A Tern for the Better at Braddock Bay

Jim Ochterski, RBA Conservation Committee

July 2014

Braddock Bay, just west of Rochester, is so well known for its hawk migration observation platform that many people forget that it is, in fact, a bay.  Bays are inlets of water alongside large lakes or the ocean.  The mixing of landforms opens up many combinations of dry land, partially submersed land, mud flats, dense plants, trees, and stretches of open water.  Bays are one of the most desirable habitats for migrating and breeding birds because they offer shelter, abundant food sources, and diverse nesting areas.

Black Tern - Montezuma National Wildlife Refuge © D. Sherony

Black Tern – Montezuma National Wildlife Refuge © D. Sherony

Braddock Bay is part of a larger complex of inlets and ponds that are sometimes directly connected to Lake Ontario and sometimes not.  Gravel and is shifted by lake currents and pounding waves, creating bars and channels.  When lake level regulation began in the 1950’s to improve commercial ship navigation through the St. Lawrence Seaway, the natural shifting was disrupted and before long, the system was almost continuously flooded.  In the wake of Hurricane Agnes, a formidable sand bar barrier was washed away, and erosion has been hitting the lake side of Braddock Bay very hard.

When years of continuous flooding, erosion, and human activity combine in a freshwater area, you can expect one thing to thrive: cattails.  A fast-growing, adaptable, and nearly invasive native plant, cattails fill in most shallow water areas completely.  In Braddock Bay, the cattails have formed a nearly lifeless monoculture.  They help stabilize sediments and are home to some species, but a lot of the habitat richness that once characterized the Bay is now gone.  Cattails can do this because the fluctuation of water levels is very limited now.  Cattails can invade former diverse meadow marshes because sustained lake levels allow them to survive and overtake sedges and grasses that otherwise put up with the frequent drier soil conditions when lake levels fluctuated naturally.

Fortunately, habitat decline in Braddock Bay caught the attention of a rather formidable force: the US Army Corps of Engineers.  In a partnership with the NYS Department of Environmental Conservation, Ducks Unlimited, the Nature Conservancy of Central and Western New York, and the Town of Greece, the Army Corps of Engineers is studying how, when, and where to build, dig, and dredge to finagle some improved coastal habitat.  The target species of all this work (an indicator of success) is the Black tern.

Black terns have not nested in Braddock Bay in almost a generation.  Even though preferred Black tern habitat is rich in cattails, they require other plant species as well, such as rushes, sedges, and cord grasses.   In other words, cattail monocultures are not desirable, and will not support a colonial nesting species like the Black tern.

So, the US Army Corps of Engineers is now conducting a feasibility study to explore if the construction of an artificial headland breakwater, the scooping of deeper potholes into the bay, and re-channeling areas through the cattails will bring in plant species to restore Braddock Bay.  If the habitat can be so modified that Black terns return as an easy-to-spot nesting species, there should be enough habitat available for other species of birds and mammals.

In the words of the US Army Corps:  “The goal of [Braddock Bay] restoration is to improve habitat diversity of the existing emergent marsh currently dominated by cattail, and to reduce erosion of the existing emergent marsh. The black tern was chosen as a target species for habitat restoration, because it represents a historic habitat no longer present in the bay. This habitat, characterized by diverse aquatic vegetation zones, sedge grass meadows, and open water areas interspersed within a matrix of emergent marsh, will be significantly more ecologically diverse than the existing cattail dominated emergent wetland and would provide high quality habitat for many species of fish and wildlife including American mink and northern pike.” During your next visit to Braddock Bay, look at the lackluster stand of cattails.  Imagine in their place a multi-faceted marsh habitat with swooping Black terns and hovering Northern harriers.  Then, look to the migrating hawks (mere specks in the sky) and delight in a possible turn for the better.

US Army Corps of Engineers Braddock Bay overview (PDF link)