Scum Line

[GLF]

I have heard the term "Scum Line" from fisherman during the summer. I have never made it out to the scum line. On average, how far out is the scum line? Is there something distinct about it so you know you are there? Rapid water change, floating scum on the water? In Lake Michigan, does the scum line run up and down the whole lake or is it mainly a southern end of the lake thing?

[CaptLevi]

The scum line is a temperature inversion in which two very different water temperatures meet. It is usually in relation to currents, winds, and upwellings. You will usually see a very flat line of water compared to the water surrounding either side of the line. When it first forms you may not notice much floating on the surface, but after it has set up for a bit you will see foam, vegetation, bugs, debris, garbage, you name it! It usually is a virtual fish magnet, although at times they may not hold fish at all.

I have fished the scum from Frankfort to St. Joe, and have found them from 20 miles out to as little as 1/2 mile from shore, probably less.

Steelhead usually can be caught at or near the surface around scum lines, and salmon commonly frequent the waters on one side or the line.

Hope this helps!

[GLF]

So pretty much, the scum line attracts the forage fish and the predators follow the prey. I can relate to that.

[J J Mac]

Scum lines are formed by Langmuir Circulation caused primarily by the wind. Here are three sites to read about how they are formed.

http://faculty.gvsu.edu/videticp/langmuir.htm

Page 3 of

http://www.lmvp.org/Waterline/Waterline%20Winter%202002.pdf

http://homepages.cae.wisc.edu/~chinwu/CEE514_Coastal_Engineering/2001_Students_Web/Dave_Calkins/Main.html