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Evidence of Envronmental Change in Rankin Basin, Central Florida Bay, Everglades National Park

Open-File Report 2010-1125
By: , , , , , , , , , , , and 
https://doi.org/10.3133/ofr20101125

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Abstract

Analyses of core GLBW601 RL1 collected in Rankin Basin, Florida Bay, Everglades National Park, in June 2001 indicate that significant environmental changes occurred at the site over the last two centuries. The core was collected at a site of documented seagrass die-off in 1987-1988. The purpose of this study was to document the long-term sequences of events leading up to the die-off event. Analyses have been conducted to examine (1) faunal changes in the ostracodes and mollusks, (2) biochemistry of the ostracode shells, (3) floral changes in the pollen assemblages, and (4) geochemical and elemental changes in the sediment. The faunal assemblage analyses provide information on the salinity and benthic habitat at the site. The biochemical and geochemical data provide information about the water chemistry and sedimentation rates. The floral assemblage provides data about the nearby terrestrial environment and the first occurrence of pollen of the Australian pine, Casuarina equisetifolia, serves as a biostratigraphic marker for the beginning of the 20th century. These data provide clues to the cause and effect of the seagrass die-off and changes in salinity patterns and also illustrate decadal-scale patterns of change.

The analyses of GLBW601 RL1 show two important results. First, prior to 1900, Rankin Basin tended to be oligohaline to mesohaline on the basis of faunal data showing the assemblage to be similar to that of the lowest portions of a core from Taylor Creek. Second, prior to the documented seagrass die-off, the faunal assemblages indicate an increase in the amplitude of salinity fluctuations; a significant increase occurs in the mollusks Brachidontes exustus and Anomalocardia auberiana, two species that tolerate fluctuations in salinity.

Suggested Citation

Murray, J.B., Wingard, G.L., Cronin, T.M., Orem, W.H., Willard, D.A., Holmes, C.W., Reich, C., Shinn, E., Marot, M., Lerch, T., Trappe, C., and Landacre, B., 2010, Evidence of envornmental change in Rankin Basin, central Florida Bay, Everglades National Park: U.S. Geological Survey Open-File Report 2010–1125, 49 p., https://doi.usgs.gov/10.3133/ofr20101125.

ISSN: 2331-1258 (online)

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Table of Contents

  • Acknowledgments
  • Introduction
  • Setting
  • Methods
  • Results
  • Discussiojn
  • References
Publication type Report
Publication Subtype USGS Numbered Series
Title Evidence of envronmental change in Rankin basin, Central Florida Bay, Everglades National Park
Series title Open-File Report
Series number 2010-1125
DOI 10.3133/ofr20101125
Publication Date June 18, 2010
Year Published 2010
Language Englsih
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Caribbean-Florida Water Science Center
Description vi, 22 p.
Country United states
State Florida
Other Geospatial Florida Bay
Additional publication details