Sea wolves using tools?

[Catherine]

First, Sea Wolves are a Grey Wolf subspecies that lives on a marine based diet. 
Something was messing with the crab traps on the central BC coast. They are trying to trap invasive Green Crabs.
They finally set up camera surveillance. Surprise, the wolves were swimming out and grabbing the buoys, bringing them in and then using the line to bring in the actual crab trap. Then the wolf  would eat the bait from the trap.


https://cheknews.ca/b-c-wolves-use-line-...s-1289765/

Is bringing in the buoy and then using the line to haul in the trap really a form of tool use. Jane Goodall said yes when consulted.
If Jane said yes, that is good enough for me.
How did the wolves figure this out and is it their only tool use? That will require more observation.