Monday, October 29, 2012

Time Heals All Wounds...

Join Intern Savi on some sharky musings...

Time Heals All Wounds... Whether Chaucer was talking about emotional or physical wounds, we know one thing is true; time is definitely a plus for the physical. An integral section of the whale shark monitoring program involves the identifying of large spotty fish for population dynamics around the island of Mahe Seychelles. However, each encounter also involves the collection of pictures of each nick and abrasion of our hungry friends. With years of post-traumatic evidence in our database, we are able to track the healing progress of our recaptured sharks. 

Why am I rambling on about what you avid whale shark blog readers already know? Because lately I’ve been assigned to a side project which handles this graphic library of wounds and must assign a label to what each shark has encountered. Speed et al. 2008 have done this with several whale shark aggregations (Australia, Seychelles and Mozambique) and have compiled a list of categories for each scar to go in. Long story short (although a very interesting read), major and minor are the two classes of categories; major being anything life threatening and minor being any shallow or superficial scrapes if you will. 

Sey2010.031 as seen in September of 2010 with some very painfull looking lacerations across the gilll slits.

During our week long whale shark extravaganza, a not so curious shark was encountered with. With the encounter code being kept, all guests were on the right side and as spotter I was desperate to get to the left for proper ID shots. Upon much frantic swimming, I achieved reaching the left and that’s when I saw it; a rather impressive dent upon the gills. After quickly snapping photos, the shark dove and the encounter ended. The next morning, the photos were I3S’d and lo and behold; Sey.2010.031 was our mystery shark. Every photo (left gill shot, left fingerprint, right gill shot, right fingerprint and the healed scar) was put into its respective folder in the Iris database. When reviewing past scar photos, we can see the gruesome lacerations upon the gill slits. 

Why is this exciting? At 14:50 on Sept. 7th. 2010, the 31st new whale shark of 2010 was encountered off Matoopa Point and seen with a life threatening gash. Trauma around the head and gill slits can severely affect the life span of Rhincodon typus seeing as this particular injury hinders the proper filtering of the nutrient he seeks in our rich Indian Ocean waters. But ho! What was thought to be a doomed shark hath now returned to Mahe to feed and be a part of the magnificent Seychelles aggregation (though not so magnificent around Mahe this year). He was seen again off South Mahe on the 17th October alive and doing very nicely, thank you!
Here he is this year with the lacerations healed up, though not the prettiest of sharks!

We can extrapolate from this that perhaps this injury was not Seychelles related but on his crossing over to feast around this tropical archipelago. Which unfortunately strengthens the question of where do these magnificent creatures go when not partaking in planktonic feasting. This gauntlet of predators and boats; where does it lie and how often does it occur? Satellite tags have of course given us a clue and hopefully more tags to come.  Here’s to many more years of research and heartier aggregations with tagging for mapping of this migratory creatures. Here’s to you sey.2010.031; hope you come back next year!

Savinien Leblonde, 2012 whale shark intern.

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