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Dr. Mike Joy
Senior Lecturer; Environmental Science/Ecology
Ecology group-Institute of Natural Resources-(PN-624)
Te Kura Matauranga o nga Taonga a Papatuanuku
Massey University
Private Bag 11 222
Palmerston North 4442
New Zealand
Ph. 64 6 3505799 ext 7363
Mob. 021 936205
Fax. 64 6 350 5623


Submission on Wellington City Council’s Resource Consent Application for Westchester Drive extension


1    Qualifications and experience

1.1    I hold a BSc, MSc (1st Class Hons) and a PhD in Ecology from Massey University.   For the last fifteen years I have been a researcher in freshwater ecology, especially native fish distribution and freshwater bioassessment.  I have been employed at Massey University Palmerston North since 2003 as a lecturer, now Senior Lecturer, in Ecology and Environmental Science. 

1.2    I am a member of the New Zealand Freshwater Sciences Society, the New Zealand Ecological Society, the Australian Society of Fish Biology and the New Zealand Royal Society.

1.3    In the last seven years I have published more than 15 peer reviewed scientific papers on freshwater ecology and bioassessment, mostly in relation to New Zealand freshwater fish, and the majority of these papers are published in international journals (Appendix 1). I have published two book chapters on native fish and bioassessment.  I am a regular reviewer of scientific papers for a number of International freshwater related journals. I have also published many reports for most regional councils in the North Island, and have supplied software to run bioassessment models developed for these regions.  Many of these council reports relate specifically to the Wellington region (see Appendix 1).

1.4    In the last seven years I have sampled fish and invertebrate communities from freshwaters at more than 1000 sites in the North Island, 550 of these were for my PhD study between 2000 and 2003.  Since 1999, I have sampled at least 350 sites in the Wellington Region.  I have supervised the research around freshwater ecosystems of 16 postgraduate students in the last 10 years, many in the Wellington Region.

I am making this submission on behalf of Glenside Progressive Association Inc.

2    Scope of submission - I will comment on:

•    Effects of sediment on biological communities and failings in how sediment is measured.
•    Effects of sediment on waterways and the likely impacts on Porirua Harbour.
•    Impacts of flocculation chemicals used in settlement ponds, if these are under-engineered and breached.
•    What should be monitored, and how, in relation to stream communities.
•    The Assessment of Environmental Effects (AEE)

3    Introduction

I have read most of the documentation relating to freshwater ecological issues for the proposed Westchester Drive extension.  I agree in general with the Greater Wellington Regional Council officers’ report, but feel they didn’t place enough emphasis on the effects of deposited sediment on stream ecosystems, or on the importance of taking duration into account when considering the effects of suspended sediment (I have specific comments below).


More emphasis must be placed on the need for continuous sediment monitoring, and this requirement is lacking from the monitoring recommendations of the officers’ report.

It is obvious to any resident in the Wellington Region over the last few years that sediment is a significant issue for freshwaters and harbours.  This suggests Greater Wellington sediment guidelines are not strong enough, or they are not followed by developers or consents are being breached. The current view seems to be that sediment impacts are inevitable and should be minimised, this is neither true nor acceptable.  I will demonstrate the importance of the interstitial spaces deep in the stream substrate for fish species and refer to a powerpoint  description of some recent work in this area.  (NB: Powerpoint not provided on website)

I will address the specifics of these reports at the end of my submission.

3.1    Effects of sediment on biological communities and failings in how sediment is measured

The effects of sediment on stream biological communities are many and complex, but first must be considered at two levels; that is (1) suspended sediment, and (2) deposited sediment .  Unfortunately the first, suspended sediment is most easily measured and is thus the most often measured.  However, it is generally of lesser importance than deposited sediment in relation to measuring sediment’s effect on biological communities.  
Suspended sediment impacts in many ways covered already by many reports in this hearing, but include:

•    clogging the gills of fish and stream invertebrates – this can be lethal if it persists for some time but is species specific and there are no general rules.
•    reducing visibility for visual feeders
•    reducing light reaching into the stream for photosynthesis - which reduces algae and macrophytes, thus reduces food availability for invertebrates and fish.

