sylvain, Harvey, Ben P, Milazzo, Marco, Wada, Shigeki, Kon, Koetsu, Floc'h, Nicolas, Komatsu, K, Kuroyama, Mayumi, Hall-Spencer, Jason M
• Format: Dataset
• Language: English
• Published: PANGAEA 2021
• Subjects: Acropora solitaryensis; Alkalinity; total; standard deviation; Animalia; Aragonite saturation state; Area/locality; Benthic animals; Benthos; Bicarbonate ion; Bottles or small containers/Aquaria (<20 L); Calcification/Dissolution; Calcification rate of calcium carbonate; Calcite saturation state; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Cnidaria; CO2 vent; Coast and continental shelf; Color description; Community composition and diversity; Coral; Diameter; Entire community; Event label; EXP; Experiment; Field experiment; Field observation; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Growth/Morphology; Growth rate; Identification; Izu_Peninsula; Laboratory experiment; Month; Net calcification rate of calcium carbonate; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.944056; https://doi.org/10.1594/PANGAEA.944056

Ocean warming is altering the biogeographical distribution of marine organisms. In the tropics, rising sea surface temperatures are restructuring coral reef communities with sensitive species being lost. At the biogeographical divide between temperate and tropical communities, warming is causing macroalgal forest loss and the spread of tropical corals, fishes and other species, termed “tropicalization”. A lack of field research into the combined effects of warming and ocean acidification means there is a gap in our ability to understand and plan for changes in coastal ecosystems. Here, we focus on the tropicalization trajectory of temperate marine ecosystems becoming coral-dominated systems. We conducted field surveys and in situ transplants at natural analogues for present and future conditions under (i) ocean warming and (ii) both ocean warming and acidification at a transition zone between kelp and coral-dominated ecosystems. We show that increased herbivory by warm-water fishes exacerbates kelp forest loss and that ocean acidification negates any benefits of warming for range extending tropical corals growth and physiology at temperate latitudes. Our data show that, as the combined effects of ocean acidification and warming ratchet up, marine coastal ecosystems lose kelp forests but do not gain scleractinian corals. Ocean acidification plus warming leads to overall habitat loss and a shift to simple turf-dominated ecosystems, rather than the complex coral-dominated tropicalized systems often seen with warming alone. Simplification of marine habitats by increased CO2 levels cascades through the ecosystem and could have severe consequences for the provision of goods and services.