Scientific Reports (Oct 2021)

Coral micro- and macro-morphological skeletal properties in response to life-long acclimatization at CO2 vents in Papua New Guinea

  • Fiorella Prada,
  • Leonardo Brizi,
  • Silvia Franzellitti,
  • Stefano Mengoli,
  • Simona Fermani,
  • Iryna Polishchuk,
  • Nicola Baraldi,
  • Francesco Ricci,
  • Quinzia Palazzo,
  • Erik Caroselli,
  • Boaz Pokroy,
  • Loris Giorgini,
  • Zvy Dubinsky,
  • Paola Fantazzini,
  • Giuseppe Falini,
  • Stefano Goffredo,
  • Katharina E. Fabricius

DOI
https://doi.org/10.1038/s41598-021-98976-9
Journal volume & issue
Vol. 11, no. 1
pp. 1 – 10

Abstract

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Abstract This study investigates the effects of long-term exposure to OA on skeletal parameters of four tropical zooxanthellate corals naturally living at CO2 seeps and adjacent control sites from two locations (Dobu and Upa Upasina) in the Papua New Guinea underwater volcanic vent system. The seeps are characterized by seawater pH values ranging from 8.0 to about 7.7. The skeletal porosity of Galaxea fascicularis, Acropora millepora, massive Porites, and Pocillopora damicornis was higher (up to ~ 40%, depending on the species) at the seep sites compared to the control sites. Pocillopora damicornis also showed a decrease of micro-density (up to ~ 7%). Thus, further investigations conducted on this species showed an increase of the volume fraction of the larger pores (up to ~ 7%), a decrease of the intraskeletal organic matrix content (up to ~ 15%), and an increase of the intraskeletal water content (up to ~ 59%) at the seep sites. The organic matrix related strain and crystallite size did not vary between seep and control sites. This multi-species study showed a common phenotypic response among different zooxanthellate corals subjected to the same environmental pressures, leading to the development of a more porous skeletal phenotype under OA.