Geoscience Reference
In-Depth Information
off the harmful effects of acidification and global warming on corals.
In the specific case of the Whiskey Creek Fish Hatchery in the United
States, adaptation methods have been implemented very quickly. The
hatchery regulates the supply of seawater to its facility depending on
its acidity (lower in the afternoon due to natural daily variations), and
adds calcium chloride and sodium carbonate in order to increase the
saturation level of CaCO
3
[BAR 12]. Another, more radical,
adaptation method has recently been implemented by a hatchery: the
relocation of the production of larvae in regions where the seawater
acidity is low. Goose Point Oysters moved part of its production from
Oregon to Hawaii [BRA 13]. The spat is then transported to the
Northwest American coast for growth, which does not seem wise due
to the CO
2
emissions caused by transportation.
Finally, the possibility of identifying species that are either resistant
or tolerant to acidification is another adaptation mechanism. Some
Australian oyster populations of
Saccostrea glomerata
are more
resistant than others to the drop in pH and the concentration in
carbonate ions [PAR 11]. Furthermore, the larvae of this species are
more resistant to elevated levels of pCO
2
when their parents have
already been exposed to elevated CO
2
[PAR 12]. These results suggest
that the genetic selection of strains resistant to ocean acidification is
possible.
As with
carbon dioxide removal techniques
, adaptation methods
should not be considered as an alternative to the reduction of CO
2
emissions but as additional measures aiming to offer temporary
protection to marine organism ecosystems.
5.6. Conclusion
Some effects of CO
2
uptake by the oceans, for example, changes in
the carbonate chemistry, are known with almost complete certainty
[GAT 11c, GAT 13]. The majority of the effects on the biology and
ecology of organisms and ecosystems are less well known. There is no
doubt, however, that calcification, primary production, nitrogen
fixation and diversity will be modified, some positively, others
