Spatial Differences in Copper and Lead Levels in Seagrasses and Seaweeds from Curaçaoan Bays

The health of aquatic coastal ecosystems in the Caribbean Sea is vital for retaining their ecological integrity and maintaining the economic value as desirable destinations to visit. A suite of contaminants, including heavy metals, may be detrimental to these ecosystems' viability, yet datasets and subsequent environmental assessments are somewhat minimal. To that end, this study used various species of seagrasses and seaweeds as bioindicators of copper and lead levels at five adjacent land sites of varying use on Curaçao. Small but statistically significant differences in metal concentrations were observed between the five sites and were largely driven by differences in site location, not plant species. Awa di Oospunt, the most remote and less human-impacted site, had mean (± standard deviation) copper and lead concentrations of 2.38 (± 1.46) and 0.60 (± 0.18) ng/g or ppb dry weight (dw), respectively. Conversely, seagrasses from Caracas Bay, adjacent to more heavily urbanized and industrialized land uses, had mean copper and lead concentrations of 5.86 (± 2.03) and 2.83 ± (0.61) ng/g dw, respectively. Differences in adjacent land-use and proximity to wastewater and industrial discharges were likely primary factors in determining observed concentrations. No site harbored elevated levels of concern based on comparison to other studies. Nonetheless, organisms feeding upon seagrasses, such as green sea turtles, may be exposed to these metals through ingestion. Future studies should expand on the spatial and temporal concentration differences with a broader suite of potential contaminants, evaluate use of different marine species as bioindicators, and more definitively identify land-based sources and inputs of potential contaminants.