The first satellite tag deployed on a very cooperative 6 m male shark
The first of the satellite tags was also to be deployed at the end of the week and the modified MK 10 PAT tag from Wildlife Computers was made ready to go on its voyage of discovery... the trouble was that David wanted to put it onto a large shark (larger than 5 m) and with eager camera teams waiting to film the process it had to be a very slow moving shark, in fact preferably one that wasn’t moving at all so that everyone could get their photos!
So with this in mind the teams set out in the afternoon to find a shark to meet David’s exacting needs which seemed to be a bit of a tall order as most sharks being found were around 3 metres in length.However, finding slow sharks proved not to be a problem as the afternoon feeding aggregation was kicking off nicely and many sharks were already into vertical feeding mode where they stay stationary for several minutes at a time just gulping in great mouths full of plankton....
Fortune was smiling and a 6 metre male shark was found placidly vertical feeding off Acacia Beach who didn’t even flinch as David attached the tag.... in fact the shark ignored the whole process and just continued gulping which seemed a little ungrateful! So the first tags is out and alive and we hope to start to get regular updates from the tag as well as its full story when it pops off in three months time.
Talking of gulping plankton, the team has been busy trying to find out exactly what the sharks are gulping by running surface plankton tows and conductivity, temperature and depth profiles.... these too had to be modified from the standard five minute tow to a much shorter two minute tow as the volume of plankton being collected was simply too much to process and we had a limited number of plankton sample pots! What was very apparent was the high number of arrow worms (chaetognaths) and sea-butterflies (pteropods) present which are regarded as prime whale shark food in the Seychelles; and while we don’t yet know the species of the arrow worms these guys were huge compared to those found in Seychelles and so it’s no wonder the sharks here seem to be in vertical feeding mode so often.... all will be revealed when the samples get to the lab!