There are several theories, including that the dolphins may have been upset by some sort of underwater disturbance.
So, er, the underwater creatures may – though we have no idea – have been upset by something under water that upset them.
I’m always reminded at times like this of my favourite bit in How to Get Ahead in Advertising:
Businessman 1: I see the police have made another lightning raid… Paddington drug orgy.
Priest: I suppose young girls was involved?
Businessman 1: (reading the newspaper) One discovered naked in the kitchen…breasts smeared with peanut butter. The police took away a bag containing 15 grams of cannabis resin… it may also contain a quantity of heroin.
Bagley: Or a pork pie.
Businessman 1: I beg your pardon.
Bagley: I said the bag may also have contained a pork pie.
Businessman 1: I hardly see a pork pie’s got anything to do with it.
Bagley: Alright then, what about a large turnip. It might also have contained a big turnip.
Priest: The bag was full of drugs.
Bagley: Nonsense.
Priest: The bag was full of drugs, it says so.
Bagley: The bag could’ve been full of anything. Pork pies, turnips, oven parts… it’s the oldest trick in the book.
Priest: What book?
Bagley: The distortion of truth by association book. The word is “may.” You all believe heroin was in the bag because cannabis resin was in the bag. The bag may have contained heroin, but the chances are 100 to 1 certain that it didn’t.
Businessman 1: A lot more likely than what you say.
Bagley: About as likely as the tits spread with peanut butter.
Businessman 2: Do you mind?
Priest: The tits WERE spread with peanut butter!