A water biology expert has identified sea lettuce, a marine plant, as the key factor behind the color changes and foul odor in certain waterways in Prince Edward Island (P.E.I.). Sea lettuce, a form of algae, occurs naturally in marine environments and thrives in high-nutrient conditions. As it decomposes, organic material consumes oxygen in the water, leading to an anoxic event.
Several discolored waterways, including an estuary in the Oyster Bed area of P.E.I., have been reported to the province this year. The Department of Land and Environment noted a greenish-grey color change in the water on July 9, indicative of low dissolved oxygen conditions.
The province regularly monitors oxygen levels in various waterways, including the mentioned estuary, and plans to analyze oxygen data trends from the past decade in collaboration with Fisheries and Oceans Canada. The expert advised caution for individuals suspecting an anoxic water body, suggesting they avoid contact as it may result in a lingering rotten egg smell on their hands or feet.
While some wildlife species have adapted to low oxygen levels, many marine organisms struggle to survive in such conditions. Most aquatic creatures require oxygen to breathe, and when oxygen levels drop, they either relocate or face the risk of being trapped in the affected area. Concerned individuals can contact the Land and Environment Department to report any issues with P.E.I. waterways.