I looked up the midge larvae and that's not what I saw. If someone was able to post a picture, I'd definitely be able to confirm or not. It may be worth noting that as best I recall I only saw them when there were jellies around. That may be because of a correlation, or it could just be that you kind of had to focus on the foreground instead of looking at the bottom in order to be able to see them, just like the jellies, so maybe I only noticed them when on alert for the jellies.
They seemed to stick to a foot or so below the surface, down to about 3-4 feet below the surface. They were maroon in color with little yellow "feet", kind of like a squigly water centipede. I think they were about 2-3 inches long and quite skinny. They seemed to move on their own and not just move with the water, but I didn't spend as much time studying them as I would have liked to as I was mostly concerned with avoiding the jellies. I don't recall ever having seen anything like them before. Great Dog may have been the only place we saw them.
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