Module 12: Invasive species

The message
Invasive species introduced by human actions are a threat to biodiversity.

The experience
Visitors pass through a woven, sculptural gate made from buckthorn—there is a feeling of a jail cell or cage. Inside they come face to face with an arapaima skull the size of a basketball, its gapping jaws lined with rows of tiny razor-sharp teeth. Visitors compare their height to an outline of this freshwater giant, more than 6-feet at full length.

A massive, barnacle-encrusted Pacific clam is perched nearby, along with an oddly familiar specimen—a massive goldfish, once someone’s pet, pulled from Lake Michigan. Peering through a magnifying lens reveals an ash bore beetle. Accompanying graphics might mimic “Wanted” signs or mugshots.
An updateable area examines a current “Public Enemy #1”—an invasive currently in Chicagoland headlines. This might be the Asian carp, zebra mussels, longhorn beetles, or others.

The story
Invasive species are some of the “villains” of conservation, engaged in an epic struggle with native species. But the reality is that invasives are the result of human actions: planted for their out-of-season green beauty, carelessly brought through channels on boats, and released into ecosystems when the became cumbersome to keep.

The arapaima is one invasive species about which we don’t know the whole story. Several escaped from Peruvian fish farms during intense floods and ended up in Bolivian lakes. The long-term effect of these non-native predators is not yet known, but the human response is already problematic. Local communities have enthusiastically harvested this tasty new fish, tangling caiman and other large aquatic life in their drag nets.

Phil Willink is collaborating with these local communities and Bolivian scientists to determine the arapaima’s impact. His longitudinal study tracks three lakes: One with arapaima for several years, one where arapaima were more recently introduced, and one without arapaima. His team also works with fishermen to find alternatives to drag nets.