Getting to and from the vessel by a small rubber boat can be challenging when the waves are high. (Photo: Charlotte Price Persson)
Captain Jesper on the bridge, Dana’s command centre. (Photo: Charlotte Price Persson)
Staff quickly learn how to arrange their fish lab kit so that they can quickly hop in and out of the lab. (Photo: Charlotte Price Persson)
You cannot get fish much fresher than this! (Photo: Charlotte Price Persson)
Some lengths are well represented while others are more difficult to find. This in itself says something about the well-being of the fish stocks, as fish grow at a fairly predictable rate. (Photo: Charlotte Price Persson)
Scientists can tell how old the fish is by studying its otolith—a calcium carbonate structure in the inner ear. It is just like counting tree rings. Scientists remove the otolith of this cod with a pair of tweezers. (Photo: Charlotte Price Persson)
The by-catch consists of the fish that the scientists do not use. They throw them back to sea, even if the fish are dead. (Photo: Charlotte Price Persson)
The scientists are looking for fish of different lengths to get a broad overview of fish stocks. So it is exciting when they find a fish of a new length. (Photo: Charlotte Price Persson)
Fish quotas in Denmark are set on the basis of the data collected during these cruises. (Photo: Charlotte Price Persson)
The Baltic Sea is brackish water with very little salt. This means that you typically do not catch jellyfish and crabs. In general, they catch lots of plaice, mackerel, and cod, even though cods have long had population problems. (Photo: Charlotte Price Persson)
...the fish lab. Here, scientists and assistants are ready to sort the fish. The uniform is a pair of overalls and a tall rubber boots, and of course some proper gloves. (Photo: Charlotte Price Persson)
The net is lifted up and emptied into a shaft that leads to… (Photo: Charlotte Price Persson)
Perhaps unsurprisingly the ship is popular with seagulls when they are out fishing. (Photo: Charlotte Price Persson)
Dana maintains a constant speed for hours at a time when the net is cast behind the vessel to collect fish. (Photo: Charlotte Price Persson)
The trawling net is deployed several times each day. (Photo: Charlotte Price Persson)
Dana sets out to cruise the Baltic Sea with the same crew and changing roster of scientists, twice a year. Here you can see the trawler net being prepared. (Photo: Charlotte Price Persson)
Equipment is deployed to measure oxygen in various parts of the aquatic environment. (Photo: Charlotte Price Persson)
Scientists work 24/7 on board Dana. Their tasks include catching jellyfish. Here, technical assistant Bastian Huwer, otherwise known as “Basti,” has started to prepare the jellyfish net that are typically used at night. (Photo: Charlotte Price Persson)
Dana is a 78 metre-long research vessel. It spends approximately 260 days at sea each year. Click on the photo to open up the gallery and see more pictures of life on board Dana. (Photo: Charlotte Price Persson)

Come aboard Denmark’s largest research vessel

ScienceNordic was invited aboard research vessel Dana to join its regular expedition in the Baltic Sea.

Charlotte Price Persson

Twice a year, Denmark’s biggest research vessel Dana sets sail on the Baltic where the scientists determine the size and health of fish stocks and help to set the fish quota for the following year.

ScienceNordic lent a hand and followed the scientists’ progress during one weekend of the one month trip.

The crew work 24 hours a day when the ship is at sea. Running Dana is an expensive operation, so the time spent aboard needs to be well spent. Each day, the crew catch fish and sort them inside the “fish lab.”

You can see the fish lab and explore Dana in the gallery above.

In the evening, the crew are busy collecting samples of plankton, jelly fish, and other small animals.

When the fish reach the lab, they slide down a chute onto a conveyor belt where the scientists are waiting to sort them. Some fish are taken for age-determination, while others have samples taken to be used for research projects back home.

Dana also sails out to the North Sea on these biannual trips, and to the Norwegian Sea where scientists are studying herrings and mackerel populations.

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Read more in the Danish story on Videnskab.dk

 

Translated by: Catherine Jex

the oceans videnskab.dk ecology denmark agriculture and fisheries agriculture & fisheries fisheries management
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