Polar bear tracks and a seal were seen close to the north pole by scientists on the icebreaker U.S. Healy, indicating a major ecological shift in the Arctic brought on by the catastrophic thinning of sea ice. This healthy polar bear, seen on the Healy's trip to the pole, has adapted to hunting for seals from sea ice far off the shores of Alaska.
The U.S. Coast Guard icebreaker Healy reached the north pole unaccompanied on September 5, an historic first, but that was a footnote to a much more important story. The real stunner wasn't the ease that the medium duty icebreaker Healy had slicing through thin first year sea ice or the sighting of open water near the pole. The stunner is that the sea ice is now so thin at the pole that the polar ecosystem has transformed. The ice is so thin that a seal was sighted near the pole and polar bear tracks were spotted near where the seal was sighted. The shockingly rapid transformation of the polar ecosystem is the jaw-dropping lede the media missed.
There was a seal near the ship at the Pole and people saw bear tracks on the way here, so the ecosystem we associate with the Arctic Ocean – a simple food chain from phytoplankton & algae, to zooplankton, to Arctic cod (a small fish that lives under the ice), to seals, and finally to bears – is active even at the Pole.
Senior scientist, Jim Swift's blog post is coldly understated. From the perspective of Arctic ocean ecology this is like the moment you see flames bursting from the engine of the plane you are flying. This is an oh shit moment. On his previous visit to the pole ten years ago ice was so thick that low amounts of light penetrated into the ocean, supporting a very simple ecosystem that peaked at Arctic cod, a very small fish. Now, seals and polar bears are fishing and hunting from thin first year ice with open leads.
At 7:47 am ship’s time Saturday, September 5th, USCGC Healy became the first US ship to reach the North Pole unaccompanied by another icebreaker. I am not certain of this, but Healy may also be the first ship of any nation to reach the pole from Bering Strait unaccompanied. It was also a milestone of sorts for me, because there have been three scientific crossings by surface ship from Bering Strait to the Pole – 1994, 2005, and 2015 – and I was on all three, doing similar work each cruise (and thus learning about ocean change in this remote part of the World Ocean).
My informal observations of the Arctic Ocean sea ice we have been traversing continue in the same vein as during the past two weeks: much of the ice appears to be first-year ice and passage through it has mostly not been difficult. Yes, there are larger, tougher floes and some pressure ridges. [Pressure ridges form when floes and sheets are pushed together and pile up high (and well below the surface) and can be very tough to pass through.] But these can usually be avoided and even the ones we have crossed have not yet been significant impediments to our progress. Extra power (provided by bringing more engines on line) has been required remarkably few times for an expedition working in the central Arctic Ocean. This is very different from the experiences we had with the ice 10 and 21 years ago.
There was a seal near the ship at the Pole and people saw bear tracks on the way here, so the ecosystem we associate with the Arctic Ocean – a simple food chain from phytoplankton & algae, to zooplankton, to Arctic cod (a small fish that lives under the ice), to seals, and finally to bears – is active even at the Pole.
There was a large lead (open water) quite close to the Pole, so we first carried out a long, 8-cast Geotraces science station. On our deep cast we attached several net bags full of decorated Styrofoam cups which were shrunk by the more than 400 atmospheres of pressure they encountered, making nice souvenirs. I earlier told some of you who asked how we handle the cold, “well, it isn’t all that cold in the Arctic Ocean in summer, just about freezing”. Perhaps it is time to eat words … yesterday a high pressure system built up, and with it came clear skies and a still, dry atmosphere, causing air temperatures to dip down to -14°C (7°F) when we were working. This was cold enough to freeze up our CTD in the time it took to move it from the sampling room and deploy it – it took nearly 20 minutes in near-freezing ocean waters to thaw it. This freezing damaged the CTD’s pumps and at least one sensor (we have spares), but we were able to complete the cast. Freezing was a problem during sampling, too. So we are considering some adjustments to our deployment and recovery methods such as making space to install one of those heater-blowers that are used to keep football players warm on the bench. We will use it to blow warm air over the rosette when it is outside on deck.
This photo of the historic meet up of German and American research ice breakers at the north pole shows very thin easily broken ice.
German and American research teams will return with detailed sets of samples and data that will take from months to years to analyze and report, but the key discovery of a rapid transformation of the ecosystem at the north pole, caused by the collapse of Arctic sea ice thickness has already been reported in one terse sentence by Jim Swift.