Environmental Engineering Reference
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lost due to the combined actions of sea-level rise, more intense monsoonal
rains and larger tidal or storm surges.
Airoldi et al. (2008) propose three major categories of habitat loss:
1) loss of native resident species ; particularly those ecosystem engineers that
have narrow distributions or are exclusive to certain habitats (Thrush
et al. 2006).
2) loss of food resources ; habitats dominated by primary producers (e.g.,
seagrass meadows, salt-marshes, kelp forests) are highly productive
(Duffy 2006, Hosack et al. 2006) and responsible for the exportation of
signifi cant amounts of C, N and P to adjacent coastal areas (Graham
2004); the loss of these food sources may have a direct or indirect
negative effect on the productivity of the whole system (Dobson et al.
2006).
3) loss of environmental complexity and related ecosystem functions ; the loss
of habitat complexity carries a loss of numerous functions that shape
the physical environment (e.g., light conditions, hydrodynamics,
sedimentation, attenuation of disturbance; Jones et al. 1994, Dobson
et al. 2006).
A 15-year study of the irreversible environmental consequences of
unplanned coastal development in the Mediterranean Sea, offers a synthetic
example of what has been previously exposed (Fraschetti et al. 2011).
Habitat fragmentation and human-induced changes in sedimentation,
ultimately resulted in a loss of > 50% of seagrass beds ( Posidonia oceanica ),
a decline in macroalgal cover ( Cystoseira spp.) and a loss in associated
faunal assemblages, which impacted negatively on the goods and services
provided for local human population.
Ecological shifts in phytoplankton and harmful algae
Ecological shifts in primary producers for coastal ecosystems have a long
historic record, spanning ~ 200 years. An often cited example is that of
Chesapeake Bay (Jackson et al. 2001) in which there is a record of a gradual
shift in the organisms responsible for primary productivity since the 18th
century (the trend is characterized by the decline of seagrasses and benthic
diatoms, to give way to planktonic diatoms and other phytoplankton).
An increase in sea surface temperature in the surface mixed layer of
the oceans is bound to alter circulation and increase density stratifi cation
(Bindoff et al. 2007). Increased stratifi cation in the coastal ocean will have
an effect in the dominance of groups of phytoplankton (Huisman et al.
2004), likely favoring motile species such as dinofl agellates (Peperzak 2003,
Peperzak 2005), over dominant components of the early spring bloom (such
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