Monitoring salt marsh vegetation and nekton at Assateague Island National Seashore: 2010 summary report

Patenaude, Erika; Pooler, Penelope

The Northeast Coastal and Barrier Network (NCBN) is one of 32 networks of parks created by the National Park Service (NPS) Inventory and Monitoring Program (I&M Program). The I&M Program has two components, 1) to collect baseline ecological inventory datasets and 2) to implement Vital Signs monitoring, a long-term ecological monitoring program, in each of the 32 networks. The Northeast Coastal and Barrier Network consists of eight parks linked by geography and shared ecological characteristics along the Northeastern Atlantic Coast. As part of the I&M Program, each network has developed detailed protocols for monitoring a select number of Vital Signs, or ecological indicators. Because the majority of parks in the NCBN are coastal parks, salt marsh monitoring was chosen as a high priority and protocols were developed for collecting long-term data on salt marsh vegetation and nekton (James-Pirri and Roman In Review-a,b). The objective of monitoring vegetation and nekton is to identify long-term trends in community structure, and to provide resource managers with a better understanding of the current status and condition of the salt marsh resources they manage. The NCBN began implementation of the salt marsh vegetation and nekton protocols at Assateague Island National Seashore (ASIS) at nine permanent sites in 2008. This report summarizes the second year of vegetation and nekton data collected at ASIS. Monitoring will continue on a biennial basis. Approximately fifty vegetation plots were sampled at each of the nine marsh sites (total = 449 plots) in July of 2010. The percent cover of each vegetation species and non-vegetation cover type within each 1 m2 plot was visually estimated using a revised Braun-Blanquet method (Kent and Coker 1992). Thirty vegetation species and four non-vegetation cover types were recorded in 2010. Non-vegetation cover types recorded included bare ground, wrack & litter, water, and horse manure.A total of 149 nekton stations were established at the nine marsh sites. Nekton in marsh pools and large tidal creeks were sampled with a 1m2 aluminum throw trap (Kushlan 1981, Sogard & Able 1991, Raposa and Roman 2001). There were 12 species of nekton recorded at ASIS in 2010, including nine fish species, one crab species, and one shrimp species. Examination of percent catch data indicates that five species account for approximately 97% of all nekton captured. The most prevalent species, Cyprinodon variegatus (sheepshead minnow), accounts for approximately 54% of all nekton recorded at ASIS in 2010. The second most common species, Fundulus heteroclitus (common mummichog), accounts for approximately 23% of all nekton.

Monitoring salt marsh vegetation and nekton at Assateague Island National Seashore: 2010 summary report

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