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Linking Land, Air and Water Management in the Southern Everglades and Coastal Zone to Water Quality and Ecosystem Restoration: Task 3, Natural Organic Matter-Mercury Interactions

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Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator: George Aiken
Publication_Date: Unpublished Material
Title:
Linking Land, Air and Water Management in the Southern Everglades and Coastal Zone to Water Quality and Ecosystem Restoration: Task 3, Natural Organic Matter-Mercury Interactions
Geospatial_Data_Presentation_Form: unknown
Online_Linkage:
<https://sofia.usgs.gov/projects/index.php?project_url=int_organic_hg>
Description:
Abstract:
This Task (Task 3 of the overall study) focuses on the factors that control the occurrence, nature and reactivity of dissolved organic matter (DOM) in the Florida Everglades, especially with regard to the biological transformation and accumulation of mercury (Hg). Our goal is to provide fundamental information on the nature and reactivity of DOM in the Everglades and to elucidate the mechanisms and pathways by which the DOM influences the chemistry of Hg throughout the system.
Purpose:
The overall objective of this next phase of our research is to extend our understanding of the interactions of Hg, sulfate, and Dissolved Organic Carbon (DOC) to areas of the Everglades that are anticipated to receive increasing water delivery from sulfate and DOC rich EAA runoff or ASR waters, including: ENP (including coastal or near coastal settings), Big Cypress, and Loxahatchee National Wildlife Refuge.

This research is relevant because of the high natural production of organic carbon in the peat soils and wetlands, the relatively high carbon content of shallow ground water systems in the region, the interactions of organic matter with other chemical species, such as trace metals, divalent cations, mercury, and anthropogenic compounds, the accumulation of organic carbon in corals and carbonate precipitates, and the potential changes in the quality and reactivity of DOC resulting from land use and water management practices. Proposed attempts to return the Everglades to more natural flow conditions will result in changes to the current transport of organic matter from the Everglades Agricultural Area and the northern conservation areas to Florida Bay. The results of this research are critical for the design of effective management strategies for the ecological restoration of the Everglades and for mitigating mercury contamination of game fish in South Florida.

Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 2006
Ending_Date: 2010
Currentness_Reference: ground condition
Status:
Progress: In Work
Maintenance_and_Update_Frequency: As needed
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -81.5
East_Bounding_Coordinate: -80
North_Bounding_Coordinate: 27
South_Bounding_Coordinate: 25
Keywords:
Theme:
Theme_Keyword_Thesaurus: none
Theme_Keyword: hydrology
Theme_Keyword: chemistry
Theme_Keyword: phosphorus
Theme_Keyword: DOC
Theme_Keyword: dissolved organic carbon
Theme_Keyword: DOM
Theme_Keyword: dissolved organic matter
Theme_Keyword: mercury
Theme_Keyword: MeHg
Theme_Keyword: methylmercury
Theme_Keyword: sulfate
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: environment
Theme_Keyword: inlandWaters
Theme_Keyword: oceans
Theme_Keyword: 007
Theme_Keyword: 012
Theme_Keyword: 014
Place:
Place_Keyword_Thesaurus:
Department of Commerce, 1995, Countries, Dependencies, Areas of Special Sovereignty, and Their Principal Administrative Divisions, Federal Information Processing Standard (FIPS) 10-4, Washington, DC, National Institute of Standards and Technology
Place_Keyword: United States
Place_Keyword: US
Place:
Place_Keyword_Thesaurus:
U.S. Department of Commerce, 1987, Codes for the identification of the States, the District of Columbia and the outlying areas of the United States, and associated areas (Federal Information Processing Standard 5-2): Washington, DC, NIST
Place_Keyword: Florida
Place_Keyword: FL
Place:
Place_Keyword_Thesaurus:
Department of Commerce, 1990, Counties and Equivalent Entities of the United States, Its Possessions, and Associated Areas, FIPS 6-3, Washington, DC, National Institute of Standards and Technology
Place_Keyword: Palm Beach County
Place_Keyword: Glades County
Place_Keyword: Collier County
Place_Keyword: Hendry County
Place_Keyword: Broward County
Place_Keyword: Miami-Dade County
Place_Keyword: Monroe County
Place:
Place_Keyword_Thesaurus: USGS Geographic Names Information System
Place_Keyword: Everglades National Park
Place_Keyword: Big Cypress National Preserve
Place_Keyword: Loxahatchee National Wildlife Refuge
Place_Keyword: Arthur R. Marshall- Loxahatchee National Wildlife Refuge
Place:
Place_Keyword_Thesaurus: none
Place_Keyword: Greater Lake Okeechobee
Place_Keyword: Central Everglades
Place_Keyword: South Coast Florida
Place_Keyword: Southwest coast
Place_Keyword: BCNP
Place_Keyword: ENP
Access_Constraints: none
Use_Constraints: none
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: George Aiken
Contact_Organization: U.S. Geological Survey
Contact_Position: Project chief
Contact_Address:
Address_Type: mailing address
Address: 3215 Marine Street, Suite E-127
City: Boulder
State_or_Province: CO
Postal_Code: 80303
Contact_Voice_Telephone: 303 541-3036
Contact_Facsimile_Telephone: 303 447-2505
Contact_Electronic_Mail_Address: graiken@usgs.gov
Data_Set_Credit:
Project personnel include Chase Gerbig, Kenna Butler, and Jennifer Schnackel
Cross_Reference:
Citation_Information:
Originator:
Haitzer, M.