Deposited sediment impacts include:

•    the blocking and sealing of interstitial spaces (the spaces between stones where most native stream fauna live or rest)
•    sealing of bed surface (colmation) – which isolates interstitial water from overlying river water and underlying hyporheic water (water under the stream bed). Movement across the boundary between water under the stream bed and surface water is crucial for stream life in the hyporheic zone  
•    degrading or destroying the interstitial habitat for invertebrates and fish
•    degrading fish spawning habitat.

Deposited sediment is generally not measured by regional councils in New Zealand or the Ministry for the Environment in New Zealand, even though it is considered to be one of the most pervasive impacts on New Zealand freshwaters. 

3.2    Effects of sediment on waterways and the likely impact on Porirua Harbour

The increase in sediment deposition in the Porirua Harbour over the last few decades is obvious from historic photos and recent surveys . The effects of this deposited sediment on the Porirua stream and the harbour are difficult to tease out from the multiple other impacts that have taken place over this time (such as, run off of agricultural chemicals and point source pollution discharges affecting water quality), but it is my opinion that this sediment would be one of the most important adverse influences on the health of a natural ecosystem.  Suspended sediment can be tolerated for some time by fish and shellfish, but it will eventually be lethal at high levels , thus the intensity and duration of sediment flows is critical - again, this is not generally included in monitoring of sediment.  Importantly, recent research has shown that land based activities have had drastic impacts on coastal fisheries .  Thus the impacts of sedimentation are not limited to the immediate receiving environment; rather they flow on to a loss of ecosystem services, thus affecting many more people.

3.3    Impacts of flocculation chemicals used in settlement ponds, if these are under-engineered and breached

Because flocculation chemicals usually include aluminium, which has many toxic effects on fish and stream invertebrates , if they are not contained they can be lethal in streams and eventually the harbour.  Similar chemicals used to clear water in water supply plants in Palmerston North (Turitea Stream) and Wellington (Wainuiomata River) have had lethal impacts on stream life when these plants have accidently back-flushed into streams .  Thus, these ponds must be substantially oversized to withstand any unexpected rainfall to ensure overflow does not occur. 

3.4    Recommendations - What should be monitored and how in relation to stream communities

3.4.1  Suspended sediment:

To effectively monitor suspended sediment, it must be done continuously or as near as continuous as possible.  I note that the water quality monitoring done at the nearby project West Wind  failed to pick up obvious serious sediment pollution, so lessons can be learned from this monitoring regime’s failures.  A number of the parameters measured are totally superfluous.  For example, dissolved oxygen, ph and temperature vary diurnally, so one-off measures are a waste of time and effort.  Effort would be better put into meaningful measures, such as deposited sediment or continuous monitoring.  It is the daily variation and or minimum and maximum values for oxygen, ph and temperature that are important for these parameters, not one-off measures.

3.4.2  Deposited or settled sediment:

The relative importance of deposited sediment versus suspended sediment depends on the length of time that sediment remains suspended in the water column.  If suspended sediment continues at high levels for a long time then it is lethal.  If however, it is for short periods, then the deposited material is more hazardous.  A number of simple measures can and should be used to monitor deposited sediment, for example:

•    NIWAs’ quorer is a simple method for estimating deposited fine sediment .  This is a bottomless bucket placed on the stream bed, the substrate is mobilised with a stirrer and a water sample taken.  Also, residual pool depth can be measured to indicate deposition over time.  

•    For the Harbour, large sheets of metal can be anchored to the stream bed and deposition rates measured directly by the depth of sediment that accrues.

4    Wellington City Council Assessment of Environmental Effects

4.1    Mention is made of aquatic invertebrate communities, and sediment control - as noted above, no sediment is acceptable furthermore these suspended sediment effects relate to duration rather than intensity and are generally, if short term, of less importance that sediment settling out.  Many New Zealand studies have shown that even small amounts of deposited sediment makes periphyton unpalatable for stream invertebrates .  

