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Historical Changes in Salinity, Water Quality, and Vegetation in Biscayne Bay

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Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator:
G. Lynn Brewster-Wingard

Thomas Cronin; Debra Willard; Charles Holmes; William Orem; Peter Swart; Gary Dwyer; Scott Ishman; Evelyn Gaiser

Publication_Date: 2007
Title:
Historical Changes in Salinity, Water Quality, and Vegetation in Biscayne Bay
Geospatial_Data_Presentation_Form: database
Online_Linkage: <https://sofia.usgs.gov/projects/historical_change/>
Description:
Abstract:
The objectives of this project are to examine in broad context the historical changes in the Biscayne Bay ecosystem at selected sites on a decadal-centennial scale, and to correlate these changes with natural events and anthropogenic alterations in the South Florida region. Specific emphasis will be placed on historical changes to 1) amount, timing, and sources of freshwater influx and the resulting effects on salinity and water quality; 2) shoreline and sub-aquatic vegetation; and 3) the relationship between sea-level change, onshore vegetation, and salinity. In addition, a detailed examination of historical seasonal salinity patterns will be derived from biochemical analyses of molluscs, ostracodes, foraminifera and corals. The corals will allow us to compare marine and estuarine trends, examine the linkage between the two systems, and will provide precise chronological control. Land management agencies (principally SFWMD, ACOE and Biscayne NP) can use the data derived from this project to establish performance criteria for restoring natural flow, and to understand the consequences of altered flow. These data can also be used to forecast potential problems as upstream changes in water delivery are made during restoration.
Purpose:
During the last century, Biscayne Bay has been greatly affected by anthropogenic alteration of the environment through urbanization of the Miami/Dade County area, and alteration of natural flow. The sources, timing, delivery, and quality of freshwater flow into the Bay, and the shoreline and sub-aquatic vegetation have changed. Current restoration goals are attempting to restore natural flow of fresh water into Biscayne and Florida Bays and to restore the natural vegetation, but first we must address of what the was environment prior to significant human alteration in order to establish targets for restoration.

This project is designed to examine the natural patterns of temporal change in salinity, water quality, vegetation, and benthic fauna in Biscayne Bay over the last 100-300 years and to examine the causes of change.

Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 19940224
Ending_Date: 20070403
Currentness_Reference: ground condition
Status:
Progress: In Work
Maintenance_and_Update_Frequency: As needed
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -80.42
East_Bounding_Coordinate: -80.08
North_Bounding_Coordinate: 26
South_Bounding_Coordinate: 25.17
Keywords:
Theme:
Theme_Keyword_Thesaurus: none
Theme_Keyword: biology
Theme_Keyword: chemistry
Theme_Keyword: hydrology
Theme_Keyword: nutrients
Theme_Keyword: ecology
Theme_Keyword: paleoecology
Theme_Keyword: geochronology
Theme_Keyword: organics
Theme_Keyword: sediment cores
Theme_Keyword: eutrophication
Theme_Keyword: SAV
Theme_Keyword: submerged aquatic vegetation
Theme_Keyword: salinity
Theme_Keyword: water quality
Theme_Keyword: vegetation
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: biota
Theme_Keyword: climatologyMeteorologyAtmosphere
Theme_Keyword: environment
Theme_Keyword: geoscientificInformation
Theme_Keyword: inlandWaters
Theme_Keyword: 002
Theme_Keyword: 004
Theme_Keyword: 007
Theme_Keyword: 008
Theme_Keyword: 012
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, D.C., 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, D. C., 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: Miami-Dade County
Place_Keyword: Monroe County
Place:
Place_Keyword_Thesaurus: USGS Geographic Names Information System
Place_Keyword: Biscayne Bay
Place_Keyword: Biscayne National Park
Place_Keyword: Florida Bay
Place:
Place_Keyword_Thesaurus: none
Place_Keyword: Central Everglades
Place_Keyword: South East Coast
Access_Constraints: none
Use_Constraints:
Any data are subject to change and are not citeable until reviewed and approved for official publication.
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Lynn Brewster-Wingard
Contact_Organization: U.S. Geological Survey
Contact_Address:
Address_Type: mailing address
Address: 926A National Center
City: Reston
State_or_Province: VA
Postal_Code: 20192
Country: USA
Contact_Voice_Telephone: 703 648-5352
Contact_Facsimile_Telephone: 703 648-6953
Contact_Electronic_Mail_Address: lwingard@usgs.gov
Browse_Graphic:
Browse_Graphic_File_Name:
<https://sofia.usgs.gov/projects/historical_change/images/ehbisbay03fig1x.gif>
Browse_Graphic_File_Description: map showing core locations in central Biscayne Bay
Browse_Graphic_File_Type: GIF
Data_Set_Credit:
Project personnel include: James Murray, Marci Marot, Harry Lerch, Marisa Beck, Robert Stamm, and Carlos Budet
Native_Data_Set_Environment: MS Access database
Cross_Reference:
Citation_Information:
Originator: Ishman, Scott E.
Publication_Date: 1997
Title:
Ecosystem History of South Florida: Biscayne Bay Sediment Core Descriptions
Geospatial_Data_Presentation_Form: report
Series_Information:
Series_Name: USGS Open-File Report
Issue_Identification: 97-0437
Publication_Information:
Publication_Place: Reston, VA
Publisher: U.S. Geological Survey
Online_Linkage: <http://pubs.usgs.gov/pdf/of/ofr97437.html>
Cross_Reference:
Citation_Information:
Originator:
Stone, Jeffery R.