Aiken, G. R.; Ryan, J. N.

Publication_Date: 2002
Title:
Binding of Mercury (II) to Dissolved Organic Matter: The Role of the Mercury-to-DOM Concentration Ration
Geospatial_Data_Presentation_Form: paper
Series_Information:
Series_Name: Environmental Science and Technology
Issue_Identification: v. 36, n. 16, p. 3564-3570
Publication_Information:
Publication_Place: Washington, DC
Publisher: American Chemical Society
Other_Citation_Details:
accessed as of 11/8/2010

The full article is available via journal subscription or single article purchase.

The abstract, tables, figures, and bibliography are available at <https://sofia.usgs.gov/publications/papers/hg_dom_binding/>

Online_Linkage: <http://pubs.acs.org/doi/full/10.1021/es025699i>
Online_Linkage: <https://sofia.usgs.gov/publications/papers/hg_dom_binding/>
Cross_Reference:
Citation_Information:
Originator:
Drexel, R. Todd

Haitzer, Markus; Ryan, Joseph N.; Aiken, George R.; Nagy, Kathlyn L.

Publication_Date: 2002
Title:
Mercury (II) Sorption to Two Florida Everglades Peats: Evidence for Strong and Weak Binding and Competition by Dissolved Organic Matter Released from the Peat
Geospatial_Data_Presentation_Form: paper
Series_Information:
Series_Name: Environmental Science and Technology
Issue_Identification: v. 36 no.19
Publication_Information:
Publication_Place: Washington, DC
Publisher: American Chemical Society
Other_Citation_Details:
accessed as of 11/8/2010.

The full article is available via journal subscription or single article purchase.

The abstract, figures, tables and literature cited are available at <https://sofia.usgs.gov/publications/papers/merc_peat/index.html>

Online_Linkage: <http://pubs.acs.org/doi/abs/10.1021/es0114005>
Online_Linkage: <https://sofia.usgs.gov/publications/papers/merc_peat/index.html>
Cross_Reference:
Citation_Information:
Originator:
Bates, A. L.

Orem, W. H.; Harvey, J.. W.; Spiker, E. C.

Publication_Date: 2001
Title:
Geochemistry of Sulfur in the Florida Everglades: 1994 through 1999
Geospatial_Data_Presentation_Form: report
Series_Information:
Series_Name: USGS Open-File Report
Issue_Identification: 01-007
Publication_Information:
Publication_Place: Tallahassee, FL
Publisher: U.S. Geological Survey
Other_Citation_Details: accessed as of 11/8/2010
Online_Linkage: <https://sofia.usgs.gov/publications/ofr/01-007/>
Cross_Reference:
Citation_Information:
Originator:
Haitzer, Markus

Aiken, George R.; Ryan, Joseph N.

