Annual report 2006-2007 - Taranaki Regional Council

Figure 1 Biomonitoring sites in the Kahouri Stream and an unnamed tributary
Results and discussion
At the time of this midday survey the Kahouri Stream flow had a moderately low flow (the
last flood event of three times the median flow or greater occurred 93 days prior to the
sampling date). The relatively steep gradient resulted in a steady to swift flow at all Kahouri
Stream sites (sites A, C, E, F, G and N). This flow was clear and uncoloured at all sites,
except for in the unnamed tributary site (D) which had a cloudy flow.
The stream bed material was similar throughout the Kahouri Stream sites monitored in this
survey, with stony beds dominated by gravels, cobbles and boulders. The stream bed
material in the tributary (site D) was dominated by hard clay and tree roots.
Periphyton mats and filamentous algal growths were patchy to widespread at all sites in the
Kahouri Stream except at the highest site in the catchment above all the discharges (Site A)
where only thin films of algae were present. This site is completely shaded by riparian
vegetation whereas the sites downstream of this were partially shaded. The tributary had no
periphyton mats and no algal filaments, as a result of the generally unsuitable substrate for
periphyton growth at this site.
Water temperatures recorded in the Kahouri Stream during this mid to late morning survey
ranged from 11.4°C to 11.6°C. The water temperature recorded in the tributary below the
drain from the stock car club was 12.0°C.
No significant heterotrophic growths of protozoa, bacteria or fungi were recorded at any of
the sites in the Kahouri Stream or the unnamed tributary.
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