Fears for aquatic life in Chapman River as city rehabilitates bushland after last year’s devastating fire

The City of Greater Geraldton is warning people that fish kills in the Chapman River may be possible following a devastating bushfire in the area late last year. On November 30 and December 1, an out of control bushfire threatened hundreds of homes in the Spalding and Waggrakine areas and burnt 160ha close to the Chapman River. One home was destroyed, while three others were left uninhabitable. In a social media post this week, the city said Chapman River could be impacted by eutrophication as a result of the December fire, which means there was an increased amount of nutrients in the water. While more nutrients sounds like a good thing, Mike Dufour, the city’s manager of climate, environment and waste, explained that destruction of plant life around the river leads to looser soil, causing runoff into the river. “If the soil runs off into the river, it can lower the oxygen levels, increase turbidity, and then that affects the aquatic quality and the life of any organisms in the river,” he said. “If we can stop the sediment before it gets into a river, that’s great, and that’s what we’re focusing on.” The conditions can cause warmer water temperatures and lead to fish deaths, which members of the public are encouraged to keep an eye out for. “The Chapman River Regional Park is a biodiverse hot spot, so it’s got a number of priority species and a wide range of vegetation types and species and animals that live in the river,” Mr Dufour said. “If one of those species is impacted, it does knock-on the ecosystem within the area. So it’s important that we try and maintain the health of that river system.” To rehabilitate the bushland and improve the health of the soil, the city’s sustainability team is aiming to plant 12,500 seedlings across the Chapman River Regional Park and do targeted weed control on impacted areas. “In terms of monitoring, we can do bird counts. We can do fish counts. We can look at the area of vegetation that’s recovered. We can look at the number of species. So there’s a range of monitoring things,” Mr Dufour said. They also work with community groups who are regularly in the area, such as Chapman River Friends and BirdLife Midwest. Anyone who sees dead fish at the river can report it to DPIRD’s FishWatch hotline 1800 815 507. They are asked to provide a GPS location if possible.