Publication_Date: 2003
Title:
Binding of Mercury (II) to Aquatic Humic Substances: Influence of pH and Source of Humic Substances
Geospatial_Data_Presentation_Form: report
Series_Information:
Series_Name: Environmental Science and Technology
Issue_Identification: v. 37, n. 11, p. 2436-2441
Publication_Information:
Publication_Place: Washington, DC
Publisher: American Chemical Society
Other_Citation_Details:
accessed online 11/8/2010

The full article is available via journal subscription or single article purchase.

Abstract, tables, figures, and literature cited are also available at <https://sofia.usgs.gov/publications/papers/bind_hg_humic/>

Online_Linkage: <http://pubs.acs.org/doi/full/10.1021/es026291o>
Online_Linkage: <https://sofia.usgs.gov/publications/papers/bind_hg_humic/>
Cross_Reference:
Citation_Information:
Originator:
Harvey, Judson, W

Jackson, Jonah M.; Mooney, Robert H.; Choi, Jungyill

Publication_Date: 2000
Title:
Interaction between ground water and surface water in Taylor Slough and vicinity, Everglades National Park, south Florida: study methods and appendixes
Geospatial_Data_Presentation_Form: report
Series_Information:
Series_Name: USGS Open-File Report
Issue_Identification: 00-483
Publication_Information:
Publication_Place: Reston, VA
Publisher: U.S. Geological Survey
Other_Citation_Details:
Prepared in cooperation with Everglades National Park

accessed online as of 11/8/2010

Online_Linkage: <https://sofia.usgs.gov/publications/ofr/00-483/>
Cross_Reference:
Citation_Information:
Originator:
Orem, W. H.

Lerch, H. E.; Rawlik, P.

Publication_Date: 1997
Title:
Geochemistry of surface and pore water at USGS coring sites in wetlands of South Florida, 1994 and 1995
Geospatial_Data_Presentation_Form: report
Series_Information:
Series_Name: USGS Open-File Report
Issue_Identification: 97-454
Publication_Information:
Publication_Place: Reston, VA
Publisher: U.S. Geological Survey
Other_Citation_Details: accessed as of 11/8/2010
Online_Linkage: <https://sofia.usgs.gov/publications/ofr/97-454>
Cross_Reference:
Citation_Information:
Originator:
Waples, Jacob S.

Nagy, Kathryn L.; Aiken, George A.; Ryan, Joseph N.

Publication_Date: 2005
Title:
Dissolution of cinnabar (HgS) in the presence of natural organic matter
Geospatial_Data_Presentation_Form: report
Series_Information:
Series_Name: Geochimica et Cosmochimica Acta
Issue_Identification: v. 69, n. 6, p. 1575-1588
Publication_Information:
Publication_Place: Oxon, United Kingdom
Publisher: Geochemical Society (Elsevier Science, Ltd.)
Other_Citation_Details:
accessed online as of 11/8/2010

The full article is available via journal subscription or single article purchase. The abstract may be viewed on the ScienceDirect website by selecting the volume and issue number.

Online_Linkage: <http://www.sciencedirect.com/science/journal/00167037>
Cross_Reference:
Citation_Information:
Originator:
Gasper, J. D.

Aiken, G. A.; Ryan, J.. N.

Publication_Date: 200708
Title:
A critial review of three methods used for the measurement of mercury (Hg+2) -dissolved organic matter constants
Geospatial_Data_Presentation_Form: paper
Series_Information:
Series_Name: Applied Geochemistry
Issue_Identification: V. 22, issue 8, p. 1583-1597
Publication_Information:
Publication_Place: Amsterdam, the Netherlands
Publisher: Geochemical Society
Other_Citation_Details:
accessed as of 11/8/2010

The full article is available via journal subscription or single article purchase. The abstract may be viewed on the ScienceDirect website by selecting the volume and issue number.

Online_Linkage: <http://www.sciencedirect.com/science/journal/08832927>
Cross_Reference:
Citation_Information:
Originator:
Aiken, G.

Haitzer, M.; Ryan, J. N.' Nagy, K.

Publication_Date: 2003
Title:
Interactions between dissolved organic matter and mercury in the Florida Everglades
Geospatial_Data_Presentation_Form: report
Series_Information:
Series_Name: Journal de Physique
Issue_Identification: v. 107, p 29-32
Publication_Information:
Publication_Place: unknown
Publisher: EDP Sciences
Other_Citation_Details:
accessed online as of 11/8/2010

The abstract is available online. The full article is available via journal subscription or single article purchase.

