there always seems to be fishing line everywhere now.
Yep, lots of discarded monofilament line. It is the bane of wildlife. I have rescued two ducks and a turtle tangled in that stuff.
Just about smacked the hell out of a redneck and his drinking buddy. A duck had it legs trapped in the line and the line was wrapped tangled in a fence post. These two redneck boys, ostensibly fishing from the dam, were laughing at it and throwing pebbles. They didn't even consider making a move to save the duck. When I went to untangle the duck they claimed I was 'messin with their fun'.
I used a spare shirt to wrap up the duck and was able to unwrap and cut the line. It was dug into the skin but not too deep. the bird looked dehydrated and the feathers were in bad shape but otherwise healthy.
The other duck I rescued lost a the lower part of a leg and was adopted by a wildlife rescue place and made part of their small children's zoo. They fitted a peg as replacement and the duck got around pretty well. That must have been around 1980.
I wish more effort was made to contain and collect the monofilament line.
On the up side as long as humans keep littering and randomly tossing away stuff there will be few places on earth where you can't find useful survival materials in the form of discarded trash. Discarded line has its uses. Soda cans can be used for boiling water or food preparation. Plastic bottles make very durable canteens. I have used one from home for eight or ten years now as a canteen on jobs. I used to carry white gas for my stove in a 12 ounce screw-top soda bottle. Worked fine.
Discarded shopping bags and newspaper can be used to make expedient shoes and newspaper crumpled and flattened by hand, so you get lots of air pockets between layers, can be stuffed under shirt and pants for insulation. Cardboard males a good sleeping pad. Plastic sheeting, vinyl flooring and old shower curtains make good tarps for shelters.
there are, IMHO, only two big obstacles. The first is simply a matter of imagination. Second is that many man-made materials degrade to practical uselessness as the elements work on them. Unfortunately long after a monofilament fishing line has lost the strength to reliably catch fish it can still entangle wildlife. Long after the shopping bag has lost the ability to carry anything it can still choke a turtle.