Lake Otis algae bloom status

Lake Otis algae bloom history

Florida's Department of Environmental Protection sampled Lake Otis 5 times between 2020 and 2022. Staff saw a bloom on 4 visits (80%).

The highest microcystin result recorded here was 1.2 µg/L, below the US EPA swimming advisory level of 8 µg/L.

Blooms have been recorded every year for the last 3 years in the data.

That puts Lake Otis in the top 25% of the 293 Florida lakes on this site for the number of years with blooms.

When do algae blooms happen at Lake Otis?

At Lake Otis, reports are most often logged in February, April and July.

Unusually, about 25% of reports here fall between November and February, so blooms aren't only a summer problem at Lake Otis. Some of this reflects when the lake is monitored, not just when blooms happen.

Blooms can appear, move with the wind and fade within hours or days, so the time of year is only a guide.

Recent Lake Otis algae reports

Recent reports came from 4 different locations around Lake Otis, including Lake Otis - at Boat Ramp, Lake Otis - Boat Ramp and Lake Otis - boat ramp. A bloom in one cove or beach doesn't mean the whole lake is affected, and conditions can differ a short distance away.

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 Otis 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 Otis in February, April and July.

• 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

• Lake Mariam2 km away, 6 reports, last in 2022
• Lake Summit2 km away, 3 reports, last in 2025
• Lake Buckeye3 km away, 4 reports, last in 2024
• Lake Idyl4 km away, 3 reports, last in 2020
• Lake Conine6 km away, 9 reports, last in 2024

All Polk County lakes with algae reports

Questions about Lake Otis

Is there algae in Lake Otis right now?

Florida's most recent sample from Lake Otis, on 28 February 2022 at Lake Otis - at Boat Ramp, found a bloom and microcystin toxin measured 0.43 µg/L, below the US EPA swimming advisory level of 8 µg/L. 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 Otis?

The most recent entry in Florida's data is from 28 February 2022 at Lake Otis - at Boat Ramp: a bloom seen during sampling.

Has Lake Otis had toxic algae before?

Yes. Blooms are recorded every year from 2020 to 2022, most often in February, April and July.

Can dogs swim in Lake Otis?

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 Otis 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.