Svalbard – forskernes viktige klimalaboratorium

Click on the Pic­ture and check out the nice arti­cle on Sval­bard and cli­mate research pub­lished on


Det er silda som dominerer blant fiskene i fang­sten som mar­in­bi­olog Jør­gen Berge og dok­tor­gradsstu­dent Svet­lana Pekko­jeva haler opp i Bille­fjor­den på Sval­bard. Silda er en av flere nykom­mere i fiske­fau­naen rundt den ark­tiske øygrup­pen. (Foto: Jan-Morten Bjørn­bakk, NTB scanpix)

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Look back…

By Mor­gan Bender

With over 240 polar cod sam­pled, 30 weeks gone by, and 2.310 bags of pre­cisely pre­pared, weighed, chopped and labeled por­tions of calanus fish food, the long term chronic dietary expo­sure exper­i­ment has come a great dis­tance! Here is a small glimpse into what the sam­pling and exper­i­men­tal design has been like so far.

 IMG_0034IMG_0104Peri­odic mea­sure­ments on all fish in the exper­i­ment has allowed us to mon­i­tor growth through­out the repro­duc­tive devel­op­ment with­out remov­ing the fish from the exper­i­ment. It also gave us a chance to check up on our favorite indi­vid­ual fish progress over the span of many months.


This cold room at Kårvika havbruk­stasjon out­side of Tromsø has been the exper­i­men­tal grounds for the dura­tion of the project. The tem­per­a­ture of the water is now 3 degrees and the air isn’t much warmer, fol­low­ing the tem­per­a­ture vari­a­tions of Kongs­fjor­den on Sval­bard, where most of the fish are from.


Inside the cold room its polar night and has been since Novem­ber fol­low­ing a 79 degree North light regime. That means that work for us is also done in the dark. A total of ten tanks in this room are used for the dietary expo­sure exper­i­ments and are mon­i­tored con­tin­u­ously by tech­ni­cians at the research station.


 Calanus cope­pods are one of the main food items for polar cod and we feed them a lot of it! The dif­fer­ent doses of crude oil are mixed with this bright orange zoo­plank­ton and fed to fish twice weekly, the remain­ing food for the week is untainted calanus. Feed­ing is done by tank and bio­mass of the tank is used to cal­cu­late how much food that tank receives. This amount is adjusted based on growth and sam­pling every 6 weeks.



Fish get sleepy from the anes­thetic used to reduce the stress dur­ing han­dling and to increase the accu­racy of our measurements.


PhD can­di­date Ireen Vieweg mid sam­pling back in the Fall. Down jacket still recommended.











Work has already been done in the lab look­ing at sex steroid hor­mones extracted from blood plasma. This will give us indi­ca­tions of hor­mone sig­nalling involved in repro­duc­tive devel­op­ment and pos­si­ble endocrine dis­rup­tion with chronic expo­sure to petro­leum compounds.




Over the course of the exper­i­ment, smaller sam­pling points using unex­posed fish have allowed us to nar­row in on spe­cific events in the repro­duc­tive process with regard to plan­ning full sam­pling events at crit­i­cal time points.






Sam­ples of gonads have under­gone his­to­log­i­cal analy­sis in pace with sam­pling to closely fol­low devel­op­ment. This meth­ods require deep con­cen­tra­tion as exem­pli­fied by Mas­ter stu­dent Libe Aranguren as she cuts 5 μm slices of tis­sue on a micro­tome using a very shape knife.


PC3-197c 2

Our first results! His­to­log­i­cal analy­sis of female gonad sam­ples from early Decem­ber reveal that fish are near­ing spawn­ing. Yolk gob­ules are form­ing the cyto­plasm of the eggs as female fish invest more nutri­ents and energy into the gonadal devel­op­ment. Tim­ing is most crit­i­cal for females thus we are fol­low­ing their devel­op­ment more closely.


Polar cod in action.



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Quality testing of fish tanks for polar cod

Text: Ingrid Wiedmann

Pic­tures: Camilla Svensen


Every­thing is pre­pared for the qual­ity test of the fish tank

High qual­ity fish tanks are essen­tial for live sam­ples of polar cod to keep the caging effect as low as pos­si­ble for sub­se­quent eco­tox­i­co­log­i­cal exper­i­ments. To ensure proper han­dling con­di­tions, 17 vol­un­teers of the Car­bon­Bridge project ( exam­ined the qual­ity of the fish tank (water tem­per­a­ture, tank size and depth) on 80.5°N, 15°E under the harsh con­di­tions in the Arc­tic Ocean. The fish tanks were found good in all aspect.


