A premature tuna tag recovery is a blessing in disguise



Posted on 10 December 2012  | 
A recovered tuna tag
© WWF / Jose InglesEnlarge
Upon learning that one of the tuna pop-up tags had been found, my immediate reaction was one of disappointment, due to the potential loss of important data I was hoping to get.

The great expense of the tag and time invested in getting the tag on the fish, plus the added expenses for the reward money, and the refurbishment of this tag made it all depressing.

But today, upon receiving the newly refurbished tag together with all the information it collected, and looking at the notes I got from the interview with the fisher who returned the tag, I realized some really positive aspects to this premature tag recovery.

For one, we have an idea of how intense tuna fishing is in the region. As I will discuss in the next blog entry, the amount of handline fishing of large tunas in the area, and for that matter, in the Philippines, is enormous beyond belief. That handline fishing is inherently sustainable is not entirely correct. I will explain this in my next blog entry too.

The news of the captured tuna with an attached tag caught fire. The news of a reward paid for the tag (equivalent to the value of the fish) spread like wildfire. It solved 2 of my main challenges for this study:
  1. formerly skeptic fishers will now probably sell their tunas for tagging in the future (these are fishers who believe that tunas released with a tag are hurt, and may alarm other tunas, causing them to migrate someplace else, never to return)
  2. buying tunas for my next expedition will probably be easier with no need for costly consultation meetings, since all boats in the area are now aware of my tagging activities.
But I believe the most interesting benefit for me came with the process of dealing with the tag manufacturer in California. In asking them to reprogramme and extract the data from its memory, I learned a great deal about the tiny details of the tag, how it is programmed, and the technology inside it.

Imagine that it is capable of recording data at 10 second interval for 6 months! It’s amazing to think about how much storage space it contains, and what kind of power is used to support these technologies!

I even learned the tricks to ship the tags in order to avoid the customs duties and comply with the stiff security requirements. Yes, this tag is shaped like a micro-torpedo!

Because we were able to recover the tag, we obtained all the data in binary format stored in its memory: all 24,480 rows and 6 columns (think of an Excel sheet)! Contained in its memory are temperature and depth profiles, summarized in batches for every 30 seconds, and light intensity measurements for every 2 minutes.

Oftentimes, our knee-jerk reaction is one of despair when something fails, but we need to see that the other side of any setback is positive opportunities.

Posted by Jose Ingles (Jingles)
A recovered tuna tag
© WWF / Jose Ingles Enlarge

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