Brendan Talwar

A crowdfunded ecology project byBrendan Talwar

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Field Update #1

Lab Note #8
Aug 05, 2014
Hey everyone!

It has been quite a while since I last posted and a lot has happened over the past few months. I'm now in Eleuthera, The Bahamas and we just finished 'Shark Week', a weeklong camp for high school students interested in hands-on applied research. These students were out with us as we did our first drop at 560 meters and witnessed some of the challenges we're facing firsthand. To the right is a photo of the crew with my buddy Ian and a Caribbean reef shark we caught, as well as an evening program with some visitors.

The two weeks leading up to this program were devoted to preparation: building the cage, gangions (the fishing gear which attaches to the mainline), organizing, and repairing anything that needs it. These are often the most challenging steps for me as I quickly run out of patience from gear not doing what we bought it to do! Thankfully everything is now set to run properly and we are just waiting on the wind to die down before attempting our second longline set and cage drop.


Our first attempt with the longline went quite
poorly. We dropped the line in the morning and had everything set up to haul it around 11 AM late last week. Soon after firing up the pot hauler, which pulls the line up from the bottom, the boat engine began coughing. In need of a new fuel filter, we had to rev the engine to power the hauler and in doing so heated the hauler's electrical wiring to its melting point. After switching boats and leaving the hauler at the dock, we again picked up the line and began hauling it by hand one meter at a time. Unfortunately, the line was stuck. We pulled on it for around an hour, driving the boat forward with the line tied off on a cleat until we had enough slack to gain anywhere from 10-50 meters at a time. As you can imagine we were all worried- losing a longline with accelerometers attached is not the way to start a field season. Eventually the line went slack and we all feared the worst. A few kids hopped in and a while later shouted up to us; the gear was still attached and on the way up. Our lines have a 'breakaway' point near the anchor, designed to pop off in the event of a hang-up. That point saved us and we got everything back, including the head of a Mustelus canis, the dusky smoothhound. The shark was eaten by what is likely another shark on the bottom. Despite the problems, the first data from this project  came up with the broken line- accelerometer data measuring hooking activity and capture duration from the point of capture until the point of predation. All in all, the drop was a success. We made a few improvements, will not set a longline in that location ever again, and collected our first information on deep sea shark hooking behavior.


While I don't yet have any photos or video of a shark in the cage, this is the view from inside which will soon be at the bottom of Exuma Sound!

Thanks again for your continued support, and I'll post another update in a few weeks.

Best,
Brendan
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