Aquatic & Fisheries Research

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Aquatic and Fisheries Research

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How do I tag fish? Where do I find tagging instructions?
You can find information on tagging fish on the Aquatic and Fisheries Research page.

What size for what species?
As a general rule the weight of the tag should not exceed 2-4% of the weight of the tagged fish. It is recommended that the logger‘s length is no more than 10% of the fishes length. However, these figures can vary depending of the fish species and is to be decided by the researcher.

Can I reuse the tags?
Yes, Star-Oddi data storage tags are reusable for as long the battery lasts.

Can you replace the batteries?
We offer a battery replacement service for the Starmon products.
For our DSTs it is not possible to change batteries since the tags can only be opened by breaking them.
Contact Star-Oddi for battery replacement services.

How can I customize the housings?
For recapture and return purposes, customers can define their own text on the housings. Please let us know if and what text you would like to have printed on your loggers.

Where do I find updates for SeaStar?
You can find the latest updates to your SeaStar software under Online Support > Software Updates.

I need other temperature/pressure/conductivity ranges than the standard range. Can you help me?
Yes. On our product pages we state the standard calibration range for our loggers but calibration outside of these values is possible. Please contact us with your individual requirements.

Do I need to let you know prior to placing an order where I will be using my tags?
You don‘t have to tell us the exact location of your project if you would like to keep it private. However, in most cases it is helpful for us to know about the environmental circumstances so we can suggest appropriate accessories or calibration ranges for you. All communication with our customers is confidential.

Can I use the same logger all over the world?
Yes, the same logger can be used at any part of the world if the studies require the same calibration ranges.

Can biofouling of my DST CT or CTD affect the measurement results? What are the other reasons for changed salinity values?
Yes, biofouling can affect the accuracy of the salinity sensor. Below you can see a list of possible reasons for incorrect recordings.

Please, note that Star-Oddi doesn't offer warranty for loggers that have been affected by these factors since they are not caused by a failure in the recorder but by changes in the environment of the sensor.

Air bubbles in the cells (sensor plates in the cup) can drastically change the results. Therefore it is essential to make sure that no bubbles are caught inside the cup when deploying the recorder.
This is especially problematic in shallow waters, where waves can capture a lot of air.
Changes in the water temperature - especially in shallow, calm waters - or difference in temperature between recorder and water when deploying can cause release of oxygen that can cling to the cells. Often this is a gradual build-up in a calm environment.
Sudden jumps in the measurements indicate this problem, showing the time of release of the bubbles from the cells.
Air bubbles atttached to the cells usually lower the conductivity measurements.

Oil can attach to the cells and cause changes in reading. This can create a thin film on the cells giving rise to an offset in the readings, that will stay with the recorder until the cells are cleaned.
Measurements can be corrected in SeaStar by applying an offset value to the measurements.

Algae can attach to the cells and change the measurements gradually, ususally lowering the conductivity measurements. To correct the measurements the user can apply a linear adjustment over the time period in SeaStar. (See under ‚salinity linear adjustment‘.)

High salinity, high mineral and metal content in the sea and unusually high temperatures will give rise to fouling and corrosion. The cells themselves are highly resistant to corrosion but under extreme conditions this may change the cells‘ characteristics in a similar manner as algae.

The measurement circuitry changes gradually with time (over years), this can be seen as an offset in the measurements.

Cleaning the cells with strong solvents
Applying strong solvents on the cells can change the cells‘ characteristics from the way they were calibrated. This can be seen as an offset, usually with a shift to higher values. SeaStar offers a solution to this problem by applying an offset value to the measurements. (See under ‚salinity offset adjustment.‘)

Small cracks and holes in the housing may introduce moisture in the recorder which can result in erroneous measurements. Usually, the pressure and conductivity measurements are most vulnerable to moisture.

Circuitry damage in recorder
Shock and hard bumps can give rise to cracking of soldering points on the circuitry board and/or of the connection to the sensors.
This can be seen as an offset , usually with extreme measurement values.

Despite the risk of biofouling we do not reccomend the use of any anti-biofouling products because they can harm the marine environment and cause damage to the sensors.

Do you sell dummy tags?
Yes, Star-Oddi sells dummy tags for all DSTs. Fur testing purposes we can place a weight inside the housing to imitate the real weight of the tag. Please contact us with your request.