Cronin, Thomas M.; Brewster-Wingard, G. Lynn; Ishman, Scott E.; Wardlaw, Bruce R.; Holmes, Charles W.

Publication_Date: 2000
Title:
A Paleoecologic Reconstruction of the History of Featherbed Bank, Biscayne National Park, Biscayne Bay, Florida
Geospatial_Data_Presentation_Form: report
Series_Information:
Series_Name: USGS Open-File Report
Issue_Identification: 00-191
Publication_Information:
Publication_Place: Reston, VA
Publisher: U.S. Geological Survey
Online_Linkage: <https://sofia.usgs.gov/publications/ofr/00-191>
Cross_Reference:
Citation_Information:
Originator:
Wingard, G. L.

Cronin, T. M.; Dwyer, G. S.; Ishman, S. E.; Willard, D. A.; Holmes, C. W.; Bernhardt, C. E.; Williams, C. P.; Marot, M. E.; Murray, J. B.; Stamm, R. G.; Murray, J. H.; Budet, C.

Publication_Date: 2003
Title:
Ecosystem History of Southern and Central Biscayne Bay: Summary Report on Sediment Core Analyses
Geospatial_Data_Presentation_Form: report
Series_Information:
Series_Name: USGS Open-file Report
Issue_Identification: 03-375
Publication_Information:
Publication_Place: Reston, VA
Publisher: U.S. Geological Survey
Online_Linkage: <https://sofia.usgs.gov/publications/ofr/03-375/>
Cross_Reference:
Citation_Information:
Originator:
Wingard, G. Lynn

Cronin, Thomas M.; Holmes, Charles W.; Willard, Debra A.; Dwyer, Gary; Ishman, Scott E.; Orem, William; Williams, Christopher P.; Albietz, Jessica; Bernhardt, Christopher E.; Budet, Carlos A.; Landacre, Bryan; Lerch, Terry; Marot, Marci; Ortiz, Ruth E.

Publication_Date: 2004
Title:
Ecosystem History of Southern and Central Biscayne Bay: Summary Report on Sediment Core Analyses - Year Two
Geospatial_Data_Presentation_Form: report
Series_Information:
Series_Name: USGS Open-File Report
Issue_Identification: 2004-1312
Publication_Information:
Publication_Place: Reston, VA
Publisher: U.S. Geological Survey
Online_Linkage: <https://sofia.usgs.gov/publications/ofr/2004-1312/>
Cross_Reference:
Citation_Information:
Originator:
Ishman, S. E.

Graham, I.; D'Ambrosio, J.

Publication_Date: 1997
Title:
Modern benthic foraminifer distributions in Biscayne Bay: Analogs for historical reconstruction
Geospatial_Data_Presentation_Form: report
Series_Information:
Series_Name: USGS Open-File Report
Issue_Identification: 97-034
Publication_Information:
Publication_Place: Reston, VA
Publisher: U.S. Geological Survey
Online_Linkage: <http://pubs.usgs.gov/pdf/of/ofr97034.pdf>
Cross_Reference:
Citation_Information:
Originator:
Ishman, S. E.

Cronin, T. M.; Brewster-Wingard, G. L.; Willard, D. A.; Verardo, D. J.

