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June 2015 Newsletter (Tracking Halibut & Monkfish w/ Pop-Up Satellite Tags)

Hey Everyone,

This month's Newsletter highlights one of SeaTag's unique capabilities, tracking demersal commercial species. Tracking fish in the absence of light is considerably more difficult, requires a significant amount of time to develop the appropriate methods, and quite novel. New and exciting science...what more do you want in a story, ha ha.

We hope that these stories will inspire you to think outside the box when it comes to tagging, and we are always here to help with that.

Thomas Gray
Desert Star Systems
tgray@desertstar.com
Alaska: Halibut Tracking
This is an excerpt from Alaska Public Media's coverage on Julie Nielsen's work tracking halibut using our pop-up satellite tags. You can read the full article here.




Image courtesy of Alaska Public Media
Do halibut leave Glacier Bay during the winter and if so, do they return the following summer? To try and answer this question Nielsen attached 25 fish in Glacier Bay with satellite tags [SeaTag-MOD] in the summer of 2013. Nielson is a PhD student at the University of Alaska Fairbanks' School of Fisheries and Ocean Sciences.

Tags scheduled to release in February popped off as expected and began transmitting their locations to satellites. “I was pretty much glued to the computer for weeks after that date,” Nielson said. “The idea was: If the halibut have gone on a spawning migration, their tags would pop off outside the Park.”

All of these tags transmitted locations within the Bay.

“I did not expect that at all; I thought we were going to find some that were out in the Gulf,” she said.

After popping off, Julie was able to recover the tags using the Argos goniometer. Tag recovery is necessary to download the tens of thousands of individual sensor readings (magnetics, accelerometer, depth, temperature, and light levels) that the tags record. While they can transmit raw sensor packets through the Argos satellite system, the bandwidth is limited and the likelihood of receiving 100% of the data is indefinitely low.

You can read the entire story through the link in the first paragraph. We wish Julie Nielsen the best in her upcoming work on her PhD, and if you have interest in tagging demersal fish know that SeaTag devices are your only option.

Iceland: Monkfish Migration Analysis
Google monkfish and your salivary glands will start to...salivate! While I can't recall whether or not I have had monkfish, I can say that at least from my first Google impressions and NOAA information that they are an important commercial species. That and they apparently taste good!

Here are a few interesting facts (pulled from the NOAA link):
a) The tails are generally the only consumed part of the fish
b) Monkfish were the highest valued finish in the Northeast, by the 1990s
c) By 1999, monkfish were deemed 'overfished' and a recovery plan was put in place
d) Monkfish rebounded to a sustainably managed fishery in 2008

NOAA has deployed a number of data storage tags (time, depth, temperature recorders) since 2010, but a search of deployed pop-up satellite tags yielded no results. Fortunately times are changing as technology coming out of Desert Star's lab opens biologists' eyes to what's going on in the deep Ocean waters.
Halldor Olafsson from Biopol deployed a number of pop-up satellite tags [SeaTag-MOD] on monkfish in late 2013, and we had an opportunity to assist in data analysis. We see this more and more now, utilizing inexpensive pop-up satellite tags instead of plastic T-Bar tags, DSTs, and TDRs.
The unique thing about monkfish as related to tagging is that they are demersal fish, and the only time that they see the light is when they're being drawn into the boat. Until Desert Star's SeaTag products came into the market there was not a tag available that could track fish in the absence of light*.

*Acoustic tags are an alternative; however, they are impractical for large scale migration or at exceedingly deep depths.
Halldor has allowed us to share a method that we developed for processing data from one of his tags that utilizes bathymetry data, total field intensity of the Earth Magnetic field, and local magnetic anomalies. You can review that data, in full, along with our methods here.
Copyright © 2015 Desert Star Systems, All rights reserved.


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