Knowledge and implications of global change in the oceans for biology, ecology, and ecosystem services - Ocean Sustainability in the 21st Century - page 136

4.3.1 Coastal water ecosystems
There is a wide consensus that coastal marine ecosystems, along with the goods and services
they provide, are threatened by anthropogenic global climate change (IPCC, 2001 ). Coastal
marine systems cover a surface c .3,102 ha × 10 8 and the economic value of all ecosystem
services provided by these areas approaches US$12.6 trillion per year globally (Costanza et
al., 1997 ) . Coastal ecosystems are particularly vulnerable, because their resilience and capa-
citytobufferadditionalenvironmentalstresseshavealreadybeenunderminedbyhumanim-
pacts such as over-harvesting, pollution, eutrophication, and habitat destruction (Hughes et
al., 2003 ) .Moreover,manydisturbances areactingattheterrestrial-marine interface andare
predicted to increase, such as increased land run-off after floods, higher wave energies (due
to increased storm frequency), and increasing turbidity. Global change severely increases
the risk of flooding and subsequent loss of coastal areas as a direct consequence of an ac-
celerating sea-level rise and also a possible increase in the frequency and intensity of storms
(Airoldi et al., 2005 ; Burcharth et al., 2007 ). Moreover, the most obvious consequence of
sea-level rise is an upward shift in species distributions and a relevant changing of ocean
circulation (which drives larval transport) with important consequences for population dy-
namics. This shift in species composition can have negative effects on coastal biota (Harley
et al., 2006 ) . Further extension, raising, and reinforcement of artificial coastal defences may
protect populated areas, but are bound to result in loss of sedimentary coastal marine habit-
ats with consequences for living marine resources (Airoldi et al., 2005 ; Martin et al., 2005 ;
Anderson et al., 2005 ) . Such artificial coastlines may act as stepping stones for species ad-
vancing with climate change (Helmuth et al., 2006 ; Hawkins et al., 2008 ) and provide hab-
itat for jellyfish polyps, contributing to the increase in jellyfish (Richardson et al., 2009 ) .
Many marine organisms, including economically important fish, spend part of their life in
relatively sheltered areas along the coast. Loss of these areas may affect these animals at
that specific stage of their life cycle. In addition, changes in the strength and seasonality
of upwelling in areas along the coast could influence the retention dispersal mechanisms of