Publication_Date: 1998
Title:
A record of ecosystem change, Manatee Bay, Barnes Sound, Florida
Geospatial_Data_Presentation_Form: report
Series_Information:
Series_Name: Journal of Coastal Research
Issue_Identification: v. 26
Publication_Information:
Publication_Place: Royal Palm Beach, FL
Publisher: Coastal Education and Research Foundation (CERF)
Cross_Reference:
Citation_Information:
Originator:
Wolfert-Lohmann, M. A.

Langevin, C. D.; Jones, S. A.; Reich, C. D.; Wingard, G. L.; Kuffner, I. B.; Cunningham, K. J.

Publication_Date: 2008
Title:
U. S. Geological Survey Science Strategy for Biscayne National Park and Surrounding Areas in Southeastern Florida
Geospatial_Data_Presentation_Form: report
Series_Information:
Series_Name: USGS Open-File Report
Issue_Identification: 2007-1288
Publication_Information:
Publication_Place: Reston, VA
Publisher: U.S. Geological Survey
Online_Linkage: <http://pubs.usgs.gov/of/2007/1288/>

Data_Quality_Information:
Logical_Consistency_Report: not applicable
Completeness_Report: not available
Lineage:
Process_Step:
Process_Description:
Specific emphasis will be placed on historical changes to 1) amount, timing, and sources of freshwater influx and the resulting effects on salinity and water quality; 2) shoreline and sub-aquatic vegetation; and 3) the relationship between sea-level change, onshore vegetation, and salinity. In addition, a detailed examination of historical seasonal salinity patterns will be derived from biochemical analyses of molluscs, ostracodes, foraminifera and corals. The corals will allow us to compare marine and estuarine trends, examine the linkage between the two systems, and will provide precise chronological control. Land management agencies (principally SFWMD, ACOE and Biscayne NP) can use the data derived from this project to establish performance criteria for restoring natural flow, and to understand the consequences of altered flow. These data can also be used to forecast potential problems as upstream changes in water delivery are made during restoration. The project officially began in March 2002. A meeting took place between SFWMD, USGS, NPS, and other interested parties on March 20, 2002. Five potential coring sites were identified and a draft-coring plan produced. Coring will take place April 28 and 30th, 2002. Compilation of data from previous Biscayne cores has begun, and biochemical analyses of ostracode shells will begin within the next month.
Process_Date: 2002
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Lynn Brewster-Wingard
Contact_Organization: U.S. Geological Survey
Contact_Address:
Address_Type: mailing address
Address: 926A National Center
City: Reston
State_or_Province: VA
Postal_Code: 20192
Country: USA
Contact_Voice_Telephone: 703 648-5352
Contact_Facsimile_Telephone: 703 648-6953
Contact_Electronic_Mail_Address: lwingard@usgs.gov
Process_Step:
Process_Description:
Geochronology and paleoecology of Biscayne Bay cores

The initial and primary task is to determine the age of the selected cores, the general salinity history, the presence of sub-aquatic vegetation (SAV), and the probable abundance of SAV using established geochronologic and paleoecologic methods. This task lays the groundwork for additional analyses as well as providing necessary data for the final interpretation of the cores. The purpose of the overall project is to determine the changes in water quality and salinity over time, and the corresponding changes in onshore and sub-aquatic vegetation. The first step is to determine if the core has a good chronology (i.e. the core has not been disrupted) and if it contains faunal remains for analyses. If the core meets these criteria, then additional work can proceed. If the chronology is not good, or if there are no preserved fauna, than another core will be selected and the tasks repeated until we identify a core that meets these criteria. The chronologic data will be used to interpret all additional analyses. Paleoecological methods also will be used to provide data on the general trends within the core in terms of salinity, SAV, and changes in water quality and nutrient supply.

Six cores were collected at three sites in FY02 (Card, "No Name", and Featherbed Banks). FY03 work will focus on completion of the analyses of these cores begun in FY02. Faunal samples are processed using standard methods and all fractions are retained for analyses. A portion of the less than 63-micron fraction is used for Pb-210 geochronology and selected shells or plant material will be used for radiocarbon dating. The greater than 63-micron fraction is sorted for faunal analyses; ostracodes, molluscs and benthic forams are picked, sorted and identified. A small portion of core material is retained and processed for diatoms. Percent abundance is calculated for the faunal and diatom data, and these data are compared to data from 28 sites in modern Florida Bay where faunal and floral associations have been studied between 1996-2000 and to sites established in Biscayne Bay. These modern data serve as proxies for interpreting the down-core data. The down-core faunal and floral assemblages and the presence or absence of key indicator species allow interpretation of trends in salinity, water quality and the presence of SAV at the core sites.

