July 15, 2013
Protecting Coastal Habitats Could Save Property And Lives
Brett Smith for redOrbit.com - Your Universe Online
In addition to being thriving ecosystems and adding to stunning seaside views, coral reefs and wetlands also protect residents and property from rising seas and destructive storm surges. Guarding about two-thirds of the US coastline, protective habitats could double the at-risk population and property if they were lost warned a new study in Nature Climate Change.
"Where we've got these ecosystems intact, we need to keep it that way. Otherwise, massive investments will be required to protect people and property," co-author Katie Arkema, a marine ecologist with the Natural Capital Project, told Nature magazine.
The study comes against the backdrop of coastal planning currently underway in New York and Louisiana to guard against the deadly and damaging storm surges that those states know all too well. While seawalls and levees are expected to be erected, the study points out that management of coastal ecosystems should also be a part of the protection plan.
Study co-author Peter Kareiva noted that his team's work could help protect coastal environments and buffer economic interests at the same time.
"It really is going to get to the point where we'll be able to put dollar values on what we gain from restoring natural habitats," said Kareiva, chief scientist at the Nature Conservancy.
In the study, the team formulated a hazard model for the US coast that considered ecosystem data, climate projections, socio-economic information and property values to see which habitats provide the greatest coastal protection. They also ranked nine habitats - including reefs, wetlands, dunes, sea-grass beds and kelp forests - according to level of protection provided. The researchers then scored each 1-kilometer strip of coastline in terms of protection.
The team also looked at the vulnerabilities of the US coastline, identifying areas with the biggest exposure to flooding and erosion with and without protective habitats. Finally, the team mapped the social variables on top of the hazard index to see what populations or properties were particularly at risk.
"We have to look at the shoreline elevation, wave exposure, and whether it's rocky or muddy to determine where habitats become important for protection," Arkema said.
Rob Thieler, a coastal geologist at the US Geological Survey, said the study is a good step toward assessing the value of coastal habitats, adding that it will probably need some adjustments.
"One key thing missing, as mentioned in the paper, is that we just don't have a good scientific understanding of how well coastal habitats will persist in the future," he said.
The authors agreed that more data is needed to refine their assessments, along with a cost-benefit analysis of engineered versus natural protections. Nature Conservancy scientists said they are already putting their findings to use in the rebuilding of oyster reefs off the coast of Alabama. These reefs act to dissipate wave energy that otherwise erodes the shore.
"Until we started putting in these oyster reefs, I don't think any of us fully appreciated the extent to which they would increase the shoreline," Kareiva said.