Annual report 2006-2007 - Taranaki Regional Council
Annual report 2006-2007 - Taranaki Regional Council Annual report 2006-2007 - Taranaki Regional Council
MCI value 140 120 100 80 60 40 20 0 Number of taxa and MCI values in the Kahouri Stream 150m u/s of SH3 (KHI000297) Jan-88 Jan-89 Jan-90 Jan-91 Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06 Jan-07 MCI value M edian M CI to date No. of taxa M edian no. of taxa to date Figure 4 Number of taxa and MCI values in the Kahouri Stream at site A (KHI000297) The moderately high proportion of ‘sensitive’ taxa (76% of total richness) in the community was responsible for the MCI score of 118 units, which was toward the maximum of past surveys’ scores at this site (Table 2,Table 3). The dominance (numerically) of sensitive taxa, particularly mayflies, accounted for the high SQMCIs value (6.4 units), which was equivalent to the previous maximum value recorded at this site (Table 2). Site C: Kahouri Stream (KHI000307) This site was located in the Kahouri Stream 50 m downstream of the tributary receiving the discharge from Taranaki Abattoirs and the Ballance Agri-Nutrients stormwater discharge. It is also 600 m downstream from site A. A moderate community richness of 29 taxa was recorded at this site, similar to the median number of taxa recorded from previous surveys (Table 3, Figure 5). The community was characterised by one ‘highly sensitive’ taxon Deleatidium mayflies), seven ‘moderately sensitive’ taxa (Coloburiscus and Austroclima mayflies, elmid beetles, Archichauliodes dobsonfly, Hydrobiosis and Pycnocentrodes caddisflies, and Aphrophila cranefly); and two ‘tolerant’ taxa (Aoteapsyche caddisfly and orthoclad midges). MCI value 140 120 100 80 60 40 20 0 Number of taxa and MCI values in the Kahouri Stream 50m d/s of abattoir discharge (KHI000307) Jan-88 Jan-89 Jan-90 Jan-91 Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06 Jan-07 MCI value M edian M CI to date No. of taxa M edian no. of taxa to date Figure 5 Number of taxa and MCI values in the Kahouri Stream at site C (KHI000307) The decrease in abundances of some ‘moderately sensitive’ taxa and increase in abundance of ‘tolerant’ midge taxa, resulted in a significant decrease in the SQMCIs score compared to 8 70 60 50 40 30 20 10 0 70 60 50 40 30 20 10 0 No. of taxa No. of taxa
site A upstream (Table 2) (Stark,1998). This may have been due to additional instream nutrients from the abattoir discharge and was coincident with increases in substrate cover by periphyton mats and filaments, as the less shaded nature at this site also provided a more suitable habitat for periphyton growth. There was also a significant decrease in the MCI score between sites A and C (Stark, 1998), which is indicative of recent impacts of the Taranaki Abattoir tributary on the macroinvertebrate communities in this reach of the Kahouri Stream. This is likely to be due to the impacts from the abattoir, but this is unclear without further monitoring. Therefore it is recommended that additional sites be included in subsequent surveys to assess the impact of the abattoir discharge on this unnamed tributary. This MCI score was much lower than the median of previous surveys at this site (Figure 5,Table 2), and slightly lower than the previous summer score (Figure 5). Site D: unnamed tributary (KHI000367) This site was located in a small tributary of the Kahouri Stream, 500 m downstream of the Stratford stockcar grounds, which received discharges from Taranaki Galvanizers, Egmont Tanneries and Firth Industries. The substrate was dominated by hard clay and wood roots. The survey found a moderate richness of 24 taxa, similar to the historical median for this site (Table 2). The community was characterised by five taxa (Table 3), three ‘moderately sensitive’ taxa (extremely abundant Austroclima mayfly, abundant Polyplectropus caddisfly, abundant acarina mites) and two ‘tolerant’ taxa (oligochaete worms and Austrosimulium sandfly). MCI value Number of taxa and MCI values in a tributary of the Kahouri Stream 500m d/s Stratford stockcar drain (site D) (KHI000367) 140 120 100 80 60 40 20 0 Jan-88 Jan-89 Jan-90 Jan-91 Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06 Jan-07 MCI value M edian M CI to date No. of taxa M