A water biology expert has identified sea lettuce, a marine plant, as the cause of color changes and foul odors in certain waterways in Prince Edward Island (P.E.I.). Sea lettuce, an algae species, naturally thrives in marine environments under rich nutrient conditions. As it decomposes, the organic matter consumes significant 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 case on July 9 where the water appeared green and grey-white, indicating low dissolved oxygen levels.
Monitoring of oxygen levels in various waterways across the island occurs annually, with a focus on estuaries. The department, in conjunction with Fisheries and Oceans Canada, intends to analyze oxygen data trends from the past decade.
Individuals should exercise caution when encountering water bodies suspected of being anoxic to avoid contact. The distinctive smell of rotten eggs may linger on skin after contact. While some wildlife species have adapted to low oxygen conditions, many marine organisms struggle to survive in such environments due to their reliance on oxygen for respiration.
Concerned individuals can report issues with P.E.I. waterways to the Land and Environment Department for investigation.