Hardening shorelines, polar lessons, and legal divides in the Aug 2015 ESA Frontiers

Highlights from the August 2015 issue of Frontiers in Ecology and the Environment

 

Armored in concrete, hardened shorelines lose the soft protections of coastal wetlands

As we expand our coastal cities and armor the coast against the ravages of the sea, we lose the resiliency of the coastlines’ natural defenses. Rachel Gittman and colleagues at the University of North Carolina, NOAA, and the US Coast Guard report in the August issue of ESA Frontiers that sea walls, bulkheads, breakwaters, and the like put in place to protect coastal communities harden 14 percent (22,842 km) of the tidal shoreline of the United States. But this conservative 14 percent hides a concentration of coastal development along soft marshy estuaries, lagoons, and tidal rivers; remote rocky coasts are less likely to be bolstered with artificial structures.

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Gittman and coauthors Danielle Keller and Joel Fodrie will present research related to this report on shoreline habitat, hardening, and the ecosystem services trade-offs of different shoreline conditions at the upcoming 100th Annual Meeting of the Ecological Society of America in Baltimore, Md. on August 9-14.

Natural and artificially hardened shorelines found in the US: (a) rocky shore; (b) beach; (c) tidal marsh; (d) mangrove; (e) seawall; (f) riprap revetment; (g) bulkhead; and (h) breakwater, from Figure 1 of Gittman et al. 2015 Frontiers in Ecology and the Environment 13: 301–307. For images of other shoreline types found in the US, refer to the NOAA ESI shoreline types image gallery (http://response.restoration.noaa.gov/esi-shoreline-types).

Natural and artificially hardened shorelines found in the US: (a) rocky shore; (b) beach; (c) tidal marsh; (d) mangrove; (e) seawall; (f) riprap revetment; (g) bulkhead; and (h) breakwater, from Figure 1 of Gittman et al. 2015. Credit, NOAA ESI shoreline types image gallery.

The ecological vibrancy of wetland habitats is valued by birders, hunters, recreational anglers, and commercial fisheries managers. Coastal wetlands succor birds, fish, and crustaceans, filter outflowing pollution, and naturally buffer the coast against storm surge and erosion. But natural dunes and salt marshes also absorb the energy of storms. Examples of natural dunes and salt marshes emerging from severe storms with little to no damage, while nearby bulkheads took a battering, suggest that storm surge protection and habitat protection need not be at odds.

Nearly a third of the shoreline in the contiguous United States could be hardened by the end of the twenty-first century if the rate of shoreline hardening observed over the last century continues. On sheltered coasts, fortification of shorelines correlates more strongly with high housing density and GDP than with wave height or frequent storms. The authors project that growing populations will direct most new hardening to the US’ south Atlantic and Gulf coasts, which encompass greater that 50 percent of the remaining salt marshes and 100 percent of the mangrove forests in the US. The authors argue for the incorporation of green infrastructure into coastal protections as managers plan for the next century of growing cities and rising sea levels.

 

Also in the August issue of ESA Frontiers:

Cold lessons

Profoundly different in topography, ecology, and social history, the Arctic and Antarctic have very similar vulnerabilities to climate change. Climate change exacerbates problems of pollution, over-fishing, and invasive species at both poles. Joseph Bennett and colleagues describe this perfect storm of threats and lessons in cooperation from the polar regions.

 

Adaptive legalese

Cover picture: Although climate change poses the largest anthropogenic threat to the Arctic and Antarctic, other impacts — including pollution, fisheries overharvesting, and invasive species — must not be overlooked. Applying lessons learned from ecosystem management at both poles may help to mitigate regional environmental risks and conserve species, such as the Adélie penguin (Pygoscelis adeliae).Environmental law has not kept up with the last 40 years of ecological discovery. The law struggles, in particular, to address dynamic ecosystems and adapt to the kind of global scale change ecologists expect in the coming century. The very different approaches to uncertainty and complexity in science and law bedevil the application of environmental research to environmental law. Lawyers and ecologists collaborate in this Concepts & Questions article by Olivia Odom Green and colleagues to recommend an adaptive governance approach to bridging the gap.

Browse the complete content of the August issue of Frontiers in Ecology and the Environment online.