Online_Linkage:
<http://jp4.journaldephysique.org/index.php?option=article&access=standard&Itemid=129&url=/articles/jp4/abs/2003/05/jp4pr5p029/jp4pr5p029.html>
Cross_Reference:
Citation_Information:
Originator:
Krabbenhoft, D. P.

Aiken, G. R.; Anderson, M. P.

Publication_Date: 2007
Title:
An Assessment of the Potential Effects of Aquifer Storage and Recovery on Mercury Cycling in South Florida
Geospatial_Data_Presentation_Form: report
Series_Information:
Series_Name: USGS Scientific Investigations Report (SIR)
Issue_Identification: 2007-5420
Publication_Information:
Publication_Place: Reston, VA
Publisher: U.S. Geological Survey
Other_Citation_Details: accessed as of 11/8/2010
Online_Linkage: <http://pubs.usgs.gov/sir/2007/5240/>
Cross_Reference:
Citation_Information:
Originator:
Ritter, K.

Aiken, G. R.; Ranville, J. F.; Bauer, M.; MacCalady, D. L.

Publication_Date: 200609
Title:
Evidence for the aquatic binding of arsenate by natural organic matter-suspended Fe(III)
Geospatial_Data_Presentation_Form: report
Series_Information:
Series_Name: Environmental Science and Technology
Issue_Identification: v. 40, n. 17, p. 5380-5387
Publication_Information:
Publication_Place: Washington, DC
Publisher: American Chemical Society
Other_Citation_Details:
accessed as of 11/8/2010

The full article is available via journal subscription or single article purchase. The abstract may be viewed on the website below.

Online_Linkage: <http://pubs.acs.org/doi/abs/10.1021/es0519334>
Cross_Reference:
Citation_Information:
Originator:
Axelrad, D. M.

Atkeson, T. D.; Lange, T.; Gilmour, C. C.; Pollman, C. D.; Orem, W. H.; Mendelssohn, I. A.; Frederick, P. C.; Krabbenhoft, D. P.; Aiken, G. R.; Rumbold, D. G.; Scheidt, D. J.; Kalla, P. I.

Publication_Date: 2007
Title:
Mercury montioring, research and environmental assessment in south Florida
Geospatial_Data_Presentation_Form: report
Series_Information:
Series_Name: 2007 South Florida Environmental Report
Issue_Identification: v. 1, chapter 3B
Publication_Information:
Publication_Place: West Palm Beach, FL
Publisher: South Florida Water Management District
Other_Citation_Details: accessed as of 11/8/2010
Online_Linkage:
https://my.sfwmd.gov/portal/page/portal/pg_grp_sfwmd_sfer/portlet_prevreport/volume1/chapters/v1_ch_3b.pdf
Cross_Reference:
Citation_Information:
Originator:
Gilmour, C.

Krabbenhoft, D. P.; Orem, W. H.; Aiken, G. R.; Roden, E.

Publication_Date: 2007
Title:
Status report on ACME studies on the control of mercury methylation and bioaccumulation in the Everglades
Geospatial_Data_Presentation_Form: report
Series_Information:
Series_Name: South Florida Environmental Report
Issue_Identification: v. 1, appendix 3B-2
Publication_Information:
Publication_Place: West Palm Beach, FL
Publisher: South Florida Water Management District
Other_Citation_Details: accessed as of 11/8/2010
Online_Linkage:
https://my.sfwmd.gov/portal/page/portal/pg_grp_sfwmd_sfer/portlet_prevreport/volume1/appendices/v1_app_3b-2.pdf
Cross_Reference:
Citation_Information:
Originator:
Hall, B. D.

Aiken, G. R.; Krabbenhoft, D. P.; Marvin-DiPasquale, M.; Swarzenski, C. M.