In the second half of FY03, additional cores will be collected. Determination of sites will depend on results from analyses of FY02 cores and will be discussed with the client agencies (SFWMD, NPS-BB, ACOE). New cores will be described, x-rayed, and cut into 2-cm intervals for processing. Samples will be processed using standard methods and all fractions will be retained for analyses as described above for FY02 cores.

Process_Date: 2003
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Lynn Brewster-Wingard
Contact_Organization: U.S. Geological Survey
Contact_Address:
Address_Type: mailing address
Address: 926A National Center
City: Reston
State_or_Province: VA
Postal_Code: 20192
Country: USA
Contact_Voice_Telephone: 703 648-5352
Contact_Facsimile_Telephone: 703 648-6953
Contact_Electronic_Mail_Address: lwingard@usgs.gov
Process_Step:
Process_Description:
Patterns, Causes, and Impacts of Salinity Changes in Biscayne Bay

Determine salinity history of several regions in Biscayne Bay for the period prior to and during large-scale 20th century urbanization and water diversion using salinity proxies from sediment cores from Biscayne and Card Sound. Relate salinity variability to changes in fresh water flow due to land-use changes and natural variability in rainfall, freshwater runoff and water temperature (evaporation) and determine the extent to which water diversion disrupted natural patterns of salinity. Develop new method to use oxygen isotope ratios in foraminifers as proxy of past salinity and/or temperature changes. Compare and “splice” together the sediment core records of paleosalinity and paleotemperature with instrumental records of rainfall, bay salinity and temperature obtained from water monitoring. The reconstructed record of physical and biological conditions in Biscayne Bay will be compared to the history of water quality obtained by W. Orem. Biscayne Bay ecosystem and salinity history also will eventually be compared to records from Florida and Manatee Bays to examine regional trends.

Work in FY 2003 will involve measurement of faunal and geochemical proxies of salinity and temperature from sediment cores taken in 2002 (Card Sound Bank, "No Name" Bank, and Featherbed Bank located in central and southern Biscayne Bay) and if time permits, an additional site in northern Biscayne Bay, near the Rickenbacker Causeway (collected in 1997), will be examined. Proxy methods include 1) oxygen isotope analyses of benthic foraminifera, 2) trace elemental (magnesium/calcium ratios) of ostracodes, 3) morphological indicators of temperature (shell size), and 4) relative proportions of species of forams, ostracodes and molluscs indicative of specific salinity ranges (i.e. oligohaline, mesohaline, etc.related to assemblage analyses). The stable isotopic and trace elemental analyses will be carried out with cooperators using mass spectrometry and direct current plasma emission spectrometry at University of Miami and Duke University, respectively. The use of paired analyses of stable isotopes of forams and Mg/Ca ratios in ostracodes should allow the quantification of changes in salinity and temperature and the impact of these changes could then be assessed from the faunal analyses of benthos from the same samples. Selected intervals identified as representing extreme salinity conditions may also be studied for seasonal salinity variability using molluscan shell chemistry, depending on preservation in cores and status of mollusk calibration studies.

A transect of modern foram, ostracode, mollusk and water samples will also be collected in summer 2002 and winter 2003 for the following purposes: (1) to calibrate the oxygen isotopic composition of foraminiferal shells to water isotope ratios and salinity for application to sediment core forams; (2) to improve understanding of the salinity tolerance of indicator species in Biscayne Bay; (3) to determine the local radiocarbon "correction" for Biscayne Bay. These modern calibration sites will be located along one or more salinity transects and will be taken during summer and winter seasons. The sites will be located strategically in relation to the sites chosen to determine the source of variations in salinity and the water chemistry stations, and will correspond to the monitoring sites established for the benthic faunal surveys.

Process_Date: 2005
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Tom Cronin
Contact_Organization: U.S. Geological Survey
Contact_Address:
Address_Type: mailing address
Address: 926A National Center
City: Reston
State_or_Province: VA
Postal_Code: 20192
Country: USA
Contact_Voice_Telephone: 703 648-6363
Contact_Facsimile_Telephone: 703 648-6953
Contact_Electronic_Mail_Address: tcronin@usgs.gov
Process_Step:
Process_Description:
Origin of salinity variations in Biscayne Bay

This task is designed to answer the question of whether variations in salinity, a common feature of the coastal environments of Biscayne, are a result of terrestrial runoff, ground water input, or local precipitation. By analyzing stable oxygen and hydrogen isotopes in the water we can determine whether the source of freshwater influx is from rainfall, overland flow, or groundwater input. This information is vital in assessing (i) the impact of water management changes within the terrestrial Everglades on the coastal ecosystem, (ii) the input of groundwater into the coastal systems, and (iii) identifying which systems are susceptible to anthropogenic water use decisions.

