Overview
- Researchers ran large outdoor experiments that added goldfish to nutrient-poor and nutrient-rich model lakes.
- Water quality declined fast in both types of waters as the fish churned bottom sediments and raised suspended solids.
- The systems crossed into a degraded state known as a regime shift, which is hard and expensive to reverse.
- Key invertebrates like snails, amphipods and zooplankton crashed, and native fish lost body condition.
- The team urges owners to rehome unwanted fish and tells managers to prevent, detect and control new invasions.