By Andrew KornackiMarch 24, 2017
As one of the largest coastal wetland on the south shore of Lake Ontario, Braddock Bay is an important migratory stop-over location for birds and waterfowl. In the spring, birders come from all over the world to participate in the annual spring hawk migration survey. Historically, Braddock Bay was an important nesting site for black tern, a marsh nesting bird considered endangered in the state of NY. However, no black terns have been confirmed nesting in the area since the early 2000s. The Bay is also important to the Lake Ontario fishery, its diverse emergent marsh and sedge grass meadows providing spawning habitat for species like northern pike until the expansion of monotypic invasive cattail stands filled in channels and altered native vegetation communities.
Braddock Bay formed behind the shelter of barrier beaches which were formed by the movement of sand along the coast by currents. Constantly shifting and reforming in response to nature's forces, they formed a highly dynamic ecosystem. Rich coastal wetlands formed in quiet protected waters behind these barriers.
Hardening of Lake Ontario's shoreline has decreased the amount of sand moving along the shore, reducing the sediment available to nourish down drift beaches. Over time, fierce storms washed most of Braddock's protective barrier beach away. Without the protection of the barrier beach, the coastal wetlands that formed in quiet waters in soft sediments are no match for the fury of storm waves. By 2014, only a remnant of the barrier beach remained.
In addition to erosion, the loss of the barrier beach also allows sand and silt to sweep into the once-clear waters of the bay, increasing turbidity, and altering native wetland plan communities. The sand and silt filling the bay have also hampered recreational use and led to a decline in the activity of the marina.
Throughout the planning and design process, project partners coordinated with local, state, and federal stakeholders and experts to develop the best plan for restoring the bay. Several public meetings were held to share project concepts and to solicit comments and concerns.
The final design addresses two main objectives: 1) Reduce the loss of wetlands due to erosion and 2) improve the suitability of existing wetland habit for fish and wildlife. The final design achieves this through several measures.
A barrier beach is constructed in the mouth of the bay to reduce wave energy and mimic the function of the Braddock's historic beaches. This structure consists of stone spine with offshore headland breakwaters. These headland breakwaters create lower energy conditions in front of the spine that allow for the placement of sand and the creation of the barrier beach. The beach portion of the structure will be planted with grasses while the stone portions will be choked with sand and planted with native shrub live stakes.
A network of channels and potholes has been excavated in the existing marsh to increase the diversity of physical conditions and ultimately support a more diverse vegetative community. This also reopens pathways for northern pike to access the interior of the marsh to reach emergent marshes and sedge grass meadows important for their spawning.
Chemical and mechanical techniques were applied to reduce the coverage of invasive hybrid cattail species and Phragmites (Frag-my-teas).
Lastly, 3 acres of emergent wetland are to be created within the bay, to replace acreage previously lost to erosion.
Construction of this project begin in January of 2016 with the excavation of channels and potholes in the existing wetland. Equipment operators where encouraged to incorporate randomness and variability into their work so as to mimic natural characteristics. Due to warmer winter conditions, a specialized pontoon excavator was needed to finish the excavation of some of the larger pothole areas. This work was immediately followed by seeding in the spring and plug plantings in the summer to jump start establishment of native vegetation communities.
Construction of the barrier beach commenced in August of 2016. Stone placement continued through the late summer and was completed in late fall. In spring of 2017, sand from the bay mouth will be placed on top of the stone to allow for plantings and in front of the structure spine to create the barrier beach. This will be followed by plantings of native shrubs and dune vegetation. Lastly, three acres emergent marsh will be created within Braddock Bay and planted with native emergent vegetation.
To understand if Braddock Bay has been successful, USACE and project partners are monitoring the various components of the project. Already, a 90% increase in the diversity of the wetland vegetation has been noted in restored areas of the wetland. This monitoring data will be used to track the health of the Braddock Bay ecosystem and to inform future adaptive management.