Appendix F:
Section 2.5 page 3 “habitat appears to be degrading and is now considered marginal” this is a subjective assessment.  The fact that Giant kokopu are present here shows that it is a refuge in a degraded system and this assessment should not be used as an excuse to allow further degradation.  On the contrary, this stream should be afforded greater levels of protection as it contains 2 threatened endemic species.   This was agreed by Mr Fuller in his evidence presented on Monday  section 4.12 “the stream still contains a high diversity of native fish relative to the regional average”

Steven Fullers Evidence presented on Monday

4.2    In 4.14 p 6 Mr Fuller said “Despite this diversity, the dominance of some species and the size classes present, indicate an ecosystem under stress and out of balance.”  I agree with this statement and this highlights the need to ensure no further impacts on the stream ecology as it may be close to collapse.

4.3    In his section 5.3  on p 8 Mr Fuller stated that “The steepness of the site and close proximity to the stream has restricted the range of tools that could be used for treatment and it has not been possible to achieve the degree of water quality management that would be expected of a project on a gentler site”, - if this is true and sediment management cannot be achieved then surely the activity cannot be allowed to take place.

4.4    In his water quality section on page 12 Mr Fuller stated that “Many submitters were concerned that the quality of stream water will deteriorate irreversibly as a result of this development. I disagree that this is a likely outcome of this project and am confident that with careful monitoring effects from sediment discharges can be minimised.” I disagree with this statement. I contend that careful monitoring will not stop harmful effects only efficient engineering could achieve this. Monitoring will at best only pick up impacts after they have happened, and in the case of deposited sediment as I have explained is by then too late. 

4.5    In his conditions section Schedule 8 pg 17 Mr Fuller says “The stream is already so heavily silted from existing activities in the catchment I do not believe it will be possible to detect small changes in sediment deposition.”  This highlights the failures in sediment control of previous developments and I’m sure that at the consent hearings for those developments the applicants would have made the same claims being made here i.e. that the sediment control systems will protect the stream ecosystem when obviously they do not.

4.6     He later says “It is therefore my opinion that monitoring of sediment disposition will be of academic interest only and I do not believe monitoring of deposited sediment should be requirement.”  -  As I have pointed out above the impacts of sediment deposition is not only academic but is in my opinion as an active researcher in this area the most pervasive impact on stream life in this catchment.

4.7    Mr Fuller later in evidence focused on an adaptive management programme for management of site works, monitoring and management of stormwater structures and sediment removal from stormwater before discharge to the stream. The idea of adaptive management is that you adapt to changing conditions, but this only happens after the impact has occurred and only if it is picked up by monitoring.  I contend that given the perilous state of this freshwater ecosystem that a more prudent approach would be to engineer the sediment control systems to ensure there is no impact to be picked up that will have to be adapted to after the damage has been done.  

5    The officers report: The report to the Hearing Committee (no officer’s name in report)

Section 10.1.3
Existing sedimentation pressures – this section provides an admission that other developments have had sediment-related impacts on waterways and even suggests that developments not yet consented will add to sediment entering waterways. However, the report then suggests that the consented cleanfill site should have a negligible effect on Stebbings stream.  It is not made clear why this would be the case – the officer appears to indicate that this is either because it is several kilometres away or because there are multiple stormwater inputs.  Neither of these explanations make sense to me.

Section 10.1.4
Fish and invertebrate communities – in the fish section it is noted that the presence of giant kokopu is significant because they are threatened but fails to point out that longfin eels are also a threatened species.

Section 10.3.1
In this section the officer states that he/she cannot categorically state that the erosion control measures will adequately treat sediment run-off.  This is not acceptable; there must be zero tolerance for sediment run-off.


6    Conclusions

The negative impacts on stream ecology are multifaceted and site dependant, however, in general, physical changes such as sedimentation often override all other impacts in New Zealand streams where forest has been cleared.  In the case of the proposed project the construction work will potentially impact on streams by increasing sedimentation rates.

The Porirua Stream and Porirua Harbour are already stretched to the limits of their ecological resilience by many existing factors, and any increase may push them beyond this point. Degradation of aquatic ecosystems never present as linear declines - they inevitably have sudden collapse  and predicting the threshold for such is impossible. The precautionary principle must be applied here and the sediment control measures used in this case must be oversized to the extent required to ensure there is no chance of sediment entering waterways.  Strict continuous monitoring of sediment entrainment and deposition must be employed so that immediate action can be taken should any sedimentation occur.  

