Sediment and Pore-Water Evaluations: Capabilities and Interests

Proceedings of the U.S. Geological Survey (USGS) Sediment Workshop, February 4-7, 1997

SEDIMENT AND PORE-WATER EVALUATIONS: CAPABILITIES AND INTERESTS

ByParley V. Winger, and Peter J. Lasier,
U.S. Geological Survey,
Biological Resources Division,
Patuxent Wildlife Research Center,
University of Georgia, Warnell School of Forest Resources,
Athens, GA 30602-2152, Phone: 706-546-2146 Fax: 706-546-2109
EMAIL: parley_winger@nbs.gov and pete_lasier@nbs.gov

Personnel:

Two research scientists and a technician at the Athens Field Station are involved in physical, chemical and biological evaluations of freshwater and estuarine (< 15 o/oo salinity) sediments. The research scientists have broad expertise in (1) acute and (2) chronic whole-sediment toxicity testing, as well as (3) contaminant bioaccumulation testing procedures. In addition, they are deeply involved in (4) methods development for pore water extraction and pore-water toxicity testing, (5) understanding pore-water chemistry and contaminant bioavailability and (6) bioassessment of aquatic ecosystems. The overall mission of this field program is to provide, using scientifically valid and state-of-the-art methodologies, information on the environmental effects of contaminants that can be used for wise management of fish and wildlife resources.

Facilities:

Facilities at the Athens Station include a culture laboratory where (1) Hyalella azteca (Amphipoda: Crustacea) are cultured in recycling systems with biological filters (cultures range in salinity from 0 to 15 o/oo) and (2) Lumbriculus variegatus (Oligochaeta), (3) Chironomus riparius (Diptera) and (4) Ceriodaphina dubia (Cladocera: Crustacea) are maintained in static cultures. The main laboratory is used for sediment and sediment pore-water testing, chemical analyses, and sediment characterization. This laboratory contains two environmental chambers (maintains controlled temperatures and light for testing purposes), chemical hood, water-renewal system for solid-phase sediment testing, U.V. light exposure system, equipment used in sediment characterization (drying oven, muffle furnace) and wet-chemistry equipment (pH, D.O., alkalinity, hardness, conductivity, sulfide, chloride, ammonia, lead, copper, acid volatile sulfides). An additional laboratory contains the water-renewal system for contaminant-bioaccumulation studies and a Microtox Bioassay system. A 23-foot mobile bioassay trailer is used for on-site assessments of water and sediment from rivers and estuaries.

Research Interests and Capabilities

The research scientists at the Station have a long history of involvement with assessment and toxicity testing of solid-phase sediment and pore water. They have been deeply involved in the development of solid-phase sediment (Winger and Lasier 1993a; Winger and Lasier 1993b; U.S. Environmental Protection Agency 1994; Ingersoll et al. 1995) and pore water testing procedures (Winger and Lasier 1991; Winger and Lasier 1993a). Their research interests encompass fresh and estuarine (< 15 o/oo salinity) sediments and pore waters.

Pore-Water Extraction:

An inexpensive, but highly effective and versatile pore-water extractor was developed that allows isolation of pore water from sediments in situ as well as in sediments transported to the laboratory (Winger and Lasier 1991). This vacuum extractor consists of a fused-glass air stone connected to a 60-cc syringe with airline tubing. To obtain pore water, the air stone is inserted into the sediment and the plunger on the syringe braced in the retracted position. The volume of pore water needed for testing and/or water chemistry determines the number of extractors used. Several studies have been completed and are underway comparing pore water collected with this method versus pore water collected by centrifugation and peepers (Winger et al. 1994). The vacuum extractor was used successfully in collecting pore water in situ during a study of mercury distribution in the Okefenokee Swamp (Winger and Lasier 1996a), but further evaluations are needed to demonstrate the utility of this method for in situ collection of sediment pore water .

Pore-Water Chemistry and Contaminant Bioavailability:

The process of extracting pore water from the sediment may influence the pore water. Though the chemistries of pore water isolated by different procedures are (for all practical purposes) similar, differences do occur and these are sediment and ion specific (Winger et al. 1994). Disturbance (stirring) of the sediment prior to extraction appears to influence the chemistry and toxicity of the pore water (Winger and Lasier 1993; Lasier et al. 1994; Lasier 1995). Recent studies demonstrated that toxicity generally increases in pore water isolated from sediments that have been allowed to equilibrate (stored at 4 oC for 10 d) compared to pore water extracted immediately after stirring (Winger and Lasier 1996a). Oxidation of pore water (which is often anaerobic in nature) generally causes flocculation or precipitation of oxy-hydroxides which can scavenge ions from the water column, thereby influencing pore-water chemistry and toxicity. The influence of common ions in pore water (such as ammonia, alkalinity, sulfide and borate) on toxicity of pore water needs further evaluation, particularly with regard to toxicity identification procedures (Lasier and Winger 1995; Lasier and Winger 1997).

