Mangakotukutuku Stream Care Group Inc.
The streams and other aquatic habitats
FishNine species of native fish are known in the Mangakotukutuku Stream system. All of these species have been caught in the Peacockes branch, and 3-4 in the Rukuhia and Te Anau branches and their associated tributaries.
Most parts of Mangakotukutuku Stream are too turbid to support aquatic plants. However, some growths of the shade-tolerant native charophyte Nitella and the floating-leaved starwort (Callichtriche stagnalis) do occur in shallow margins. Filamentous algae and mosses are also
present in some parts on stable substrates such as
large rocks and logs.
|There are around 18 km of stream mapped in the Mangakotukutuku catchment. In
addition to the three main branches which have rural headwaters,
several small tributary streams that start in the suburbs and have
varying levels of influence from stormwater drainage. Small
seepages also occur throughout the gullies. These small streams
and seepages can provide important habitat for native
Poor streambed stability has been identified as the major ecological stressor in the Mangakotukutuku, followed by lack of habitat cover and heavy metal contamination (Williamson 2001). Peak flows from stormwater along with rural runoff contribute to streambed instability and poor habitat quality. The main part of Mangakotukutuku Stream running through
Along with habitat quality, water quaity is a very important factor influencing the range of species that can live in the stream. The Mangakotukutuku has been monitored for water quality at Peacockes Road by Environment Waikato monthly since 1990 (Beard 2011). Two other major streams in Hamilton City, the Kirikiriroa and Waitawhiriwhiri, are also monitored for water quality.
|What is measured?||How much is there?
(based on annual
median values in 2005)
|Is that good or bad?||Is it going up or down?||How does it compare to the two other major Hamilton streams?|
|Water acidity (pH)||7.0||OK||Going down||Similar|
|Ammonia||0.72 g N/m3||OK||Stable||Lowest|
|Phosphorus||0.43 g/m3||Poor||Going up||Highest|
|Bacteria (E. coli)||1260 per 100 mL||Poor||Stable||Highest|
Turbidity - a measure of light scattering or light availability for plant growth; tells us something about how dirty the water is
Water temperature - measured using a thermometer; tells us how hot the water gets
Dissolved oxygen - amount of oxygen dissolved in the water as a percentage of oxygen saturated water; tells us whether there is enough oxygen for aquatic life
Water acidity - measure of whether the water is acid (pH below 7) or alkaine (pH above 7); water that is too acid or too alkaline can be bad for aquatic life
Ammonia - measure of ammoniacal nitrogen which can be toxic to fish in high concentrations
Bacteria (E. coli) - number of colony forming Escherichia coli bacteria in 100 mL of streamwater; tells us how polluted the water is from mammalian wasteFind out more about water quality and sources of contaminants in Mangakotukutuku Stream.