Q.Composting
Living by Lake Michigan, the zebra mussels have made the water clear so now algae forms on the bottom of lake and wave action stirs this up ending up on shore in piles at times. Is this crusty goo good to mix in with my good compost? I use a tumbler.
Here are a few articles for you.
I think more investigation is important and you may want to contact the local DNR office for information on your local lakes.
https://www.gardeningknowhow.com/composting/ingredients/pond-scum-garden-fertilizer.htm
https://www.gardeningknowhow.com/ornamental/water-plants/wgen/what-is-algae.htm
http://www.buffalo.edu/news/releases/2013/07/027.html