Most likely a stash by some wild rodent. :p

Do rodents usually grow their own food? This was still on the vine.

I thought cranberries were water growers...as in floating in them.

Maybe BC has some smart rodents...

That was on top of a sphagnum island, which itself was floating, and the whole area was saturated with water. My feet kept sinking in the moss. Cranberries grow in damp, acidic mossy soil. You flood the fields when you grow cranberries commercially, then thrash the vines with a rake or similar implement to dislodge the berries, and then they float up to the surface to be readily scooped up and processed into sauce, juice, and other food.

ah, okay. :p