4. Coastal systems and wetlands
Convenors: John Day, Peter Herman, Hans Paerl
Despite their limited surface area, coastal ecosystems, such as estuaries, wetlands and mangrove forests, play a critical role in biogeochemical cycling and food web dynamics of the planet. They are highly productive, provide habitat to migrating animals and breeding and nursery space to marine and freshwater organisms. In addition, they serve as reactors and filters, mediating fluxes of nutrients, and carbon from land to ocean. Finally, they provide structural protection for deltas from floods and storm surges.
Coastal systems will be among the areas of the earth most affected by the megatrends of the 21st century. They are vulnerable to climate change and the effects of accelerating human population pressure in the coastal zone. The increasing cost and scarcity of energy (and thus the inability of coastal planners to rely on expensive, energy-intensive solutions) adds to the challenge of coping with these changes. Coastal systems are physically modified by land reclamation, dredging, harbour construction and other disturbances. This is amplified by sea level rise which reduces the emergent area of coastal ecosystems. Growing demands on the planet’s limited supplies of freshwater, eutrophication, and human contaminants will alter the bio-geochemical (nutrient and carbon) cycling and the biodiversity of these ecosystems. Sustained climatic trends, e.g. in temperature, and changed patterns in stochastic events (storms, floods, droughts) can strongly interact with these anthropogenic influences.
Because of their limited size yet immense ecological and economic value, deltas are critical to society. The crucial question is whether it will be (or remain) possible to sustainably manage them in the 21st century. In this theme we welcome contributions that explore how the ecological and economic value of coastal areas can be sustainably preserved in the deltas of the future, and how the coastal ecosystems may contribute to the establishment of climate proof delta areas and possible adaptation strategies.
In particular, we invite contributions that explore how the major changes in climate and human activities will alter the physical extent and integrity, the biogeochemical functioning and the biodiversity of coastal ecosystems; how this affects the ecosystem services provided by the systems and their valuation; what strategies can contribute to sustainable management of coastal systems under the large long-term trends of global change; and how coastal ecosystems can be used for sustainable, low-energy delta management in the future.