Defense Date

12-9-2021

Document Type

Thesis

Degree Type

Master of Science

Degree Name

Marine Science

First Advisor

Dimitri Giarikos

Second Advisor

Amy Hirons

Third Advisor

Paul Baldauf

Fourth Advisor

Andre Daniels

Keywords

Elemental contamination, sediment, marine sediment cores, Port Everglades, coral reefs, SECLER

Abstract

Port dredging is of economic importance worldwide but its impacts to the marine environment through the remobilization of elemental contaminants are not well understood. A massive deepening and widening of Port Everglades, Florida, will begin in 2023. Contaminated sediment disturbed during the dredging process could be released and prove to be harmful to three coral reef tracks located beginning 1.5 miles away from the port. This study focused on identifying and quantifying 14 different trace elements: arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), mercury (Hg), lead (Pb), manganese (Mn), molybdenum (Mo), nickel (Ni), selenium (Se), tin (Sn), vanadium (V), and zinc (Zn) in Port Everglades, West Lake, and the coral reef sites before dredging commences, using induced coupled plasma mass spectrometry. All 14 elements were found within 5 of 10 port cores, with five cores displaying non-detected (n/d) values of mercury (Hg). West Lake contained all 14 elements, 13 out of 14 elements were found in North Reef samples (n/d values of Hg), and all 14 elements were found in the South Reef samples. Arsenic (As) concentrations in all cores exceeded probable effect levels (PEL, 41.6 µg/g) and molybdenum (Mo) concentrations in all cores exceeded the background continental crust (1.5µg/g) by up to 256 %. Additional element concentration spikes above the threshold effect levels (TEL) included cadmium, chromium, copper, lead, mercury, nickel, and zinc. This study provides evidence of elemental contamination within Port Everglades and its potential harmful impact through remobilization to the threatened reef sites.

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