Publication_Date: 2008
Title:
Wetlands as principal zones of methylmercury production in southern Louisiana and the Gulf of Mexico region
Geospatial_Data_Presentation_Form: report
Series_Information:
Series_Name: Environmental Pollution
Issue_Identification: v. 154, n. 1, p. 124-134
Publication_Information:
Publication_Place: Amsterdam, The Netherlands
Publisher: Elsevier, B. V.
Other_Citation_Details:
accessed as of 11/8/2010

The full article is available via journal subscription or single article purchase. The abstract may be viewed on the ScienceDirect website by selecting the volume and issue number

Online_Linkage: <http://www.sciencedirect.com/science/journal/02697491>
Cross_Reference:
Citation_Information:
Originator:
Brigham, M. E.

Wentz, D. A.; Aiken, G. R.; Krabbenhoft, D. P.

Publication_Date: 2009
Title:
Mercury cycling in stream ecosystems: 1. Water column chemistry and transport
Geospatial_Data_Presentation_Form: report
Series_Information:
Series_Name: Environmental Science and Technology
Issue_Identification: v. 43, n. 8, p. 2720-2725
Publication_Information:
Publication_Place: Washington, DC
Publisher: American Chemical Society
Other_Citation_Details: accessed as of 11/8/2010
Online_Linkage: <http://pubs.acs.org/doi/full/10.1021/es802694n>
Cross_Reference:
Citation_Information:
Originator:
Marvin-DiPasquale, M.

Lutz, M. A.; Brigham, M. E.; Krabbenhoft, D. P.; Aiken, G. R.; Orem, W. H.; Hall, B. D.

Publication_Date: 2009
Title:
Mercury cycling in stream ecosystems: 2. Benthic methymercury production and bed sediment-pore water partitioning
Geospatial_Data_Presentation_Form: report
Series_Information:
Series_Name: Environmental Science and Technology
Issue_Identification: v. 43, n.8, p. 2726-2732
Publication_Information:
Publication_Place: Washington, DC
Publisher: American Chemical Society
Other_Citation_Details: accessed as of 11/8/2010
Online_Linkage: <http://pubs.acs.org/doi/full/10.1021/es802698v>
Cross_Reference:
Citation_Information:
Originator:
Cesar, L. C.

Scudder, B. C.; Stewart, A. R.; Bell, A. H.; Aikne, G. R.

Publication_Date: 2009
Title:
Mercury cycling in stream ecosystems: 3. Trophic dynamics and methylmercury bioaccumulation
Geospatial_Data_Presentation_Form: report
Series_Information:
Series_Name: Environmental Science and Technology
Issue_Identification: v. 43, n. 8, p. 2733-2739
Publication_Information:
Publication_Place: Washington, DC
Publisher: American Chemical Society
Other_Citation_Details: accessed as of 11/8/2010
Online_Linkage: <http://pubs.acs.org/doi/full/10.1021/es8027567>
Cross_Reference:
Citation_Information:
Originator:
Dittman, J. A.

Shanley, J. B.; Driscoll, C. T.; Aiken, G. R.; Chalmers, A. T.; Towse, J. E.

Publication_Date: 2009
Title:
Ultraviolet absorbance as a proxy for total dissolved mercury in streams
Geospatial_Data_Presentation_Form: report
Series_Information:
Series_Name: Environmental Pollution
Issue_Identification: v. 157, n. 6, p. 1953-1956
Publication_Information:
Publication_Place: Amsterdam, The Netherlands
Publisher: Elsevier, B. V.
Other_Citation_Details:
accessed as of 11/8/2010

The full article is available via journal subscription or single article purchase. The abstract may be viewed on the ScienceDirect website by selecting the volume and issue number.

Online_Linkage: <http://www.sciencedirect.com/science/journal/02697491>

Data_Quality_Information:
Logical_Consistency_Report: not available
Completeness_Report: not available
Lineage:
Process_Step:
Process_Description:
Work planned for FY 2007 included:

1) Field Surveys in Everglades National Park (ENP), Big Cypress National Preserve (BCNP), and Loxahatchee National Wildlife Preserve (LOX)