Appendix 1:  Research/Scholarship

Selected refereed journal papers

Atkinson, N. K. and M. K. Joy. 2009. Longitudinal size distributions of bluegill bullies (Gobiomorphus hubbsi) and torrentfish (Cheimarrichthys fosteri) in two large New Zealand rivers. New Zealand Journal of Marine and Freshwater Research 43.

Lewis, R. M., A. Bergeren, D. Armstrong, R. Boulton, and M. K. Joy. 2009. Artificial nest use to predict nest survival at reintroduction sites. New Zealand Journal of Ecology 33.

Atkinson, N., and M. K. Joy. 2008. Response of Gobiomorphus hubbsi (bluegill bully) to odours of conspecific fish in the presence of natural stream odours: does habitat have an influence? New Zealand Journal of Marine and Freshwater Research 42.

Olden, J. D., M. K. Joy, and R. G. Death. 2006. Rediscovering the species in community-wide predictive modeling. Ecological Applications 16:1449-1460.

Low, M., M. K. Joy, and T. Makan. 2006. Using regression trees to predict patterns of male provisioning in the stitchbird (hihi). Animal Behaviour 71:1057-1068.

Joy, M.K. & Death, R.G. (2004) Predictive modelling and spatial mapping of freshwater fish and decapod assemblages: an integrated GIS and neural network approach. Freshwater Biology, 49, 1036-1052.

Joy, M.K. & Death, R.G. (2004) Application of the index of biotic integrity methodology to New Zealand freshwater fish communities. Environmental Management, 34, 415-428.

Olden, J.D., Joy, M.K., & Death, R.G. (2004) An accurate comparison of methods for quantifying variable importance in artificial neural networks using simulated data. Ecological Modelling, 178, 389-397.

Death, R.G. & Joy, M.K. (2004) Invertebrate community structure in streams of the Manawatu-Wanganui region, New Zealand: the roles of catchment versus reach scale influences. Freshwater Biology, 49, 982-997.

Duignan, P. J., P. M. Hine, M. K. Joy, N. Gibbs, G. W. Jones, and C. Okeoma. 2003. Disease surveillance in freshwater fish from the lower North Island. Surveillance 30:6-8.

Joy, M. K., and R. G. Death. 2003. Biological assessment of rivers in the Manawatu-Wanganui region of New Zealand using a predictive macroinvertebrate model. New Zealand Journal of Marine and Freshwater Research 33:367-379.

Joy, M. K., and R. G. Death. 2003. Assessing biological integrity using freshwater fish and decapod habitat selection functions. Environmental Management 32:747-759.

Joy, M. K., and R. G. Death. 2002. A discriminant analysis investigation of reference site fish assemblages in the Manawatu-Wanganui region, North Island, New Zealand. Verhandlungen der Internationalen Vereinigung fur Theoretische und Angewandte Limnologie 28:319-322.

Joy, M. K., and R. G. Death. 2002. Predictive modelling of freshwater fish as a biomonitoring tool in New Zealand. Freshwater Biology 47:2261-2275.

Joy, M. K., and R. G. Death. 2001. Control of freshwater fish and crayfish community structure in Taranaki, New Zealand: dams, diadromy or habitat structure? Freshwater Biology 46:417-429.

Joy, M. K., and R. G. Death. 2000. Development and application of a predictive model of riverine fish community assemblages in the Taranaki region of the North Island, New Zealand. New Zealand Journal of Marine and Freshwater Research 34:243-254.

Joy, M. K., and R. G. Death. 2000. Stream invertebrate communities of Campbell Island. Hydrobiologia 439:115-124.

Joy, M. K., I. M. Henderson, and R. G. Death. 2000. Diadromy and longitudinal patterns of upstream penetration of freshwater fish in Taranaki, New Zealand. New Zealand Journal of Marine and Freshwater Research 34:531-543.

Chapters in books

Joy, M. K. (2006). Fish in freshwaters. Pages 166-172 in B. Harvey and T. Harvey, editors. Waitakere Ranges. Waitakere Ranges Protection Society, Auckland.

