Lake Eustis algae bloom history
Florida's Department of Environmental Protection sampled Lake Eustis 12 times between 2021 and 2025. Staff saw a bloom on 6 visits (50%).
The highest microcystin result recorded here was 0.35 µg/L, below the US EPA swimming advisory level of 8 µg/L.
That puts Lake Eustis in the top 20% of the 293 Florida lakes on this site for the number of years with blooms.
- 2021 4 of 7 visits
- 2022 No visits
- 2023 No visits
- 2024 1 of 3 visits
- 2025 1 of 2 visits
When do algae blooms happen at Lake Eustis?
At Lake Eustis, reports are most often logged in March, May and August.
Reports are spread across the year, with 67% between May and September.
Blooms can appear, move with the wind and fade within hours or days, so the time of year is only a guide.
Recent Lake Eustis algae reports
Recent reports came from 7 different locations around Lake Eustis, including Lake Eustis - Near Center, Lake Eustis - North East and Lake Eustis - Center. A bloom in one cove or beach doesn't mean the whole lake is affected, and conditions can differ a short distance away.
| Date | Location | Result |
|---|---|---|
| 14 May 2025 | Lake Eustis - Near Center | Bloom seen · microcystin not detected |
| 7 January 2025 | Lake Eustis - North East | No bloom seen · microcystin not detected |
| 17 June 2024 | Lake Eustis - Center | No bloom seen · microcystin not detected |
| 7 May 2024 | Lake Eustis - Southeast | Bloom seen · microcystin not detected |
| 27 March 2024 | Lake Eustis - south near 441 boat ramp | No bloom seen · microcystin not detected |
| 9 November 2021 | Lake Eustis - canal near Linda Lane | No bloom seen · microcystin not detected |
| 30 August 2021 | Lake Eustis - canal near Linda Lane | Bloom seen · microcystin not detected |
| 30 August 2021 | Lake Eustis - NW Corner | Bloom seen · microcystin not detected |
| 16 August 2021 | Lake Eustis - NW Corner | No bloom seen · microcystin 0.27 µg/L |
| 9 June 2021 | Lake Eustis - NW Corner | No bloom seen · microcystin not detected |
| 28 April 2021 | Lake Eustis - NW Corner | Bloom seen · microcystin not detected |
| 4 March 2021 | Lake Eustis - NW Corner | Bloom seen · microcystin 0.35 µg/L |
What the Florida results mean
Florida records whether staff saw a bloom at each visit and, when a sample is tested, how much microcystin it contained.
- Bloom seen
- Staff saw a bloom at the sampling site, and no toxin was found or tested.
- Toxin detected
- Microcystin, a liver toxin made by blue-green algae, was found in the sample.
- 8 µg/L or more
- At or above the level where the US EPA recommends swimming advisories.
Is Lake Eustis safe for dogs?
Dogs are at the greatest risk from toxic algae. They swallow water while swimming, eat scum on the shore and lick algae off their fur afterwards, and a small amount can kill a dog within hours. With blooms recorded in 3 different years here, take particular care at Lake Eustis in March, May and August.
- Keep your dog on a lead near water that looks green, scummy, foamy or discoloured, and away from algae washed up on the shore.
- If your dog gets in, rinse it straight away with clean water and don't let it lick its coat.
- Call a vet immediately if your dog vomits, drools, has diarrhoea, staggers, shakes or seems weak after being near the water.
Read the full guide to toxic algae and dogs: symptoms, what to do in the first minutes and how vets treat it.
Health effects of toxic algae
Blue-green algae (cyanobacteria) can produce toxins that affect the liver, nervous system and skin. Swallowing water during a bloom can cause stomach pain, vomiting and diarrhoea. Skin contact can cause rashes, and breathing spray from the water can irritate the eyes, nose and throat. Children are at higher risk because they are smaller and more likely to swallow water.
How to spot a bloom
Toxic blooms can look like pea soup, spilled paint or green streaks on the surface, and they can also be blue, brown, white or red. Scum often collects along the shore downwind. If you can't see your feet in knee-deep water, or you aren't sure, stay out.
Don't drink untreated lake water, and don't boil it to make it safe: boiling doesn't destroy algal toxins. If you feel unwell after contact with the water, contact a doctor or Poison Control on 1-800-222-1222.
Nearby lakes with algae reports
- Dead River4 km away, 4 reports, last in 2021
- Dead River Canal5 km away, 4 reports, last in 2022
- Trout Lake Canal6 km away, 6 reports, last in 2021
- Trout Lake6 km away, 2 reports, last in 2023
- Lake Yale7 km away, 28 reports, last in 2025
Questions about Lake Eustis
Is there algae in Lake Eustis right now?
Florida's most recent sample from Lake Eustis, on 14 May 2025 at Lake Eustis - Near Center, found a bloom and no microcystin toxin was detected. Florida publishes its data in yearly batches, so for today's conditions check the DEP Algal Bloom Dashboard and the signs at the shore.
When was the last algae bloom at Lake Eustis?
The most recent entry in Florida's data is from 14 May 2025 at Lake Eustis - Near Center: a bloom seen during sampling.
Has Lake Eustis had toxic algae before?
Yes. Blooms are recorded in 3 of the 5 years from 2021 to 2025, most often in March, May and August.
Can dogs swim in Lake Eustis?
Keep dogs out of the water whenever a bloom is reported or the water looks green, scummy or discoloured. Dogs are the animals most often killed by algal toxins because they swallow water and lick their fur. If your dog swims in water that might have algae, rinse it with clean water and call a vet if it vomits, drools, staggers or seems weak.
Can you eat fish caught in Lake Eustis during a bloom?
If you keep fish caught during a bloom, health agencies advise removing the guts and liver and rinsing the fillets in clean water before cooking, because toxins collect most in the organs. Some agencies advise not eating fish from an active bloom at all, so follow local guidance.
About this data
This page uses official records from the Florida Department of Environmental Protection (DEP), which published as a yearly file; current sampling is shown on the DEP dashboard. Reports are grouped by waterbody. The site was last rebuilt on 24 October 2026.
States only test some lakes, some of the time, so a lake without a recent report hasn't necessarily been checked. This page is independent, isn't affiliated with the State of Florida, and isn't health advice. View the source data.