Isotopic tracers have been successfully used in Florida Bay. The technique works because although groundwater, surface water and precipitation all have essentially zero salinity, they have different oxygen, hydrogen, and carbon isotopic compositions, which are a result of evaporation, degradation of organic material and interaction with local rocks. Since 1993 samples collected by the Southeast Environmental Research Center (SERC) at Florida International University (FIU) in Florida Bay have been analyzed for their stable isotopic composition (O, H, and C). In 1998, the network was expanded to include all of the samples collected by SERC on the West Coast of Florida and in Biscayne Bay. Samples were also collected from the Everglades and from rainfall at four locations. This work demonstrated that between 1993 and 1999 over 70% of the freshwater in the western portion of Florida Bay was derived from rainfall rather than runoff. The extent of freshwater runoff from the Everglades into the NE corner of Florida Bay has been clearly demonstrated. The purpose of this task is to utilize the methods demonstrated in Florida Bay to obtain data on current sources of freshwater input into Biscayne Bay that are essential for successful restoration of natural flow. These data can then be compared to downcore data gained in task 2 to determine the extent to which freshwater sources for Biscayne Bay have change over the last 100-200 years.

Isotopic analyses will be conducted on samples of water from 45 stations sampled monthly and eight stations sampled quarterly in Biscayne Bay, Barnes Sound, and north Florida Bay by SERC at FIU. This sampling has been carried out in conjunction with FIU since 1993. In addition we will analyze freshwater samples from the Everglades (collected by ENP) and precipitation samples from stations in Key Biscayne, Key Largo, and a new station to be installed at Biscayne Park Headquarters operated by Rosenstiel School of Marine and Atmospheric Science (RSMAS). A series of groundwater wells installed by Biscayne National Park also will be sampled. These wells provide a transect from Black Point out onto the reef tract.

All samples are preserved and filtered according to conventional procedures. Fifty-five water samples per month will be analyzed for hydrogen, oxygen and carbon isotopes using mass spectrometric techniques. Data will be compiled, interpreted, and used to produce contour maps. These data will include all analyses completed between 1993 and the present day. In addition to a spatial analysis of the data, samples will be analyzed in a temporal sense and related to natural and anthropogenic changes in the South Florida Everglades Ecosystem in conjunction with results from the previous process step.

Process_Date: 2003
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Peter Swart
Contact_Organization: University of Miami, RSMAS
Contact_Address:
Address_Type: mailing and physical address
Address: 4600 Rickenbacker Causeway
City: Miami
State_or_Province: FL
Postal_Code: 33031
Country: USA
Contact_Voice_Telephone: 305 361-4103
Contact_Facsimile_Telephone: 305 361-4632
Contact_Electronic_Mail_Address: pswart@rsmas.miami.edu
Process_Step:
Process_Description:
Palynological analysis and reconstruction of shoreline vegetation

This step is to reconstruct vegetational trends at selected sites using pollen and seeds preserved in sediment cores. Although temporal resolution depends on sedimentation rates at core sites, vegetational changes on a decadal scale should be identifiable. Also, to document fire history of region through quantitative analysis of charcoal in sediment cores.

Analyze pollen assemblages from cores collected during FY02 and from marsh cores to be collected in FY03; initial examination will be at 10 cm increments, with other samples filled in as appropriate. Vegetational trends will be reconstructed through statistical comparison with database of approximately 200 surface samples collected in different vegetation types throughout the Everglades; secondarily, changes in hydroperiod and water depth will be estimated from vegetational proxies. Charcoal analyses will be undertaken using chemical digestion to isolate charcoal and morphometric analysis to quantify charcoal in each sample. Geochronologies established in the geochronology and paleoecology part of the project will allow determination of the timing of changes in vegetation or charcoal abundance and correlation with specific environmental or anthropogenic changes.

