State of the Environment Surface Water Quality in Otago 2006-2017 [pdf, 5.8 MB]
...all forms of N and P respectively in a sample. TN and TP are most relevant for assessments in lakes and coastal waters. At sufficiently elevated concentrations, nitrate and ammonia forms of nitrogen have toxic effects on aquatic biota (and on humans in the case of nitrate). This effect is independent of their significance as plant nutrients (Norton, 2012). Visual periphyton cover and biomass estimates (as chlorophyll-a); visual clarity (as black disk sighting distance) and fine de...