Fewer blooms in these lakes


The Laconia Daily Sun

Published: 08-09-2023 4:00 PM

LACONIA — Despite a near record-breaking number of cyanobacteria blooms in New Hampshire this year, the Lakes Region has been largely spared.

“We broke the record every month for the number of advisories issued,” said Kate Hastings, cyanobacteria harmful algal bloom program manager for the Department of Environmental Services. “So far, we’ve issued 38 advisories this year. The total last year was 46.”

Hastings takes the lead, and is the only employee within DES when it comes to documenting blooms. A vital part of her duty includes issuing warnings and alerts when a bloom is discovered and reported. These warnings and alerts are tracked at des.nh.gov/water/healthy-swimming/healthy-swimming-mapper, where anyone can check to see if their local water body is safe for swimming, as well as report sightings of potential blooms.

Blooms can come in a variety of shapes and colors, from blues and greens to even reds. They can appear as scum, foam, mats, or look like paint floating on top of the water.

If you see a bloom, call or text 603-848-8094 to report it to DES.

“If we get a photo on a Friday and we can’t sample for the weekend, we can issue an alert,” Hastings explained. “Sometimes we issue an alert when it’s below that recreational threshold. We’ll also issue alerts if the bloom has passed and we can’t sample it.”

Contact with certain types of cyanobacteria can sicken or even kill pets and humans, so checking before taking a dip is recommended. Swimmers and boaters should also known the difference between warnings and alerts. According to Hastings, a warning is a formal statement where citizens are advised to stay out of the water to avoid contact with bacteria identified as above the DES’s threshold of 70 thousand cells per milliliter. An alert is one step down from that, when DES has received evidence, such as a photograph, by a concerned citizen, but hasn’t been able to collect a sample yet.

“We have seen blooms in the Lakes Region. ... Every water body is different and depends on the nutrient inputs in that watershed,” Hastings said. “We see more in the southern part of the state but we certainly are up in the Lakes Region a lot.”

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Cyanobacteria maintains a constant presence in the water, but in low enough concentrations that allow for safe recreation. When an area is hit by heavy rains, nutrients like phosphorus are washed out of yards, lawns, garden beds and other human structures into the water, providing the bacteria with a sudden rich burst of energy. Developed surfaces like concrete and asphalt allow more rainwater to run off and back into water bodies, instead of being absorbed into the ground.

“We have actually not had a lot of blooms on the lake this year,” said Bree Rossiter, a conservation program manager at the Lake Winnipesaukee Association. “We had one alert in Blackey Cove in Moultonborough in June. We have the tracking map on our website.” To see the tracking map, visit winnipesaukee.org/winni-water-quality-report-card-cyanobacteria-map.

Although the Lakes Region has been largely spared from blooms this summer, increasing development, as well as the frequency of heavy rainfalls spurred on by climate change, are still a threat.

“The storms followed by warm periods are definitely contributing to the record we’ve seen, as well as milder winters,” Hastings said. “So we had shorter periods of ice-covered lakes.”

To help combat this, both Rossiter and Hastings cited the Lakesmart program, in which qualified professionals visit lake-adjacent properties and make recommendations for friendlier landscaping and storm water management.

“Avoiding the use of fertilizer is a great start, planting native vegetation along the edge of the water helps, too,” Hastings said. “The native plants are great at filtering the water before it flows into the body. Folks can also get their septic system inspected and pumped regularly. That will help with excess nutrients.”

These articles are being shared by partners in The Granite State News Collaborative. For more information visit collaborativenh.org.]]>