Persistent natural acidification drives major distribution shifts in marine benthic ecosystems.
Ocean acidification is receiving increasing attention because of its potential to affect marine ecosystems. Rare CO2 vents offer a unique opportunity to investigate the response of benthic ecosystems to acidification. However, the benthic habitats investigated so far are mainly found at very shallow water (less than or equal to 5 m depth) and therefore are not representative of the broad range of continental shelf habitats. Here, we show that a decrease from pH 8.1 to 7.9 observed in a CO2 vent system at 40 m depth leads to a dramatic shift in highly diverse and structurally complex habitats. Forests of the kelp Laminaria rodriguezii usually found at larger depths (greater than 65 m) replace the otherwise dominant habitats (i.e. coralligenous outcrops and rhodolith beds), which are mainly characterized by calcifying organisms. Only the aragonite-calcifying algae are able to survive in acidified waters, while high-magnesium-calcite organisms are almost completely absent. Although a long-term survey of the venting area would be necessary to fully understand the effects of the variability of pH and other carbonate parameters over the structure and functioning of the investigated mesophotic habitats, our results suggest that in addition of significant changes at species level, moderate ocean acidification may entail major shifts in the distribution and dominance of key benthic ecosystems at regional scale, which could have broad ecological and socio-economic implications.
Departament d'Ecologia, Facultat de Biologia, Universitat de Barcelona, Avda. Diagonal 643, Barcelona 08028, Spain cristinalinares@ub.edu.
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0000-0003-3855-2743
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Linares
Departament d'Ecologia, Facultat de Biologia, Universitat de Barcelona, Avda. Diagonal 643, Barcelona 08028, Spain.
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0000-0002-7878-3290
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Vidal
GRC Geociències Marines, Departament d'Estratigrafia, Paleontologia i Geociències Marines, Facultat de Geologia, Universitat de Barcelona, Martí i Franquès s/n, Barcelona 08028, Spain.
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Canals
Departament d'Ecologia, Facultat de Biologia, Universitat de Barcelona, Avda. Diagonal 643, Barcelona 08028, Spain.
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Kersting
GRC Geociències Marines, Departament d'Estratigrafia, Paleontologia i Geociències Marines, Facultat de Geologia, Universitat de Barcelona, Martí i Franquès s/n, Barcelona 08028, Spain.
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0000-0002-6248-5512
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Amblas
Departament d'Ecologia, Facultat de Biologia, Universitat de Barcelona, Avda. Diagonal 643, Barcelona 08028, Spain.
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Aspillaga
Centre d'Estudis Avançats de Blanes, CSIC, Accés Cala St Francesc 14, Blanes, Girona 17300, Spain Departament de Ciències Ambientals, Universitat de Girona, Campus Montilivi, Girona 17071, Spain.
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Cebrián
Instituto Andaluz de Ciencias de la Tierra, CSIC-UGR, Avenida de las Palmeras 4, Armilla 18100, Spain.
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Delgado-Huertas
Instituto Español de Oceanografía, C/ Moll de Ponent s/n, Palma de Mallorca 07015, Spain Institut de Ciències del Mar, CSIC, Passeig Marítim de la Barceloneta 37-49, Barcelona 08003, Spain.
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Díaz
Institut de Ciències del Mar, CSIC, Passeig Marítim de la Barceloneta 37-49, Barcelona 08003, Spain.
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Garrabou
Departament d'Ecologia, Facultat de Biologia, Universitat de Barcelona, Avda. Diagonal 643, Barcelona 08028, Spain.
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Hereu
Departament d'Ecologia, Facultat de Biologia, Universitat de Barcelona, Avda. Diagonal 643, Barcelona 08028, Spain.
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Navarro
Stazione Zoologica Anton Dohrn, Villa Dohrn-Benthic Ecology Center, Punta San Pietro, Ischia, Naples 80077, Italy.
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Teixidó
Centre d'Estudis Avançats de Blanes, CSIC, Accés Cala St Francesc 14, Blanes, Girona 17300, Spain.
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Ballesteros
D000143:Acids / Q000737:chemistry; D000818:Animals; D037421:Anthozoa / Q000502:physiology; D002013:Bryozoa / Q000502:physiology; D002245:Carbon Dioxide / Q000494:pharmacology*; D002254:Carbonates / Q000737:chemistry; D017753:Ecosystem; D006863:Hydrogen-Ion Concentration; D007795:Laminaria / Q000502:physiology; D008522:Mediterranean Sea; D000461:Rhodophyta / Q000502:physiology; D012623:Seawater / Q000737:chemistry*
D000143:Acids; D002254:Carbonates; D002245:Carbon Dioxide
CO2 vents; calcification; climate change; ocean acidification; pH