Environmental Engineering Reference
In-Depth Information
Effects on other non-skeletal, calcifi ed secretions of marine fauna.
The use
of calcium minerals in gravity sensory organs is widespread in many
zooplankton organisms that possess statoliths, statocysts, or statocontia.
Thus, changes in the carbonate chemistry of seawater would affect
mineralization of the various types of gravity receptors and so might
impact the overall fi tness of organisms. Fabry et al. (2008) hypothesized
that the potential impacts would depend on the ability of the organisms to
regulate the acid-base balance in the tissues surrounding those structures.
Other carbonate secretions of marine fauna that could be impacted include
gastroliths, mineralized structures formed in the lining of the cardiac
stomachs of some decapods that serve as storage sites for calcium during
moult intervals (cf. Lowenstam and Weiner 1989).
Effects on other physiological processes.
Acidosis and hypercapnia occur
as a consequence of the disruption of the acid-base balance of marine
animals, and are the detrimental result of low seawater pH and high
pCO
2
, respectively (Pörtner et al. 2004). These homeostatic disorders
influence most physiological processes (Roos and Boron 1981), such as
neural signaling (Waggett and Buskey 2008), development, reproduction
(Kikkawa et al. 2004), metabolism and even gene expressions (Pörtner et al.
2010) as well as behavior (Thistle et al. 2007). Regulation of body acid-base
depends upon energy and acidosis or hypercapnia can affect the energy
acquisition and allocation (Whiteley 2011). Recently, Li and Gao (2012)
analyzed the possibility that marine secondary producers increase their
respiration and feeding rate in response to ocean acidification to balance the
energy cost against increased acidity and CO
2
concentration. They found
that the copepod
Centropages tenuiremis
can perceive chemical changes in
seawater under elevated CO
2
concentration with avoidance strategies. The
copepod's respiration and its feeding rate increased at the elevated pCO
2
(1000 uatm) and its associated acidity (pH 7.83). The ability to perceive the
chemical changes in seawater and to escape from the adverse circumstance
is the key for
C. tenuiremis
to survive in coastal waters where pH changes
are intensifi ed by eutrophication and atmospheric CO
2
rise (Cai et al. 2011).
To respond to and cope with the increased external acidity, the copepod
C. tenuiremis
increased its food acquisition to compensate the extra energy
demand via enhanced respiration.
Effects on zooplankton behavior.
Studies relative to acidifi cation effects on
zooplankton reproduction reveal changes on swimming and mating
behaviors as well as mating success. Specifically, ocean acidification
decreases the ability of male copepods to detect, track and capture a
female. Seuront (2010) found that the level of ocean acidifi cation expected
to occur in 2100 (i.e., pH = 7.8 to 7.6) signifi cantly modifi es the stochastic
properties of successive displacements of the copepods
Eurytemora affi nis
