A Cupful of Smelly Gooey Phytoplankton
It was the color of the ocean from space that brought us here. We knew it was a gamble, a dogleg away from our main sampling plan. But satellites were telling us that phytoplankton were flourishing here, over deep water, where no one could explain it and no one had ever been to study it before.
To come here and still get the rest of our work done would require long shifts at the pumps and filters and spectrophotometers and microscopes. But it might turn up something unexpected. And I guess that’s why these people are scientists. They are drawn toward the unknown.
When we got here the water, which is normally blue in the open ocean, was green with phytoplankton. The first net over the side brought up cloudy water that people described as smelling like broccoli, seaweed, sulfur, or brussels sprouts. To me it was briny and sharp and smelled like freshly shucked oysters. That’s the smell of the ocean—a gas called dimethyl sulfide—and it meant we had stumbled on a different kind of phytoplankton bloom. Read on through the slideshow to find out more about our day:
Throughout the Ross Sea, the two major kinds of phytoplankton are Phaeocystis and diatoms. But wherever blooms happen, they tend to be made up mostly of one of these types, with far fewer of the other. Before today, our expedition had found blooms dominated by diatoms. This is the first mostly Phaeocystis bloom we have seen.
Scientists aren’t sure why the two types don’t occur in more equal proportions in all blooms. Some think that Phaeocystis blooms earlier, beating out the diatoms but requiring more iron, and perhaps performing better in low light. Then, later in the summer when less iron is available and there’s more sunlight, the diatoms take over. But these ideas have not been thoroughly researched yet.
The Phaeocystis bloom we found will make an interesting comparison to the diatom blooms we’ve been finding. It’s happening at the same time, in the same light conditions as the diatom blooms. And the iron measurements Dr. Chris Measures and Dr. Lam are making will tell the scientists whether this Phaeocystis bloom has more iron in it than the diatom blooms. Perhaps they’ll find enough new information that they’ll come back and test a new hypothesis… and make some more keepsake cups.
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