This appears to be referring to dead whales that explode because of a buildup of gases inside the animals. In some cases, the gases can escape through the mouth or anus.
Interested in Language
I have not actually understood the following statement. I'd be grateful if someone could explain it to me. :)
"...until the pressure is released through some weak point," he says. The weak points are often ones that are already in place, such as a whale's mouth or anus."
That happens to me a lot, and I'm still alive.