Living Shorelines Are Being Created Along Florida's Coast

Nov 14, 2018

It's a modern alternative to a hard seawall that can soften the impact of strong storms and rising seas due to a warming planet.

Living shorelines, which are made of all-natural materials like marsh seedlings or even bags of oyster shells, are an increasingly popular option to protect coastal homes and property in Florida.

Creating a living shoreline can reverse the effects of erosion and protect sensitive wetlands. The rising costs from flooding and erosion are prompting homeowners, military bases and government agencies to opt for this natural protection method, which can improve water quality, support fisheries and also provide a protective barrier.

"What we're seeing is a real shift away from hard seawalls, in the direction of living shorelines which are much more cost-effective, and better for people and wildlife," said John Upton, Features Journalist at Climate Central. Upton notes that homeowners tend to overestimate the effectiveness of seawalls and bulkheads and underestimate natural alternatives, but that is slowly changing here in the Sunshine State.

"Florida has a lot of vulnerabilities when you talk about coastal erosion, but Florida is also a leader in developing living shorelines," Upton said. "Florida accounts for about half of the permits in this category issued in recent years. People tell their neighbors, they love looking at the wildlife, they see the erosion being reversed and they want one, too."

Upton was in Northeast Florida for a visit to the The Guana Tolomato Matanzas National Estuarine Research Reserve, a protected landscape along A1A in St. Johns County with many interconnected habitats and ecosystems. On a boat trip through the GTM Reserve in the Intracoastal Waterway, it's apparent that growing numbers of mangroves — salt-tolerant trees and shrubs — are cropping up in the salt marshes that line the water. This too, is an effect of climate change.

"We sit right at a place along the Florida coast that is at the change point from marsh grass to mangroves," said Mike Shirley, Director of the GTM Reserve. "This is a great place to study living shorelines. Because mangroves, which are not tolerant of cold weather, are moving further north and displacing salt marshes. So they begin to form part of the living shoreline, as well."

Shirley says several studies are currently underway at the GTM Reserve, including one looking at the impact of heavy boat traffic on Northeast Florida's coastal ecosystem.

"We're observing rapid erosion of the salt marsh habitat," said the study's author, Christine Angelini.

Angelini is Assistant Professor in Environmental Engineering Sciences at the University of Florida. "In a lot of occasions this rapid erosion is being driven by boat traffic. So we designed an experiment to develop a new type of living shoreline that's built to withstand high-energy conditions from battering boat wakes. We are finding sediment accreting behind these hybrid branch-filled breakwalls we've built. This is a technique we've borrowed from the Dutch, and we've transplanted it to Florida. We find it's dissipating boat wakes before they reach shore and building up sediment behind it, despite the effects of hundreds of boats a day."

You can learn more about Living Shorelines in Wednesday's First Coast Connect Going Green segment.

Melissa Ross can be reached at mross@wjct.org, 904-358-6382 or on Twitter at @MelissainJax.