Newsletter // Issue 7 // September 2013 // 



Brown Trout tagged with DST-magnetic featured on Animal Planet

When the final episode in series 5 of River Monsters on the Animal Planet was released in beginning of summer 2013 it grabbed 2.2 million record-breaking viewers. The episode was dedicated to the Loch Ness Monster, but other giants are introduced as well. One of them is the big brown trout in Lake Thingvallavatn that drew the attention of the River Monster Team and they decided to pay the king of Icelandic freshwater fish a visit when in Iceland. In the program, the biologist and host, Jeremy Wade, meets Johannes Sturlaugsson from the Icelandic research company Laxfiskar when Johannes is tagging brown trout with a data storage tag (DST).

The tag used is of the type DST magnetic that records the compass direction of the fish as well as the fish depth (pressure) and temperature. The tagged fish was a 15 pound male; the DST measured its behaviour and environment throughout the feeding migration during the summer and the beginning of the spawning migration. Johannes captured the fish on October 11th where it was fighting for females at the spawning grounds in River Oxara that runs into Lake Thingvallavatn. The data from the DST gave an insight into dial feeding activity of the brown trout. The directional data was gathered from a subsampling period of 2 days during the summer with a measuring interval of 10 seconds.

Johannes Sturlaugsson has used data storage tags from 1999 to monitor the migration and activity of brown trout in Lake Thingvallavatn and adjacent rivers throughout the year. The longest continuous recording for one fish gave a record dataset of 4 years ranging for Autumn 2003 to Autumn 2007 and the biggest trout tagged was 27 pound.

                 

Product in focus: Tilt measurements in 3-D

Star-Oddi‘s DST tilt measures tilt in three directions, depth (pressure) and temperature, it has an accuracy of +/-3° over a range of +/-180°. The DST tilt data logger has been on the market for a few years and has been well received by scientists worldwide who are doing studies on, for example, fishing gear and valuable underwater equipment for orientation studies at different depths.

Star-Oddi has been using accelerometers in the Data Storage Tags (DSTs) for several years, giving tilt angle in degrees. The user can view the accelerationed data (m/s2) in the application software, SeaStar, in addition to tilt angle and other measured data (depth and temperature). To get information on velocity it's possible to use the PatternFinder analysis software.

Star-Oddi has designed a special adjustable housing for securing the logger. The housing has a mounting bracket inside where the logger can be immobilised, preventing it from rolling inside. The shape of the housing is designed so that it can be bolted to a flat surface or strapped on a cable. Housing material is robust polyethelyne.

For more information, please visit the DST tilt product site.

 

Star-Oddi Online

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See you at ICES in Reykjavik

ICES (International Council for the Exploration of the Sea) Annual Science Conference will be held in Reykjavik, Iceland, 23-27 September.
 
If you are attending we welcome you to visit our booth at the Harpa conference centre where Star-Oddi will display its wide range of small data loggers in the DST and Starmon series.

An Atlantic wolffish tagging project in which Star-Oddi participated with the Icelandic Marine Research institute is also introduced at ICES. The objective of the project is to locate the spawning grounds and the migration pattern of the Atlantic wolffish using DST milli-L temperature and depth archival tags.


Data Storage Tags - DSTs

Star-Oddi has been manufacturing and developing DSTs since 1993. The data loggers are used for various studies, such as fish tagging, fishing gear studies and oceanography. You can find our whole product range here. The following sensors are available:


Fun fact: Very superstitious

Despite being a very modern society, the belief in supernatural creatures such as elves and trolls is still quite salient in Iceland.

Elves or the Hidden People as they are known in Iceland feature prominently in Icelandic folklore. They are thought to live in rocks and cliffs and earn their living as farmers. It is considered to be very dangerous to disturb them and this superstition still affects life in Iceland today. On numerous occasions the construction of roads and buildings has been altered in order to prevent the removal or damage of rocks which are believed to be inhabited by the Hidden People.

Trolls are believed to live in caves and canyons. In some stories the trolls are good-natured and kind, but in others they are described as man-eating monsters, the most notorious being Grıla, the mother of the 13 Icelandic Yule Lads. One species of trolls are the "Night trolls" that turn to stone if they are exposed to the sun. It is a common pastime when travelling around the country to look for peculiar rock formations and try to discern the figure of a hapless night troll that didn't make it to their cave before sunrise.


 




Star-Oddi | Skeidaras 12 | 210 Gardabaer | Iceland | Tel: +354 533 6060 | Contact  | www.star-oddi.com
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