Process_Date: 2006
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Debra Willard
Contact_Organization: U.S. Geological Survey
Contact_Position: Project Chief
Contact_Address:
Address_Type: mailing address
Address: 926A National Center
City: Reston
State_or_Province: VA
Postal_Code: 20192
Country: USA
Contact_Voice_Telephone: 703 648-5320
Contact_Facsimile_Telephone: 703 648-6953
Contact_Electronic_Mail_Address: dwillard@usgs.gov
Process_Step:
Process_Description:
Isotopic analyses of corals from Biscayne National Park

Biscayne National Park (BNP) contains the northern-most extension of the Florida Keys Reef Tract, extending from Fowey Rocks in BNP 130 miles south to the Marquesas. The Florida Reef Tract is a unique natural resource – the only reef ecosystem in the continental US and among the largest bank reef systems in the world. Yet, this unique ecosystem is threatened by "upstream" changes in freshwater flow through the terrestrial Everglades. It is critical to understand the linkages between the terrestrial system, Biscayne Bay and the Reef Tract prior to implementing substantial restoration changes. This step examines these linkages by comparing isotopic records obtained from coral to records from the near shore cores and to water chemistry data. In addition it provides a long term continuous record of offshore water chemistry that will provide information on the relationship of coral health to water chemistry pre- and post-alteration of terrestrial flow. If corals can be located within the Bay and permission to sample them obtained, additional comparisons can be made between offshore and Bay waters.

Following the methods used by Swart et al., (1996) at Alina’s Reef near Elliot Key, a second reef site within Biscayne National Park will be selected and sampled at a relatively low resolution transect (5 samples per year) over a 200 year period of time. Two additional short cores will be taken at the site of the original coral sampling at Alina’s Reef in 1986, allowing us to bring the record up to date and to compare the isotopic data and the instrumental records. In addition, we hope to locate and utilize corals situated within Biscayne Bay in order to compare salinity records inside and outside the Bay.

Process_Date: 2003
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Peter Swart
Contact_Organization: University of Miami, RSMAS
Contact_Address:
Address_Type: mailing and physical address
Address: 4600 Rickenbacker Causeway
City: Miami
State_or_Province: FL
Postal_Code: 33031
Country: USA
Contact_Voice_Telephone: 305 361-4103
Contact_Facsimile_Telephone: 305 361-4632
Contact_Electronic_Mail_Address: pswart@rsmas.miami.edu
Process_Step:
Process_Description:
Geochemical History of Biscayne Bay: Nutrients and Organics

Nutrients from agricultural and urban runoff are causing eutrophication and microalgal blooms in many of the estuaries in south Florida, including Biscayne Bay. The effects of this excess nutrient input on biotic assemblages within the estuaries, however, are not understood, but may be substantial. Eutrophication and microalgal blooms may be responsible for seagrass dieoff in Florida Bay, and coral mortality in the Florida Keys. In Biscayne Bay, seagrass dieoff, changes in microalgal population structures, and changes in other benthic species may be occurring. Linking eutrophication to these changes in the biotic community, however, is a difficult problem.

Our major objectives are to determine the historical record of eutrophication in Biscayne Bay and to evaluate the linkage between eutrophication and changes in the biotic community in the bay. The approach we will take in this task is to examine the historical record of nutrients in Biscayne Bay from dated sediment cores. Results will also be compared to water flow records to determine if known changes in the water control system of south Florida may correspond to distinct nutrient changes within the cores. Historical changes in sulfur content of the cores will also provide information on historical changes in salinity in Biscayne Bay related to construction of canals within the Everglades. We will also examine organic geochemical markers of seagrass and microbial communities in the cores to determine historical changes in these biota. These results will be compiled with faunal and floral data. Comparing the timing of changes in nutrient input to that of changes in the biological community will allow a determination of whether eutrophication of the estuary and changes in biota are directly linked.

Six cores from three sites were collected in FY02. Splits of the <63-micron fraction from these cores are available for nutrient history studies. Results from 210Pb and 137Cs dating of these cores, and paleoecological studies will be available for comparison to the nutrient data. In FY03, nutrients will be analyzed from every 2-cm interval in the cores, meeting the criteria defined previously. Additional piston coring will be conducted as needed in FY03 and FY04 using existing equipment available to this project task. This additional coring may be needed for obtaining fresh core material (unoxidized sediment) for organic biomarker studies. Processing procedures and sectioning of these additional cores will follow the same protocol as that used in the FY02 coring. Work in FY04 will involve continued analysis of the core samples, especially the time-consuming biomarker work.

