Page content Page content Section navigation Topic navigation Accessibility keys Sitemap Search Contact us www.govt.nz portal
Go to Waikato Regional Council homepage
search icon mail icon contact us icon

  Services » Publications » Technical reports - by year » tr201227

The ecological condition of Waikato wadeable streams based on the Regional Ecological Monitoring of Streams (REMS) Programme

On this page: Abstract, table of contents

Report: TR 2012/27

Author: Kevin Collier, Mark Hamer

Abstract

The Waikato Regional Council has been carrying out summer assessments of invertebrate community composition and habitat in streams and rivers annually since 1994 for the Regional Ecological Monitoring of Streams (REMS) programme. The aim of this work is to document the state and trend of ecological health in the region‘s streams as part of State of the Environment monitoring. The current sampling network comprises (i) ‗long-term sites‘ that have been sampled for 10 years or more using consistent protocols for assessment of trends over time (40 sites including 3 reference sites and 6 ‗restoration‘ sites where riparian management has been implemented or is planned) (ii) ‗random sites‘ selected using a probability-based survey design to provide an unbiased estimate of the regional condition of perennial non-tidal wadeable streams on developed land (60 sites sampled once each year for 3 years–180 sites in total; this cycle is repeated every 3 years); and (iii) ‗reference sites‘ in undeveloped (native forest) catchments to provide a baseline against which to measure change (24 sites sampled annually since 2005). The sites include wadeable hard-bottom streams with stony beds, and wadeable soft-bottom streams with beds dominated by sand and silt. Some long-term sites on rivers that are not wadeable have been retained while appropriate non-wadeable monitoring protocols are developed.

The ecological condition of Waikato wadeable streams based on the Regional Ecological Monitoring of Streams (REMS) Programme (2MB)

Table of contents

  Acknowledgements i
  Summary vi
1 Introduction 1
2 Network design 2
2.1 Reference site monitoring network 2
2.2 Long-term site monitoring network 2
2.3 Random site monitoring network 6
3 Methods 9
3.1 Sample collection and data compilation 9
3.2 Statistical analyses 10
3.2.1 Trend analysis (long-term sites) 10
3.2.2 State analysis (random sites) 10
4 Results & Discussion 11
4.1 Ecological state (random sites) 11
4.1.1 Reference sites 11
4.1.2 Physical characteristics 11
4.1.3 Macroinvertebrate condition metrics 13
4.2 Ecological trends (long-term sites) 15
4.2.1 Overall trends 15
4.2.2 Site trends 17
4.2.3 Relationships with water quality trends 20
5 Key findings 21
References 22  
Appendix 1: Effects of sampling substrate on macroinvertebrate metrics 24
Appendix 2: Effects of stand down triggering flood event on macroinvertebrate metrics  
Appendix 3: Summary statistics from spsurvey for physical variables and plant metrics measured at randomly selected sites (probability design) over 2009-11 (all years combined, n = 180). 27
Appendix 4: Summary statistics from spsurvey for macroinvertebrate metrics measured at randomly selected sites (probability design) over 2009-11 (all years combined, n = 180). 29
Appendix 5: Cumulative distribution function plots for metrics calculated using spsurvey for each year (2009, 2010, 2011) and for all 3 years combined. 31
Appendix 6: Macroinvertebrate metrics for reference sites sampled over 2009-11. 48
Appendix 7: Mann Kendall trend results for MCI and ASPM. 51
Appendix 8: Time-series plots of invertebrate trend metrics. 65
Appendix 9: Provisional water quality trends (not flow-adjusted) at sites where water quality (RRIMP) and ecological (REMS) monitoring overlap. 72
About this site     Contact us     Feedback and complaints New Zealand Government