The Concept of a Living Shoreline
A living shoreline is a shoreline stabilisation approach that relies primarily on natural materials—vegetation, shell, sand, and organic matter—rather than rock, concrete, or steel. The term became widely used in coastal management circles in the United States over the past two decades and has been adopted in Canadian provincial guidance documents as a preferred approach where wave exposure allows it.
The core principle is that an intact or restored coastal ecosystem (saltmarsh, beach grass fringe, or vegetated dune) provides the same wave attenuation and sediment retention function as a hard structure, while also supporting fish and wildlife habitat, maintaining natural sediment exchange with adjacent areas, and allowing gradual landward migration as sea levels change.
Vegetation Types Used in Canada
Saltmarsh Grasses
Spartina alterniflora (smooth cordgrass) is native to Atlantic Canadian saltmarshes and is the principal plant in low-marsh restoration. Its dense root matrix binds sediment and its above-ground biomass attenuates wave energy across the intertidal zone. The plant tolerates regular inundation and has been used in marsh restoration projects in the Bay of Fundy region, where tidal range is extreme.
Spartina patens (saltmeadow cordgrass) occupies the higher marsh zone, which is inundated less frequently. Together, these two species form the structural foundation of Atlantic Canada's saltmarshes and are the most commonly transplanted species in restoration projects.
Beach Grass
Ammophila breviligulata (American beach grass) is native to Atlantic Canada's barrier beaches and foredunes. It is the primary dune-building species along PEI, Nova Scotia, and New Brunswick coastlines. Its rhizomatous root network traps windblown sand and binds the dune face. Restoration projects typically transplant nursery-grown plugs at prescribed spacing patterns, and the plant's clonal spread fills gaps over multiple growing seasons.
In the Great Lakes region, Ammophila breviligulata is also native and has been used in dune restoration along the Ontario shores of Lake Huron and Lake Erie. The Lake Huron Centre for Coastal Conservation and various conservation authorities have documented restoration plantings on Lake Huron's eastern shore.
Freshwater Shoreline Vegetation
Along Great Lakes and river shores, Phragmites australis (common reed) is generally considered invasive in Canada and is not used in restoration. Instead, native species such as Scirpus spp. (bulrushes), Carex spp. (sedges), and Schoenoplectus acutus (hardstem bulrush) are planted in low-energy nearshore zones to stabilise sediment and provide habitat.
Hybrid Living Shoreline Designs
In higher-energy settings, purely vegetative approaches may not establish successfully without some degree of wave sheltering. Hybrid designs combine a low-profile structural element—often a sill of oyster shell, stone, or prefabricated reef module—placed at or below the low-tide line to reduce wave energy reaching the planted zone behind it. This approach has been refined in the southeastern United States and is increasingly referenced in Canadian coastal management literature as applicable to moderate-energy embayments in Atlantic Canada.
The sill does not prevent all wave action; it is sized to allow sufficient water exchange for plant establishment and to avoid creating stagnant conditions behind it. The vegetation behind the sill provides long-term stability and the system's net ecological benefit.
Vegetation Buffers: Upland and Transition Zones
Distinct from intertidal living shorelines, vegetation buffers refer to upland plantings along the landward edge of the shore. These are typically shrub or tree plantings that intercept surface runoff, reduce wind speed near the water's edge, and provide a setback zone that slows the rate at which development approaches active erosion areas.
In Ontario, the shoreline buffer guidelines developed under the Oak Ridges Moraine Conservation Plan and various conservation authority policies specify minimum vegetated buffer widths for shoreline properties. The intent is to maintain a transition zone of native vegetation between lawns or structures and the water's edge.
In Prince Edward Island, the provincial Coastal Areas Protection Policy designates shoreline buffers as a baseline requirement before any coastal development is permitted. The buffer width is determined by the rate of shoreline change at the site.
Carbon and Habitat Co-Benefits
Saltmarsh and seagrass ecosystems are recognised for their capacity to accumulate organic carbon in their soils at rates that exceed those of many terrestrial ecosystems. This has been termed "blue carbon" and is referenced in Environment and Climate Change Canada's assessments of coastal ecosystem services. While quantification of carbon stocks in restored Canadian coastal wetlands is still ongoing in the research literature, the potential co-benefit is an additional consideration in project assessments.
Fish and invertebrate habitat values are more immediately measurable. Saltmarsh edges provide juvenile fish nursery habitat, and restored marshes adjacent to estuaries support species regulated under the federal Fisheries Act. DFO's habitat management framework includes provisions for offsetting habitat loss, and living shoreline restoration can in some cases serve as a habitat offset measure for approved developments elsewhere.
Documented Projects in Atlantic Canada
The Acadian Peninsula and Northumberland Strait coasts of New Brunswick have seen marsh restoration work coordinated by Ducks Unlimited Canada and provincial natural resources agencies, targeting degraded saltmarshes that had been isolated by road causeways or blocked tidal exchange. Restoring tidal connectivity is typically the first step before any planting occurs; vegetation re-establishes naturally once water flow is restored to appropriate inundation regimes.
In Nova Scotia, the Coastal Wetlands Restoration Initiative under provincial and federal cost-sharing programmes has involved replanting of saltmarsh species at former agricultural dyke lands along the Bay of Fundy. These projects are documented in project reports available from the Nova Scotia Department of Natural Resources and Renewables.