Sediment samples will be analyzed for total and organic C, total N, and total S using a Leco elemental analyzer available in USGS organic geochemistry labs (Orem) in Reston, VA. Total P content will be analyzed using a standard geochemical method involving baking at 500&deg;C, extraction in acid, and colorimetric analysis. Organic geochemical studies will involve the use of published methods. These methods involve soxhlet extraction of biomarkers from sediments, isolation procedures involving column chromatography, and identification and quantification using GC and GC/MS. All geochemical data will be plotted down-core, and compared to results of other tasks. Accumulation rates for total and organic C, total N, total P, and total S will be calculated using sediment accumulation rates calculated from 210Pb dating and the concentrations of these chemical species in the sediments. Accumulation rates for these elements in Taylor Slough and the C-111 Basin, and eastern Florida Bay have already been published by Orem. Comparison of accumulation rates in Biscayne Bay and Florida Bay may provide additional insights into processes and flow patterns

Process_Date: 2006
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: William Orem
Contact_Organization: U.S. Geological Survey
Contact_Address:
Address_Type: mailing address
Address: 956 National Center
City: Reston
State_or_Province: VA
Postal_Code: 20192
Country: USA
Contact_Voice_Telephone: 703 648-6273
Contact_Facsimile_Telephone: 703 648-6419
Contact_Electronic_Mail_Address: borem@usgs.gov
Process_Step:
Process_Description:
Work planned for FY 2004 includes:

1. Geochronology and paleoecology of Biscayne Bay cores Six cores were collected at three sites in FY03 (Middle Key, Inlet north of Black Point, and Chicken Key). The work will focus on analyzing these cores. Faunal samples are processed using standard methods and all fractions are retained for analyses. A portion of the less than 63-micron fraction is used for Pb-210 geochronology and selected shells or plant material will be used for radiocarbon dating. Special emphasis will be placed on refining the age models for the FY02 cores by obtaining modern sediment samples to examine background radioisotopes in Biscayne Bay. Additional carbon-14 ages will be obtained for the FY02 cores as well. The same methods will be applied to the FY03 cores.

The greater than 63-micron fraction of the cores is sorted for faunal analyses; ostracodes, molluscs and benthic forams are picked, sorted and identified. A small portion of core material is retained and processed for diatoms and pollen. Percent abundance is calculated for the faunal, diatom, and pollen data, and these data are compared to data from 28 sites in modern Florida Bay where faunal and floral associations have been studied between 1996-2000 and to sites established in Biscayne Bay. These modern data serve as proxies for interpreting the down-core data. The downcore faunal and floral assemblages and the presence or absence of key indicator species allow interpretation of trends in salinity, water quality and the presence of SAV at the core sites. Data obtained in FY04 will be compiled with data from FY03 and older cores from Biscayne to determine trends. Any information gaps and additional questions will be identified. If necessary, a few additional cores may be selected and processed to address specific information needs.

2. Patterns, causes, and impacts of salinity changes in Biscayne Bay Work will involve measurement of faunal and geochemical proxies of salinity and temperature from sediment cores taken in 2002 and 2003 and if time permits, an additional site in northern Biscayne Bay, near the Rickenbacker Causeway (collected in 1997), will be examined. Proxy methods include 1) oxygen isotope analyses of benthic foraminifera, 2) trace elemental (magnesium/calcium ratios) of ostracodes, 3) morphological indicators of temperature (shell size) and 4) relative proportions of species of forams, ostracodes and molluscs indicative of specific salinity ranges (i.e. oligohaline, mesohaline, etc.)(related to assemblage analyses). The stable isotopic and trace elemental analyses will be carried out with cooperators using mass spectrometry and direct current plasma emission spectrometry at University of Miami and Duke University, respectively. The use of paired analyses of stable isotopes of forams and Mg/Ca ratios in ostracodes should allow the quantification of changes in salinity and temperature and the impact of these changes could then be assessed from the faunal analyses of benthos from the same samples. Selected intervals identified as representing extreme salinity conditions may also be studied for seasonal salinity variability using molluscan shell chemistry, depending on preservation in cores and status of mollusk calibration studies.

Modern forams, ostracodes, and mollusks and associated water samples will continue to be collected this year for the following purposes: (1) to calibrate the oxygen isotopic composition of foraminiferal shells to water isotope ratios and salinity for application to sediment core forams; (2) to improve understanding of the salinity tolerance of indicator species in Biscayne Bay; (3) to determine the local radiocarbon 'correction' for Biscayne Bay. These modern calibration sites are located at core sites and along salinity transects. The sites will be located strategically in relation to other investigators' water chemistry stations, and will correspond to the monitoring sites established for the benthic faunal surveys.

