Ex­treme div­ing in icy wa­ters — cru­cial to Arc­tic re­search

The China Post - - FEATURE - BY CILINE SERRAT

How do al­gae re­act to the warm­ing of the Arc­tic Ocean? How is it af­fect­ing wildlife in the fjords? To find an­swers, re­searchers rely heav­ily on divers who brave the icy wa­ters to gather sam­ples.

“With­out them, we wouldn’t be able to suc­cess­fully com­plete our projects,” ad­mits Cor­nelia Buch­holz, a marine bi­ol­o­gist who is work­ing at Ny-Ale­sund on Spits­ber­gen, the largest is­land of the Sval­bard ar­chi­pel­ago in the heart of the Nor­we­gian Arc­tic.

Un­til the start of the 1960s, this town — the north­ern­most per­ma­nent hu­man set­tle­ment in the world — was pop­u­lated by coal min­ers.

To­day it is en­tirely ded­i­cated to science.

Be­tween mid-April and the end of Au­gust when the sun never sets, dozens of re­searchers stay there.

The site, which cep­tional fa­cil­i­ties boasts de­spite ex­its ex­treme lo­ca­tion just 1,000 kilo­me­ters ( 600 miles) from the North Pole, has a unique win­dow on cli­mate change, the ef­fects of which are far more pro­nounced in the Arc­tic re­gion.

Un­der wa­ter at Ny- Ale­sund, ris­ing sea tem­per­a­tures have al­ready led to the ap­pear­ance of new species of krill (small crus­taceans) and fish, such as At­lantic cod and mack­erel.

“The sci­en­tists give us a sort of ‘shop­ping list,’” ex­plains Max Sch­wanitz, 52, a diver who has been work­ing since 1994 at the French-Ger­man re­search sta­tion.

“For ex­am­ple, they tell us the type, the size and the quan­tity of al­gae they want and from what depth.”

At the end of July, the sur­face tem­per­a­ture of the wa­ter was be­tween 3 and 7 de­grees Cel­sius in the fjord. But ear­lier in the sea­son, they were en­ter­ing wa­ters of less than 2 de­grees Cel­sius.

“Salt wa­ter freezes less easily than fresh wa­ter, at around mi­nus 2.6 de­grees Cel­sius here,” he ex­plains, and div­ing un­der the ice is rare here.

Work­ing with him are two stu­dents, Mau­ritz Halbach, 24, and Anke Bender, 29. To­gether they form the only div­ing team at NyAle­sund.

“Ob­vi­ously, the tem­per­a­ture is on the ex­treme side for div­ing in here,” ex­plains Halbach, stu­dent at Olden­bourg in north­east­ern Ger­many.

“When vis­i­bil­ity is very bad or the cur­rents are strong, the dives them­selves can also be ex­treme,” he says.

Hands: the Achilles’ Heel

Although the divers wear spe­cially made gloves, the cold is felt in the hands.

“Hands are al­ways a prob­lem be­cause it’s the part of the body which is most sen­si­tive to cold,” Halbach ex­plains.

“We gen­er­ally stay 30 to 45 min­utes in the wa­ter. We can stay up to 90 min­utes but by that point, your hands are re­ally cold,” adds Sch­wanitz.

Be­yond the dis­com­fort, it can also ham­per the pre­ci­sion of the work they are some­times re­quired to do in the depths, ad­just­ing both pho­to­graphic equip­ment and fixed un­der­wa­ter in­stru­ments for mea­sur­ing tem­per­a­ture, light and wa­ter clar­ity, as well as gath­er­ing sam­ples.

The rest of the body is well pro­tected against the cold with divers wear­ing Arc­tic cold-wa­ter wet­suits, which are 7-mil­lime­ters thick.

“We also wear warm un­der­gar­ments like for skiing,” says Bender, who has a doc­tor­ate in marine bi­ol­ogy from Ro­s­tock in Ger­many.

Be­tween their bulky suits and bal­last weigh­ing 18 to 20 kilo­grams, the divers are each car­ry­ing a weight of around 40 kilo­grams.

Aside from the cold, se­cu­rity is another big worry for the trio — and for their in­sur­ers who lay down very spe­cific de­mands.

When one of them en­ters the wa­ter “another is ready to dive in in case of a prob­lem, while the third is in charge of the boat,” Sch­wanitz says.

In 2005, the in­stal­la­tion of a de­com­pres­sion cham­ber — in­dis­pens­able in event of an ac­ci­dent — has made pro­ce­dures much sim­pler.

Pre­vi­ously, they would check ev­ery morn­ing to see if the weather was suf­fi­ciently good to al­low a plane to come from Longyear­byen, the main town on Spitzberg, in case of an emer­gency, to fly some­one to main­land Nor­way where the near­est de­com­pres­sion equip­ment was lo­cated — a jour­ney of some four hours.

But in the 10 years since it was in­stalled, the cham­ber has has only ever been used in prac­tice ex­er­cises.

“We usu­ally dive to depths of 18- 20 me­ters,” ex­plains Sch­wanitz, pat­ting the side of the cylin­dri­cal white cham­ber.

“Most ex­per­i­ments here are done at that depth, so they are safe dives.”

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