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  • Terry Gronwall

Tuesday June 13th, 2023 Honeoye Lake Water Quality

Surface Water Temperature: ~67.6 F

Water Clarity: ~15.4 Feet

Lake Level: 803.5 Feet above sea level

Lake level relative to long term average lake level: +0.0 Feet

Observations: Tuesday (6/13/23), Over the last week the water clarity increased by ~3.5 feet to ~15.4 feet and the surface water temperature decreased by ~3.8 F to ~67.6 F. It was a beautiful day to be out on Honeoye Lake!

We found a moderate amount of Gloeotrichia lake wide, but not at bloom level yet. Right on schedule for a mid-June arrival. Gloeotrichia is a blue-green algae. You should expect to see isolated near shore Gloeotrichia blooms over the next few weeks. See picture on the left. More information on Gloeotrichia can be found at:

We did not expect the DEC Allum Treatment to reduce our traditional Gloeotrichia blooms starting in mid-June given that the Alum Treatment was in water depths 18 feet and deeper. When Gloeotrichia dies its seed goes to the lake bottom in shallow water. Then in the spring it acquires nutrients directly from the shallow water bottom sediments. Then it blooms.

Spirogyra, a green filamentous algae, in shallow water is still present. Also, Curly Leaf Pond Weed, an early season aquatic plant, growing to the lake surface is in the early stage of dying off naturally. It typically completely dies off by late June.

Please report any Honeoye Lake HABs you observe to us and DEC by submitting a HABs report at:

There have been no public reports of Honeoye Lake blue-green algae blooms to the DEC HABs alert map site yet this season. Link in the next paragraph below:

Always use your own visual assessment before making contact with the lake water at this time of year as the blue-green algae situation can change daily if not hourly. Please regularly check the DEC HABs alert map for more detailed updates on Honeoye Lake HABs alerts:


Why is Curly Leaf Pond Weed so abundant this spring?

Curly Leaf Pond Weed is unusually abundant this spring because we had a very mild winter and early ice out date in 2023.

Curly Leaf Pond Weed is unusual in that it germinates in the fall rather than the spring like most other aquatic plants. Then its growth rate under the ice during winter is affected by the duration of ice cover and amount of snow accumulation on the ice. It will start growing rapidly shortly after ice out until late June to early July when it dies off naturally.

We had only ~4 weeks of ice cover during the winter of 2022-2023. See table below:

Ice in Ice out

12/25/2022 1/4/2023

1/16/2023 1/18/2023

1/31/2023 2/15/2023

In 2021-2022 the ice in/ice out dates were: ice in 1/11/22 ice out 3/21/2022. About 10 contiguous weeks of ice cover.

In 2023 the ice out date was ~5 weeks earlier than 2022.

Therefore, due to a 6-week reduction in weeks of ice cover and an ice out date 5 weeks earlier than 2022, the 2023 Curly Leaf Pond Weed grew more robustly last winter and its rapid growing season, after ice out, started 5 weeks earlier than 2022. This accounts for the unusually abundant Curly Leaf Pond Weed growing to the lake’s surface this spring.

You can Google Curly Leaf Pond Weed to learn more about its life cycle.


You will find this video from WCNY PBS and the Finger Lakes Land Trust on what causes HABs interesting:

This video focuses mostly on reducing storm water runoff into a lake to reduce phosphorus levels. You can read about our Honeoye Lake Watershed mitigation projects in our 2023 Winter HLWTF Newsletter.

Several studies over the last 20 years have concluded that the largest source of phosphorus in Honeoye Lake comes from bottom sediments when the lake has been stratified and then mixes due to a strong wind. This lake mixing occurs in Honeoye Lake because the lake is only 30 feet deep. The deeper Finger Lakes do not mix in the summer. Most of this legacy phosphorus reached the Honeoye Lake’s bottom sediments 100+ years ago when the lake’s hillsides were clear cut. Last November the DEC Alum Treatment Pilot Project was done to address the lake bottom source of phosphorus in Honeoye Lake.


Please click on this link for the Winter 2023 HLWTF Newsletter:


June FLCC Muller Field Station Events

Click on the link below to see the June Muller Field Station Newsletter:


New York Safe Boating Class Certificate will be required of all boaters on this schedule:

If born on or after: You will need boating safety certificate to operate motorized vessel in:

January 1, 1988 2022

January 1, 1983 2023

January 1, 1978 2024

All operators of motorized vessels, regardless of age, will need a boating safety certificate by January 1, 2025.

Click on the link below for more information and the schedule of local NYS Safe Boating classes:


Honeoye lake is included in the DEC's Big Panfish Study. Please click on the link below to read their Interim report:


Please visit the Honeoye DEC Project website for more information on the Honeoye Lake Nutrient Inactivation (Alum Treatment) Project: Honeoye Lake Nutrient Inactivant Pilot Study (


- Click on this link to see the new HLWTF Honeoye Lake Watershed Storm Water Took Kit if you are planning any storm water projects on your property:


Click on the blue outlined box that says "Log in / Sign up" in the upper right-hand corner of this page to sign-up to be notified when we update our weekly Honeoye Lake water quality blog.


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