Grantee Research Project Results
1999 Progress Report: Health Indicators for Salt Marsh Estuaries of the South Atlantic Bight
EPA Grant Number: R825147Title: Health Indicators for Salt Marsh Estuaries of the South Atlantic Bight
Investigators: Alberts, James J. , Wall, V. Daniel , Kneib, Ronald T. , Newell, Steven Y. , Pennings, Steven
Current Investigators: Alberts, James J. , Kneib, Ronald T. , Newell, Steven Y. , Pennings, Steven
Institution: University of Georgia
EPA Project Officer: Packard, Benjamin H
Project Period: October 1, 1996 through September 30, 1999
Project Period Covered by this Report: October 1, 1998 through September 30, 1999
Project Amount: $786,349
RFA: Ecological Assessment (1996) RFA Text | Recipients Lists
Research Category: Ecological Indicators/Assessment/Restoration , Aquatic Ecosystems
Objective:
The research examines development and testing of simple, inexpensive, and rapid methods for assaying and monitoring the general health of salt marsh ecosystems in the southeastern United States. It is designed to examine a suite of salt marsh indigenous organisms to: (1) evaluate methods that determine critical rates within the macrophyte community, focusing on sublethal impacts; (2) determine the efficacy of using reproductive potential of three species of estuarine crustaceans as another measure of sublethal stress; and (3) evaluate a battery of physiological bioassays using short-lived marine microorganisms as indicators of salt marsh ecosystem condition.
Progress Summary:
During the third year of the study, our study sites included: Terry Creek in Brunswick, GA, which was contaminated with toxaphene as a result of operations at the Hercules plant and is being considered for inclusion in the Superfund site listings, and 12 sites in Charleston Harbor that represent sites contaminated by a broad spectrum of chemicals. In addition, a 1-year no cost extension of the grant was approved to allow for completion of data analyses and publication of results.
LCP Site - Brunswick, GA. Fieldwork at the LCP Superfund site in Brunswick, GA, was conducted in the first year of the grant. Most analyses were completed at this site. However, monthly sampling of crustaceans at one impacted site in Brunswick and a reference site on Sapelo Island continued into Year 3. The general conclusions from the study of this site were that there was little measurable impact of mercury and PCB contamination on indicators of Spartina alterniflora physiology, bacterial activity, or fungal biomass. The tendency of larger individuals (grass shrimp) and greater brood size (grass shrimp and tanaids) at the impacted site did not continue during the second year. However, average egg size of tanaids did remain significantly larger at the impacted site relative to the Sapelo Island (reference) site. The presence of greater frequency of parasitic isopods (Probopyrus pandalicola) on grass shrimps at the reference site relative to the Brunswick site was confirmed. Tanaid densities were significantly higher in the reference site than at the Brunswick site near LCP (t=7.195, df=11, P 0.001).
Toxaphene Site - Brunswick, GA. Fifteen stations along approximately 1.5 miles of creek bank were established on Terry Creek, which is known to have high levels of toxaphene in the sediments. Analyses indicate alterations in gas exchange and enzyme activity at some but not all stations with high toxaphene concentrations. No significant correlations were observed between these indicator measurements and sedimentary toxaphene concentrations. Mercury and PCBs were shown at the LCP site to have no adverse effects on fungal living standing crops or sexual reproductivity. Extension of these studies to sites containing other pollutants, including toxaphene, chromium, lead, copper and PAHs, also showed no adverse effects of these pollutants on the fungal stress indicators. Unless the fungal and plant resistance mechanisms involve degradation of the toxicants, this may imply that salt marshes are especially dangerous as receiving sites for toxic waste, because they may have the potential to readily move toxicants into the food web.
Charleston Harbor Sites. Twelve sites were chosen in the Charleston Harbor area with the aid of the South Carolina Department of Natural Resources. Six sites are heavily contaminated and six lightly polluted with differing amounts of numerous chemicals, but including high levels of various metals and PAHs. At each site, sediment samples were collected for Microtox? analyses; plant samples were collected for measurement of enzyme activity and gas exchange measurements were taken of creek bank Spartina alterniflora. Glutathione (GSH) activity was reduced at impacted sites, but peroxidase (POD) activity, photosynthesis, transpiration and Microtox? activity did not differ between highly impacted and reference sites. In addition, crustacean sampling conducted at an impacted and reference site demonstrated that average egg size in tanaids did not show a detectable difference between sites as had been observed in Georgia. Only marginally significant differences in frequency of the parasitic isopod (Probopyrus pandalicola) in shrimp of the reference and impacted sites were observed in this study area. Again, tanaid densities at the reference site were greater than the impacted site (t=3.262, df=11, p=0.008), suggesting that high tanaid densities are probably a good indicator of a relatively unimpacted marsh site.
