Download Ecological Monitoring of Healthy and Unhealthy Salt

Ecological Monitoring of Healthy and Unhealthy Salt Marsh Sites
to Reach Educational, Research and Management Objectives
1
Curran ,
1,2
Hoskins ,
1
Pride ,
1
Richardson
3
Sweeney-Reeves
M. Carla
Dionne
Carol
Joseph
and Mary
1Savannah State University, 2 National Marine Fisheries Service, NOAA, 3University of Georgia, Marine Extension Service
ABSTRACT
In the spring of 2003 the “dead marsh” phenomenon
in the Savannah, GA area will be examined by a multiinvestigator team consisting of the Marine Ecology Lab
class at Savannah State University (SSU), a high school
Adopt-a-Stream/Adopt-a-Wetland group, and 4 SSU marine
sciences program faculty. Since the issue of “dead marsh”
areas in coastal Georgia is of interest to the GA DNR, we
will prepare a report for this agency. Both healthy marsh
and marsh areas experiencing Spartina alterniflora die-off
will be studied. The surface area of dying marsh will be
monitored for change over the course of the semester.
Health of the salt marsh ecosystem will be gauged by
determining the density of live and dead S. alterniflora
shoots, the density of snails and crab holes, and the density
and diversity of benthic fauna, including agglutinated
foraminifera. Transects will be performed and samples
taken three times during the spring semester.
Physical/chemical properties that could be impacting the
health of the system will also be monitored. The properties
to be measured include pore water salinities at each transect
site and the temperature, salinity, pH, [DO], [NO3-], [PO43-],
and turbidity of adjacent tidal creeks.
METHODS
“Dead Marsh” Sites
The initial study will focus on several on Talahi
Island, Oatland Island, and the Isle of Hope to be monitored
by SSU undergraduates, graduate students, and Adopt-aStream/Adopt-a-Wetland groups, respectively. The latitude
and longitude of each site has been determined by GPS and
coordinates will be supplied to the GA DNR for groundtruthing of aerial photographs. The most thorough array of
analyses will initially be carried out at the Talahi Island site,
which will be sampled at 1-month intervals from midFebruary through mid-April by SSU undergraduate marine
ecology students. Sampling at one or two of the sites will
continue throughout the year through a combination of SSU
internship projects and a graduate student thesis project.
Figure 2. Transect line through healthy marsh starting at die-back
margin (foreground)
INTRODUCTION
“Dead marsh” is an area with little or no live aboveground vegetation (Figure 1). It has been documented in
LA, TX, FL, GA, SC, and NY. Reasons for the dieback are
unclear but may be related to drought/increased salinity,
biogeochemistry, changes in organismal composition and
density, or anthropogenic disturbances. The purpose of this
study is to determine differences in water quality,
macrofauna, meiofauna, and shoot density between live and
dead marsh. We will involve undergraduate students,
graduate students, and volunteer citizens with the ultimate
goal of elucidating this phenomenon and distributing
information to the scientific and lay communities, and GA
DNR.
OBJECTIVES
 To assist the Coastal Resources Division of the Georgia
Department of Natural Resources in making management
decisions regarding salt marsh regions experiencing
dieback.
Erosion/Accretion
Stakes will be placed at each cite with cm markings
both above and below the sediment surface to monitor
sediment erosion/accretion throughout the study.
 To monitor environmental factors that may contribute to
the dead marsh phenomenon.
Water Quality
Water quality parameters (DO, temperature, salinity,
turbidity, and concentrations of orthophosphates and
nitrogenous compounds) will be monitored at each study
site in adjacent tidal creeks and/or within the healthy and
dead marsh regions during high tide.
 To have undergraduate marine science majors and
graduate students take a lead role in collecting and
analyzing data, and documenting their findings.
Pore waters
Pore waters will be sampled at select healthy and
dead sites for salinity determinations.
 To determine the ecological impact of salt marsh dieback
in the Savannah, GA region.
 To involve high school Adopt-a-Stream/Adopt-a-Wetland
groups in ecological studies through the monitoring of shoot
densities, epifauna, and water quality parameters at
designated “dead marsh” sites.
 To provide a collaborative research project for Savannah
State University faculty and colleagues at the University of
Georgia.
Figure 1. Discrete “square” area of dead marsh
Expansion/Regrowth of Impacted Areas
Flagged stakes will be placed along the borders of
“dead marsh” regions so that any expansion or reduction of
the impacted area through time can be determined. In
addition, the investigators and nearby residents are
documenting changes in the marsh through periodic photos
of affected regions.
The density of Spartina alterniflora will be quantified
using a 0.5 m2 quadrat along 2 transects of healthy marsh
and 2 transects of dead marsh at each site (Figures 2 and 3).
Number of live and dead shoots will be tabulated separately.
OUTCOMES
An environmental database and archival documents will be
maintained at the Asa Gordon library available for public
use, undergraduate instruction, and postgraduate research
 A series of reports on marsh conditions that are
appropriate for a variety of stakeholders (managers,
educators, citizens, politicians, scientists)
 Undergraduate research and reports
 Postgraduate theses
 Community involvement in habitat assessment and
increased public awareness of coastal habitat quality
 Increased collaboration among Savannah State
University, the University of Georgia, and the Georgia
Department of Natural Resources in terms of establishing
sampling protocol, collecting data, and analyzing the results
of our study
 Information that will assist in the development of
potential marsh restoration projects
ACKNOWLEDGMENTS
The authors would like to express their gratitude to Adopta-Stream, Adopt-a-Wetland, and Oatland Island
Educational Center.
Meiofauna
Meiofauna from the top 3 cm of sediment will be
identified to major taxa and enumerated.
Benthic
foraminifera will be identified from samples representing
the upper 20 cm of sediment. Results will be compared
between live and dead marsh.
Macrofauna
Snail and crab hole densities will be determined at
intervals along the transects.
Figure 3. Students counting Spartina shoots in a quadrat area
along a transect line.