In real life, these abstracted zebra mussels, underwater in a Minnesota lake, are tiny. Described by the Minnesota Department of Natural Resources: “Zebra mussels are small animals with a striped, D-shaped shell composed of two hinged valves joined by a ligament. The shells are typically one-quarter inch to one and one-half inches long, depending on age, with alternating yellow and brownish colored stripes.”
Last summer (2017) I read a particularly frightening series in the Minneapolis Star Tribune invasive zebra mussels, “How the Scourge of Zebra Mussels Spread Across Minnesota.” The tiger-striped mussels reproduce in clumps that clog boat motors and water treatment facilities. The shells break down into shards that make beaches sharp and unpleasant. And as further described in the article:
The thumbnail-sized mollusks spread rapidly, and silently but relentlessly upend the fragile ecology of a lake. They smother and kill native mussels. They strain out and consume tiny, edible material, robbing native fish of a fundamental link in the food chain. They excrete a carpet of waste that fosters the growth of hairy, stinky, toxic mats of algae.
I knew about zebra mussels, but the details in this series made me think about my childhood, and how I assumed that the lakes and the environment would always remain the same. And now everything is fragile.
As a child, I viewed the biggest outdoor threats as woodticks, poison ivy, and leeches lurking near the shore at Lake Bemidji, ready to leap on the legs of unsuspecting children. Summer evenings on the farm my mother would check each of her children for woodticks. My cousin and I would grimace at the huge blood-filled ticks on her dog. All that seems so innocent and innocuous compared to the really scary tiny deer ticks that can damage people’s long-term health.
During my long career at the Minnesota Legislative Reference Library, I was one of many who monitored periodicals for articles of importance to legislators and staff. My set of topics included agricultural and environmental issues. Over the years I read about pollution, climate change, and invasive species. At every turn, our state was beleaguered. Earthworms. Purple loosestrife. Climate change means snakes will come further north. Sea lampreys! And who could even believe the stories of flying carp leaping out of the river to smash against boaters?
The zebra mussels are the start of a series… Next up: the eastern larch beetle and brainworms in moose.