Homing Basking Sharks! Tag Found on Scottish Beach


Manx Basking Shark Watch Scientists have proved that some individual basking sharks revisit summer feeding grounds in Manx waters and winter feeding grounds off Morocco. Last month Dan Calvert found a tag from one of these sharks on a Scottish beach.

You may remember that the Manx Basking Shark Watch scientific research team put a Wildlife Computers SPOT satellite tag on a HUGE bulky 8m long female basking shark on 7th August 2015. We nick-named her DONG MEGALODON. See more about her at http://www.wildlifetracking.org/index.shtml?tag_id=129180. After feeding on the surface for a few days she confounded our efforts to track her by staying underwater for a whole year, but we were delighted when she displayed site fidelity (i.e. she came back to the same site 2 years running) by reappearing in the same area that she had been tagged almost exactly a year after she was given her tag. A couple of days after returning to Manx waters Dong Megalodon shed her tag. We do see courtship behaviour in that area so she may have been rubbing up against another shark, causing the tag to come off.

See pictures of Dan Calvert with the retrieved tag and Dong Megalodon with her satellite tag.

The same day that we tagged DONG MEGALODON we tagged FLOWRIDER, an 8m long male basking shark. He has returned to the same winter feeding grounds off Morocco two years running. See http://www.wildlifetracking.org/index.shtml?tag_id=138610

DONG MEGALODON’S tag finally settled on a Scottish beach where it was found by Dan Calvert in April 2017. He very kindly declined the £50 reward saying “Please keep that for all the valuable work you are doing”. Dan has had an interest in basking sharks since visiting SW Scotland as a child in the 70’s. Dan says that ‘they were once a regular sight to the fishing village of Garlieston (as happens 20km west of where I found the tag), and I had the privilege of seeing them from there a couple of times.