A water biology expert has identified sea lettuce, a marine plant, as the cause behind the color and odor changes in certain waterways in Prince Edward Island (P.E.I.). Sea lettuce, categorized as algae, naturally thrives in marine environments, particularly under conditions rich in nutrients. When sea lettuce decomposes, the organic matter consumes oxygen in the waterways, leading to a lack of oxygen, known as an anoxic event.
According to Kyle Knysh, a provincial surface water biologist, several discolored waterways, including an estuary in the Oyster Bed area of P.E.I., have been reported to the province this year. The estuary was noted on July 9 for exhibiting green and grey-white discolored water, indicating low dissolved oxygen levels, as stated by the Department of Land and Environment.
The province regularly monitors oxygen levels in various waterways, including the reported estuary, and plans to analyze oxygen data trends from monitored estuaries over the past decade in collaboration with Fisheries and Oceans Canada. Knysh advised individuals to be cautious if they suspect a body of water to be anoxic and to avoid contact with it to prevent the unpleasant smell resembling rotten eggs.
While some wildlife species have adapted to low oxygen levels, many marine organisms lack the mechanisms to cope with such conditions. Knysh highlighted the importance of avoiding unfamiliar water areas during low oxygen periods to prevent trapping marine life that rely on oxygen for respiration.
In case of concerns about waterways in P.E.I., individuals can contact the Land and Environment Department for investigation.
