Leading freshwater scientists have panned the Government's proposed amendments to the National Policy Statement for Freshwater Management as meaningless and lacking necessary science.
Massey University Centre for Freshwater Ecosystem Management and Modelling director Associate Professor Russell Death told the Science Media Centre the bottom lines lacked ''any appropriate measure to protect rivers'' and believed degradation of New Zealand's rivers would continue.
''To protect our rivers there should have been limits for in-stream nitrogen concentration, in-stream phosphorus concentration, MCI (macroinverterbrate community index), IBI (index of biotic integrity) and deposited sediment,'' Assoc Prof Death said.
''These variables we have known about for at least 20 years as important for assessing river health or that can influence river health and for most of which we have well established limits already.''
He believed some of the bottom line values showed the Government was on the right track, but questioned why other water health measures were ''not in the mix''.
''I am not sure which scientists have been involved, but I would be surprised if many freshwater scientists in New Zealand would suggest we can protect the environmental bottom line of rivers without considering the parameters listed above,'' he said.
Massey University Institute of Agriculture and Environment senior lecturer Dr Mike Joy said the bottom lines were ''not measuring anything meaningful'' and some of the measures, such as nitrogen toxicity, were ''pointless''.
He believed measurements of biological communities were necessary if freshwater quality and ecosystem health were to be protected.
''Freshwater health will continue to decline, until we look at the drivers, mainly farming intensification,'' Dr Joy said.