The Dark Side of Light
NEUGLOBSOW, GERMANY—Martina Bauchrowitz put her back into it, swinging the oars in a wide arc, and the small boat lurched away from the lakeshore. I gripped the hull, shivering in the early-spring air, and watched our progress toward the rose-shaped metal platform floating on the surface of Lake Stechlin, one of the deepest lakes in northern Germany.
After a few minutes of rowing, we bumped against the side of the rosette. Bauchrowitz and I secured the boat and climbed out. Beneath the blue sky and puffy clouds, beneath the shiny platform and the dark, choppy waves, is another world—invisible in daylight and, more important, in darkness.
We stood on a floating plastic pontoon anchored among 24 aluminum cylinders, each protruding a few inches above the surface so that they resembled connected rings, like the petals of a flower. Each is a miniature ecosystem. They are, essentially, giant test tubes, each the size of a grain silo, nestled in Lake Stechlin. In this system of artificial lakes, scientists at the Leibniz-Institute of Freshwater Ecology and Inland Fisheries can test their hypotheses in a natural environment.
“Watch your step,” Bauchrowitz said. I thought she was worried that I would fall, or worse, drop my notebook into one of the ringed enclosures, but that wasn’t what she meant. She gestured toward browning spots of caked-on guano.
“The birds are a problem. When they shit here, we have extra nutrients we would not have without the platform,” she said.
Most biologists conduct their laboratory experiments inside well-appointed rooms within nondescript buildings at research centers or on university campuses. But here, the lake is the lab. Every fish is counted, the density of microscopic plants and animals is carefully calibrated, and any excess bird crap must be cleaned up. The cylinders inside the lake are kept as pristine as possible until an experiment begins, and the scientists tinker with them the way their counterparts might meddle with the contents of a petri dish.
The Lake Lab was built so that ecologists could study a form of environmental change that rivals climate change in its scale and reach: the spread of artificial light at night.
Since 2010, the scientific literature has exploded with research examining light’s effects on individual species, from birds to fish to trees to humans. The news, in general, isn’t good. Artificial light changes animal migration and reproduction, tree leaf growth, bird nesting and fledging, pollination, human sleep, and much more. It even affects the spread of diseases. In July, researchers reported that West than those that live in darkness are, .
