@Rampstriker
"We developed the RATS to track the model V22P acoustic transmitter [...] which is specified to transmit a 36-kHz “ping” at 165 dB once every 700–1100 ms. The pulse duration of the ping is 10 ms"
Before people buy the hype from that article, let me remind you that these types of acoustic tracking tags are designed for SHORT TERM deployments on whales allowing for high resolution tracking with suitable distributed receivers.
For example the unit in the above paper lasted for 4 and a half hours attached to the whale.
These types of pingers are NOT deployed for long term detection.
Examples of pingers that ARE designed for long term (mentioned in @overthewing's post) are higher in frequency (62kHz), do not ping as regularly, and and rather low power (~145dB SL). These are used for shark tagging around Australia.
Now I'm not saying the signals detected by Ocean Shield are NOT from acoustic whale tags. All I am saying is it is HIGHLY IMPROBABLE that they originated from a whale tag.