A water biology expert has identified sea lettuce, a marine plant, as the cause behind the color changes and foul odor resembling rotten eggs in certain waterways in P.E.I. Sea lettuce, a type of algae, naturally occurs in marine environments and thrives in high-nutrient conditions. When it decomposes, it depletes oxygen levels in the water, leading to an anoxic event.
Several discolored waterways, including an estuary in the Oyster Bed area, have been reported to the provincial authorities this year. The Department of Land and Environment reported a case on July 9 where the water appeared green and grey-white, indicative of low dissolved oxygen conditions.
Regular monitoring of oxygen levels in waterways, including estuaries, is conducted by the province in collaboration with Fisheries and Oceans Canada. A review of oxygen data trends from monitored estuaries over the past decade is also planned.
Concerned individuals are advised to avoid contact with water bodies suspected of being anoxic due to the potential foul smell resembling rotten eggs. While some wildlife species have adapted to low oxygen levels, many marine species lack mechanisms to cope with such conditions and may need to relocate to survive.
For reporting concerns about water quality in P.E.I., residents can contact the Land and Environment Department for investigation.