Toxicity of Solid-Phase Sediment and Pore Water:

Toxicity is generally more pronounced in pore-water exposures than in solid-phase sediment exposures (Winger et al. 1993; Winger and Lasier 1995a; Winger and Lasier 1997b). A large data base, consisting of sediment chemistry and toxicities from solid-phase and pore-water exposures from the same sediment, is being compiled that will allow the exploration of relationships between the toxicities of these two matrices (Winger and Lasier 1997a). Preliminary evaluations suggest that inclusion of both measurements of toxicity increases the ability to identify contaminated sediments.

U.V. Light Exposure to Identify PAH Contamination:

During the last two years, animals surviving at the end of solid-phase sediment and pore water tests have been exposed to U.V. light (Winger and Lasier 1997b). This exposure has caused significant toxicity to animals tested with many sediments and pore waters that did not show toxicity during the regular testing procedures. These toxicities suggest that the animals were exposed to PAHs during the testing period. PAHs have been shown to elicit toxicity when the exposed animals are placed under U.V. light (Ankley et al. 1994). The utility of this exposure as a toxicity identification procedure that could be incorporated into the routine toxicity-testing protocol needs further evaluation. Standard operating procedures for this method also need to be developed.

Contaminant Bioaccumulation:

Studies have shown that some contaminants found in sediments accumulate in benthic organisms (U.S. Environmental Protection Agency 1994). Bioaccumulation studies are particularly useful in the laboratory using spiked sediments and evaluations of dynamics and uptake of single contaminant exposures. However, the significance of laboratory bioaccumulation studies to field bioassessments of habitat quality needs to be established. Guidance needs to be developed for interpreting laboratory bioaccumulation data from field samples that normally contain a suite of contaminants.

Aquatic Bioassessments Using Benthos:

Both scientists at the Station have experience (field collecting, identification and data interpretation) in the use of benthic organisms in aquatic bioassessments in freshwater (Lasier 1986; Winger and Lasier 1995b). The use of benthic assemblages in conjunction with sediment and pore-water chemistry and sediment and pore-water toxicity (Sediment Quality Triad) needs additional application in freshwater systems. Guidance needs to be developed on which benthic metrics are most suitable for use in these evaluations.

Recent Sediment and Pore-Water Studies:

Toxicity tests on sediments and pore waters from Savannah River and Savannah National Wildlife Refuge were used to evaluate habitat quality and potential impacts of industries, harbor developments, municipal outfalls and runoff from dredge-disposal areas on fish and wildlife resources (Winger and Lasier 1995a). Impacts of major cities on the Mississippi River were evaluated using toxicity testing of sediments collected upstream and downstream of the cities (Cairo, Memphis, Vicksburg, Baton Rouge and New Orleans) (Winger and Lasier 1996c). Toxicities of sediments and pore water from canals and rivers flowing into Biscayne Bay are being compared to samples collected from the estuary for NOAA's Status and Trends program (Winger and Lasier 1997b). Sediments from St. Andrew Bay, Brunswick Harbor (Winger et al. 1993), Charleston Harbor, Perdido Bay (Brim 1993) and Mobile River have also been evaluated. Sediment and pore water were evaluated during a three-year study of the fate and effects of contaminants (emphasis on mercury and lead) in atmospheric deposition on Okefenokee National Wildlife Refuge (Winger and Lasier 1996a). The influence of common ions, such as ammonia and alkalinity, on the toxicity of sediments and pore water have also been evaluated (Lasier and Winger 1995; Lasier and Winger 1997).

References Cited

Ankley, G.T., S.A. Collyard, P.D. Monson, and P.A. Kosian. 1994. Influence of ultraviolet light on the toxicity of sediments contaminated with polycyclic aromatic hydrocarbons. Environ. Toxicol. Chem. 13:1791-1796.

Brim, M.S. 1993. Toxics characterization report for Perdido Bay, Alabama and Florida. U.S. Fish and Wildlife Resources, Atlanta, GA, Publ. No. PCFO EC-93-04.

Ingersoll, C.G., G.T. Ankley, D.A. Benoit, G.A Burton, F.J. Dwyer, I.E. Greer, T.J. Norberg-King, and P.V. Winger. 1995. Toxicity and bioaccumulation of sediment-associated contaminants with freshwater invertebrates: A review of methods and applications. Environ. Toxicol. Chem. 14:1885 1894.

Lasier, P.J. 1986. The use of benthic macroinvertebrates as indicators of acid sensitivity in headwater streams of the Southern Blue Ridge Province. MS Thesis, University of Georgia, Athens, GA.

Lasier, P.J. 1995. Influence of physical and chemical factors on the toxicity of sediment and pore water to Hyalella azteca. PH.D. Dissertation, University of Georgia, Athens, GA

Lasier, P.J. and P.V. Winger. 1995. Toxicity of alkalinity to Hyalella azteca. Paper presented at the 16th Annual Meeting Society of Toxicology and Chemistry, November 5-9, 1995, Vancouver, BC. (Manuscript in review)

Lasier, P.J. and P.V. Winger. 1997. Toxicity of ammonia to Hyalella azteca. (Manuscript in preparation)

Lasier, P.J., P.V. Winger and B.P. Jackson. 1994. Effects of handling, temperature and storage time on sediment and pore-water chemistry and toxicity. Paper presented at the 15th Annual meeting of the Society of Environmental Toxicology and Chemistry, October 30 - November 4, 1994, Denver, CO.

