Algal Blooms

Many types of algae occur naturally in lake waters. They are generally categorized as a large, diverse group of photosynthetic organisms that can be subdivided into the larger and more complex green algae and the much smaller and simpler blue-green algae (more specifically referred to as cyanobacteria).
Blooms of blue-green algae in Lake Mattatall occurred in Sep-Dec 2014, Sep-Dec 2015 and Aug-Nov 2016 (see photo below). No algae bloom occurred in 2017.
A very brief information pamphlet about algal blooms has been provided to the MLSA by Helping Nature Heal.
A particularly unusual feature of these blooms is that they continued even into freezing conditions.
Taxonomy of the cyanobacteria was determined as the cell counts rose during the blooms. Results indicated that the percentage of Anabaena plancktonica species becomes dominant.
This species has the potential to produce fatal neurotoxins. Only a few US labs can test for these toxins and such tests are expensive.
Toxicity of the Lake was tested in 2015 and 2016 but significant amounts of either anatoxin-a or microcystins were not detected. In addition, there were no reports of any sick pets or wildlife that entered the water during the blooms.
However, since we cannot be absolutely certain whether toxins might exist, lake residents were warned to keep themselves and their pets out of the water during the blooms.