Environmental Engineering Reference
In-Depth Information
for particular species will continue and that at any particular location the
frequency of replacement of “cool-water” species by “warm-water” species
will likely increase. Individual marine species will be impacted differen-
tially; for example pelagic fish ranges may be impacted more than demer-
sal ranges, which will lead to changes at the community and ecosystem
model. Few studies have looked comprehensively across many marine taxa
and geographic regions, but a recent pilot model projection suggests the
potential for significant changes in community structure in the Arctic and
Southern Ocean biodiversity due to invasion of warm water species and high
local extinction rates in the tropics and subpolar domains. Fish stock size
may either grow or decline due to altered primary production, prey abun-
dance, and temperature-dependent growth rates, the trend for each species
depending on its particular biology and habitat (Brown et al., 2010; Hare
et al., in press). Complex predation and competition interactions may re-
verse the expected responses for some species (Brown et al., 2010). Climate
change may also disrupt larval dispersal and development patterns as well
as existing predator-prey interactions through altered currents and seasonal
phenologies for spawning and plankton blooms (Parmesan, 2006).
Specific marine habitats may be particularly sensitive to changing cli-
mate. Rising sea-level would impact, and in many cases degrade, coastal
wetlands and estuaries, coral reefs, mangroves, and salt-marshes through
inundation and enhanced coastal erosion rates; these coastal environments
serve as important nursery habitats for larval and juvenile life-stages. Re-
gional impacts depend on local vertical land movements and would be
exacerbated where the inland migration of ecosystems is limited by coastal
development and infrastructure. The thermal tolerance of many coral spe-
cies is limited, and over the past several decades, warmer sea surface tem-
peratures have led to widespread tropical coral bleaching events (loss of
algal zooxanthella) and increased coral mortality. Warming and more local
human impacts have been associated with declines in the health of coral
reef ecosystems worldwide. Bleaching can occur for sea surface tempera-
ture changes as small as +1-2°C above climatological maximal summer sea
surface temperatures, and more frequent and intense bleaching events are
anticipated with further climate warming (e.g., Veron et al., 2009). Sea-ice
dependent species are also at risk, and rapid warming in the Arctic and parts
of Antarctica has resulted in substantial shifts in whole food-webs (Ducklow
et al., 2007; Montes-Hugo et al., 2009).
