Citizens in the state of Florida have 825 miles of coastline to enjoy. This coastline has caused people to flock to Florida and is a large part of why the Sunshine State is such a popular vacation destination. The Floridian economy relies heavily on the beaches staying as beautiful and safe as possible, which is why living shorelines are becoming so common.
The economy’s reliance on beautiful beaches is why coastal erosion is a major concern within the state. From homeowners to real estate agents to tourists, everyone is affected by the erosion of Florida’s coastlines. According to the Florida Department of Environmental Protection’s (FDEP) Office of Resilience and Coastal Protection, 35 counties in the state have coastlines that are either critically or noncritically eroded. That is over half of the counties in Florida.
The FDEP defines a critically eroded shoreline as “a segment of the shoreline where natural processes or human activity have caused or contributed to erosion and recession of the beach or dune system to such a degree that upland development, recreational interests, wildlife habitat, or important cultural resources are threatened or lost.”
In 2010, the length of critically eroded beaches increased by 70.7 miles in just ten years. As of 2021, 527.3 miles of the 825 are considered either critically or noncritically eroded (including coastal inlets); that equals 63.9% of Florida’s coastline.
Erosion is an expensive issue for environmentalists, homeowners and the government. The National Oceanic and Atmospheric Administration (NOAA) said that coastal erosion is responsible for about $500 million per year in coastal property loss. The federal efforts to mitigate this erosion costs an average of $150 million every year, which is used for beach nourishment and other control measures.
Due to these threats, environmental managers and planners have looked for ways to slow the process of erosion. For many years this meant seawalls and bulkheads along the coast. Strong, immobile walls of concrete off the coast slowed wave action and kept sediment in its place. Instead of waves pounding against the shoreline, they met with a strong wall and dissolved without damaging the shoreline.
Unfortunately, seawalls and bulkheads lead to less-than-desirable effects. They limit biodiversity, economic value, and they are not a permanent solution. In addition to these, seawalls are also expensive to construct and have been shown to have negative net cost benefits.
The Environmental Science Associates (ESA) found that seawalls had a negative net cost-benefit because the loss in recreational and habitat value was greater than the costs to build the bulkhead. Seawalls also have a high maintenance cost.
“There are all sorts of maintenance costs to maintaining a seawall or replacing a seawall, as well as negative ecological effects of that wave reflection and the loss of the intertidal zone,” said Taylor “Chips” Kirschenfeld, the Natural Resources Director for Escambia County. “You can ride through any of our Bayous and you’ll see failing seawalls all through there. Maybe they’ll last ten years, maybe they’ll last 15 years, but sooner or later they’re going to get undermined and they’re going to need some repair work.”
The desire for a more aesthetically pleasing and economically friendly way of slowing erosion led to the idea of a “living shoreline.” A living shoreline is a softer approach that involves a stabilized shoreline made out of natural materials such as sand, rock, plants, or even oyster shells.
In Escambia County, Florida, the living shorelines are becoming more and more popular. In fact, there are already several living shorelines that have been established for many years. These shorelines are considered both maintenance-free and a permanent solution.
The process involves oyster reefs or other permitted materials being installed in the water and native shoreline and vegetation being planted closer to the shore. This combination results in reduced wave energy and sediment staying in its place, which decreases the level of erosion. These projects go through permitting and have to receive authorization from the Florida Department of Environmental Protection and the U.S. Army Corps of Engineers.
Living shorelines are far more beneficial to the ecology and economy than seawalls, bulkheads, or riprap. With seawalls, you will find that the land behind the wall begins to erode which leads to the seawall falling apart.
Florida experienced this when Hurricane Irma hit in 2017 when the west coast experienced negative tides.
Without water pressure holding seawalls in place, they begin to crack and fall forward; however, a living shoreline can withstand all of this.
Kirschenfeld said there are four main benefits to living shorelines: fishery habitat, water quality, reducing wave energy and a calm area for expansion of seagrasses and emergent vegetation.
“You lose habitat with a seawall whereas you gain habitat with a living shoreline project,” Kirschenfeld said.
Not only do you gain habitat, but you also see a healthier ecosystem. Upland vegetation plays the same role in an aquatic ecosystem that plants do in a terrestrial ecosystem. They take up excess nutrients that can cause habitats harm.
“Vegetation takes up nitrogen and phosphorus from the water column,” Kirschenfeld said. “These nutrients are responsible for algae blooms which can deplete oxygen in the water and cause fish kills. And some of those algae blooms can be quite toxic.”
These nutrients are the same ones that are in fertilizers. They promote the growth of the vegetation that is so critical to a shoreline habitat; however, Kirschenfeld said that if there’s nothing to control that growth then it can get out of control. That’s when you have those toxic algae events such as Red Tide.