Beginning in FY07, field surveys were conducted in the study areas ENP, BCNP, and LOX. The proposed field surveys were similar to surveys we conducted previously in the northern and central Everglades. Samples of surface water, pore water, sediments, and biota were collected using "clean" methods previously validated by our team in the Everglades, and now used by other researchers. Samples were analyzed for Dissolved Organic Carbon (DOC) concentration and composition, sulfur species, nutrients, and ancillary biogeochemical parameters. The work in ENP included both the freshwater areas and the coastal zone. Survey work in the freshwater area of ENP focused on how restoration is impacting DOC loads, composition, and reactivity to ENP, and how DOC impacts mercury methylation and bioaccumulation. Sampling was conducted at sites specifically selected to answer the question. Sites where canal water is discharged into ENP (sites P33 and P34) were targeted. Field surveys conducted in BCNP examined potential impacts of the planned diversion of DOC contaminated water from the L28 feeder canal. This diversion has not yet been implemented, but is likely to result in increased MeHg production in BCNP. Proposed field surveys would establish present conditions within BCNP, and examine areas where water with elevated DOC levels is currently entering the Preserve. The threat of DOC contaminated canal water infiltrating LOX from the new Stormwater Treatment Area (STA) STA-1E and associated drainage canals bordering LOX is also of concern, with regard to increased stimulation of MeHg production and other ecological impacts associated with the transport of reactive DOC (metals, pesticides and herbicides, controls on primary productivity). We planned field surveys here in coordination with Paul McCormick (SFWMD). McCormick has been working with LOX staff to establish sites where contaminated canal water is infiltrating the Refuge, and sites chosen for our field survey were established after consultation. We continued collaboration with Paul McCormick on water quality in LOX (WCA 1), specifically focused on DOC geochemistry in Water Conservation Area (WCA) WCA1 as it supports the Arthur R. Marshall Loxahatchee NWR Internal Canal Structure Project by addressing the impacts of water quality (sulfur/nutrients/mercury) and water management practices on refuge resources.

(2) MeHg Production in the Coastal Zone - The coastal zone of ENP and the southwest coast will receive increased freshwater flow from restoration activities, but the impacts on MeHg production and bioaccumulation are unknown. Of particular significance are the influences of DOC on Hg reactivity. The concentrations and composition of DOC in freshwater and marine systems are very different and coastal zones are dynamic areas for DOC cycling, consumption and alteration. Results of research conducted by this project in the Everglades, including field surveys, mesocosm studies, and laboratory experiments have provided a working model for MeHg production and bioaccumulation in the freshwater Everglades and similar environments. As this model, however, does not appear to apply to coastal marine systems, an important goal of the field studies in the coastal zone was to determine the relative importance of MeHg flux from the freshwater Everglades, compared to in situ production of MeHg in coastal sediments. It is also unclear how the coastal system differs from the freshwater Everglades in the complex biogeochemical interactions between Hg, sulfur, and DOC in MeHg production. The proposed field studies examined the key factors promoting MeHg formation in coastal areas. This task specifically focused on the processes that control DOC concentration and composition in coastal environments and the influences these processes have MeHg production in coastal environments. Field surveys were conducted using an approach similar to that used by this team in the freshwater Everglades. Surface water and pore water were collected for analysis of DOC, sulfur species, nutrients, anions, and other biogeochemical parameters by this task. Field surveys were followed by experimental work (microcosms and/or mesocosms) in later years. The project will provide Comprehensive Everglades Restoration Plan (CERP) and Greater Everglades Ecosystem Restoration (GEER) management with quantitative information for critical decisions, such as estimates of the maximum DOC, sulfur, nutrient, and mercury loads producing permissible levels of methylmercury in the ecosystem and the impacts of these contaminants.

