The Saltmarsh Habitat & Avian Research Program
(SHARP) was founded by a group of academic, governmental, and non-profit collaborators to provide critical information for the conservation of tidal-marsh birds.
OUR GOAL in the short term is to set priorities across the Northeast (see figure to the right, or see the high resolution spatial data for our survey locations or demographic study sites) for the long-term conservation of tidal marsh birds. Our program provides a consistent platform for monitoring the health of North America’s tidal-marsh bird community and the marshes they inhabit in the face of sea-level rise and upland development.
THE SPECIFIC OBJECTIVES of the initiative are to: 1) Produce population estimates for tidal marsh birds, 2) Provide estimates of population change in these species over the past two decades, 3) Model geographic variation in the reproduction and survival of our six focal species (listed below), 4) Provide the ten states in the region with a detailed description of their responsibility for conservation, 5) Identify the most critical areas for the long-term preservation of the tidal marsh bird community, 6) Explore tidal marsh community resistance to extreme storm events and other climate change stressors, and 7) Build on an existing working group of local, state, and NGO stakeholders to implement the findings of this project throughout the region.
TO DATE we have completed three field seasons of tidal marsh bird surveys from Maine to Virginia and collected detailed reproductive and survival data across the seaboard on our six focal species: (1) American Black Duck, (2) Clapper Rail, (3) Willet, (4) Saltmarsh Sparrow, (5) Nelson’s Sparrow, and (6) Seaside Sparrow. We plan to continue all data collection efforts for the 2014 field season. To read some of our preliminary findings, see the brief annual synopses at the top of the page.
THE NEED FOR TIDAL MARSH BIRD CONSERVATION
Global & Local Importance of North American Tidal Marsh – Tidal marshes form the dominant transition zone between terrestrial and marine communities in eastern North America with the Atlantic coast alone possessing over one-third of the global extent of tidal marsh. Further, eastern North American marshes possess the highest level of vertebrate biodiversity and endemism (those species found in one location and no where else) of any tidal marsh region worldwide. These wetlands are home to 83 breeding vertebrate species, 22% of which occur only in tidal marshes or possess subspecies found only in tidal marshes (Greenberg and Maldonado 2006). Therefore, tidal marshes as an ecosystem are primarily a North American resource, and it is a primary North American responsibility to conserve the ecosystem’s global flora and fauna.
Risk of Ecosystem Loss and Degradation – The global importance of and local services provided by North America’s tidal marshes may justify our attention to their preservation, but it is their high risk of degradation and loss that necessitates detailed information to prioritize and coordinate conservation actions. Tidal marshes compete for space with (and are downstream of) some of the continent’s most highly developed areas. This leaves the ecosystem open not only to outright loss, but also to the severe degradation of all remaining habitat. Along the highly developed eastern U.S. seaboard, tidal marshes are found at the mouths of some of the country’s most human-impacted drainages (e.g. the Susquehanna, Delaware, Hudson, and Connecticut Rivers) and along the shipping routes of some of the busiest ports (e.g. Norfolk, Baltimore, Philadelphia, New York, and Boston). There are no pristine tidal marshes left in this region. By the late 20th century, 90% of northeastern salt marshes had been ditched for mosquito control to some degree (Daiber 1986).
Tidal marshes are also threatened by sea-level rise. Over the last century sea level has risen ~2 mm/year (although local effects vary: Douglas 1991), and this change has altered marsh vegetation and caused marsh loss across the Atlantic seaboard. Sea-level rise is projected to accelerate over the next century with predicted annual tidal marsh losses of 0.5-1.5% (Greenberg 2006). Together, this information suggests that small sea-level increases could push tidal marsh bird populations to a threshold beyond which rapid declines are likely.
Risk of Species & Endemic Population Loss – Many organizations recognize these risks as threats to tidal marsh birds. Two species are “red-listed” by the International Union for Conservation of Nature (IUCN); six are on the American Bird Conservancy/National Audubon Society’s Watch List; and 10 are considered priority species by Partners In Flight. Overall, 26 bird species that breed in or use these habitats during summer are listed as “Species of Greatest Conservation Need” by states along the eastern seaboard of the United States.
Species of Interest – We are gathering the data necessary to set conservation goals for all 26 species identified by state conservation plans in the region and are developing detailed conservation recommendations for six focal species that breed in Atlantic tidal marshes: (1) American Black Duck, (2) Clapper Rail, (3) Willet, (4) Saltmarsh Sparrow, (5) Nelson’s Sparrow, and (6) Seaside Sparrow.
Our efforts have been funded by a diversity of state wildlife divisions and agencies within the U.S. Department of the Interior. The majority of our initial funding was provided by a Competitive State Wildlife Grant (which can be downloaded here: SWG Proposal (1028)), administered by the U.S. Fish & Wildlife Service. Since then we have had generous support by the US Fish and Wildlife Service, the National Park Service, and the National Science Foundation.