Have recently thought back to perhaps 12-13 years ago when my son, Dan, and I met up with Kingfisher, Mrs. Kingfisher, Magic Paddler and Jimbo on Wicksteed Lake early in June and traveled together a few days.  The next day's route took us through some old logging camp areas (wood tick infested meadows!), small creeks and big beaver ponds.  At one point I was following in Dan's track as we paddled up a small creek.  Apparently few if any had paddled there yet that spring.  Dan's kayak was leaving a HEAVY trail of rising and bursting methane bubbles as he went over shallow silty areas.  I've seen that before when you shove your paddle into muck, but this particular day the bubbles were  remarkably profuse.
Lately I've been watching a lot of YouTube regarding the melting of the Arctic and Siberian permafrost and often think back on that route we were on as a closer to home example.  :-?