Minimal pristine salt marsh habitat remains and changes in marsh habitat from development, agriculture, ditching and channelization, marsh burning, invasive species, and pollutants, have contributed to massive marsh loss and degradation of remaining marshes. However, global sea level rise has become the foremost cause of immediate marsh loss. Sea levels have risen ~2 mm/year over the last century and predicted marsh losses due to sea level rise are 0.5 – 1.5%/year. The extensive loss of marsh habitat and continuing degradation owing to development pressures on land and rising oceans on the seaside place an insurmountable pressure on the integral structure of tidal marshes and harm endemic species populations. Several tidal marsh bird species spend their entire annual life cycle in the marsh and are near-ground nesters, so reproduction is naturally influenced by daily and extreme flood events. Increases in flooding from sea level rise and global climate change pose real immediate challenges to the persistence of tidal marsh bird populations. The extreme importance of the northeast tidal marsh ecosystem and its unique wildlife requires immediate regional conservation action to address the imminent threat of permanent marsh loss or severe degradation from sea level rise.
The focus of my dissertation will be to use the data collected from our regional avian surveys in 2011 and 2012 to identify focal tidal marsh areas for our five focal salt marsh species: Clapper rail (Rallus longirostris), Willet (Tringa semipalmata), Saltmarsh sparrow (Ammodramus caudacutus), Nelson’s sparrow (Ammodramus nelsoni), and Seaside sparrow (Ammodramus maritimus). I will use existing sea level rise models, such as NOAA’s Sea Level Rise and Coastal Impacts Viewer, to assess habitat loss at focal areas, and consequently, bird loss due to sea level rise. Present-day data and NOAA’s predictions of marsh movement will be modeled to predict future abundance hotspots of our focal species. My final step will be to use an economic model to create a portfolio for each state that identifies the best set of cost-effective areas (land parcels to purchase) that maximize overall conservation benefits. In other words, how can we spend limited conservation resources most efficiently to protect areas of concentrated bird abundance? The final state portfolios will represent the best use of conservation dollars to conserve important core tidal marsh bird populations for the persistence of key species in light of predicted sea level rise.