Well, it looked highly promising for a while, the snow cover melting back, turning granular, bare ice in spots, and air temperature almost above freezing.  The ice algae, a generic category of phytoplankton, which we’ve been seeing in abundance on the bottom of the ice when Healy overturned it, was dropping off into the water as it does when the ice platform begins to soften—another good sign that the melt would begin.  But then, on Thursday, the wind backed northeasterly, and it snowed, not exactly the return of winter, but it reversed the melt by reflecting the light, as white things do.  No melt ponds.  Zero.  And almost no biological activity.  So as planned, after the three days parked, the scientists, grad students, and Coasties lugged their gear to the ship, craned it back aboard, and we got underway, heading south.

Though Chris would just as soon have waited for the melt ponds to form, which they inevitably will, time grows short.  To hang around longer might have jeopardized other segments of the expedition, among them measurements of primary production along the ice edge compared to that in open water.  (They call it primary production because the phytoplankton comprise the base of the food chain.)  It was surprising this morning to look outboard and see water in its liquid form; I admit I’ve missed it, but now we’re back in the ice.

Head scientist, Kevin Arrigo, monitors the water sampling results as they come in.

Head scientist, Kevin Arrigo, monitors the water sampling results as they come in.

Kevin and his team use water samples captured at various depths through the entire water column to measure, among other things, chlorophyll content as a proxy to determine the quantity of biological activity; someone called it a “quick and dirty” method.  Instead of measuring the entire water column in a single swoop, which might be misleading if, say, the biological activity were rampant in one particular layer, but sparse in others, they measure the chlorophyll per unit volume (“milligrams per meter squared”). For instance, some of the algae we’ve been seeing every day have relinquished their clutch on the bottom of the ice and drifted down to the seabed where scientists would find a lot of chlorophyll, thus skewing data toward greater chlorophyll than actually present. However, this method reveals nothing about the individual species contained in those square meter “blocks,” only the quantity of phytoplankton photosynthesizing.  To identify the species is one of the next steps.

A visit to the main lab where this goes down is a bit confounding to the likes of me unused to biochemical oceanography.  It’s hard to separate a single thing from the welter of other things, the filtration towers, refractometers, fast-rate fluorimeters, carbon analyzers, various graduated cylinders and beakers, snakes of plastic hoses that transport, well, something.  Microscopes I recognize.  All these things have acronymic names, and some of the hard-working grad students are so used to the shorthand they don’t immediately remember what the acronyms stand for.  (By the way, none of this stuff was a priori present on the ship; it all had to be inventoried, packed, and hand carried from institutions all over the country, then assembled in the shipboard lab during the three-day steam north from Dutch Harbor.)

Don’t worry, though, for our purposes, it won’t be necessary to explain each and every piece of esoteric apparatus, but let’s pause on one, the “imaging flow cytobot.” When a cell containing chlorophyll passes through the innards of the machine, it triggers a camera and delivers the image to a computer, and in some cases the actual species can be identified, in others the genus.  Species can also be determined by their differing pigmentation and, microscopically, by examining their genetic makeup.  In addition to learning what phytoplankton are present, scientists want to know what they’re doing in the water column, what nutrients they’re “eating,” and the state of their health.  Some of these plants are absolutely otherworldly, as if designed in a special-effects studio.

I’ve made this process sound far more streamlined than it actually is.  The basic chlorophyll measurements can take place relatively quickly, but the speciation and other more finely grained analysis can take an entire day.  That’s why water sampling and lab work goes on 24 hours a day, seven days a week and will continue until Healy puts her dock lines over in Dutch Harbor, then it will continue in other shoreside labs.

Water samples being tested for biological matter.

Water samples being tested for biological matter.

And what of the melt ponds?  One might say that their absence during our three-day stop was disappointing, but there’s no reason to assume that they won’t appear when, later, we turn back north.  In any case, these scientists are leading figures in their fields, well aware that humans can’t make appointments with nature’s physical processes.  Also, they’re nimble minded enough to recognize that there are many things to learn from this unique opportunity to observe those processes so early in the year.  For just one example, hitherto, no one figured that a light, late season snowfall had the clout to delay the melt.  But it does, and the scientists were on scene to see it happen.  Earth scientists are used to the fundamental fact that they will spend their careers chasing after nature’s functioning trying to figure out first what’s actually going on and second, why—and to take the lessons when they serendipitously present themselves.  There will be other lessons to come in the final two weeks of our stay in the frozen Chukchi.

About The Author

Dallas Murphy

Dallas is an author with nine published books, a mix of fiction and nonfiction, most recently "To the Denmark Strait", an account of a 2011 oceanographic expedition with Bob Pickart. The Healy cruise will be his sixth Arctic expedition serving as outreach writer.

Leave a Reply

Your email address will not be published.