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  Services » Publications » Technical reports - by year » tr201220

Review of the Waikato Regional Council shallow lakes indicators project

On this page: Abstract, table of contents

Report: TR 2012/20

Author: D Ă–zkundakci and DP Hamilton (University of Waikato)

Abstract

This report was commissioned to provide an independent review of Waikato Regional Council's shallow lakes indicators project.

The primary objectives of this review were to determine:

  • whether shallow lake indicators as used currently are appropriate for the
    purposes of evaluating lake health and effectiveness of management activities
  • whether the frequency of monitoring as currently employed is sufficient for
    these purposes
  • whether additional indicators exist that should be investigated for future
    monitoring purposes.

Review of the Waikato Regional Council shallow lakes project (1mb)

Table of contents

  Executive summary v
1 Introduction 7
2 Methods 10
2.1 Adequacy of sampling frequency 10
2.2 Regime shift and/or alternative stable states 11
2.3 Alternative indicators 12
3 Results 12
3.1 Adequacy of sampling frequency 12
3.1.1 Variability of water quality variables across different temporal scales 12
3.1.2 Is December, March and May the most stressful period of the year? 17
3.1.3 Implications of variability on the ability to detect changes in water quality 18
3.1.4 Comparison of TLI vs Rotifer TLI 21
3.2 Regime shift and/or alternative stable states 22
3.2.1 Signs of regime shift and/or alternative stable states in the Waikato shallow lakes 22
3.3 Alternative indicators 25
3.3.1 Hypolimnetic oxygen demand 25
3.3.2 Phytoplankton as biological indicators for lake health 26
4 Discussion 27
4.1 Variability of water quality variables 27
4.2 Comparison of TLI vs Rotifer TLI 28
4.3 Evidence of regime shifts and/or alternative stable states 28
  References 30
  Appendix I : Water quality monitoring methodology and sampling (Waikato Regional Council) 33
  Appendix II : Annual CV values of different water quality variables 35
  Appendix III : Seasonal CV values of different water quality variables 43
  Appendix IV : Monthly CV values of different water quality variables 51
  Appendix V : Compilations of CV values across different temporal scales 59
  Appendix VI : Probability distributions for trophic state variables in eight lakes 62

 

 

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