Camper’s braved Denver’s sudden burst of winter Tuesday to get fishy with SPREE! We learned all about local fish and their adaptations that allow them to survive in the urban South Platte River and Colorado. Our mission of the day even hinted about a fish that came back from the dead!
It turns out there are no zombie fish- luckily, but in our first activity, camper’s learned about the South Platte River’s Greenback Cutthroat Trout. This fish, Colorado’s state fish, was presumed extinct in 1937. But, in the 1950s two small populations were found in CO, in the Arkansas River and the South Platte River. Quickly, rehabilitation efforts were started. Today, while not the most common trout in our waterway, Greenback Cutthroat Trout can be caught and released in the city of Denver!
Camper’s warmed up and learned about trout predator-prey relationships with a fun game of Trout Tag! In the picture above you can see trout “fry” (campers) getting hunted by one of our River Rangers, aka a “Great Blue Heron”.
Campers swam deeper in the life of fish during our second activity, where we learned about the protective slime coating all fish have. Fish have a coating of slime over their skin which acts as a barrier keeping bacteria and other bad things out of the fish. Fish slime can be damaged by many things including human touch, predation, or scraping it on riverbeds. A fish can heal its broken slime, but if slime is too damaged the fish could die. We whipped up a batch of clear fish slime using glue & borax, and then braved the weather again for a game of Slime Tag!
SPREE instructor aka “big trout” nips pieces of slime (clothespins) from camper fish. Luckily no camper fish lost too much slime, this round….
Once again, campers endured the winter weather for our third activity. Typically we would wade in the river for a “critter crawl”, but it was far too chilly for that. Instead, campers went on a hike down by the South Platte River and made observations about what they saw. As they observed, campers thought about how everything they see might impact the fish in the river- even goose scat! After making observations, campers warmed up by drawing an ecosystem mural.
We concluded the day practicing the art of Gyotaku, or fish printing. This science art style began in the mid 1800s when Japanese fishermen wanted a way to record their daily catch. At SPREE, we used “actual size” fish molds of native Colorado fish. We rolled the fish in stamp ink, and then stamped the fish onto a piece of paper. The results were unique and beautiful educational works of art!