I am part of the Silver Lake Watershed Advisory Committee. We are working on the water issues of the lake which include the cyanobacteria blooms - blue green algae. Blue green algae is actually sold in stores but when it gets to toxic levels it can definitely cause harms to humans and pets.
When there is a bloom the Department of Health will list and advisory. It will be something similar to what was recently issued at Vancouver Lake:
Tests for algae bloom show risks to swimmers at Vancouver Lake
Park to remain open; health officials say avoid water to prevent illness
Vancouver, WA – Clark County Public Health and Vancouver-Clark Parks and Recreation are advising the public to avoid direct contact with water at Vancouver Lake due to elevated levels of cyanobacteria (blue-green algae) revealed by routine testing. Because exposure to cyanobacteria can cause disease, public health officials are recommending:
• No swimming or wading
• No water contact for animals
• Precautions against contact with water while boating or fishing
“It is especially important to keep children out of the lake because they are more likely to swallow some of the water than adults,” said Dr. Alan Melnick, Clark County Health Officer. The health warning will remain in effect until tests show that cyanobacteria (blue-green algae levels) do not exceed World Health Organization guidelines.
Vancouver Lake Regional Park will remain open to the public. Water within the restrooms and shelters is unaffected by the lake water and remains safe to drink.
Clark County Public Health will continue to test the lake and will advise the public when water contact is considered safe again. Swimmers are encouraged to visit the Vancouver-Clark Parks & Recreation website at http://www.cityofvancouver.us/parks-recreation/
for other swimming options.
About cyanobacteria (blue-green algae)
A blue-green algal bloom is a rapid and massive buildup that gives the water a scummy texture and a green color. It may also appear bluish, brownish or reddish green. A bloom may appear during warm weather, usually between May and October.
Warm, sunny weather and pollutants can cause algal blooms. Possible sources include phosphorus and nitrogen, found in fertilizers and in agricultural, human and animal waste.
Some algae may contain toxins that can lead to liver injury, nausea, vomiting and diarrhea. In addition, the toxins can damage the nervous system and lead to muscle tremors, paralysis and respiratory distress. Skin irritations, allergic reactions, rashes and blisters also are possible. Symptoms may occur within minutes or appear hours or days later following exposure. If you have had contact with the water and experience any of these symptoms, you may wish to contact your health care provider. Because warm- blooded animals, such as cats, dogs and livestock are at risk from exposure, please keep pets out of the lake.
Now, I've talked with the DOH in lenght about anglers because I think if you have a ban for swimmers it should include anglers because they get their hands in the water as well. However, they have continued to indicate that it's not a problem but say, was the fish well after removing the internal organs and wash your hands well.
I think if you don't already, keep hand sanitizer on the boat and handy at all times.