HARMFUL ALGAL BLOOM WATCH
Conditions at the lake make the water susceptible to harmful algal blooms. Be alert and avoid areas that are noticeably green or blue green, have algae-like scum, foam, mats, or clumps present, or have a paint spill like or streaked appearance. Do not ingest the water.
This status can change quickly during the season as regular testing is completed to monitor the water conditions. Be sure to check current water conditions before your visit.
Blue-green algae, also known as cyanobacteria, are microscopic organisms found naturally in all types of water. In warm, nutrient-rich environments, cyanobacteria can multiply quickly, creating blooms that spread across the water's surface.
Harmful algal blooms, or HABs, are known as the intense, rapid growth of algae or cyanobacteria in the water with the potential to harm human health or aquatic ecosystems. Some cyanobacteria can produce toxins that are harmful to people and animals.
You may or may not be able to see algal blooms. They sometimes stay below the water's surface, or they may float on the water's surface. Some blooms can look like foam, scum, or mats, particularly when the wind blows them toward a shoreline. Harmful algal blooms sometimes look like paint streaked on the water's surface and can be different colors. The blooms can be blue, bright green, brown, or red. As cyanobacteria in a bloom die, the water may smell bad, similar to rotting plants, as they decompose in the water.
Heavy rainfall and significant runoff conveys nutrients to the reservoir. When followed by hot weather, blue-green algae can thrive and multiply.
When in doubt, stay out!
Algal blooms are an annual occurrence at Blue Marsh Lake. Algae can be present year round within the lake, however large algal blooms and HABs typically occur and persist throughout the summer months (June - September). Generally, algal blooms disappear in late September or early October once water temperatures start cooling off.
Throughout the summer, algal bloom conditions can worsen or improve depending on:
Algal bloom statuses change depending on the current conditions present within the lake. Risks to humans and animals increase as a status increases from Watch to Advisory to Warning. Algal bloom statuses can change quickly throughout the season, especially from June through October.
WATCH - The conditions for an algal bloom to occur are present, however there has not been a HABs sighting/report.
ADVISORY - Algal blooms are currently occurring in the lake and the conditions for a HAB are present.
WARNING - Harmful algal blooms are currently occurring in the lake.
Blue Marsh Lake Office
1268 Palisades Drive
Leesport, PA 19533-9750