SALT MARSH VEGETATION AND NEKTON COMMUNITY MONITORING AT GEORGE WASHINGTON BIRTHPLACE NATIONAL MONUMENT
2008 Summary Report
Natural Resource Report
NPS/NCBN/NRDS—2010/069

Erika L. Patenaude
Penelope S. Pooler
National Park Service
Northeast Coastal and Barrier Network
University of Rhode Island
1 Greenhouse Rd
Kingston, RI 02881

August 2010

U.S. Department of the Interior
National Park Service
Natural Resource Program Center
Fort Collins, Colorado
________________________

Executive Summary

The Northeast Coastal and Barrier Network (NCBN) is one of 32 networks of parks created by the Inventory and Monitoring Program (I&M Program) of the National Park Service. 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 Network parks. 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 Vital Signs 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 a protocol was developed for collecting long-term data on salt marsh vegetation and nekton (James-Pirri In Development a,b).

This annual report summarizes the first year of data collected at George Washington Birthplace National Monument (GEWA) located in Virginia. Forty-Four vegetation plots and a subset of creeks and shoreline were sampled for nekton at one marsh in August of 2008. Monitoring data is to be collected at this same marsh site biennially. Nekton in large tidal creeks, and shoreline habitats (all less than 1m deep) were sampled with a 1m2 aluminum throw trap (Kushlan 1981, Sogard & Able 1991, Raposa and Roman 2001). Vegetation was monitored using 1m2 plots and a revised Braun-Blanquet method (Kent and Coker 1992) to estimate percent cover of each vegetation species and non-vegetation cover type within each plot.

At the GEWA site, 35 vegetation species along with 3 non-vegetation cover types were recorded during vegetation sampling in 2008. Non-vegetation cover types recorded included wrack and litter, bare ground, and water. Six species of nekton were recorded at GEWA in 2008, including 4 fish species, 1 crab species, and 1 shrimp species. Examination of percent catch data indicates that two species account for approximately 90% of all nekton captured. The most prevalent species, common mummichog (Fundulus heteroclitus), accounts for approximately 54% of all nekton recorded at GEWA in 2008 and was found only at tidal creek stations. The second most common species, daggerblade grass shrimp (Palaemonetes pugio), accounts for approximately 36% of all nekton recorded and was found only at shoreline stations. Substantial differences in species between tidal creek and shoreline stations at GEWA have reinforced our decision to limit future nekton monitoring at GEWA to tidal creek habitat.

The information collected through this long-term monitoring program will equip park managers with scientific data to make informed decisions on both the aquatic and terrestrial resources they manage. This report summarizes the 2008 baseline data for the GEWA salt marsh selected for monitoring. Changes in salt marsh condition will be examined following data collection in 2010. By understanding the changes or trends occurring in salt marsh vegetation and nekton communities, managers will be able to better adapt and respond to these changes through their management practices.

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