REMS report for 2001
Report: TR 2001/15
Author: Andrew Taylor
About this report
Information collected from the Regional Ecological Monitoring of Streams (REMS) programme in the year 2000 was analysed using a multimetric approach. Streams were classified as Excellent, Satisfactory and Unsatisfactory using a modified United States Environmental Protection Agency (USEPA) protocol. Data collected from three consecutive years starting in 1998 were also analysed using four metrics to examine trends in the invertebrate communities over time. The data from the three years was also examined for significant differences between pastoral and native streams.
The majority of the streams in the Waikato region were classified as unsatisfactory. These streams tended to be in catchments that were developed for either intensive or extensive pastoral farming. Streams that were classified as Satisfactory or Excellent were generally located in the undeveloped catchments in higher elevation areas e.g., Coromandel Ranges.
The Macroinvertebrate Community Index, Species Number, Ephemeroptera Plecoptera and Trichoptera (EPT) and Percent Ephemeroptera indices all showed consistent results over the three years with no significant differences observed. There were however, significantly higher scores for the MCI and EPT scores in the native streams over the three years. The results from 1998 showed a larger range in values for both of these indices and overlapped with the scores from the native streams. The implication from these results is that improved management of land and riparian margins is likely to significantly improve the quality of our aquatic ecosystems in the Waikato region. It is also prudent to note that some streams in the region will be more easily improved than others. More study will be required in order to prioritise the catchments in the Waikato region for improvement and increase our knowledge of the riparian management options for differing catchments.