The household pet plaguing local lakes and wetlands

Our Aquatic Ecologist, Alex Hickling, recently spoke with ABC reporter Ashleigh Davis about the growing threat of invasive fish species in waterways around Perth, Western Australia.

In the interview, Alex explained that “we’re fairly certain the main way [invasive species] get into areas is by people putting them into the local lakes by their homes or backyards.” He went on to note, “the longer you have invasive species in the waterway systems, the worse the impact - you’ll see degradation of the environment, native species disappearing, and a decrease in water quality.”

While many in the community believe they’re doing the right thing by releasing pet goldfish or koi into wetlands, the reality is quite the opposite. Once introduced, these species are difficult to remove. Their bottom-feeding behaviour also disturbs sediments and pollutants, resuspending toxic debris into the water and contributing to algal blooms and fish kills.