According to Linda Merchant-Masonbrick, a harmful algae bloom coordinator with the Ohio EPA, the recent hot and humid weather, combined with the abundant levels of nutrients in Grand Lake have caused the algae blooms seen on Monday , June 14th. The bloom is from blue-green algae, but possibly a different species than the one from last year that led the Ohio EPA to announce a water quality advisory. The bands of blue-green algae were spotted all the way from the east bank to the west bank of the lake. The Ohio EPA in April of this year tested the water along the Grand Lake St. Marys beach. The tests showed that the algae toxins previously found in the lake, had fallen below the World Health Organization's guideline for concern. The recent algae blooms are said to be a "scum with some iridescent blue colors that glow. It's very striking and also very characteristic of blue-green algae, but not planktothrix." said Masonbrick. The planktothrix algae is the species which produces the toxins. The windless evening made no waves to move the algae slicks, but in harbored areas, such as channels, the algae formed mats covering the water surface completely. Read more about this algae bloom.