First tags

Posted on 19 September 2012  | 
Over the past two weeks, three large yellowfin tunas caught by handline were tagged using a pop-up satellite tag, and released back. This is part of the 16 tags that will eventually be put in the water, anchored into the back portion of the fish just below the second dorsal fin.

Once in the water, the pop-up tags automatically collect and store information on water temperature, depth, and amount of illumination from which its location is derived. The information are recorded every 30 seconds and stored in its memory. The tags automatically detach from the tuna after a pre-program duration between 4 to 6 months. Upon release, the tags will float to the ocean surface and send information using satellite technology to a server in Los Angeles, California.

The tuna handline fishery operates only during the dark phase of the moon and once the catching begins and the weather cooperates, the tagging will resume. The first tagging event was hampered by uncooperative seas and the tunas didn’t take the bait.

Hopefully, in the next two weeks, we will have all the remaining tags in the water.

Posted by Jose Ingles (Jingles)
Tuna being tagged with a pop-up satellite tag off the coast of Mindoro, in the Philippines.
© Jose Ingles / WWF Enlarge

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