Never, in my 60+yrs of fishing have I ever seen a blue/green algae bloom until today. Two weeks ago we had an algae bloom that turned the water pea green.  That didn’t stop me from launching, but when I saw this today, I didn’t venture out. 
Anyone know what the name of this is and if it’s detrimental to the fish?  
 

 

It’s actually not an algae, it’s a Cyanobacteria. We have it here in Minnesota too. It often shows up in late September in waterways that are stagnant and warm. The Minnesota Pollution Control Agency will issue an alert when they discover it.

 

It usually does not result in fish kills, but if dogs ingest it, it can be fatal. Our duck hunting opener often coincides with the presence of it in ponds and marshes, right when hunters take to the water with their retrievers to hunt ducks.

 

It can cause health issues in people too but rarely does anyone go for a swim with the intent of drinking it. But in rare cases, someone like a swimmer or water skier does ingest some and get sick. 
 

It’ll go away on its own with some rain or drop in temperatures.

Thats a nasty bloom, you know it's bad when the surface looks like paint.

Gotta admit, that's the worst I've seen.

Would fish even bite in that ?

We get it in the Willamette some summers. It is toxic. Please keep your pets and people off the water while it is present. 

all of the above.  That's a pretty bad one.  I've fished in them that bad and it can be tough at times.  If the water is otherwise clear/clean and its just the bloom then you can still catch fish.  It takes them a couple days to a week to reacclimate to it (kinda like a bad storm that muddies the water bad).  See the thread from NJtristatebassin about lures for green water.  That water looks milky too, not just surface, so that's going to be hard going for a little bit.  You'll need some lures with a thump or else have to put it right on their nose.  Dark baits will be your friend in that color of water.  

Be careful fishing around that stuff if there is wind. If the water gets choppy, some of it will aerosolize and potentially irritate your throat and lungs. It's an occasional/seasonal thing here, too.

 

Like others said, the fish should be ok. Probably still fine to eat, too. Here's a blurb about it from Florida's Department of Health (https://www.floridahealth.gov/environmental-health/aquatic-toxins/harmful-algae-blooms/index.html):

 

"BLUE-GREEN ALGAE AND FISH  Fish tested from water with blue-green algae show that cyanotoxins do not significantly accumulate in the edible parts—muscle or filet—of fish, but can in other organs. Prior to consuming, rinse fish fillets with tap or bottled water, throw out the guts, and cook the fish well. Do not eat shellfish in waters with blue-green algae blooms."

Wow, we get blue-green algae blooms here a few times per year, but nothing like that!!   That is nasty.  When we get it, it pops up in dinner plate sized blobs throughout the shoreline by stagnant water.  It doesn’t last long, but a warning goes out to not swim or have pets in the water.  That is a crazy looking breakout.  Yikes.