Avian Monitoring of Coastal Salt Marshes

The N.J. Department of Environmental Protection (NJDEP) received a grant for this project from the National Fish and Wildlife Federation. Grantees were charged with providing increased resilience to natural infrastructure that will in turn increase the resiliency of coastal communities in the face of future storms like Hurricane Sandy. Due to the need to maintain navigation channels and assist in the adaptation of tidal marshes to sea level rise and subsidence, the project was completed to investigate and assess the use of dredged material disposal placement, and the effectiveness of this method in maintaining marshes at an elevation that supports native marsh vegetation to reinforce the subsoils and protect the local community.

One of the metrics analyzed was the impact, if any, of the placement of dredged material on the community composition, abundance, and distribution of avian species within the two dredged material placement sites, one proximal to the Atlantic Ocean in Avalon, New Jersey and the other proximal to Delaware Bay Fortescue, New Jersey.

Princeton Hydro, in conjunction with the Fish and Wildlife Service, Wetlands Institute, and The Nature Conservancy, developed a monitoring plan that utilized the BACI (before, after, control, impact) study design and the protocols from the “Standardized North American Marsh Bird Monitoring Protocols” developed by Courtney Conway in 2012 for both the Fortescue and Avalon sites.

Surveys were implemented over a period of four years, 2014-2017, occurring during the spring, summer, and fall periods to capture the avian community composition changes both seasonally and year over year at both sites with seven survey areas at Fortescue and nine at Avalon. Post thin layer placement surveys indicated that (1) avian species richness increased at Avalon, but was negligible at Fortescue; (2) species guild assemblage experienced a shift, with an increase in shorebirds coinciding with a decrease in waders and passerines at Avalon, while there was an increase in gulls and waders and a decrease in passerines at Fortescue; (3) loafing by shorebirds and gulls increased at Avalon, while Fortescue had negligible changes in loafing. Over time, loafing activities at both sites decreased with an increase in foraging observed and the communities of both sites shifted from gull/shorebird dominated to passerine/wader dominated as the marsh vegetation developed.