Sunday July 6, 2025 Honeoye Lake Water Quality

Terry Gronwall
8 minutes ago
3 min read

****

Surface Water Temperature: ~79.2 F

Water Clarity: ~8.3 Feet

Lake Level: 803.2 Feet above sea level

Observations: Sunday (7/6/25), Water clarity was ~8.3 feet about 2.6 feet less than last week due to an increase in algae in the open water column. The surface water temperature was ~79.2 F about an increase of 1.7 F over the last week. It was a sunny day with a calm wind today. It was a very nice day to be out on Honeoye Lake.

We found an increase in Gloeotrichia (lots of small spikes) in the open water column. 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 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

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 ~7.5 m (~24.8 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 ~6 m (~19.8 feet) deep. See temperature and DO graphs to the left.

Yesterday (Saturday July 5^th) a lake resident who lives on the NE shore of Honeoye Lake reported a Gloeotrichia bloom with surface scum to us. It has been reported on the Honeoye Lake DEC HABs alert map (NYHABS). See picture on left. We checked 10 near shore areas for Gloeotrichia blooms this morning. We found Gloeotrichia in the water column at all the locations we checked, but did not see any Gloeortichoa blooms with surface scum. However, 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).

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:

https://experience.arcgis.com/experience/e5dec19912454731a308bbb7af605fb3/

****