BY LEANDRA ROLLE

Tribune Chief Reporter

lrolle@tribunemedia.net

A new environmental study has revealed the long-term impacts of Hurricane Dorian on Abaco’s coastal ecosystems, uncovering troubling levels of metal pollution in seawater, sediments, and seagrass beds years after the storm’s passage.

Published in the latest issue of the Marine Pollution Bulletin, the study was led by researchers from the Louisiana Universities Marine Consortium, the Bahamas Marine Mammal Research Organisation, the University of New Orleans, and other partners.

Between November 2019 and December 2021, the team conducted a comprehensive survey of 15 metals — including arsenic, chromium, copper, and lead — across 19 coastal sites around Abaco.

The findings showed that metal concentrations were consistently higher in marinas than in seagrass beds, likely due to storm debris, anti-fouling paints, and post-Dorian reconstruction.

Copper levels, the study added, exceeded the US government’s chronic toxicity thresholds at several sites — and even surpassed acute toxicity levels at one marina — posing serious risks to marine life, particularly top predators like dolphins and sharks.

Barium, chromium, arsenic, and other metals also surpassed safety benchmarks in several sediment samples.

The study also found that metals from surrounding waters were actively accumulating in seagrasses, particularly turtle grass, raising concerns about bioaccumulation risks in the food chain.

The report also found high variability in seagrass metal concentrations across sites, noting some readings were among the highest ever recorded in the Caribbean and Gulf of Mexico for turtle grass.

Researchers also noted that metal concentrations in sediments increased over time while variability between sites decreased — suggesting either a slow return to pre-storm conditions or continued contamination from storm debris and land based runoff.

The study concluded that further research is needed to identify the sources of contamination, explore remediation options, and implement monitoring of seafood harvested around Abaco.

Is also noted that metal contamination in Abaco’s marinas is linked to human activities such as antifouling paints (copper), pressure-treated lumber (arsenic), oil and gas combustion (chromium and barium), and landfills (all metals).

However, researchers said it did not attempt to identify the specific sources of the metals detected.

In a statement, lead author Dr Yanila Salas-Ortiz called the report the first dataset of its kind on metal contamination in marine environments in The Bahamas.

“It not only establishes a crucial environmental baseline for Abaco but also raises important questions about how natural disasters like Hurricane Dorian amplify pollution risks in vulnerable coastal regions,” Dr Salas-Ortiz added.