The carbon dioxide vents of Ischia, Italy, a natural system to assess impacts of ocean acidification on marine ecosystems: an overview of research and comparisons with other vent systems
Foo, S.A.; Byrne, M.; Ricevuto, E.; Gambi, M.C. (2018). The carbon dioxide vents of Ischia, Italy, a natural system to assess impacts of ocean acidification on marine ecosystems: an overview of research and comparisons with other vent systems, in: Hawkins, S.J. et al. Oceanogr. Mar. Biol. Ann. Rev. 56. Oceanography and Marine Biology: An Annual Review, 56: pp. 237-310 In: Hawkins, S.J. et al. (2018). Oceanogr. Mar. Biol. Ann. Rev. 56. Oceanography and Marine Biology: An Annual Review, 56. CRC Press: Boca Raton. ISBN 978-1-138-31862-5. 509 pp., more In: Oceanography and Marine Biology: An Annual Review. Aberdeen University Press/Allen & Unwin: London. ISSN 0078-3218; e-ISSN 2154-9125, more |  |
| Authors | | Top | - Foo, S.A.
- Byrne, M.
- Ricevuto, E.
- Gambi, M.C., more
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| Abstract | As the ocean continues to take up carbon dioxide (CO2), it is difcult to predict the future of marine ecosystems. Natural CO2 vent sites, mainly of volcanic origin, that provide a pH gradient are useful as a proxy to investigate ecological effects of ocean acidication. The effects of decreased pH can be assessed at increasing levels of organisation, from the responses of individuals of a species up through populations and communities to whole ecosystems. As a natural laboratory, CO2 vent sites incorporate a range of environmental factors, such as gradients of nutrients, currents and species interactions that cannot be replicated in the laboratory or mesocosms, with the caveat that some vent systems have confounding factors such as hydrogen sulphide and metals. The rst CO2 vent sites to be investigated in an ocean acidication context were the vents at the Castello Aragonese on the island of Ischia, Italy. The gas released is primarily CO2 with no evidence of toxic substances. They have been the focus of a wealth of studies, which are reviewed here and in context with research at other vent systems. Investigations of the species that occur along the pH gradients at Ischia show that, as the pH decreases, there is a reduction in calcifying species, reecting the trends seen at other vent systems and in laboratory studies. The species assemblages at the Castello vents living at near future (2100) ocean acidication conditions (mean pH 7.8), show the resilience of many species to elevated CO2, including many calcifying species (e.g. sea urchins, serpulids, bryozoans, foraminifera and corals). These taxa show different physiological and ecological mechanisms for acclimatisation and adaptation to low pH. As the oceans continue to acidify to pH levels <7.8, species assemblages are likely to become dominated by eshy algae and smaller-bodied, generalist invertebrates. These observations suggest that ocean acidication will result in a simplication of marine food webs and trophic complexity. |
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