Altering pH changes competition dynamics between two crayfish species for both food and shelter resources

As climate change continues, alterations in abiotic variables within habitats will also change. One of the key variables for aquatic systems is pH. We were interested in how lowered pH altered the behavioral characteristics of two keystone species: Faxonius rusticus , a non-native crayfish in the upper midwest and Faxonius virilis , the native crayfish. We dosed size-matched individuals in separate tanks for four days and than placed these individuals in a flow through mesocosm to allow them to compete over food and shelter resources. Behavior was recorded from midnight to 4 am. Pairs of animals were exposed to pH levels varying from ambient (8.4) to 6.4. The experiment took place at the University of Michigan's Biological Station in northern Michigan in the United States.