Its clearly Nessies South American cousin farting.
Noooo, you just beat me to it!
I was just thinking who I could say that farted. 
Its clearly Nessies South American cousin farting.
I was just thinking who I could say that farted. 
This sound was recorded May 19, 1997 on the Equatorial Pacific Ocean autonomous hydrophone array. The sound slowly descends in frequency over about 7 minutes and was of sufficient amplitude to be heard on three sensors at 95W, and 8S, 0, and 8N, at a range of nearly 2,000 km. This type of signal has not been heard before or since. It yields a general location near 15oS; 115oW. The origin of the sound is unknown.
Most of the sounds detected obviously emanate from whales, ships or earthquakes, but some very low frequency noises have proved baffling.

I rekon it's more likely to be seismic in origin, not some huge dogfisheel.

Icequakes (Bloop)
The broad spectrum sounds recorded in the summer of 1997 are consistent with icequakes generated by large icebergs as they crack and fracture. NOAA hydrophones deployed in the Scotia Sea detected numerous icequakes with spectrograms very similar to “Bloop”. The icequakes were used to acoustically track iceberg A53a as it disintegrated near South Georgia Island in early 2008. Icequakes are of sufficient amplitude to be detected on multiple sensors at a range of over 5000 km. Based on the arrival azimuth, the iceberg(s) generating “Bloop” most likely were between Bransfield Straits and the Ross Sea, or possibly at Cape Adare, a well know source of cryogenic signals.