Health officials in northern Utah continue to warn visitors to Mantua Reservoir that toxic blooms of slimy, blue-green algae have returned to the popular summer recreation spot in Sardine Canyon.
Earlier this month, the Bear River Health Department issued a warning advisory for the reservoir located near the Box Elder-Cache county line, informing people that water samples taken from the northeast boat ramp and along the north shore contained concentrations of cyanobacteria that were more than 11 times greater than what the Utah Division of Water Quality deems safe. A subsequent test on July 21 reaffirmed the findings.
Cyanobacteria are microorganisms that are a natural part of fresh water ecosystems but under certain conditions can multiple rapidly, creating scums and blooms on the waterâs surface and along shorelines. The bacteria typically thrive during summer months, their growth fueled by a combination of sunlight, slow-moving water and excess nutrients (phosphorus and nitrogen) from agricultural runoff and other human sources.