Fish wash up dead on Collie River's banks

On the banks of Collie River in Western Australia, about 700 fish have washed up dead. It's believed the fish died due to low dissolved oxygen levels in the river, the Department of Water and Environmental Regulation (DWER) said. A statement said dissolved oxygen levels have fallen rapidly following recent intense heavy rainfall. “The flows associated with rainfall at this time of year can wash in nutrients and organic matter, mobilise nutrients in sediments, and mix the water, bringing low oxygen conditions to the surface,” DWER spokesperson said. “As this was the first significant rainfa

On the banks of Collie River in Western Australia, about 700 fish have washed up dead. It's believed the fish died due to low dissolved oxygen levels in the river, the Department of Water and Environmental Regulation (DWER) said. A statement said dissolved oxygen levels have fallen rapidly following recent intense heavy rainfall. “The flows associated with rainfall at this time of year can wash in nutrients and organic matter, mobilise nutrients in sediments, and mix the water, bringing low oxygen conditions to the surface,” DWER spokesperson said. “As this was the first significant rainfall since October 2023, with heavy rains falling in a very short period, a large amount of nutrients and organic matter entered the Collie River in a short space of time.” The dead fish include black bream and mullet.