Into the Ice

We are now, finally, in ice.  The ship is shuddering along, not breaking ice but rather pushing floes of pancake ice aside.  When occasionally we break into a lead of open water, the ship glides unfettered, seemingly not moving because there is no irregular bumping and jostling by the ice floes, no shaking and vibrating.  This is not ice breaking, with its crashing and banging but rather we are moving through an ice field rather as a human walking through a tall field of corn, pushing aside the stalks easily but still not walking a straight, smooth path.  It is a relief to finally be in the ice, where the seas are dampened.  We are heading to a station near the Alaskan town of Wainwright where we will start sampling along a line that extends from the nearshore 58 miles to the NW.

Moving through pancake ice. Note the ice all over the bow and foredeck of the ship; this is from freezing spray as we moved north through the Bering and Chukchi.  The crew has been busy breaking it up and shoveling it overboard.

Yesterday we saw our first ice, just a smattering of small pancakes that nonetheless evoked amazement and wonder in even those of us who have seen it many times before. We were in the ice long enough to collect a few chunks for Krista to melt down to collect the organic carbon.  We’ve been working northwards through the Chukchi Sea to this first transect line but on the way we paused to deploy a mooring for some colleagues.  The deployment went well, with the mooring placed only 12 yards from the intended position.   Now we begin a marathon of stations, stopping every 6-7 miles along the track to sample.

View of the ice from the ship at the end of our three-hour day (the sun was up for only 3 hours and did not rise far above the horizon).

We’ve been collecting plankton regularly in the net tows.  Each tow brings a sense of anticipation and a great curiosity – what will we find here?  We have found many krill, or euphausiids, that are important prey for bowhead whales in the Beaufort and Chukchi Seas particularly near Barrow. We also have found Calanus copepods, in particular a very large abundance of males.  Male Calanus are rarely seen so it is quite strange to see so many!  At the last station, we caught some larval crabs that were busily trying to eat the krill in the sample.  Yesterday further to the south we caught a number of fish, much to Joel’s delight.  Many of the copepods and krill are picked out, photographed, and saved for later analysis of their carbon and nitrogen content to see how much fat they have stored for the winter, their RNA/DNA content to see how active they are (are they entering diapause/hibernating?), and their genetics.

Bob picks krill out of a plankton sample using a spoon.

Celia picking copepods using a microscope in the lab.

One of the copepods we have collected this trip.  Photo by Celia Gelfman.

A krill, or euphausiid, collected this trip.  Photo by Celia Gelfman.

The real work of the cruise begins, now that we have beaten, bounced, pitched, and clawed our way through the storms of the Bering Sea up to the northern Chukchi.   We are coming up to our first station on the line shortly (30 minutes).  The air temperature is 17 F and the sea temperature is -1.75 C, just above the freezing point of seawater (-1.8C).  Ice is forming around us.

Small bits of ice on the surface of waves in the afternoon sun.