Sunday, October 27, 2013

Moorea Reef Sharks Day 7: shark cam trial

26 October, 2013

It was another great day of work in Moorea today!  We started out early, setting the stationary cameras again.  Finding the stakes was a bit trickier today with seriously reduced visibility!  But, Johann and Jeremy made fast work of it, and we soon ducked inside the lagoon to try to catch a blacktip reef shark to deploy the shark cam.  I still wasn’t totally happy with our design so while we waited for the sharks to show up (which took them what seemed like forever) I worked on it.  In the end, I was pretty happy with the field fix and I am now confident that the camera will come off when it is supposed to and that we have absolutely minimized the drag.  Even better, the new design puts the camera right in front of the dorsal fin so it isn’t causing drag on one side of the animal but not the other.

For a while it looked like the sharks were going to win again today.  Four sharks came and went, sniffing the bait and then leaving, for more than an hour before a big female finally bit.  Jeremy got it to the boat and we quickly measured it, took identification photos and samples, then put the camera on.  The release went smoothly and the camera rode perfectly on the shark.  She showed no reaction at all to the camera, slowly cruising away.  Unfortunately, my desire to make sure the camera came off was a bit over-zealous and it detached before the dissolving link was gone.  However, the video showed that the system will work and I am really encouraged by the lack of reaction to the tag.  One more set of tiny tweaks to the attachment and we will be in serious business!!

After getting the camera back it we returned to CRIOBE to refill tanks.  Jeremy and Johann headed back out to get the stationary cameras and Linda and I managed to squeeze in a snorkel since our days are disappearing fast!  The fish life on the snorkel was amazing.  The diversity is wonderful to see and although the coral isn’t what it used to be before the cyclone and the crown-of-thorns starfish outbreak there are signs of a robust recovery everywhere!  We did have one entertaining encounter with a triggerfish that decided it did not like us in its territory…or really didn’t like it’s reflection in the camera lens!

 In the early evening we planned to head out to a nursery area but the weather thwarted us again.  That’s the breaks of fieldwork though!

View from the back of a blacktip reef shark swimming over a shallow sand flat.  There is a whipray in the upper right corner of the picture.
The shark cruises out into a deeper channel in the lagoon.

The shark cam floats to the surface after releasing from the shark as it swims slowly away.

Triggerfish attack!  This triggerfish really didn't like its reflection in the camera lens! Or maybe it was my swimsuit.  It successfully chased the intruder away!

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