University of South Florida Scholar Commons Graduate Theses and Dissertations Graduate School 2005 Foraminiferal Assemblages As Bioindicators Of Potentially Toxic Elements In Biscayne Bay, Florida Elizabeth A. Carnahan University of South Florida Follow this and additional works at: https://scholarcommons.usf.edu/etd Part of the American Studies Commons Scholar Commons Citation Carnahan, Elizabeth A., "Foraminiferal Assemblages As Bioindicators Of Potentially Toxic Elements In Biscayne Bay, Florida" (2005). Graduate Theses and Dissertations. https://scholarcommons.usf.edu/etd/2810 This Thesis is brought to you for free and open access by the Graduate School at Scholar Commons. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Scholar Commons. For more information, please contact [email protected]. Foraminiferal Assemblages As Bioindicators Of Potentially Toxic Elements In Biscayne Bay, Florida by Elizabeth A. Carnahan A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science College of Marine Science University of South Florida Major Professor: Pamela Hallock Muller, Ph.D. Barb Lidz, B.S. Gary Mitchum, Ph.D. Date of Approval: March 31, 2005 Keywords: estuary, heavy metals, Cu, Pb, Hg, Zn, FORAM index, benthic, sediments © Copyright 2005, Elizabeth A. Carnahan ACKNOWLEDGEMENTS I am greatly indebted to my advisor, Dr. Pamela Hallock Muller. Her continuing patience, support and guidance have been invaluable to me throughout my graduate career. I also acknowledge my committee members, Barb Lidz and Gary Mitchum, for their critical reviews of my thesis. This research would not have been possible without samples collected by Christopher Reich and Eugene Shinn of the U.S. Geological Survey. I acknowledge Rickard Curry and Biscayne National Park for the issuing of sampling permits. Special thanks to Ana Hoare, Kate Sheps, Heidi Gillum, Camille Daniels, and Nicole Caesar for their help with sample preparation. Thanks to the students of the Reef Indicators Lab, family, and friends for their patience and moral support. Funding was provided by the University of South Florida/U.S. Geological Survey cooperative agreement 99HQAG0004. Water quality data were provided by the SERC- FIU Water Quality Monitoring Network which is supported by SFWMD/SERC Cooperative Agreements #C-10244 and #C-13178 as well as EPA Agreement #X994621- 94-0. I dedicate this thesis to my mother, Susan, who continues to learn, grow and develop and who has been a source of encouragement and inspiration to me throughout my life TABLE OF CONTENTS LIST OF TABLES iii LIST OF FIGURES iv ABSTRACT vi 1. INTRODUCTION 1 Biscayne Bay, Florida 1 Heavy-Metal Contamination in Estuaries 3 Sources of Heavy Metals 5 The Biological Effects of Heavy Metals 6 The Human-Health Implications of Heavy-Metal Pollution 7 Heavy Metals in Biscayne Bay 8 Foraminifera as Bioindicators 11 Foraminiferal Studies in Biscayne Bay 11 Foraminifers as Bioindicators of Heavy-Metal Pollution 16 Estuaries: Each a Unique Setting 19 Objectives and Goals 20 2. METHODS 21 Sample Collection 21 Sample Processing 22 Geochemical Analysis 26 Grain-Size Analysis 26 Analysis of Foraminiferal Assemblages 28 Data Analyses 29 Grain-Size Analysis 29 Geochemical Data Analysis 29 Multivariate Analyses of Foraminiferal Assemblages 31 FORAM Index Analyses 33 Environmental Data Analysis 35 Synthesis of Biotic and Environmental Data 35 i 3. RESULTS 36 Grain Size 36 Trace-Metal Distribution 39 Foraminiferal Assemblages 44 Sample Distribution 44 Key Genera 50 FORAM Index 56 Environmental Data 57 Multivariate Analyses 61 4. DISCUSSION 68 Limitations of Data 68 Heavy Metals: Comparisons with other Studies 72 Foraminiferal Distributions throughout Biscayne Bay 76 Foraminiferal Assemblages: Comparisons with Previous Studies 82 Recommendations for Future Work 86 5. CONCLUSIONS 88 REFERENCES 90 APPENDICES 98 Appendix I List of genera identified in Biscayne Bay 99 Appendix II Sample collection details 103 Appendix III Samples deleted from various analyses 106 Appendix IV Grain size reported as weight percent 107 Appendix V-a Values for 32 chemical parameters measured in the 112 mud fraction Appendix V-b Values for 32 chemical parameters measured in the 131 sand fraction Appendix VI Raw counts of foraminiferal abundance in sediments from 132 Biscayne Bay Appendix VII Correlation matrix of measured elements and mud 201 Appendix VIII SIMPER output of dissimilarity between sample groups 203 Appendix IX Environmental data collected by the Southeast Research Center 213 Appendix X Cluster analysis of genera present in >5% of the samples 228 ii LIST OF TABLES Table 1 Detection limits for 32 measured elements 27 Table 2 Functional groups and example genera defined by Hallock et