*LIFTED* Cyanobacteria ALERT issued for Lake Wentworth 8/24/23

A cyanobacteria ALERT has been issued for Lake Wentworth, Wolfeboro. As previously mentioned, surface blooms are dynamic and can rapidly change and accumulate in various locations around a water body. Cyanobacteria activity was reported again on August 23, appearing as green clouds of material accumulating along the shoreline. Samples collected and reviewed on August 24 had the unique cyanobacteria Gloeotrichia, appearing in a range of densities. This unique cyanobacteria often stays suspended in the water (looking like small balls) and does not accumulate to large concentrations. Under certain conditions, however, they can accumulate along shorelines in more dense concentrations of material, occasionally forming green or yellow clouds or surface scums. Oftentimes these accumulations do not last long and become mixed back into the water to lower densities. Gloeotrichia is a particularly dynamic cyanobacteria. It can accumulate to higher densities in cove areas, and then become more distributed to lower densities within a short amount of time. Cyanobacteria bloom conditions can change rapidly, so it is best to be on the watch for developing conditions. Always perform a personal risk assessment prior to recreating or letting pets in the water. In this case, look for what is shared in the pictures attached. If the density looks low, the risk of recreating in that water should be low. If it looks high, stay out of the water, keep pets out until it dissipates, and report it. Some folks compare it to a night sky – if it looks like a starry night, the risk is low, but if it looks like a galaxy (or dense clouds, or a surface scum) stay out of the water and keep pets out.

NHDES will resample in a week.  Alerts remain active until the bloom subsides.  Surface blooms can rapidly change and accumulate in various locations around a waterbody. Please continue to monitor your individual shorelines for changing conditions and avoid contact with cyanobacteria bloom accumulations. This is not an official cyanobacteria advisory, and signs do not need to be posted.

Residents/community members can receive email through a water body-specific email distribution list, by signing up through this form to be directly included on future communications from NHDES. For more information: 

Information about Gleotrichia- Cyanoscope/ iNaturalist

WWA  Cyanobacteria Fact Sheet

Report a CyanoHAB

Healthy Swimming Mapper  

Frequently Asked Questions

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