12,000 shark teeth found in aquarium substrate


When staff at Blackpool Sea Life centre drained their ocean display tank for refurbishment, they were amazed to find more than 12,000 shark teeth in the gravel bed.

Sharks shed their teeth at regular intervals, but staff were still shocked at just how many teeth they found, the number having built up over almost 25 years.

The teeth have been handed to scientists at the University of Birmingham. Oxygen atoms in the discarded teeth can reveal the temperature the sharks lived in, and a University of Birmingham research team hopes by studying them it can perfect the technique for use on fossil shark teeth.

Establishing the prevailing sea temperatures can help explain sudden crashes of marine species as well as sudden evolutionary spurts in prehistoric times.

"The principle has already been used by several research groups," said research lead Dr Ivan Sansom, a senior lecturer in palaeobiology from the University of Birmingham.

"By examining the teeth of sharks whose water temperature has been carefully recorded, we can refine the technique to make fossil studies more reliable," he added.

Dr Sansom’s students began their probe a year ago using just the few teeth collected occasionally by Sea Life centre scuba divers.

Now the emptying of Blackpool Sea Life’s ocean display for the first time in 23 years has delivered a windfall that meets all their research needs.

"We have teeth from every shark species that lived in the tank, including lots of Sand tiger teeth, a species that hasn’t featured in the display for over eight years,’ said Dr Sansom. "Most sharks have rows of teeth and shed them regularly. The biggest number we have are from Black-tipped reef sharks, but that’s hardly surprising since this species sheds a whole row of over 40 teeth every month."

Blackpool Sea Life senior aquarist Scott Blacker said: "We always found a few teeth whenever we dived in the tank, but we were all astounded just how many were lurking in every handful of gravel.

"It's a delicate job sorting them out, because they tend to be the same colour as the gravel and easy to overlook.

"It's great to know that our sharks are helping some really pioneering research."

The sharks from the Blackpool display have been temporarily re-homed in aquaria at London and Weymouth while the refurbishment is under way. It's expected that they will return to their new look home in March.

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