Future Activities:
Microtox? Studies. All laboratory and field studies using this protocol have been concluded. Effort will be concentrated on analyzing collected data and preparing presentations and manuscripts for submission to peer-reviewed journals.
Fungal Studies. Given the lack of detectable impact by PCBs, toxaphene, or PAHs on living fungal standing crops in impacted marshes and the positive impact on this parameter in urbanized marshes, the last year's effort will be concentrated either on determining whether complex organic pollutants are altered by the lignocellulolytic enzymes of saltmarsh-ascomycetes, or examining the nitrogen subsidy hypothesis for increased fungal standing crops in urbanized marshes. Work also will continue on manuscript preparation and submission.
Gas Exchange Studies. Fieldwork during the third year of the study suggested that plant gas exchange measurements vary as a function of tidal stage and range. If true, successful use of gas exchange measurements as an environmental tool would require that variation due to tidal fluctuation be avoided in the sampling design or factored out in the analysis stage. The following hypotheses currently are being tested: (1) gas exchange rates would differ between plant types, i.e., tall versus short forms; and (2) gas exchange rates would be maximal at low tide and suppressed at high tide. Preliminary results support both hypotheses. Work in the final year of the grant will focus on data analysis and manuscript preparation.
Crustacean Reproductive Potential Studies. Emphasis continues on counting and measuring the extensive set of samples collected from the Georgia and South Carolina sites. It is expected that these enumerations will be completed for all samples by June or July 2000. The remaining effort will be placed on statistical data analyses and preparation of manuscripts of publication in the peer-reviewed literature.
Journal Articles on this Report : 7 Displayed | Download in RIS Format
Other project views: | All 32 publications | 14 publications in selected types | All 11 journal articles |
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Ewel KC, Cressa C, Kneib RT, Lake PS, Levin LA, Palmer MA, Snelgrove P, Wall DH. Managing critical transition zones. Ecosystems 2001;4(5):452-460. |
R825147 (1998) R825147 (1999) R825147 (2000) |
Exit Exit |
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Levin LA, Boesch DF, Covich A, Dahm C, Erseus C, Ewel KC, Kneib RT, Moldenke A, Palmer MA, Snelgrove P, Strayer D, Weslawski JM. The function of marine critical transition zones and the importance of sediment biodiversity. Ecosystems 2001;4(5):430-451. |
R825147 (1998) R825147 (1999) R825147 (2000) |
Exit Exit |
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Newell SY, Wall VD, Maruya KA. Fungal biomass in saltmarsh grass blades at two contaminated sites. Archives of Environmental Contamination and Toxicology 2000;38(3):268-273. |
R825147 (1998) R825147 (1999) R825147 (2000) R825147 (Final) |
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Newell SY. Fungal biomass and productivity in standing-decaying leaves of black needlerush (Juncus roemerianus). Marine & Freshwater Research 2001;52(2):249-255. |
R825147 (1998) R825147 (1999) R825147 (2000) |
Exit |
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Newell SY. Spore-expulsion rates and extents of blade occupation by ascomycetes of the smooth-cordgrass standing-decay system. Botanica Marina 2001;44(3):277-285. |
R825147 (1998) R825147 (1999) R825147 (2000) R825147 (Final) |
Exit |
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Pennings SC, Moore DJ. Zonation of shrubs in western Atlantic salt marshes. Oecologia 2001;126(4):587-594. |
R825147 (1998) R825147 (1999) R825147 (2000) R825147 (Final) |
Exit Exit |
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Wall VD, Alberts JJ, Moore DJ, Newell SY, Pattanayek M, Pennings SC. The effect of mercury and PCBs on organisms from lower trophic levels of a Georgia salt marsh. Archives of Environmental Contamination and Toxicology 2001;40(1):10-17. |
R825147 (1998) R825147 (1999) R825147 (2000) |
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Supplemental Keywords:
ecotoxicology, trace metals, anthropogenic, pollution, humic substances., RFA, Water, Geographic Area, Ecosystem Protection/Environmental Exposure & Risk, Ecosystem/Assessment/Indicators, Ecosystem Protection, exploratory research environmental biology, Chemical Mixtures - Environmental Exposure & Risk, Ecological Effects - Environmental Exposure & Risk, Monitoring/Modeling, Ecological Effects - Human Health, Southeast, Mercury, Ecological Indicators, aquatic, monitoring, health indicator, bacteria, cordgrass, biodiversity, salt marsh estuaries, estuarine ecosystems, regional scale, South Atlantic Bight, aquatic ecosystems, fishRelevant Websites:
http://www.arches.uga.edu/~rtkneib/
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.