I was amazed at that as well about the Elephant Seal.
"One final note about life in the abyss: not all intruders from the lighted world are ROVs
or submarines. A southern elephant seal tagged by Census project TOPP recently dove
down 2,388 meters (~1.5 miles) from the surface. At that depth, water pressure is
roughly equal to 240 times the air pressure at sea level. The human eardrum can rupture
at 10 meters"
"One final note about life in the abyss: not all intruders from the lighted world are ROVs or submarines. A southern elephant seal tagged by Census project TOPP recently dove down 2,388 meters (~1.5 miles) from the surface. At that depth, water pressure is roughly equal to 240 times the air pressure at sea level. The human eardrum can rupture at 10 meters"
http://www.coml.org/comlfiles/press/CoML_Beyond_Sunlight_11....