We could map the entire ocean floor by using whale songs
Several whale species in the world utilize sound to attract mates. Their “songs” can travel pretty far, and because of this, experts theorize that they could be used to map the ocean floor.
Whales can make sounds that go up to 1.6 in depth. By measuring how the soundwaves bounce back, they can determine how the ocean floor looks. This method has a significantly lower impact than shooting a large air gun, which is how the bottom of the sea is commonly mapped.