Biological
Thermal and hydrological regimes are master variables driving river
ecosystems.44 Temperature is a primary climate change driver, while
flow has been shown to change substantially in response to changes
in rainfall patterns.5 It is therefore likely that climate change will affect
aquatic assemblages with biological consequences of climate change
acting at several levels, including that of the individual and community.
Susceptibility of aquatic organisms to climate change is likely to vary
between species and will in part depend on their biological traits. Those
species with specialised habitat and/or microhabitat requirements,
narrow environmental tolerances or thresholds that are likely to
be exceeded at any stage in the life cycle, dependence on specific
environmental triggers, dependence on interspecific interactions, and
poor ability to disperse to or colonise a new or more suitable area, are
likely to be more susceptible.45 Potential biological consequences of
climate change (Table 2) include changes in aquatic biodiversity, changes
in individual life-history patterns, changes in communities, changes in
species distribution and range, extinction of vulnerable species, increase
in the number and spread of invasive and pest species, and an increase
in waterborne and vector-borne diseases