How Much Do Coastal Ecosystems Protect People from Storms and What Is It Worth?

Posted Fri, 10/11/2019 - 12:40

This blog was originally published in Aug. 11, 2014. 

A dune in the foreground with sky and water in the background.
Dunes offer storm protection but can also obstruct views. Image credit: NOAA.

In 2013, one lawsuit spurred the question — how much do coastal ecosystems protect people from storms and what is that worth? It's a question NOAA scientists and economists are working to answer. At NOAA, our job is to protect our coasts, but often, coastal ecosystems are the ones protecting us. 

A mangrove.
Mangrove forest in Loxahatchee, Florida. Mangroves are a type of living shoreline that help to protect against storms. Image credit: NOAA.

When a severe storm hits, wetlands, sand dunes, reefs and other coastal ecosystems can slow waves down, reducing their height and intensity, and prevent erosion. That means less storm surge, more stable shorelines, and more resilient coastal communities. When the coastal Borough of Harvey Cedars, N.J. replenished beaches with sand dunes to offer this ecosystem service, a New Jersey couple, the Karans, sued on the grounds that the newly placed dunes obstructed the ocean view from their home.

Initially, the court barred the jury from considering storm protection benefits from the dunes in their decision. The jury awarded the Karans $375,000, but New Jersey Supreme Court overturned the ruling. The jury should consider storm protection benefits, according to the Supreme Court, and when it did, the Karans' settlement dropped to $1.  

Cases like this one spur a lot of questions for both science and the courts. NOAA has been supporting ecosystem services in court for decades through Natural Resource Damage Assessments (NRDA), but putting a price tag on ecosystem services isn't easy. Instead, NOAA often determines how ecosystem services were hurt and what it will take to replace them. Following a spill or chemical release, NOAA is one of a number of mandated state and federal natural resource trustees that assess if and how ecosystem services were injured and typically focuses on habitat and recreation. That assessment is then used to determine how much restoration the responsible party must provide to compensate for the injury. 

An aerial image of a flooded area with hurricane damage.
At the end of October 2012, Hurricane Sandy sped toward the East Coast, eventually sweeping waves of oil, hazardous chemicals, and debris into the coastal waters of New Jersey, New York, and Connecticut. Image credit: U.S. Air Force.

Determining exactly how much storm protection may have been lost is another challenge. We know that already; there are a variety of estimates showing how much coastal ecosystems reduce a storm’s impact. Still, the science of storm protection is complicated. For example, an ecosystem’s type, location, topography, and local tides all impact its ability to protect us from storms. So, determining how much storm protection services were lost, who they benefited, and what type of restoration could compensate depends on all those factors too.

Ultimately, the decision on how to assess storm protection benefits may be up to the courts. Cases like Borough of Harvey Cedars v. Karan may provide some clues, but while the answer remains uncertain, we’ll keep working on the science.