Studies have shown that a marsh running 10 feet across (from water to land) can remove 90% of the nutrients running off. These nutrients can lead to the negative effects mentioned above: low dissolved oxygen, algae blooms, seagrass loss and fish kills. These marshes can also remove other contaminants and plastics.
The vegetation along shorelines is an essential part of that ecosystem. Kirschenfeld said that the seagrasses are part of the life cycle of 90% of Pensacola’s recreationally and commercially important seafood species.
All of these aquatic organisms spend some part of their life cycle in seagrass beds. This means it is crucial to protect the seagrass beds Pensacola has and also facilitate the expansion of them when possible.
There are varying designs for a living shoreline that address the issues you find with a seawall. Sediment transportation is a large part of keeping a coastal ecosystem healthy, but too much sediment transportation and you have erosion problems.
“A living shoreline is different than a bulkhead - a bulkhead just, it locks things in place,” said Robert Turpin, the Marine Resources Manager for Escambia County. “What a living shoreline does is it allows the littoral transport of sediment to move through the system.”
Bulkheads and seawalls do not allow this transportation to happen. An eroding shoreline is a source of sediment for the areas downstream so if you keep that sediment in place completely, you starve somewhere else further down the line.
“Allowing [a] segmented breakwater design is an accommodation for that natural process to occur and it slows that process down,” Turpin said. “So in slowing it down you don’t completely starve the littoral downdrift area and it allows you to come in and do replenishment.”
A living shoreline designed to be a segmented breakwater protects the area from a drastic and fast loss, Turpin said.
Unfortunately, living shoreline installation depends somewhat on the community around it. In Pensacola, a popular argument against living shorelines is the possible risk that comes with them. The community near the Navy Point park project felt that the bagged oyster shells that make up the living shoreline would pose a threat to swimmers, especially children.
"I think living shorelines and offshore breakwaters may be preventing drownings each year because of that protected and calm environment." - Chips Kirschenfeld, Natural Resources Director for Escambia County
While the concern for the public is understandable, the marine environment is a dangerous one with or without a living shoreline. There is glass, jellyfish, sharks, and a plethora of other aquatic organisms that can cause harm to a swimmer. Kirschenfeld argues that a living shoreline actually makes the environment safer.
The Green Shores project that was established in 2000 in Pensacola has not had any reported injuries, nor have there been any reports since the Navy Point shoreline was established a few years ago. Education is critical to avoid wrong assumptions of living shorelines.
“I think living shoreline projects improve water quality and make it less hazardous for people to venture in the water, and I think living shoreline projects provide a calm protective area for children to swim in,” Kirschenfeld said. “By reducing boat wakes, and by reducing wave energy, I think living shorelines and offshore breakwaters may be preventing drownings each year because of that protected and calm environment.”
The county does its best to work with the communities they are impacting. Turpin said that when the Navy Point area expressed concerns about the segmented breakwater limiting their freedom to swim, the county listened.
“We compromised and left some fairly substantial gaps in that segmented breakwater and that appeased most of the people who had objections to it,” Turpin said.
The county is currently planning a living shoreline that will stretch about seven miles: around White Island, Magazine Point, Naval Air Station (NAS) Pensacola all the way to the south side of the lighthouse. The concept for this project started before the BP oil spill; hurricane Ivan in 2004 had caused White Island to be pushed back to the west and it was severely impacted, which inspired the county to take action.
The oil spill resulted in a $4 billion settlement which has helped Escambia County begin projects that they couldn’t before. The concept for the Pensacola Bay living shoreline began small, but slowly expanded as the money from the oil spill began to pour into the county.
“It [the living shoreline] is under design right now, we have a good coastal engineering firm that’s doing that design and permitting,” Kirschenfeld said. “We hope to have all the permits from the federal and state regulatory agencies by this summer, and we hope to start construction maybe as soon as this fall.”
Unfortunately, the public really won’t be able to see the project as it begins construction. Unlike the Bayfront Parkway shoreline, there is not a road where you can drive by and see it. If you are interested in it, you can take a boat through the bay for a nice view of the project.
The interesting thing about this project is NAS Pensacola’s and other Department of Defense installations’ support. Maryland’s naval academy in Annapolis built a living shoreline to help protect the infrastructure on that base from erosion and foreign boats, Kirschenfeld said. NAS Pensacola is a large supporter of the project for the same reason - homeland security.
The offshore breakwaters will help prevent boats from coming to the shore at the base.
“The Department of Defense has recognized that these offshore breakwaters and these living shoreline projects are to their benefit also,” Kirschenfeld said.
To learn more about the Pensacola Bay living shoreline project, check out Escambia County’s Matt Posner, the Estuary Program Director, discuss it in this video: NAS/Pensacola living shoreline project site tour.
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