Geoscience Reference
In-Depth Information
Figure 5.11.
Planktonic mesocosms used in the context of the European project
MedSeA (Mediterranean Sea Acidification in a changing climate). a) Aerial view of a
group of three mesocosms (© A. Sallon), b) underwater view of a group of three
mesocosms (© A. Sallon), c) in situ benthic enclosures (Coral-Proto Free Ocean
Carbon Enrichment System; CP-FOCE; © University of Queensland) used on Heron
Island (Australia; [KLI 12])
Experiments in mesocosms were also carried out early on to study
benthic communities [LAN 00]. Hale
et al
. [HAL 11] carried out a
two-month experiment aiming at quantifying the effects of a reduction
in pH and an increase in temperature on a natural community of
marine invertebrates. It highlighted the changes in the structure of the
community with a notable reduction in the diversity in response to a
drop in pH. While mollusks appear very sensitive, with large
decreases in abundance and diversity in response to an increase in
acidity and temperature, the response of other organisms, such as
annelids, is more complex with a decline in abundance with a decrease
of pH and an increase in abundance with an increase in temperature.
Several recent studies have looked at the effects of ocean acidification
on micro- and macro-organisms living within the sediment and which
are responsible for bioturbation and bioirrigation. These effects lead to
modifications in the flow of nutrients between the sediment and the
overlying water [WID 11]. Recently, Campbell and Fourqurean
