Check out this footage shot by Russel Hird on the north west coast of Lewis in the Outer Hebrides. The basking shark behaviour seems to be swimming close to shore and then ends up washed on the beach flopping around before it gets taken back out to sea.
The sharks are known to breach clear of the water, thought to be potentially getting rid of parasites and it has been suggested that they could abrade themselves on rocks to do the same. However the risk to shark being in so close must be too much. Why would it choose such a risky place when it could easily do so underwater? Was there such an annoying itch - it had to scratch it!!? The swimming pattern seems to indicate that it wasn't in poor health and it doensn't seem to be trapped with a clear exit to open water.
However during the video you can see the shark has a number of scrapes along its nose and belly, indicating that it had abraded itself already. So could this be a sign of being unhealthy in the same way a cetacean would strand?
With so little known about the sharks could this be a behaviour unseen by science?
Answers on a postcard.