Publication Date:
2021-02-03
Description:
Ocean acidification is one of the most
dramatic effects of the massive atmospheric release of
anthropogenic carbon dioxide (CO2) that has occurred
since the Industrial Revolution, although its effects on
marine ecosystems are not well understood. Submarine
volcanic hydrothermal fields have geochemical
conditions that provide opportunities to
characterise the effects of elevated levels of seawater
CO2 on marine life in the field. Here, we review the
geochemical aspects of shallow marine CO2-rich
seeps worldwide, focusing on both gas composition
and water chemistry. We then describe the geochemical
effects of volcanic CO2 seepage on the overlying
seawater column. We also present new geochemical
data and the first synthesis of marine biological
community changes from one of the best-studied
marine CO2 seep sites in the world (off Vulcano
Island, Sicily). In areas of intense bubbling, extremely
high levels of pCO2 ([10,000 latm) result in low
seawater pH (\6) and undersaturation of aragonite
and calcite in an area devoid of calcified organisms
such as shelled molluscs and hard corals. Around
100–400 m away from the Vulcano seeps the geochemistry
of the seawater becomes analogous to future
ocean acidification conditions with dissolved carbon
dioxide levels falling from 900 to 420 latm as
seawater pH rises from 7.6 to 8.0. Calcified species
such as coralline algae and sea urchins fare increasingly
well as sessile communities shift from domination
by a few resilient species (such as uncalcified
algae and polychaetes) to a diverse and complex
community (including abundant calcified algae and
sea urchins) as the seawater returns to ambient levels
of CO2. Laboratory advances in our understanding of
species sensitivity to high CO2 and low pH seawater,
reveal how marine organisms react to simulated ocean
acidification conditions (e.g., using energetic tradeoffs
for calcification, reproduction, growth and survival).
Research at volcanic marine seeps, such as
those off Vulcano, highlight consistent ecosystem
responses to rising levels of seawater CO2, with the
simplification of food webs, losses in functional
diversity and reduced provisioning of goods and
services for humans.
Description:
Published
Description:
93–115
Description:
2IT. Laboratori analitici e sperimentali
Description:
JCR Journal
Keywords:
Calcifying species , Ecosystem effects, Natural analogues, Submarine hydrothermalism
;
03. Hydrosphere
;
03.04. Chemical and biological
;
03.02. Hydrology
;
04.08. Volcanology
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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