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Harmful Algal Bloom (HAB) Monitoring in the Musconetcong Watershed

With HABs proliferating in Lake Hopatcong, headwaters to the Musconetcong River, action to identify them throughout the Watershed must be taken to prevent growth.


What is a HAB?

A Harmful Algal Bloom is caused by a type of blue-green algae, or more specifically, cyanobacteria. When given ideal conditions (warm temperatures, stagnant water, excess nutrients), these photosynthetic bacteria can bloom and negatively impact the aquatic ecosystem, human/animal health, and the economy.

Where are HABs? Know Before You Go

In the summer of 2021, MWA partnered with the Lake Hopatcong Foundation and Lake Hopatcong Commission to monitor HABs in Lake Hopatcong and other lakes and ponds in the watershed as well as some slow-moving sections of the River. A team of volunteers went out to over 30 sites weekly to take readings of temperature, phycocyanin (the pigment associated with cyanobacteria), and other indicators of compromised water quality. HABs that exceeded the NJ Department of Environmental Protection's criteria limit for phycocyanin were reported using their “Report a HAB” page.

See the map below to view the data for each site:

Source: NJDEP

How to Prevent HABs

HABs thrive in areas with excess nutrients. These nutrients, like phosphates and nitrates, enter waterbodies from stormwater runoff containing fertilizers used in agriculture and on lawns. Limiting use of fertilizers on your lawn will limit the amount of nutrients that makes it into waterways. Soaps and detergents released into waterbodies also increase nutrient levels. Avoid washing your car in your driveway where soap will flow into storm drains. Instead, take your car to a car wash or use a biodegradable soap. If you have property near a waterbody, plant a buffer of native trees, shrubs, and perennials between your lawn and the water. The root systems of these plants will catch some of the nutrients that would have washed through your lawn and right into the water. Leaky septic systems also release nutrients that can runoff into waterbodies. To prevent this, make sure to pump your septic tank every 3-5 years. 

HABs Infographic.jpg

Thank you to our funder!

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