issues

Newsletter //

Issue 1 //

February 2010 //

Spring fieldwork

Spring is approaching and many of you researchers are planning your tagging projects. We encourage you to consider the Star-Oddi data storage tags. The whole DST product range can be studied at our website, where different products can be compared in table.

The most popular tags for tagging projects from Star-Oddi record temperature and depth (DST centi TD, milli TD and micro TD). We would also like to remind you of our more specialized tags such the new DST magnetic that records apart from temperature and depth, tilt in 3D and magnetic field strength in 3D. Other options to consider could also be the DST CTD measuring conductivity, temperature and depth and DST tilt measuring temperature, depth and tilt in 3D. Give us a call or write an email and we will make you a fair quote!

Star-Oddi can also provide all needed accessories for the tags for external and internal tagging. You can choose from two different tag holders for external tagging, the traditional tag holder plates or our new tag holder capsule. We can burn a permanent text on the ceramic logger housing stating the return address, email, reward etc.

If you would rather tag internally Star-Oddi loggers are ideal for that too! Star-Oddi tags are housed in biocompatible ceramic housings that are suitable for implantation in living organisms. We will attach a colorful rubber tube on the implants that works as an external identification for whomever catches the tagged fish. Especially the DST micro T(D) loggers are ideal for implantation even in smaller fish.

We are soon ready to launch a new software, PatternFinder, where you can easily compare data from several loggers, analyze the data, import other kind of data to compare the logger data with, e.g. weather parameters and of course find patterns. We will keep you posted on this new software this spring!

Please don't hesitate to contact us with your questions, we are happy to help you with your tagging and other logger needs!

Salmon behaviour in Norwegian sea cages

Salmon production cages at sites with a pronounced thermal stratification give individual fish an opportunity to choose their thermal environment. DST milli TD tags (temperature and depth) were used in a groundbreaking research conducted by the Norwegian Institute of Marine Research in cooperation with the Finnish Game and Fisheries Research Institute in a cage-laboratory in Solheim in Norway (Johansson, Ruohonen, Juell & Oppedal, 2009). The study was first published in Aquaculture journal (2009).

The objective of the research was to study the behavioural responses of individual salmon to thermal stratification in Salmon production cages. Fish were stocked at normal or high densities in production cages and data were collected for total 23 salmon over 4 months period.

There were large inter- and intra-individual variations in swimming depth, with indications that the salmon performed behavioural thermoregulation in an attempt to maintain body temperature within the range of 8–20 °C. Stocking density influenced the average swimming depth and body temperature, indicating competition for preferred thermal space in periods of unfavourably high temperature (towards 20 °C) in large parts of the cage volume. Analysis of temporal behavioural patterns demonstrated a higher variability during day than night and that 60 to 70% of the individuals displayed cyclic diel patterns in either swimming depth or body temperature in at least one out of three sub-periods.

The results are discussed in relation to bio-energetic and thermal stress theory and possible consequences for growth variation in salmon cages. Generally, this study suggests that individual swimming depth and body temperature is in part a response to available temperature interacting with stocking density and time of day. This is the first comprehensive application of tags in a commercial salmon aquaculture setting. The DST milli TD tags display individual behaviours that needs further investigations to reveal dynamics and to ensure individual coping and welfare under commercial production.

Read the full paper here.

Star-Oddi at Oceanology International

Star-Oddi will display its products at the Oceanology Internation (OI) taking place at ExCeL in London, March 9th to 11th. OI is the world's premier meeting place for the marine science and ocean technology community. We wish you welcome to come meet Baldur and Hákon at booth no. K155!

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:

New tag capsule for external tagging!

Star-Oddi now offers a plastic, see through "tag capsule" as an alternative for external fish (or other animal) tagging. The capsule is available for each size of the tags we offer: centi, milli and micro size. The capsule comes with a plastic plate, silicone pads and wire harness. The capsule has holes at each end, to ensure water flow to the sensors.

Did you know that..?

On the16th of February (this year, it is one of those travelling days) Icelanders celebrate the "Sprengidagur". Directly translated sprengidagur would mean the bursting day, but generally this day is known as the Shrude Tuesday in the English speaking world. Actually a variation of this same celebration can be found all over the world, in Hawaii it is called Malasa Day, in Finland Laskiais Tiistai and in France Mardi Gras. The roots of this celebration leads to Christian traditions of having a one last good meal before fasting.

Traditionally in Iceland on Sprengidagur people get together with friends and family to enjoy beans, salted lamb meat and often also yellow turnip and potatoes and eat up to the point of bursting. If you ask an icelander why we celebrate sprengidagur you will probably get as many answers are there is people (circa 320 000).

A popular "holler" today even in Star-Oddi office has been "Saltkjöt og baunir, túkall!", which refers to the price of this festive meal some 50 years ago (a two krona coin). Why do we still keep shouting out the half a century old price is a mystery to me!

We wish you all an enjoyable Shrove Tuesday!