This is a blue green algae bloom caused by nutrients we put in the river. Years ago the blooms were worse and I remember seeing a video in High school showing a canoeist lifting his paddle to take a drink from, yes it can be done but takes practice and quite a thirst, as the paddle is lifted with pristine water clinging to it's sides and this person opens his mouth to catch the water a trick photography switch is made to Lake Erie algae water. Actually more algae than water and he gets a mouth full of blue green algae, which can be toxic so don't try to sample any. The old culprit was phosphorus which has been addressed. The toxicity can be present or not which can lead to problems. We can make that decision but fish have no choice so if they eat in one of these blooms they will ingest the algae. The toxins attack the liver and can cause death. I you catch fish in the bloom areas don't eat the entrails only the flesh. Thanks for the pics Dr. Hartwell and Feisty The new or still existing, but in much higher concentration now, problem is the run off from farms in fertilizer and the treated waste from animals and humans. These are the out of sight out of mind things that can build up to cause problems. Sometimes we hear of untreated run off kills like this one in the Thumb: CROSWELL, Mich. (AP) —A judge has ordered a Sanilac County farm to pay $75,000 in penalties for a 2009 manure spill that killed more than 200,000 fish in the Black River near Croswell. The Times Herald of Port Huron reports (http://bwne.ws/GXX4hi) Sanilac County Circuit Judge Donald Teeple ruled Monday on the payout from Noll Dairy Farm Inc. The Michigan Department of Natural Resources cited Noll Dairy Farm as the source of the contamination. The runoff flowed into a creek that feeds the Sanilac County river. Smallmouth bass, catfish, northern pike, rock bass, sunfish, suckers, minnows and darters died after the spill. A message seeking comment was left Wednesday by The Associated Press at a listing for the farm, which has said the discharge was accidental. Nearly 20 miles of the river was affected. If the run off was treated you wouldn't hear anything but the "nutrients" make their way to the Great Lakes and Lake Erie is a catch basin and where the blooms are evident. This is another sign and one of which points to over crowding. Along those lines is the Detroit River Clean-Up on April 28th. Anyone interested in helping with or without a boat should meet at the Rotary Park in Trenton at 9 am. Bring gloves and dress for the weather, life jackets are needed if you have them. For more info go to www.detroitriver.org Get Outdoors Downriver.Travis Hartman's talk at the DWF April meeting covered a big problem appearing in Lake Erie that was controlled for a while but now has come back.