Qual­ity test­ing of the fish tank, accom­pa­nied by “King Neptune”



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The Beginning of our Long Term Experiment

By Mor­gan Bender

Chose fish care­fully, anes­thetize effi­ciently, tag tact­fully, mea­sure and weigh accu­rately, place promptly in tank, repeat 700 times!!


This was the lat­est progress on the long-term expo­sure exper­i­ment. Despite the 25 degree sun­shine bless­ing Kårvika, the bio­log­i­cal sta­tion on Ring­vassøya, Jas­mine and I have toiled inside in the cooled 6 degree sea­wa­ter lab. Over the course of 2.5 days, we have placed small rice grain sized PIT tags intraperi­toneally in 716 polar cod, which will be exposed to three dif­fer­ent doses of crude oil mixed with a diet of Calanus over the course of 6 months start­ing in the begin­ning of July. Ini­tial mea­sure­ments of length and weight were taken using a fancy fish mea­sur­ing board that com­mu­ni­cates with an antenna read­ing the tag inside the fish. The polar cod were admit­tedly quiet hardy and accepted the tags with­out much of a flinch in their sleepy state. IMG_1854These fish will be fol­lowed for changes in sex­ual hor­mone lev­els, growth, repro­duc­tive devel­op­ment, and energy, enzyme activ­i­ties, and PAH con­cen­tra­tions in select tis­sues. Most fish are in a post spawn­ing or imma­ture stage with many larger fish in a thin state. We selected fish for the exper­i­ment from the many hun­dred col­lected dur­ing Polar night cruise this Jan­u­ary based on size and con­di­tion, only “aver­age” sized fish with some “meat on their bones”. With 1000+ choices, we hope that our quick deci­sions dur­ing net­ting will bring us closer to an even sex ratio. DSCN2354Our final exper­i­men­tal design includes a few extra tanks than pre­vi­ously planned; an addi­tion con­trol tank was added to be fol­lowed more atten­tively with nar­rower inter­vals between sam­pling events, allow­ing us to time sam­pling of the treat­ment tanks uti­liz­ing base­line knowl­edge from our “pop­u­la­tion” in the lab. We have also included two tanks that will pro­vide infor­ma­tion on sig­nif­i­cance of tim­ing and recov­ery in the response to dietary crude oil expo­sure. One tank will not be exposed until after vitel­lo­ge­n­e­sis, a cen­tral stage in the devel­op­ment of eggs and the other tank will be switched from a high dose to clean food at this same point, thus giv­ing us infor­ma­tion about recov­ery of fish. Cur­rently all tanks are under a mid­night sun light cli­mate with 3 degree sea­wa­ter, these con­di­tions will change with the sea­son to ensure that fish receive the nec­es­sary envi­ron­men­tal queues to sig­nal repro­duc­tive devel­op­ment. With fish hap­pily set­tled in their new homes for the next six months, I start my next task– mak­ing 150 kilos of Calanus J-ello shots laced with crude oil! IMG_1865Mathilde and Mor­gan tag­ging the last 250 polar cod on the last day!!

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Polar cod embryotoxicity to crude oil water soluble compounds

Exper­i­ment Com­pleted: Three days ago, we com­pleted our exper­i­ment. It was not with­out a lot of work and some trou­bles on the way.

After a mass mor­tal­ity that seemed pretty much out of con­trol in all our incu­ba­tors and not at all dose related we were left with too few sam­ples. After barely a week of expo­sure (start of gas­tru­la­tion), we decided over a week-end (it always hap­pens then) to start from scratch again!!!

Not with­out a lot of doubts and ques­tions: Since our rock oiled sys­tem had been run­ning for a week already, con­cen­tra­tion is the water were already very diluted for this new start. Would we see any effects at all? Were we in such low lev­els that even sub-lethal effects would be tricky to see?

