Newsletter // Issue 5 // November 2009 // 

NEW DST magnetic

Star-Oddi is proud to present the first new generation magnetic field strength logger, the DST magnetic. The DST magnetic measures apart from temperature and depth, tilt in three directions and magnetic field strength. The magnetic field strength is measured in three directions providing relative reading of the magnetic field strength at each point. These measurements along with the tilt measurements are converted to compass heading readings in the supporting SeaStar software. Magnetic field inclination is also calculated for each reading.

By comparing the recorded data to known hydrographic and geomagnetic field data on the globe, the researcher can gain e.g. new insight into geolocation of fish that migrate over long distances.  DST magnetic was develeped in co-operation with IMR of Norway. Read more about the product here in Star-Oddi website.

The earth's geomagnetic field and geolocation of fish - NEW approach!

The first results of the new approach on geolocation of fish were recently presented at the annual ICES (International Counsil for the Exploration of the Sea) conference in Berlin by Hagen Stockhausen (Institute of Marine Research, Bergen, Norway).

The DST magnetic is the first implantable logger to measure magnetic field strength in 3D that can be used in tagging fish and other marine animals. The information gathered on the earth's geomagnetic field with the DST can be compared to magnetic field models, such as  the IGRF (international geomagnetic reference field) in order to track the migratory patterns of the tagged animals.

Experimental work was carried out at the University of Bergen where DSTs with a sensor for magnetic field strength were calibrated using coil-generated artificial magnetic fields. Additional measurements were carried out to control the temperature drift of the DSTs. The first version of DST magnetic was then tested further. The first conclusion of a migration simulation yields that the method can help to locate broad scale fish migration paths. Hagen Stockhausen's poster on this can be read here in whole.

NEW Scientific paper on Atlantic salmon migration in relation to magnetic field

A migration study on the homing behaviour of Atlantic salmon was carried out in waters off SW-Iceland in 2009 by Johannes Sturlaugsson. The first results were presented in a scientific paper "Orintation of Homing Atlantic Salmon Mapped in Relation to Geomagnetic Field" released at the ICES conference. The study was carried out by Salmon and Trout Research in co-operation with Star-Oddi and the Institute of Marine Research in Norway.

The main objective for the scientist in charge, Johannes Sturlaugsson at Salmon and Trout Research, was to bring to shore new valuable information on the homing migration of the Atlantic salmon in sea, especially on the orientation and navigation. These objectives were met and further salmon tagging with DST magnetic will be carried out in the future. Sturlaugsson states in the abstract that "by taking advantage of this new research tool [DST magnetic], we have managed in this study to bring forward new information on salmon orientation."

In the study the DST magnetic was used to measure the earth's magnetic field strenght and fish tilt in three directions, fish depth and ambient temperature. In August 2009 nine salmon were tagged externally to follow up their homing migration in coastal waters. The first two salmon finished their migration from release site to home estuary (shortest seaway = 123 km) in roughly 4 days. The recovered DSTs from these two fish had recorded throughout their migration with 30 sec interval. The data from these two tags was used to present the first results from the study in the fore mentioned ICES paper. Later on five additional fish were recaptured giving a total recapture rate of 78%. The total data set will be analysed further this winter. Also some further calibration will be performed to the recaptured tags in order to get the absolute geomagnetic values (magnetic field strength) from the data.

You can read the scientific paper

here.

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:


Update your SeaStar online!

We recommend all SeaStar users to keep their software updated. You can always find the latest update on our website. Version 4.371 is available now, get it while its hot!


Did you know that..?

16th of November is the day of the Icelandic language and it was celebrated widely all around Iceland.

Many children in Reykjavik had prepared poems, stories, and even short films to participate in the yearly "Icelandic" competition held for the elementary school students. The aim of the competition is to encourage all Icelandic children, and foreign as well, to explore, challenge and use the Icelandic language in an imaginative way. 

The patron of the competition, former president of Iceland, Vigdís Finnbogadóttir awarded over 70 students in the Reykjavík city hall.

For those of  you who want to have a go at Icelandic you can find easy Icelandic language lessons on line in You Tube here.

Have fun! Skemmtið ykkur vel!

Star-Oddi | Vatnagardar 14 | 104 Reykjavik | Iceland | Tel: +354 533 6060 | Fax: +354 533 6069 | Contact  | www.star-oddi.com