(3) Canal Water Addition Mesocosm Studies - We used environmental chambers (~ 1 m. wide mesocosms) to examine the effects of the discharge of high ionic strength/high sulfate/high DOC canal water on the ecosystem. Anticipated impacts of contaminated canal water in the mesocosm experiments include: stimulation of methylmercury production and bioaccumulation, internal eutrophication of the system (release of nutrients and DOC from peat), and changes in the microbial, faunal, and floral assemblages. The mesocosm work was intended to validate field observations, and to provide data for the prediction of the response of the environment to future conditions. We previously used mesocosms to examine the effects of various contaminants (DOC, sulfur, phosphorus, mercury (Hg) on methlmercury (MeHg) production and bioaccumulation in the central Everglades (WCA's). This work provided experimental validation of the effects of Hg and sulfur loading, and DOC complexation on MeHg production and bioaccumulation in this portion of the Everglades. Different environmental conditions in the target areas for this project (ENP, BCNP) require additional mesocosm work. For example, the marl prairie area in ENP, and the cypress swamp of BCNP are ecologically and environmentally different from the ridge and slough environment of the central WCA's. Planned mesocosm studies will examine how these environments respond to changing freshwater inputs with variable water quality characteristics, with respect to MeHg production and bioaccumulation. Another difference from our previous studies is that this experiment uses canal water to dose mesocosms instead of specific chemical amendments. It was anticipated that this will better simulate the actual effects of canal discharge on the ecosystem.

Mesocosms were left open to the outside environment until experiments are to be run. During experiments, mesocosms were closed off and addition of specific canal water doses were made to sets of mesocosms to test the effects of contaminants in the canal water on: methylmercury production and bioaccumulation, internal eutrophication, and changes in the microbial, faunal, and floral assemblages. Each canal water addition (variable) was tested at multiple concentration levels. Following the additions, changes in chemical species (MeHg and other Hg species, sulfur species, DOC, nutrients, anions, cations, Fe and Mn, redox, conductivity, pH) and microbial activity (Hg methylation) were determined in surface water, pore water, and sediments over time (6-12 months). Results of mesocosm experiments l allow prediction of how the environment in different ecotones in the Greater Everglades Ecosystem will respond to changes in water flux, and increased flux of chemical contaminants (notably sulfur). Of particular importance will be changes in MeHg production and bioaccumulation, redox conditions (from sulfide buildup in anoxic soils), and DOC and nutrient recycling (from increases in sulfate reduction rates).

(4) Sulfur Toxicity Mesocosm Experiment - This experiment was completed in FY07, with the final sampling in December 2006, and a brief follow-up sampling in March 2007. The experiment tested the hypothesis that excess sulfate entering the Everglades from EAA canal water has numerous impacts on the ecosystem, including: toxicological effects on native macrophytes and other organisms, internal eutrophication with enhanced recycling of nutrients and DOC, stimulation of mercury methylation, sequestration of metals in sediments as metal sulfides, and changes in the microbial community. This task provided analytical support to investigate the role of sulfate reduction on the geochemistry of DOC, especially with regard to Hg cycling. A total of 30 mesocosms were placed in central WCA 3A in FY03; half in sawgrass and half in cattails. Monthly dosing of these mesocosms with varying amounts of sulfate began in November 2003 and continued through November 2006. Sampling included geochemical studies of surface water, pore water, and sediments, and biological studies of macrophytes, microbial populations, and microfauna.

(5) Other: Laboratory studies designed to provide fundamental information about chemical interactions between DOC and Hg that are needed to improve Everglades Hg Cycling models will continue. This aspect of our work is providing improved binding constant data required for chemical speciation models, data on the nature and strength of interactions of DOC with HgS that control Hg solubility, data on the influence of DOC on the bioavailability of both Hg and MeHg, and data on the role of DOC in the photolytic reduction and subsequent evasion of Hg from the Everglades. In addition, analytical support and technical advice were provided to Laurel Larson (Univ of Colorado) working with Jud Harvey and Greg Noe (both USGS) to study the factors controlling formation of ridge and slough structures in the Everglades and the transport of phosphorous in the system.

Process_Date: 2008
Process_Step:
Process_Description:
Work planned for FY 2008 included:

1. Field Surveys in ENP, BCNP, and LOX: Collaboration will continue with Paul McCormick (SFWMD) on water quality in LOX (WCA 1), specifically focused on DOC geochemistry in WCA 1.

