Monday July 14, 2025 Honeoye Lake Water Quality
- Terry Gronwall
- 24 hours ago
- 3 min read
Updated: a few seconds ago
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Monday July 14, 2025 Honeoye Lake Water Quality
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Surface Water Temperature: ~82.9 F
Water Clarity: ~8.3 Feet
Lake Level: 803.4 Feet above sea level
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Observations: Monday (7/14/25), Water clarity was ~8.3 feet the same as last week. The surface water temperature was ~82.9 F about an increase of 3.7 F over the last week. It was overcast with a calm wind today. It was a pleasant day to be out on Honeoye Lake.
Gloeotrichia (lots of small spikes) is currently the dominant blue-green algae.  See picture on the left.  Also found Anabaena (Dolchospermum) (looks like a spring or chain of beads), Aphanizomenon (looks like a leaf) and Limnoraphis (looks like a rod). You should be watchful for Gloeotrichia, Anabaena, Aphanizomenon, and Limnoraphis blooms lake wide. These are all blue-green (cyanobacteria) algae species. We expect to see Gloeotrichia, Anabaena, Aphanizomenon, and Limnoraphis blooms continue over the next few weeks particularly when we have 80-90 F days with calm winds. See microscope pictures below: More information on Gloeotrichia and Anabaena can be found at: https://www.honeoyelakewatershed.org/habs  Â
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Several research studies have found that most of the phosphorus that fuels Honeoye Lake’s blue-green algae blooms is released from the lake bottom sediments when the lake’s dissolved oxygen level goes below 0.5 mg/L in the deeper parts of the lake breaking the phosphors/iron bond in the bottom sediments releasing phosphorus into the water column. The dissolved oxygen (DO) level near the lake bottom at ~7.0 m (~23.1 feet) was 0.43 mg/L and at ~9 m (~30 feet) was 0.19 mg/L today. This means that phosphorus is currently being released from the deep bottom sediments into the deepest part of the lake water. When we have a complete lake mixing event the deep lake water, with excessive amounts of phosphorus, will be mixed into the whole water column potentially fueling a blue-green algae bloom. Lake was stratified (i.e. had a thermocline) at ~5 m (~16.5 feet) deep. Today's temperature and DO graphs are posted above on the left.
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The lake has been having a lake wide Gloeotrichia bloom over the last week. There is a heavy concentration of Gloeotrichia in most open water areas (see picture on left) and many near shore Gloeotrichia blooms with surface scum (see picture below).  Sandy Bottom Park Swimming Beach has been closed due to a Gloeotrichia bloom. There has been 8 Gloeotrichia blooms reported to the DEC HABs alert map over the last 10 days. Since Honeoye Lake has ~10 miles of shoreline your most accurate source of blue-green algae blooms is the crowd source bloom data found on the DEC HABs alert map (NYHABS).Â
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When Gloeotrichia dies its reproductive resting cells settle on the shallow water bottom sediments where it directly absorbs phosphorus from the bottom sediments over winter and spring and blooms again the next year in mid-June to early July. Gloeotrichia does not depend on the deep-water phosphorus release cycle to get its nutrients like the rest of the blue-green algae species.
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:
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Click on the link below to see the Honeoye Lake Watershed Task Force 2025 Winter Newsletter:
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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:
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Click on the link below to see the Honeoye Lake Watershed Stormwater Toolkit:
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