I know we have fish traps and the like, but how about some actual fishing rods. Allow us to cast out with bait attached like ammo and reel in when we feel a bite. We could have multiple tier rods that unlock through the cooking skill tree. We could also make it so we need long handles or short handles depending on the rod. It would make better use of the string skill tree.
Speaking of string and rope, why not a grappling hook. The better it is the longer and stronger it is. Make it so each tier of the rope has a weight limit. Have to be light to hold your weight. It would add a new level to raiding and anticlimb techniques. Imagine making one like the one described in The Tower of the Elephant story.
Imagine using it to swing from or rappel down into a ravine. We could even use it as a way to get into hatch ways into our bases. Pull it up when we get in, drop it down to slide out.