If you click on Unidentified sounds and then on Bloop and then compare it to those show on the Whale sounds page, it is not unlike several of the Whale songs. The frequency is slightly broader, up to 50Hz where most whale sounds seem to cut off at 40Hz, but shows a similar form.
It will be interesting to see just what this leads to. The location, South Pacific off the coast of South America is not one where there is lots of research going on. The closest land mass is South America and one island way north and slightly west.
Aslan is not a Tame Lion