You may have noticed that in some parts of the lake we have an unusual algae bloom that has many of us concerned. We’ve reached out to Orange County EPD and FWC for input/feedback. Jim Sweatman from FWC, toured the lake and on February 11 and 12 to evaluate the issue.

He was on Johns Lake Monday doing creel and Tuesday electrofishing for bass. He did notice the algae bloom in the area we reported. They did not see that type of algae bloom anywhere else on the lake and in fact, the west side of Deer Isle that hooks up to the boat ramp cove did not have a noticeable bloom, nor did the north shoreline east of Johns Cove. They reported that they had a similar winter bloom on the west side of Clear Lake last year. It took a few weeks, but it eventually went away.

When we first mentioned algae they thought we meant filamentous algae. Filamentous algae are colonies of microscopic plants that link together to form threads or mesh-like filaments. While they did notice some  filamentous algae in Johns Cove and in a few places around the lake, it was not at nuisance levels.

Julie Bortles, OC Regulatory Compliance Program Coordinator has confirmed that OC does sample Johns Lake on a quarterly basis throughout the year. The last visit to the lake was February 14 and we typically sample the east and west main lobes. They will be looking at sources of nutrient pollution this year into the lake. You may want to visit the Orange County Water Atlas to look at historic trends in the lake. Overall, the nutrient pollutants look like they are trending down in a good way.

As mentioned, the areas north of Deer Island and south of Johns Cove appeared to the worst area. The rest of the lake is not impacted as much. Several comments at this point:

  1. The areas that are the most stagnant are more vulnerable.
  2. Many other lakes in Orange and Lake County are seeing the same thing right now.
  3. The recent treatment of Hydrilla and the resulting vegetation decay may have added to the issue by increasing nutrient levels.
  4. The water levels are unusually high for “dry season”.
  5. Water Quality test results show the lake overall to be in good health.
  6. Warmer winter water temperatures could also contribute to the additional algae.