31 Jul Crayfish Corps at Valley Forge

Today I was able to work at Valley Forge National Historical Park (Hopewell Furnace sister park) with their Natural Resources staff and Interns. They invited me along to help with a seasonal program they do with the Crayfish Corp. What is the Cray Fish Corp you ask? It is a group of people who help with the removal of The Rusty Crayfish. In 2008, the rusty crayfish invaded Valley Creek in Valley Forge NHP and members of the Crayfish Corps joined National Park Service staff in the removal of the rusty crayfish populations by physically removing them from the creek. Their long-term goal is to maintain a ratio of one rusty crayfish or less for every four native crayfish present in Valley Creek. The rusty crayfish are considered a non-native, invasive species in the park, and throughout Pennsylvania. Originally, from the Ohio River Basin, this crayfish has been transported to new environments throughout the northeast primarily by bait fishermen, biological supply houses, aquaculture, and the pond and aquarium trade. The rusty crayfish is bigger, more aggressive, and eats up to twice as much as native crayfish in Valley Creek. They are able to eliminate all other crayfish species through direct competition for food and shelter and increasing the vulnerability of native crayfish to predators. Rusty crayfish also may cut the amount of aquatic vegetation, reduce aquatic insect populations and ultimately negatively affect large predators such as trout. We started our day by putting on waders and heading to the creek where we then used our nets to catch the crayfish. In order to find them we had to lift up rocks and place our nets directly in the opening so the crayfish could flow in. When we found a cray fish, we would then check if it is native or invasive and keep count by using the corresponding clicker. To tell if it its invasive, you would check the crayfish’s claws and back, if it had black bands around the claws and red spots on the back sides then its invasive. This was such a fun experience, I was able to learn about something completely new and have my office be the outdoors for the day! Who can complain about that! I am glad VAFO offers this program not only to staff but to the community too. It is a great way to get people out doors and take part in an activity that helps their local National Park.