U.S. Environmental Protection Agency. 1994. Methods for measuring the toxicity and bioaccumulation of sediment-associated contaminants with freshwater invertebrates. EPA 600/R-94/024, Duluth, MN.

Winger, P.V. and P. J. Lasier. 1991. A vacuum-operated pore-water extractor for estuarine and freshwater sediments. Arch. Environ. Contam. Toxicol. 21:321-324.

Winger, P.V. and P.J. Lasier. 1993a. Sediment toxicity testing: Comparison of methods and evaluation of influencing factors. Pages 640-662 In: J.W. Gorsuch, F.J. Dwyer, C.G. Ingersoll and T.W. LaPoint, Eds., Environmental Toxicity and Risk Assessment: 2nd Volume, American Society for Testing and Materials, Philadelphia, PA, STP 1216.

Winger, P.V. and P.J. Lasier. 1993b. Age and size of Hyalella azteca for sediment toxicity testing. Paper presented at the 14th Annual Meeting of the Society of Environmental Toxicology and Chemistry, November 14-18, 1993, Houston, TX. (Manuscript in preparation)

Winger, P.V. and P.J. Lasier. 1995a. Sediment toxicity in Savannah Harbor. Arch. Environ. Contam. Toxicol. 28:357-365.

Winger, P.V. and P.J. Lasier. 1995b. Rocky Creek Bioassessment-1995. Report Submitted to Textiles, Merchandising and Interiors, University of Georgia, Athens, GA, Consortium on competitiveness for the Apparel, Carpet, and Textiles Industries.

Winger, P.V. and P.J. Lasier. 1996a. Fate of airborne contaminants in Okefenokee National Wildlife Refuge. Preliminary Report submitted to U.S. Fish and Wildlife Service, Region IV, Atlanta, GA, Cooperative Agreement 14--26-0009-1551, Research Work Order Number 21.

Winger, P.V. and P.J. Lasier. 1996b. Toxicity of fresh versus equilibrated pore water. Paper presented at the 17th Annual Meeting of the Society of Environmental Toxicology and Chemistry, November 17-21, 1996, Washington, DC.

Winger, P.V. and P.J. Lasier. 1996c. Toxicity of sediment collected upriver and downriver of major cities along the lower Mississippi River. Preliminary Report Submitted to the U.S. Fish and Wildlife Service, Region IV, Atlanta, GA (Manuscript in preparation)

Winger, P.J. and P.J. Lasier. 1997a. Comparison of toxicity of Hyalella azteca exposed to solid-phase sediment and pore water. (Manuscript in preparation)

Winger, P.J. and P.J. Lasier. 1997b. Toxicity of sediment from Dade County, Florida to Hyalella azteca. (Manuscript in preparation)

Winger, P.J., P.J. Lasier and H. Geitner. 1993. Toxicity of sediments and pore water from Brunswick Estuary, Georgia. Arch. Environ. Contam. Toxicol. 25:371-371.

Winger, P.V., P.J. Lasier and B.P. Jackson. 1994. Influence of extraction method on pore-water chemistry. Paper presented at the 15th Annual Meeting, Society of Environmental Toxicology and Chemistry, October 30 November 3, 1994, Denver, CO (Manuscript in preparation)

Autobiography
Parley V. Winger, USGS-Biological Resources Division, Patuxent Wildlife Research Center, University of Georgia, Athens Field Station, Athens, GA: As an aquatic ecologist/toxicologist, current responsibilities include identifying and evaluating contaminant impacts on aquatic resources in the Southeast. Sediment and pore water are important matrices used in these evaluations. Research conducted during the past 20 years has dealt primarily with understanding the effects of human perturbations on aquatic ecosystems. Studies have included: impacts of acid-mine drainage on streams, influence of atmospheric deposition on streams in the Southern Blue Ridge Province, contaminant impacts on National Wildlife Refuges, significance of atmospheric deposition of mercury and lead on Okefenokee National Wildlife Refuge, impacts of industry and dredge spoils on Savannah River, methods for sediment and pore water testing.
Peter J. Lasier, Fishery Biologist, USGS - Biological Resources Division - Patuxent Wildlife Research Center, Warnell School of Forest Resources, University of Georgia, Athens, Ga 30602 2152. Serves as an aquatic ecologist/toxicologist investigating contaminant impacts on aquatic systems in the southeast. Expertises include water, sediment and pore-water chemistry, and toxicity assessments of freshwater and estuarine sediments and pore waters as well as municipal and industrial effluents. Recent studies include sediment toxicity evaluations from the Savannah River, Ga, freshwater canals entering Biscayne Bay, Fl, the lower Mississippi River, Charleston Harbor, Mobile Bay, Al, and Perdido Bay, Fl, fate of trace metals entering the Okefenokee Swamp via atmospheric deposition, physical and chemical factors affecting sediment toxicity, and common ion (ammonia, carbonate, sulfate, borate) toxicities to test organisms.
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