The Halifax Regional Municipality is advising residents that due to the presence of a possible blue-green algae bloom, a risk advisory is in effect for Chocolate Lake Beach in Chocolate Lake, Halifax. Residents are encouraged to avoid swimming in the lake until further notice.
Staff are currently investigating whether or not it is a toxin producing algae.
Blue-green algae (cyanobacteria) is naturally occurring in freshwater environments and may become visible when weather conditions are calm. These organisms can multiply rapidly during the summer, leading to extensive growth called a bloom. Some types of blue-green algae produce toxins during blooms and when these blooms decay, the toxins may be released into the water, posing a risk to people and pets.
Lake users are encouraged to take the following precautions:
- Avoid water contact. If contact occurs, wash with tap water as soon as possible;
- Do not swim or wade (or allow your pets to swim or wade) in any areas where blue-green algae is visible or in areas where a risk advisory has been issued;
- Avoid consuming water from this lake; and,
- Avoid consuming fish that has come from this lake.
People who come in contact with blue-green algae or who ingest water containing blue-green algae may experience skin irritation, rash, sore throat, sore red eyes, swollen lips, fever, nausea and vomiting and/ or diarrhea. Children and immune-compromised individuals are at a higher risk. If you have these symptoms, you are advised to seek medical assistance.
Risk advisories are issued based on a number of factors, including the visual observation of algae blooms, test results and information regarding the current life-cycle phase of algae blooms. As algae blooms die and decay, toxins are released. Unsafe toxin levels can remain in the water even after the bloom is gone.
When an algae bloomis observed, a risk advisory is issued and initial testing is done to determine whether the algae bloom is toxin producing. If the algae bloom is not toxin producing, the risk advisory will be lifted and no further testing is required.
If the algae bloom is toxin producing, further testing will be carried out and the risk advisory will remain in effect until blooms have disappeared and post-bloom test results indicate water is within safe limits.