al. (2003) 34 Table 3 Summary of median grain size in 139 sediment samples from Biscayne Bay 37 Table 4 Correlation matrix of metals of concern 39 Table 5 SIMPER groups, indicating within-sample group similarity 48 Table 6 Means and standard deviations of diversity, density, and grain-size data for SIMPER groups 50 Table 7 Correlation matrix of foraminiferal taxa and % mud 53 Table 8 Correlation matrix of measured environmental variables versus key foraminiferal taxa and measures of density and diversity for samples collected in April 2002 59 Table 9 Correlation matrix of geochemical parameters and key foraminiferal taxa 62 Table 10 BIO-ENV results of measured environmental parameters as correlated to foraminiferal assemblage for samples collected in April 2002 65 Table 11 BIO-ENV results of measured geochemical parameters as correlated to overall foraminiferal assemblage for all three collections 66 Table 12 BIO-ENV results of measured geochemical parameters as correlated to FORAM Index components 66 Table 13 BIO-BIO results of foraminiferal genera as correlated to overall assemblage 67 Table 14 Uses and sources of metals of concern 75 Table 15 Summary data for samples with FORAM indices >3.0 77 iii LIST OF FIGURES Figure 1 Map of southeast coast of Florida, including Biscayne Bay, main waterways and urbanized areas 2 Figure 2 Classifications of the relative degree of toxicity in four sediment tests 10 Figure 3 A petite Ponar grab 21 Figure 4(a) Chart of northern Biscayne Bay indicating sample sites 23 Figure 4(b) Chart of central Biscayne Bay indicating sample sites 24 Figure 4(c) Chart of southern Biscayne Bay indicating sample sites 25 Figure 5 Schematic diagram of the BIO-ENV procedure: selection of the abiotic variable subset maximizing Spearman-rank correlation (ρ) between biotic and abiotic similarity matrices (from Clark and Warwick, 2001) 36 Figure 6 Grain-size distribution in Biscayne Bay as (a) median phi and (b) % mud 38 Figure 7 Cluster analysis (R-mode) of geochemical data in sediment samples from Biscayne Bay 41 Figure 8 Metal distributions for mud-sized sediments in Biscayne Bay 42 Figure 9 Plot of density versus diversity of samples 44 Figure 10 MDS ordination of sample sites according to SIMPER groups 45 Figure 11 Chart of distribution of foraminiferal density in Biscayne Bay and surrounding canals with sample sites represented by SIMPER groups 47 Figure 12 Cluster analysis of key foraminiferal taxa in Biscayne Bay 52 Figure 13 Distribution of FORAM Index values throughout Biscayne Bay 56 Figure 14 Contours of environmental data obtained from Southeast Environmental Research Center 60 iv Figure 15 Comparison of concentrations of Cu, Pb, Zn, and Hg in the mud versus sand fractions of six samples 70 Figure 16 Bathymetry profile of Biscayne Bay 74 Figure 17 MDS plot of sample sites represented by SIMPER groups showing urban, ocean, freshwater, and estuarine influences 78 Figure 18 Distribution of relative abundance of (a) Ammonia and (b) Miliolinella with sample sites represented by SIMPER groups 80 Figure 19 Distribution of the relative abundance of Ammonia, Cribroelphidium, Haynesina, Elphidium, and Nonion 81 Figure 20 Cluster analysis of foraminiferal genera using data from Almasi (1978) 83 v FORAMINIFERAL ASSEMBLAGES AS BIOINDICATORS OF POTENTIALLY TOXIC ELEMENTS IN BISCAYNE BAY, FLORIDA Elizabeth Carnahan ABSTRACT Heavy-metal pollution is an issue of concern in estuaries such as Biscayne Bay that are heavily influenced by agricultural, urban, and harbor activities. The goals of this study were to provide a “state of the bay” assessment that can be used to interpret changes that have occurred over the past 60 years in Biscayne Bay, to provide a baseline to compare changes in the ecosystems during and after execution of the Comprehensive Everglades Restorations Plan (CERP), and to determine if benthic foraminiferal assemblages in Biscayne Bay reflect heavy-metal contamination in sediments. Surficial samples were collected at 147 sites throughout the bay. Analyses included geochemical assessment of the mud fraction for 32 chemical parameters, grain- size analysis, and assessment of foraminiferal assemblages at the genus level. Geochemical analyses revealed elevated concentrations of a suite of heavy metals in the sediments of the northern bay, between Miami and Key Biscayne, and the periphery of the southern bay from Black Creek Canal south to Turkey Point. Cluster analysis, multi-dimensional scaling, and multivariate-correlation analyses revealed three distinct foraminiferal assemblages. One assemblage, characteristic of the northern bay, was defined by stress-tolerant taxa including Ammonia, Cribroelphidium, Nonion, and Haynesina, which were present