Lake Mohawk Preservation Foundation
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Blue-green algae are not algae at all, but types of bacteria called cyanobacteria that are normally present in many lakes. This type of bacteria thrives in warm, nutrient-rich water. When conditions are right, the bacteria can grow quickly forming “blooms.” 

In general, algae are not harmful.  HABs are different.  People or animals exposed to cyanotoxins through direct skin contact or inhalation may experience symptoms such as skin, eye, nose, throat and respiratory irritation, allergylike reactions and flu-like symptoms. People can also be exposed to cyanotoxins by eating freshwater fish from cyanotoxin-contaminated lakes or ponds or by drinking cyanotoxin-contaminated water. People who ingest cyanotoxins may show symptoms such as abdominal pain, headache, vomiting and diarrhea. Dogs are especially susceptible to harmful algae because they swallow more water while swimming and doing activities like retrieving a ball from the water. They are also less deterred by green, smelly water that may contain harmful algae. Animals can experience symptoms within minutes of exposure to the toxins. 

Cyanobacteria, also known as blue-green algae, are responsible for the majority of freshwater HAB occurrences. Cyanobacteria are naturally present in lakes and streams in low numbers. Cyanobacterial HABs are not true algae but are capable of excessive growth and can cause harm to animals, people, or the local ecology. HABs can occur in warm fresh, marine, or brackish waters with abundant nutrients. HABs are responsible for “red tides” at the Jersey Shore.

Blue-green algae prefer warm, calm, sunny weather and water temperatures higher than 75 °F so HABs will thrive in warm, shallow, nutrient-rich lakes like those in Sussex County. Since we can’t control the water temperature, the best thing we can do is to reduce the amount of nutrients getting into the lake. This can best be accomplished by reducing the amount of phosphorus and nitrogen from man-made sources such as lawn fertilizer and runoff from homes and our roads. This is the best long-term solution to minimizing algal blooms.  Go to for information on minimizing your home’s impact on our lakes. LMCC is committed to controlling and minimizing HABs. We request that if members, particularly along shoreline areas, notice any signs of algae indicative of the green-blue variety, to call the Club directly.  There is a well-developed plan in place for LMCC to monitor, maintain the relative parameters and manage unbalanced or harmful conditions in all the lakes.  LMCC takes this responsibility seriously. 

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