We needed to through away (well fix…) all the remain­ing eggs of exper­i­ment 1, to pre­pare the incu­ba­tors for the new batches. But the fish left in our tanks seemed almost all done with spawning…would we find enough of then for a new start? Were we going to throw all away and not get enough eggs and sperm?

We took our courage “under our arms” and just did it!

New strat­egy: Obvi­ously the egg qual­ity was very dif­fer­ent from female to female…basically spoil­ing all the incu­ba­tors if you mixed all the eggs of all avail­able females together. We thus sep­a­rated the eggs from incu­ba­tor to incu­ba­tor, hop­ing that at least some of the eggs would be of good qual­ity and not just die as soon as the devel­op­ment would reach a lit­tle more com­pli­cated stage than division…



And it worked, not with­out the (almost) loss of 2 out of 5 egg batches. But so far the data is really nice…not mor­tal­ity from the treat­ment, but clear sub-lethal effects (see fig). The pic­ture shows bach­e­lor stu­dent Antoine and col­league Mar­i­anne strip­ping polar cod on sun­day evening!

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The Fig­ure shows the larva from one batch of eggs (out of 5) at the end of the exper­i­ment (larva left after all pre­vi­ous sam­plings, etc). The blue bars are the per­cent­age larva free swim­ming in the incu­ba­tors, the red are those (still alive) mal­formed and lay­ing on the bot­tom of the incu­ba­tor. The num­bers on the bars are the total count of larva per incubator.

Click on this link and you will see the heart beat of our eggs: embry­otox



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Polar cod & Petroleum in a international meeting!

What is the sci­en­tific com­mu­nity doing these days in the Arc­tic? What are the chal­lenges and risks for Arc­tic ecosys­tems? What are the effects of petro­leum related com­pounds on eggs, larva, juve­niles and adults? Is the Arc­tic more sen­si­tive than other regions. We are cer­tainly not (yet) find­ing answers to these ques­tions… but by look­ing at a spe­cial Arc­tic fish — the polar cod– from all pos­si­ble angles, we hope to come a bit closer to the answers.

A fan­tas­tic oppor­tu­nity to share knowl­edge and develop new research ideas around this tiny but so impor­tant fish and the chal­lenges of man-made activ­i­ties in the Arc­tic. Click on the pic­ture to down­load the pre­lim­i­nary pro­gramme. Pass this on, every one is wel­come. If you would like to join, send an email to

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2014´s most exciting experiment?

By Jas­mine

Yes­ter­day, we started one of the years most excit­ing experiment..the oiled polar cod embryo exper­i­ment!! I am right now start­ing my 15th hour at work for today (only an hour more than yes­ter­day) and the night is not over yet.… my sleep­ing bag is next to me just in case, but I do hope that I actu­ally can drive the 40km home to Tromsø in about 2 or 3 hours.


After the won­der­ful job Eka­te­rina and Mor­gan did, fish­ing polar cod in the Bar­ents Sea, the last few days have been punc­tu­ated by sleep­less nights won­der­ing whether our catch would spawn unex­pect­edly and thereby just throw away all our efforts to run an embry­otox­i­c­ity expo­sure in the begin­ning of February.

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The last few months, there has been a lot of peo­ple hard work­ing on the design of the study and the set up. The engi­neers at our bio­log­i­cal sta­tion have been doing a great job putting together incu­ba­tors and oiled-rock columns. The pic­ture above shows Mor­gan fill­ing the columns will oiled rocks, that Luca prepared.


Finally the ripe fish were just too ripe for us to dare post­pone the big day one week more: strip­ping and in vitro fer­til­iza­tion was on the timetable. The small group of Flem­ming, Luca, Mor­gan and myself spent much of yes­ter­day find­ing out what we may have for­got­ten for a suc­cess­ful start. We were both ner­vous and impa­tient. I spent quite some time draw­ing a scheme on how the fer­til­iza­tion would look like. How many eggs in that beaker, so much sperm into this vial … I drew the plan at least 4 times, just to make sure I new it by heart and it made sense.

Finally we started and it went just perfect.



Today, for the first time of my life, I saw fer­til­ized polar cod eggs, reach­ing the 2 cell cleav­age stage, and the four and now they are at 32 cells. They are so beautiful.…I feel like a mother.…sleepless nights tak­ing care of the newborn.

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