Living shorelines provide habitat, protect inland areas

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Mangroves naturally recruited to a seawalll enhancement project at Ulele Springs when the appropriate substrate was installed. Photo by Victoria Parsons.

Like estuaries themselves, shorelines are relatively small places within a much larger body of water, but they can be ranked as among the most productive areas in the world.

In their natural form, estuarine shorelines overflow with habitat that wildlife depends upon, from mangroves and marsh grasses to wrack lines that provide forage for birds and crabs along white sand beaches.

But shorelines, both in Tampa Bay and around the world, are also among the most-impacted spaces – and the most vulnerable as sea levels continue to rise. Man-made structures like seawalls, bulkheads, groins and jetties provide temporary protection for man-made infrastructure, but at a significant cost to wildlife.

Some local organizations are out to change that.

“I realize that some seawalls and docks will always be with us, but do we really need that much hardening or can we do better?” asks Tom Ries, a principal scientist at Scheda Ecological Associates and founder of the not-for-profit Ecosphere Restoration Institute. “In many locations, a living shoreline may be more appropriate than a seawall and would be more productive for wildlife while improving the site aesthetics — often in a much less expensive fashion.”

Along with work at the national level helping to coordinate workshops on living shorelines through Restore America’s Estuaries, Ries and his not-for-profit organization have been involved in multiple shoreline restoration projects in the region.

A prime example is Stewart Middle School on the Hillsborough River, where Ries worked with a team to retool a shoreline which had been so smothered in invasive plants that students could barely see the water to sample it. A collaborative effort with funding through the Southwest Florida Water Management District, the restored shoreline now features a plastic retaining wall with honeycomb structures to hold native plants that filter runoff before it enters the water. Offshore, a small breakwater, partially constructed of recycled sidewalk found at the site, protects the shoreline from boat wakes.

Across the river from the school, Ecosphere led the redevelopment of Ulele Springs where a long-forgotten spring flowed into a small pond and then was piped to the river. Winner of the 2012 Golden Mangrove Award from the Tampa Bay Estuary Program, Ulele Springs now features a small freshwater inlet with nearly 100 yards of landscaped shoreline. Manatees, which drink fresh water, are regular visitors to the inlet.

Along the river, where a previously installed seawall protects the shoreline from erosion, Ecosphere designed a seawall enhancement project since the seawall could not be removed. A rocky breakwater included a planting bed to support native vegetation for additional habitat. “We planted some of the mangroves as part of the project, but others have naturally recruited to the site,” Ries said. “It was kind of surprising to see it happen this far up the river, but it shows that this design was appropriate for plants to thrive.”

Thousands of Tampa Bay residents have been introduced to the concept of living shorelines as part of the programs offered through Tampa Bay Watch, including last winter’s record-setting marsh grass planting at Rock Ponds in south Hillsborough County.

“We’ve been planting living shorelines for years but just started using the term because people didn’t understand what it meant,” says Martha Gruber, environmental specialist who manages the Bay Grasses in Classes Program, coastal clean-ups and community salt marsh restoration projects.

Definitions vary dramatically, but Gruber looks at living shorelines as those needing protection from wave-driven erosion but still providing critical habitat for myriad marine creatures. MacDill Air Force Base, where the southeastern corner catches waves generated by ships heading to Port Tampa Bay, is a perfect example.

“Originally we planted marsh grasses but they weren’t really holding,” she said. “Then we added oyster balls offshore to break the waves before they hit the shore and a light bulb went on – it worked perfectly.”

Audubon Florida also is building living shorelines with reef balls placed off islands created with dredged materials in the 1920s. “You could see where the beaches were eroding but now the sand is coming back and we’re seeing natural recruitment of both mangroves and marsh grasses,” said Ann Paul, Audubon’s Tampa Bay regional coordinator.

Living shorelines will become even more important as sea level rise accelerates, Paul adds. “We can’t hold the line forever, but they will help us keep this imperiled habitat alive at least for the short term.”

Nationally, living shorelines are becoming more accepted as a habitat enhancement tool. “There are a wide variety of approaches that can be taken, and it’s something NOAA (National Oceanic and Atmospheric Administration) is pursuing nationwide,” notes Heidi Stiller, coastal management specialist in the agency’s St. Petersburg office. “We’re seeing real growth in both dialogue and projects coming out of the ground.”

Locally, the Tampa Bay Estuary Program is including living shorelines in its upcoming Comprehensive Conservation and Management Plan for the first time ever. Specific actions proposed for the region include:

  • Expand use of living shorelines instead of traditional seawalls along waterfront properties.
  • Support demonstration projects and explore regulatory rule revisions to support living shorelines
  • Assess the use of living shorelines to mitigate climate change
  • Support education of waterfront homeowners about the benefits of living shorelines.
Living shorelines are becoming a national trend as lessons learned from Hurricanes Katrina and Sandy show that they are more effective than hardened shorelines -- plus improve habitat for the wildlife that depends upon them. Photo Lee Ann Wilde.

Living shorelines are becoming a national trend as lessons learned from Hurricanes Katrina and Sandy show that they are more effective than hardened shorelines — plus improve habitat for the wildlife that depends upon them. Photo Lee Ann Wilde.

For many people, Hurricane Sandy slamming into the Eastern Seaboard was a wake-up call showing that healthy shorelines protected lives and property inland. “It was a classic example of areas with extensive dune systems and wetlands faring better than areas without them,” Stiller said. “We saw the same thing with Hurricane Katrina – the parts of Louisiana that were protected by wetlands came through in much better shape.”

Funding from the Deepwater Horizon oil spill in the Gulf has been used to build a number of living shorelines in Florida’s Panhandle, and Stiller expects to see more of them across the state as additional funds become available.

Port Tampa Bay, which manages most of the submerged waters of Hillsborough County, also supports the expanded use of living shorelines. “They don’t work in every instance but we do require that people consider them before just building another seawall,” notes Chris Cooley, the port’s environmental director.

Even the Army Corps of Engineers is working to make permitting for living shorelines less complicated. “Anytime you do anything different, the process slows down,” Ries said. “As it stands now, you don’t even need a permit to replace an aging seawall but if you look at alternative solutions – even when they offer significant benefits – it can take months to go through the process.”

And a lot of questions remain about which technologies work best in which situations. “We’re still learning by trial-and-error,” Ries says. “There isn’t a one-size-fits-all solution, but it’s our best bet to provide habitat and protect man-made infrastructure going into the future.”

What is a Living Shoreline?

Living shorelines use natural habitats for erosion control, sometimes in conjunction with built infrastructure (such as rock or oyster features) and other times through the use of off-shore breakwaters to minimize erosion by waves. Typically using deeply rooted, fast-growing plants, the living shorelines provide shallow-water habitat for marine species, reduce wave energy, help build wider beaches, improve water quality, reduce pollution via wetland filtration and moderate the effects of storms and floods. In other areas, where seawalls already are built and are considered necessary, seawall enhancement projects may be built to attract plants like mangroves that actually protect the seawall from erosion while providing habitat for myriad wildlife.

Multiple websites provide in-depth information on how (and why) to build living shorelines:

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