Du må være innlogget for å få tilgang til alle nyheter! Logg inn eller opprett brukerkonto.

New spring for the giant

The painting shows whaling north of Svalbard. The waling started as early as in 1670.

New spring for the giant

Quickly spreading ice was an equally important reason as hunting for the collapse of the Greenland whale population, Arctic researchers believe.

Tekst:

Publisert:

Whalers Bay – Kvalbukta – is the area from the ice edge, just north of Spitsbergen, from ancient times as called by sailors. From around 1670 there was an intense search for the Greenland whale around northern Svalbard, but in the early 1880s it suddenly ended and the population collapsed. 

Changed conditions
Until now the conclusion was the stock broke down because of vigorous hunting pressure, but professors Jørgen Berge with UNIS/UiT and colleague Stig Falk-Petersen with Akvaplan-niva/UiT are not certain that is the lone reason.

After several years of study, they argue climate change with rapidly expanding sea ice was an equally important factor because the ice kept light from necessary penetration, and production of algae and zooplankton – the latter being whales' most important food source – was greatly reduced. Meanwhile, the living conditions of the Greenland whale also quickly changed.

"We are very confident about it," Berge said when challenged about the ice theory. "It follows with previously published results and our own theses."

In addition to evidence from various expeditions and logbooks of whalers who confirmed the area was free of ice from 1670 to 1800, they used satellite measurements. The satellite measurements show the area was completely covered by ice from 1979 to 1998, but it then declined. 

The same conditions
In 2004, scientists Kit Kovacs and Christian Lydersen at the Norwegian Polar Institute successfully attached a radio transmitter to a Greenland whale. The transmitter showed whales followed the earlier traffic artery along the Greenland coast and north to Kvalbukta.

When, as now, there is little ice around the area, the researchers believe it provides a basis for the upwelling of nutrient-rich water, which in turn results in high production of zooplankton.

"Our hypothesis is therefore that conditions now are favorable for an increase in the population of Greenland whale, and the dinner plate north of Svalbard is the treasure chest the surviving Greenland whales are looking for on their journey across the North Atlantic and the Arctic" they wrote in an essay that has also been published in Aftenposten.
 
Chimney
In 2012, researchers demonstrated for the first time an upwelling of warm Atlantic water along the Arctic continental shelf edge. Such "chimneys" occur when the ice retreats to the shelf edge during the winter and point out entirely east to Nordaustlandet. The warm, nutrient-rich water is transported in the fresh, cold water until it comes up. Berge and Falk-Petersen also recorded large amounts of the fat-rich zooplankton , which is the Greenland whales' food.

"Due to less ice in recent years, we see relationships as the basis for recreating the chimney effect," Berge said.

And the changes in the ice are cyclical?

"Yes, but it's important to say that we are not trying to make contributions to a climate debate," said Berge, who is not certain the Greenland whale will become a plentiful species again. "The only thing we are trying to do is bring in other aspects. When it comes to population trends of the Greenland whale, we believe this is an aspect that is not taken into account."

"This study shows that there are plenty of nutrients present so that the bloom of algae may start when the sun comes back, which in turn are food for the zooplankton," the researchers assert. "The food for the Greenland whale is therefore back."

Nøkkelord

Siste nytt i Nyheter

Elleville scener for hundreåringen

Et imponerende show, en porsjon nakenhet og god trening for lattermusklene da Longyearbyen gratulerte Store Norske med 100-årsdagen i går.

Mistet broren i gruva

Frank Robert og Bent Jakobsen mistet broren Geir Arne Jakobsen i en gruveulykke i 1991. Torsdag avduket de minnesmerket.

Verdig og rørende markering

Brødrene Bent og Frank Robert Jakobsen mintes sin bror Geir Arne og de 123 omkomne da de avduket minnesteinen i ettermiddag.

Ble hørt av politikerne

Ungdomsrådet føler de har blitt hørt etter at sentrumsplanen er lagt fram. Nå ønsker de ny flerbrukshall.

Vil overvåke nøye i vinter

NVE starter opp den lokale skredvarslingen for vinteren når snøen kommer.

Får endelig ro til barndomsboken

Tone Nødtvedt har dratt fra mann, datter, katt og hus i Bergen for å skrive om å vokse opp i Longyearbyen på 1950-tallet.

Annonse
Annonse
Do NOT follow this link or you will be banned from the site!