3. Palynological analysis and reconstruction of shoreline vegetation Analyze pollen assemblages from cores collected for geochronology and paleoecology analysis during FY03 and from marsh cores to be collected in FY04; initial examination will be at 10 cm increments, with other samples filled in as appropriate. Vegetational trends will be reconstructed through statistical comparison with database of ~200 surface samples collected in different vegetation types throughout the Everglades; secondarily, changes in hydroperiod and water depth will be estimated from vegetational proxies. Charcoal analyses will be undertaken using chemical digestion to isolate charcoal and morphometric analysis to quantify charcoal in each sample. Geochronologies established as part of task 1 will allow determination of the timing of changes in vegetation or charcoal abundance and correlation with specific environmental or anthropogenic changes. Based on results from initial wetland cores, additional cores may be collected near the end of FY04 or early FY05. All analyses will be completed and compiled in FY05.

4. Geochemical history of iscayne Bay: nutrients and organics Six cores from three sites were collected in FY03. Splits of the <63-micron fraction from these cores will be analyzed for nutrient history studies. Results from 210Pb and 137Cs dating of these cores, and paleoecological studies will be available for comparison to the nutrient data. This year nutrients will be analyzed from every 2-cm interval in the FY03 cores, meeting the defined criteria for geochronology and paleoecology analysis. Additional piston coring will be conducted as needed in FY04 using available existing equipment. This additional coring may be needed for obtaining fresh core material (unoxidized sediment) for organic biomarker studies. Processing procedures and sectioning of these additional cores will follow the same protocol as that used in the FY02 coring. Work in FY05 will involve continued analysis of the core samples, especially the time-consuming biomarker work, and compilation of the results.

Sediment samples will be analyzed for total and organic C, total N, and total S using a Leco elemental analyzer available in USGS organic geochemistry labs in Reston, VA. Total P content will be analyzed using a standard geochemical method involving baking at 500&deg;C, extraction in acid, and colorimetric analysis. All equipment for this procedure is also available at USGS labs in Reston. Organic geochemical studies will involve the use of published methods. These methods involve soxhlet extraction of biomarkers from sediments, isolation procedures involving column chromatography, and identification and quantification using GC and GC/MS. All organic geochemical equipment and instrumentation needed from this work is available in lab facilities at the USGS in Reston, VA. All geochemical data will be plotted down-core, and compared to results of other tasks. Accumulation rates for total and organic C, total N, total P, and total S will be calculated using sediment accumulation rates calculated from 210Pb dating and the concentrations of these chemical species in the sediments. Accumulation rates for these elements in Taylor Slough and the C-111 Basin, and eastern Florida Bay have already been published. Comparison of accumulation rates in Biscayne Bay and Florida Bay may provide additional insights into processes and flow patterns.

Process_Date: 2006
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Lynn Brewster-Wingard
Contact_Organization: U.S. Geological Survey
Contact_Address:
Address_Type: mailing address
Address: 926A National Center
City: Reston
State_or_Province: VA
Postal_Code: 20192
Country: USA
Contact_Voice_Telephone: 703 648-5352
Contact_Facsimile_Telephone: 703 648-6953
Contact_Electronic_Mail_Address: lwingard@usgs.gov

Spatial_Data_Organization_Information:
Indirect_Spatial_Reference: Biscayne Bay

Distribution_Information:
Distributor:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Heather S.Henkel
Contact_Organization: U.S. Geological Survey
Contact_Address:
Address_Type: mailing address
Address: 600 Fourth St. 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: hhenkel@usgs.gov
Resource_Description: Ecosystem History of South Florida Estuaries Data
Distribution_Liability:
The field data contained in this database have not been reviewed for publication and therefore may contain inconsistencies or errors.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: MS Access
Format_Version_Number: unknown
Format_Specification: The Access database is available as a zipped file
File_Decompression_Technique: The file must be "unzipped" before use
Transfer_Size: 4.8
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name: <https://sofia.usgs.gov/exchange/flaecohist/>
Access_Instructions: The database may be downloaded from the SOFIA website
Fees: none

Metadata_Reference_Information:
Metadata_Date: 20080408
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
Metadata_Standard_Version: FGDC-STD-001-1998

This page is <https://sofia.usgs.gov/metadata/sflwww/hist_salinity_wq_veg_bb_04.html>

U.S. Department of the Interior, U.S. Geological Survey
Comments and suggestions? Contact: Heather Henkel - Webmaster
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