Marine Ecosystems under Toxic Pressure - Vulnerability of Coastal Ecosystems and Adaptation - page 35

for exchanges with air and/or running water [MAC 05]. This
availability will also augment the degradation processes [BEY 03,
BRU 98, MA 04, SCH 05].
In addition to numerous abiotic factors that can influence the
behavior of contaminants, modifications in the migratory habits of
several species due to climate change could be an important
modulating factor for the transport of POP [BLA 07]. In effect,
migratory species, such as fish, birds and sea mammals, can be
exposed to contaminants in an impacted geographic zone (coastal or
estuary zone) and by migrating, transport these contaminants in
substantial quantities to other sites that are not directly impacted. This
“biotic” transport of contaminants can have an order of size similar to
atmospheric and oceanic transport [BUR 08]. In effect, Blais et al.
[BLA 07] have shown that birds from the Arctic and Antarctica act as
vectors for persistent contaminants from oceans to land systems via
their guano. Thus, on the Canadian coast under the cliffs where
northern fulmars nest ( Fulmarus glacialis ), concentrations in
HexaChloroBenzene (HCB), DDT and mercury are 10-60 times
higher than concentrations of contaminants in sediments not impacted
by nesting. Similar results have been observed for Antarctica
[BLA 07]. Thus, if climate change modifies the migrations of several
species, the local and global transport of POPs will also be modified
with impacts on other ecosystems [BUR 08, WRO 05].
Finally, the adaptation of societies to climate change (CC) also
risks affecting the presence of contaminants in different regions due to
modifications in agricultural practices, the more significant use of
pesticides due to the proliferation of pests [KAT 11] and an increase
in the exploitation of resources from polar regions [DE 11].
1.5.2. Effects of contaminants and climate change on different
organization levels of life forms
Physiological mechanisms implicated in the combined effects of
toxic substances and climatic stresses can be interpreted from two
different angles, as proposed by [HOO 12] (Figure 1.9):
(1) the increased sensitivity to toxins caused by the climate, where