Most of New Zealand's native freshwater species are at risk of extinction as water quality faces "serious pressures", a Government report says. The report by the Ministry for the Environment and Statistics New Zealand, titled Our fresh water environment 2017, found nearly three quarters of native freshwater fish species are threatened by or at risk of extinction, as well as a third of native freshwater invertebrates and a third of native freshwater plants. It found nitrogen levels were worsening at more than half of the measured sites. Nitrogen levels were worst at urban sites, but were declining significantly in pastoral areas. The decline in pastoral areas coincided with increased intensive agriculture. Nitrogen leaching from agriculture had increased by 29 per cent since 1990, it said. The main source was livestock urine. "New Zealand's population and agriculture-based economy are growing, and it is expected that high-intensity agriculture and urbanisation will continue to expand to new areas, potentially affecting water quality in more water bodies," the report said. The report said 72 per cent of native freshwater fish were threatened by or at risk of extinction, including four whitebait species, lamprey, and longfin eels. One species, the once-common grayling, is already extinct. A third of native freshwater invertebrates were in the same category; 10 per cent were in the highest threat category, nationally critical. The report added to mounting evidence that freshwater quality will get worse unless fundamental changes are made.
Source: Stuff, 27 April 2017
http://www.stuff.co.nz/environment/91956116/serious-pressures-facing-ri…
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