I am surprised that Tauranga City Council believe that rain killed fish in waterways in Papamoa by de-oxygenating the water ('Rented fish keep city's waterways clear”).
Heavy rain usually has the opposite effect, and actually raises oxygen levels. It is very unlikely that rain would cause the stream to become deoxygenated unless it was associated with some other event that caused large amounts of organic matter to be washed into the stream (i.e. pollution). Wairakei Stream was in a poor state before the rain and oxygen levels were low because the stream is too shallow and warm, the water flow is impeded, and it is choked with rotting weed. Amur fish were never really very effective at managing the weed problem.
The stream is slow-flowing, shallow, smelly, and mosquito-infested, and the poor water quality has got the better of the expensive, and now dead, fish. Amur fish may or may not have a role in Wairakei Stream in future, but conditions in the stream need to be improved before more ratepayers money is invested in them. The reserve is used for recreation and is next to a school and I see children looking for tadpoles and wading in the shallows. I'm concerned that they are risking their health by doing so.
I urge Tauranga City Council to take a fresh look at the way they are managing Wairakei Stream, to identify all of the causes of the poor water quality, and to implement best-practice solutions to improve the health of the Wairakei Stream and the functioning of the reserve.
L Collins, Papamoa East.