Friday, January 16, 2015

University of Miami Shark Tagging

Teach a Chamorro to fish and he'll likely never work again.
Last year during the Science Online Oceans conference I had the opportunity to go shark tagging with the University of Miami RJ Dunlap Marine Conservation Program.  Last Thursday I had the chance to do it again with my shark conservation colleagues from The Pew Charitable Trusts.

I think about sharks and I write about sharks and I talk about sharks every single day, but I actually get to see very few of them.  Last year I only saw living sharks on a few days (two dives in Fiji, a few dives in Palau, and a snorkel in the British Virgin Islands).  So it's a really special day when I get to go out and see them!

Intrepid Team #1 was made up of the Caribbean Shark Sanctuary All-Stars and the big boss.
The RJD lab has a very strong conservation focus.  The day starts with a conservation briefing on the boat.  David Shiffman did the honors.

David made one really great point in his talk that stuck with me.  There was a government official on a Caribbean island about a year ago who told me that he was part of the ecosystem, and couldn't he regulate the ecosystem as a top predator?  I was speechless, and said I'd have to get back to him.  I've heard about similar sentiments by native American groups on the West Coast who claim that their cultures are evolved in perfect harmony with nature.

David's point was that humans target the healthy, strong individuals in a fish population while sharks mostly eat the weak and sick.  Humans and sharks are very different top predators.  The next time I see that government official, I will have a better answer for him.

From nose to tail, this lemon shark was 197 cm (78 inches). That's about 7 inches taller than me!
The lab allows volunteers to help with taking several measurements and to insert the tags.  They also take blood and tissue samples.  The data is analyzed and used in over 10 different research projects at RJD.  I was able to measure and tag this lemon shark.  Later in the day I was able to tag a nurse shark.

The volunteers also get to help out with the fishing.  The lab sets out a series of drum lines, which are weighted and baited to sit at the bottom.  The volunteers help set the bait with giant chunks of barracuda, then we get to pull in the lines by hand.  I was able to pull in 4 of the 35 drum lines we set, and there were sharks on three of them, including a 260 cm (102 inches) bull shark.  That's a foot taller than Yao Ming!

I think this boat is big enough, but damn that's a big bull shark!
Sadly, it's possible that we'll be the last generation to see some of these species.  The bulls and lemon sharks are assessed as near threatened with extinction by the IUCN Red List, meaning that they are not considered threatened now, but are close or likely to qualify in the near future.  The nurse shark is assessed as data deficient, meaning there just isn't enough data to determine its conservation status.  Overall, 30% of sharks (74 species) assessed by IUCN are threatened with extinction.  Additionally, just over one-quarter (68 species) of the assessed species are near threatened.

The nurse shark has a very beautiful, unique hide
In fact, if you can name a shark species, there's a good chance that it's threatened or near threatened with extinction.  The mako and thresher sharks are threatened, as are great whites, basking, and whale sharks.  The species you're most likely to encounter on the reefs around Saipan, grey reefs, whitetip reefs, and blacktip reef sharks, are all near threatened.

It was extremely exciting and fulfilling to be able to participate in this day of science.  The results from this work will help inform the management of these important predators.  The team of conservationists can't function without the work from the team of scientists.  Also, it was a hell of a lot of fun!

As I write this I'm back in the cold grey of Washington, DC fighting the good fight from behind a computer screen.  The day with the lab was a great reminder of why my team does what we do every day.

Thank you, University of Miami!
And of course it is always great to see Twitter celebrity David Shiffman, who has turned social media outreach into an art form.  The lab also keeps a very active Facebook page and posted more than 50 photos from our day on the water.

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