We contacted PLM Lake & Land Management Corp regarding blue green algae in Lake Monterey and wanted to follow up with their response to address any possible concerns. PLM conducts our seasonal lake treatments and are the foremost authority on the topic.
There is no clear cut answer to danger to people when it comes to blue greens. Yes, they can be harmful if 1) they are producing the toxins and 2) releasing them. Often they have to be concentrated and heavy to be harmful. To be on the safe side, it is recommended for swimmers to avoid swallowing lake water and avoid these areas altogether.
This is a common occurrence on lakes as blue greens are always in the water, just typically in lower amounts. When they become over abundant, the result is what is shown in the photos.
The PLM Lake Monterey Treatment Schedule can be found on our Event Calendar.