Honors Theses
Date of Defense
2026
Document Type
Honors Thesis
Degree Type
Bachelors of Science
Declared Major
Marine Biology
Degree Other
Marine Biology
College
Halmos College of Arts and Sciences and the Guy Harvey Oceanographic Research Center
Faculty Advisor
Dimitrios G. Giarikos, PhD., Department of Chemistry, Engineering, and Physics
Faculty Advisor
Amy C. Hirons, PhD., Department of Marine & Environmental Sciences
Honors Program Director
Aileen Miyuki Farrar, Ph.D., Director, Farquhar Honors Program
Faculty Fellow for Student Research
David Kerstetter, Ph.D., Faculty Fellow for Student Research
HCAS Dean
Robin Cooper, Ph.D., Dean, Halmos College of Arts and Sciences
Home College Dean
Robin Cooper, Ph.D., Dean, Halmos College of Arts and Sciences
Abstract
Coastal wetlands near industrialized waterways face increasingly heavy‐metal contamination, posing risks to benthic communities and food webs. Mangroves can influence metal cycling through sediment trapping, root‐zone sequestration, and internal physiological regulation, yet their effectiveness in urbanized systems remains debated. This study quantified concentrations of 17 heavy metals in sediments and mangrove tissues from four sites near Port Everglades, Florida, examined tissue‐specific partitioning, spatial and temporal contamination patterns, and examined the mangroves’ role in mediating metal loads. Ecological risk metrics identified STB as a contaminant hotspot with exceedances of TEL values across multiple elements (Ni, Pb, and Zn) as well as As, Cd, Cu, Mo, Pb, and Zn surpassing both the Florida and continental background crust concentrations. Sediments generally had higher metal concentrations than mangrove tissues, with two sites identified as contamination hotspots showing moderate to very high ecological risk for As, Zn, and Cu. Temporal comparisons with previous studies from 2019 and 2023 showed significant increases (2 to 11 times higher) in multiple metals by 2025 at most sites, indicating rising regional inputs or enhanced sediment retention. Mangrove roots accumulated most lithogenic and toxic metals, while cadmium and tin moved to and concentrated in leaves and stems, showing element-specific translocation. Weak links between sediment concentrations and tissue levels indicate that metal uptake is not only driven by ambient loads. Overall, mangroves at Port Everglades function mainly as biogeochemical buffers, trapping metals in sediments and roots rather than as hyperaccumulators capable of large‐scale metal remediation. Continued monitoring and source tracking are needed to determine whether these systems will remain long‐term sinks or become active recyclers of contaminants.
NSUWorks Citation
Sophie Welch. 2026. From Sediment to Mangrove: Tissue-Specific Metal Accumulation in Red Mangroves of Southeastern Florida. Capstone. Nova Southeastern University. Retrieved from NSUWorks, Halmos College of Arts and Sciences and the Guy Harvey Oceanographic Research Center. (57)
https://nsuworks.nova.edu/honors_theses/57.
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