2. Periphyton-Based Stormwater Treatment Areas (PASTA) and STA Studies: In coordination with USACE we will conduct initial field surveys in the PASTAs (periphyton STAs) to examine mercury and DOC biogeochemistry. We will also examine the macrophyte-dominated STAs for comparison. Questions to be asked include: (a) how do the different STA approaches differ in terms of mercury chemistry and production and bioaccumulation of methylmercury, (b) how do PASTAs perform in terms of DOM removal or generation compared to the macrophyte-dominated STAs, (c) how do these two different STA systems differ in terms of DOM biogeochemistry, and nutrient remobilization from internal eutrophication effects. The proposed field surveys will be similar to surveys we have previously conducted in the northern and central Everglades, and STA 1W (formerly Everglades Nutrient Removal area (ENR)). Samples of surface water, pore water, sediments, and biota are collected using "clean" methods previously validated by our team in the Everglades, and now used by other researchers. Samples for this task are analyzed for Dissolved Organic Matter (DOM), common anions and cations.

3. Mesocosm Studies in LNWR The Loxahatchee National Wildlife Refuge (LNWR) represents one of the last vestiges of the historic soft-water Everglades. This is evidenced by the low conductivity of surface water in the marsh interior (~100 micro-siemens, mS) compared with that in the canal surrounding the Refuge (1000-1500 mS). Low conductivity waters in LNWR interior are associated with a characteristic soft-water periphyton community, wetland plant species that may also be adapted to the soft-water conditions, and lower rates of key ecosystem processes (e.g., decomposition) than in areas of the Everglades impacted by canal discharges. While it has long been known that the fringes of the LNWR are affected by high conductivity canal water, recent monitoring data indicate a trend towards increased intrusion of this water into the LNWR interior with noticeable impacts on water chemistry and sensitive biota, including the possibility of increased methylmercury production and bioaccumulation.

To address this concern, Paul McCormick established a suite of experimental plots (mesocosms) in the LNWR to examine the effects of this encroachment of contaminated canal water on the Refuge. We are cooperating with Paul and LNWR staff on this project to examine mercury, sulfur, and DOC biogeochemistry in the dosed mesocosms. The mesocosms are dosed with artificial canal water that mimics the chemical composition of the canal water surrounding the refuge. We will collect samples of surface water, pore water, sediments, and using "clean" methods. Samples are analyzed for DOM, common anions and cations.

4. Canal water monitoring: We plan to continue to monitor canal water for DOM transport and reactivity. Canals are the major conduit of water to enter the Everglades from the source in the Everglades Agricultural Area (EAA). The DOM entering the Everglades has significant impacts on the ecosystem, including acting as a major control on mercury methylation in the ecosystem, enhancing remobilization of nutrients and metals from soils (internal eutrophication), and posing a threat to macrophytes and other biota through facilitated transport of undesirable compounds (metals, pesticides) and limiting the depth of the photic zone by the absorption of light.

5. Other: Laboratory studies designed to provide fundamental information about chemical interactions between DOC and Hg that are needed to improve Everglades Hg Cycling models will continue. This aspect of our work is providing improved binding constant data required for chemical speciation models, data on the nature and strength of interactions of DOC with HgS that control Hg solubility, data on the influence of DOC on the bioavailability of both Hg and MeHg, and data on the role of DOC in the photolytic reduction and subsequent evasion of Hg from the Everglades. In addition, analytical support and technical advise are provided to Laurel Larson (Univ of Colorado) working with Jud Harvey and Greg Noe (both USGS) to study the factors controlling formation of ridge and slough structures in the Everglades and the transport of phosphorous in the system.

Process_Date: Not complete
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: George Aiken
Contact_Organization: U.S. Geological Survey
Contact_Position: Project chief
Contact_Address:
Address_Type: mailing address
Address: 3215 Marine Street, Suite E-127
City: Boulder
State_or_Province: CO
Postal_Code: 80303
Contact_Voice_Telephone: 303 541-3036
Contact_Facsimile_Telephone: 303 447-2505
Contact_Electronic_Mail_Address: graiken@usgs.gov

Metadata_Reference_Information:
Metadata_Date: 20101129
Metadata_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Heather Henkel
Contact_Organization: U.S. Geological Survey
Contact_Address:
Address_Type: mailing and physical address
Address: 600 Fourth Street South
City: St. Petersburg
State_or_Province: FL
Postal_Code: 33701
Country: USA
Contact_Voice_Telephone: 727 803-8747 ext 3028
Contact_Facsimile_Telephone: 727 803-2030
Contact_Electronic_Mail_Address: sofia-metadata@usgs.gov
Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata
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