There has been a lot of blame in our area about high coli-form counts and nutrient overloading of rivers and its often aimed at the farmers. This is sometimes warranted when certain farmers use bad management practices and I will post on this later. Often over looked is the natural causes from wildlife and run off during heavy rains or snow melt.
During the past few weeks I have had a flock of some 40 to 60 mallard ducks roosting on the ice on a bend in the river next to where our sheep are. The photos show the ducks and also the ice, look at the two of the ice only and you will see many brown marks and stains of the ducks calling cards. This of course all goes into the river and lake once the weather warms up.Over the last two years research has been done on several local rivers to see who or more to the point whats poo is the biggest culprit. A trapper was sent to collect the "scats" or poo of all the birds mammals and amphibians in the watershed. As each species has a different set of microbes in their scats these could then be used to test water at the rivers mouth before entering the lake to see who was the biggest polluter. Turns out that cattle came fourth much to the chagrin of local tree huggers, so I guess they don't all back up to the creek to do their thing! Third were dogs ,coyotes and foxes. Second were fish, no surprise as after the salmon spawn they all die and decompose in the river feeding all the insect and fingerling fish. The worst polluter was birds, ducks, geese, birds of prey and all the little twittery types. This came as a shock to many of us and a relief to us ranchers, for once we didn't get the lions share of the blame. So remember if your favorite swimming spot is closed due to high coli-form count, stop feeding the ducks!
Its easy to test for humans as we are the only animal to consume caffeine and it is easy to test for. Yet the test was not done, may be the truth is just to unpalatable and blame much to hard to lay.