When I was a child we would visit my grandparents’ home in Bartholomew County several times each summer. They lived near a lake and the memories of that lake have a deep hold in my subconscious: I often think of that dark, cool, green lake, filled with bluegill and minnows. In the winter we would walk on the ice, breaking icicles off the neighbors’ docks, and in the summer, we water-skied and tubed and swam and dove. One of the most magical memories I have of the creatures in that lake is of tiny, translucent jellyfish. In several years, we pulled buckets of water out of the lake to find them filled with these creatures.

My grandfather would take a tall, cylindrical vase and pour lakewater and jellies in it. The jellyfish would float up and down eating bits of detritus out of the water for a few days, making a mesmerizing centerpiece. Freshwater jellyfish seemed as magical as mermaids or as terrifying as the Great White Catfish that my mother promised lurked at depth to chomp unwary children.

In later years, as I studied biology, I thought again of those freshwater jellyfish. The freshwater jellies found in Indiana’s waters are Craspedacusta sowerbii, or the peach blossom jellyfish: a beautiful name for a beautiful little organism. These delicate predators eat tiny, barely visible swimming creatures, but their stinging tentacles are too weak to hurt a human. Peach blossom jellyfish are originally native to the Yangtze River region of China but have spread throughout the world, as humans move them accidentally with our boats and water traffic. Learning they are not a native species made me think about the way humans have changed the ecosystems we inhabit with introduced and invasive species.

Technically an introduced species is any species brought to a new habitat by humans, either intentionally or unintentionally. Many favorites that can be found in the forests and streams of Indiana are introduced: apples, honeybees, broadleaf plantain and rainbow trout. An invasive species is an introduced species that does so well in its new habitat that it damages the environment or human well-being. Some local examples include autumn olive, Japanese stiltgrass, starlings, or the emerald ash borer. There are rightfully many campaigns to manage and remove invasive species from many habitats. But all these species are where they are because we put them there. We think that autumn olive is beautiful, that plantain soothes skin and that apples, honey, and trout are delicious. We carefully build homes and barns that are perfect environments for starlings and sparrows and should not be surprised when they move in. We carry ash borers and jellyfish to the corners of the earth as we ship lumber and bilgewater. It does not reflect well on us to be contemptuous of the things we spread and that flourish alongside us, even when we work to help them flourish elsewhere.

Modern ecologists no longer talk about wildernesses of untouched forest or seashore. We recognize that humans have always been an integral part of ecosystems and that our impact needs to be included in learning to manage current ecosystems. We can learn to be mindful of the creatures we re-distribute and be good stewards of the world we all share. Learning to live well with our apple and jellyfish neighbors is a good lesson for learning to live in a world of imperfections and complex histories.

Rebecca Young is descended from some of the original land grant settlers of Brown County and lived there on and off for 4-5 years. She comes back often to visit her parents. Her PhD is in biology, with an emphasis on physiological ecology, aging and animal behavior.

Rebecca Young is descended from some of the original land grant settlers of Brown County and lived there on and off for 4-5 years. She comes back often to visit her parents. Her PhD is in biology, with an emphasis on physiological ecology, aging and animal behavior.