The Wake

So you say you’re sick of all the bullshit on TV. Pets that can talk, progress on the bill on drying paint, that kind of thing? Well, sink your ass into that booth, Mr. PBR, because I’ve got some cool stuff for you to read. It’s got intrigue, adventure, and oh, also, it’s about algae.

So I suppose everyone’s entitled to their own interests, but let me tell you, algae do it for me, and I’m going to tell you why. First, algae were among the earliest forms of life. Rather than killing and eating other organisms to power their growth and reproduction like some other assholes do, algae harness the sun’s energy. By providing food and oxygen, algae set the table so that more complex life forms could come to the dinner party. Today, algae remain the most important primary producers (organisms that can harness the sun’s energy, thereby inserting it into the food chain). If providing the basis for all of life on earth isn’t enough, we care about algae now since we’ve discovered that we can use it (that’s what science is for, right?). Algae are being used in some of the latest biodiesel research going down at the University of Minnesota and many other institutions. In addition, algae are important indicators of biological problems—changes in algae growth are often the first signs of environmental disturbance in a certain area.

Now, my personal relationship with algae is based on one such unusually changing individual, Didymosphenia geminata (Didymo, for short). Didymo is a diatom—its cell wall is composed of silica, an element rarely found in organisms outside of Los Angeles. Didymo is the mother of all river algae—its cells are about ten times as big as most other diatoms, and it sometimes blooms in mats so thick and wide that people call the authorities. The media have even coined a tacky nickname: “rock snot.”

The particularly onerous blooms that inspired such reactions have been a relatively recent (5 - 10 years) phenomenon. But are these blooms being caused by some external environmental change (i.e. global climate change) or by an internal change in the organism’s genetic make up by mutation or hybridization? This was the question guiding my research at the University of Alaska’s Environmental and Natural Resources Institute, where I spent this past summer, playing with goop in the stream.

Didymo in Campbell Creek, Anchorage, Alaska, did not seem to be exhibiting the kind of problematic, out-of-control growth that disturbed people in some places like New Zealand and British Columbia. To see whether the Didymo exhibited other characteristics typical to invasive species, I monitored Didymo blooms in relation to rainfall and river flow. In addition, I placed clean rocks in the river and scraped and identified the types of algae growing on the rocks every week, in order to observe how Didymo colonized a fresh environment, in relation to other diatoms.

I found that Didymo was very sensitive to rainfall, and experienced severe die-backs when flow fluctuated much. In addition, Didymo appeared to colonize very slowly, appearing only weeks after many other species of diatoms were growing on the rocks. Both findings were not typical for nuisance and invasive species, which are typically characterized as quickly growing, pioneers with a very broad range of conditions in which they can succeed.

The Didymo found in Campbell Creek did not seem to be acting in the same way as Didymo in New Zealand and British Columbia, suggesting the geographically separate Didymo are perhaps different strains. This points to an internal change, rather than global climate change as the cause of invasive and nuisance Didymo blooms. The next step is to compare genetic analysis of Didymo from different parts of the world. And that’s how science is done—rarely with trumpets announcing monumental discoveries, but bit by bit, link by link. Alright, that’s it, hope you learned something.