Fisheries data shows that through either pollution, abstraction or modification, trout populations have collapsed in the Ruamahanga, Riuwaka, Takaka, North Ashburton, Irwell and Selwyn Rivers and lakes Ellesmere, Tutira and Hayes to name a few.
Land clearance and disturbance from forestry, high stocking rates and ploughing causes sediment to wash into rivers and estuaries during high rainfall. Sediment blankets spawning areas for fish and invertebrate habitat as well as reducing clarity.
In 2017 the Ministry for the Environment reported that 61% of rural lowland rivers have worsening nitrogen pollution, phosphorus pollution was improving for half of measured sites but we do not have sufficient data to measure e.coli trends for two thirds of our rivers.
Fisheries data shows that through either pollution, abstraction or modification, trout populations have collapsed in the Ruamahanga, Riuwaka, Takaka, North Ashburton, Irwell and Selwyn Rivers and lakes Ellesmere, Tutira and Hayes to name a few.
Land clearance and disturbance from forestry, high stocking rates and ploughing causes sediment to wash into rivers and estuaries during high rainfall. Sediment blankets spawning areas for fish and invertebrate habitat as well as reducing clarity.
Big irrigation schemes enable intensive agriculture which in turn increases run off and eases run off and pollution into our surface and groundwater. To date, the Government has spent less than 2% of its funds committed to such irrigation schemes. Thus continuing to irrigate will lead to a fifty fold increase above current pollution levels.
More irrigation and nutrients from animal waste and fertilisers will lead to increased freshwater pollution over the next 30 to 50 years. Our rivers and lakes will be less likely to provide safe swimming, good fishing or to sustain food gathering in the future if we carry on as we are currently.
Government freshwater standards allow for levels of nitrates toxic to fish and only sets swimmable standards for 10% of our rivers and lakes.