edian no. of taxa to date Figure 6 Number of taxa and MCI values for site D in the unnamed tributary of Kahouri Stream since monitoring began in 1988 The presence of a moderately high proportion of ‘sensitive’ taxa (63% of total richness) resulted in the MCI value of 95 units, similar to the historical median for this site (Table 3, Figure 6). The SQMCIs value at this site (6.4 units), was the highest recorded at this site to date, and significantly higher than the median value (5.0) from the eight previous surveys at this site (Table 2) (Stark, 1998). The abundance of ’sensitive’ taxa, especially the extremely abundant ‘sensitive’ mayfly resulted in the high SQMCIS value, indicating that industrial discharges upstream of this site had not had a recent detrimental effect on the macroinvertebrate communities of this stream, and that discharges may have even improved. 9 70 60 50 40 30 20 10 0 No. of taxa
- Page 173 and 174: To Job Manager, B Jansma From Scien
- Page 175 and 176: Figure 1 Biomonitoring sites in the
- Page 177: Table 3 Macroinvertebrate fauna of
- Page 182 and 183: Site E: Kahouri Stream (KHI000400)
- Page 184 and 185: mayflies, elmid beetles, Archichaul
- Page 186 and 187: Further downstream at Flint Road, t
MCI value<br />
140<br />
120<br />
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40<br />
20<br />
0<br />
Number of taxa and MCI values in the Kahouri Stream 150m u/s of<br />
SH3 (KHI000297)<br />
Jan-88<br />
Jan-89<br />
Jan-90<br />
Jan-91<br />
Jan-92<br />
Jan-93<br />
Jan-94<br />
Jan-95<br />
Jan-96<br />
Jan-97<br />
Jan-98<br />
Jan-99<br />
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Jan-02<br />
Jan-03<br />
Jan-04<br />
Jan-05<br />
Jan-06<br />
Jan-07<br />
MCI value M edian M CI to date<br />
No. of taxa M edian no. of taxa to date<br />
Figure 4 Number of taxa and MCI values in the Kahouri Stream at site A (KHI000297)<br />
The moderately high proportion of ‘sensitive’ taxa (76% of total richness) in the community<br />
was responsible for the MCI score of 118 units, which was toward the maximum of past<br />
surveys’ scores at this site (Table 2,Table 3). The dominance (numerically) of sensitive taxa,<br />
particularly mayflies, accounted for the high SQMCIs value (6.4 units), which was equivalent<br />
to the previous maximum value recorded at this site (Table 2).<br />
Site C: Kahouri Stream (KHI000307)<br />
This site was located in the Kahouri Stream 50 m downstream of the tributary receiving the<br />
discharge from <strong>Taranaki</strong> Abattoirs and the Ballance Agri-Nutrients stormwater discharge. It<br />
is also 600 m downstream from site A. A moderate community richness of 29 taxa was<br />
recorded at this site, similar to the median number of taxa recorded from previous surveys<br />
(Table 3, Figure 5). The community was characterised by one ‘highly sensitive’ taxon<br />
Deleatidium mayflies), seven ‘moderately sensitive’ taxa (Coloburiscus and Austroclima<br />
mayflies, elmid beetles, Archichauliodes dobsonfly, Hydrobiosis and Pycnocentrodes<br />
caddisflies, and Aphrophila cranefly); and two ‘tolerant’ taxa (Aoteapsyche caddisfly and<br />
orthoclad midges).<br />
MCI value<br />
140<br />
120<br />
100<br />
80<br />
60<br />
40<br />
20<br />
0<br />
Number of taxa and MCI values in the Kahouri Stream 50m d/s of<br />
abattoir discharge (KHI000307)<br />
Jan-88<br />
Jan-89<br />
Jan-90<br />
Jan-91<br />
Jan-92<br />
Jan-93<br />
Jan-94<br />
Jan-95<br />
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Jan-99<br />
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Jan-03<br />
Jan-04<br />
Jan-05<br />
Jan-06<br />
Jan-07<br />
MCI value M edian M CI to date<br />
No. of taxa M edian no. of taxa to date<br />
Figure 5 Number of taxa and MCI values in the Kahouri Stream at site C (KHI000307)<br />
The decrease in abundances of some ‘moderately sensitive’ taxa and increase in abundance<br />
of ‘tolerant’ midge taxa, resulted in a significant decrease in the SQMCIs score compared to<br />
8<br />
70<br />
60<br />
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70<br />
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No. of taxa<br />
No. of taxa
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