You could train an llm on all existing whale sounds, get it to “listen” to live whales and respond with what it “thinks” it should, then do human analysis on the results, maybe find one shred of meaning, rinse and repeat.
That assumes that the speaker is similar to the person correlating the sounds. For example, if you had statistical data for utterances of English sounds in the context of Magic the Gathering tournaments, and you tried to decipher the speech of a Swahili electrical engineer talking about transistors, you could very well decipher something that's seemingly coherent but entirely incorrect.
It would be an overgeneralization to assume that whales speak about things in the same statistical patterns that humans do.