An AMAZING day for (putative) basking shark courtship behaviour
3rd July 2008 What a day for Basking Sharks, maybe it has something to do with the new moon. For the first time in a fortnight, the weather was really good for shark watching and we set up our telescope at about seven in the morning, A mother Harbour Porpoise and her calf swimming slowly and peacefully off the harbour mouth at Port St Mary. The phone rang and some neighbours had seen a large shark in Perwick Bay just off Kallow point. Sure enough, there it was slowly swimming in the tidal flow, a large shark more than 20 feet long giving me a show for more than an hour. Another Harbour Porpoise and her calf swam close to it before scurrying off. Bob Taylor had been to the Sound and spotted sharks there too.
We set off in Happy Jack from Port St Mary and with a helpful tip-off from Malcolm Kelly, we found about 12 sharks about a mile off Glen Maye. We stayed with them for nearly 3 hours, as they slowly moved offshore and towards Contrary Head. This proved to be a wildlife extravaganza, sharks close following, swimming in groups of up to five. Close to the boat and a number of times right alongside. One came right up to my pole camera stopping only an inch or two from it. The spectacular experience continued with sharks breaching clear of the water FOUR times. Thankfully they were a good way off but the sight, noise and the splash from this is a stunning event. We stayed there for over three hours just watching and letting the sharks go by. This was the most amazing day for courtship behaviour.
Not only did we have the four breaching sharks, we had TWO groups of sharks displaying what scientists describe as ‘putative’ courtship behaviour for nearly three hours! One of these groups was of 3-4 sharks close nose to tail following (less than ¼ of a shark body length apart) and the other was of 2-3 sharks doing the same. Occasionally the group of 3-4 sharks was swimming parallel but one slightly behind the other. There were 2 aspects of the courtship behaviour that were very interesting. There were several sharks involved intimately with the close following that I would have thought were slightly small to be involved in courtship behaviour. They were 18 foot long. The other aspect that struck me was that the behaviour was so consistent over such a long time.
On other occasions when we have watched courtship behaviour the courting sharks have swapped between parallel swimming and nose to tail following every few minutes. VERY interesting. We look forward to reviewing our video footage in the morning. Gannets, harbour porpoises, jelly fish, the fish-finder full of echoes. The sea was alive. I cannot remember a better day with the sharks, a wonderful experience and the sight of those breaching sharks still plays in my mind. We were joined by Claire Pickett, an undergraduate Marine Biology student from Newcastle University. I don’t think she knows exactly how unusual her day out with our Manx sharks was! MANY thanks to Mal Kelly for towing us back to Peel when our engine packed up temporarily due to dirty fuel (oh the joys of boating)!