Joy, M.K. & Death, R.G. (2005). Neural network modelling of freshwater fish and macro-crustacean assemblages for biological assessment in New Zealand. In Modelling community structure in freshwater ecosystems (eds S. Lek, M. Scardi, P.F.M. Verdonschot, J.P. Descy & Y.S. Park), pp. 518. Springer, Berlin Heidelberg New York.

Selected research/technical publications

Belgrave, M., A. Bennett, J. Millner, A. James, M. Joy, D. Belgrave, S. Gardiner, J. Procter, and J. Watson. 2008. RAUKAWA WATERWAYS AND ENVIRONMENTAL IMPACT. Massey University.

Rowe, D., K. Collier, C. Hatton, M. K. Joy, J. Maxted, S. Moore, M. Neale, S. Parkyn, N. Phillips, and J. Quinn. 2008. Stream Ecological Valuation (SEV): a method for scoring the ecological performance of Auckland streams and for quantifying environmental compensation =- 2nd edition.

James, A., and M. K. Joy. 2008. A preliminary assessment of potential barriers to fish migration in the Manawatu River catchment, North Island, New Zealand. "A report prepared for Horizons Regional Council, June 2008." - "Massey University, Foundation of Research, Science & Technology." - Includes bibliographical references (p. 120-121). EnviroLink Contract Ref: 437-HZLC45, Massey University.

Joy, M. K. (2008). A Fish Index of Biotic Integrity using quantile regressions Fish QIBI for the Auckland Region, Massey University.

Joy, M. K. (2007). A new fish Index of Biotic Integrity using Quantile regressions: the Fish QIBI for the Waikato Region.

Kelly, F., T. Champ, T. McDonnell, M. Kelly-Quinn, S. Harrison, A. Arbuthnott, P. Giller, M. Joy, K. McCarthy, P. Cullen, P. Jordan, D. Griffiths, and R. Rosell. 2007. Investigation of the Relationship between Fish Stocks, Ecological Quality Ratings (Q-Values), Environmental Factors and Degree of Eutrophication. ENVIRONMENTAL PROTECTION AGENCY, Dublin.

Rowe, D., Quinn, J.F., Collier, K., Hatton, C., Joy, M.K., Maxted, J., Moore, S.J., & Parkyn, S.M. (2005). Ecological valuation: a method for scoring the ecological performance of perennial Auckland streams, Rep. No. HAM2004-073. national Institute of Water and Atmospheric Research, Hamilton.

Joy, M.K. (2005). A fish Index of Biotic Integrity (IBI) for the Wellington Region. Massey University, Palmerston North.

Joy, M.K. (2005). A Fish Index of Biotic Integrity (IBI) for the Waikato Region. Massey University, Palmerston North.

Joy, M.K. (2005). Point-click-fish a predictive model of fish occurrence for the Hawkes Bay region. Centre for Ecosystem Modelling and Management; Massey University, Palmerston North.

Joy, M.K. (2004). A Predictive Bioassessment Model using Fish for Southern Ireland. Massey University, Palmerston North.

Joy, M.K. (2004). A Fish Index of Biotic Integrity (IBI) for the Auckland Region. Massey University, Palmerston North

Joy, M. K. 2002. Freshwater fish survey of the Wellington Region a report to the Wellington Region Council. Massey University, Palmerston North.

Joy, M. K. 2002. Freshwater fish survey of the Wellington Region: a report to the Wellington Regional Council. A report to the Wellington regional Council Massey University, Palmerston North.

Joy, M. K. 2002. Lake Pounui Fish Survey. A report prepared for the Wellington Regional Council Massey University, Palmerston North.

Joy, M. K., and R. G. Death. 2002. The potential for enhancement of fish communities of a fish pass on the Orongorongo Intake Dam. A report to the Wellington Regional Council. Massey University, Palmerston North.

Phillips, J., and M. K. Joy. 2002. Native fish in the Manawatu-Wanganui Region. State of Environment Report 2002/EXT/489, horizons.mw, Palmerston North.

Rebergen, A. R., and M. K. Joy. 1999. Freshwater fish survey of the Aorangi Range, Wairarapa. Department of Conservation, Masterton.

Joy, M. K. 1999. Freshwater fish in the upper Manawatu River: a contribution to a life supporting capacity study. A Report to the Manawatu-Wanganui Regional Council Massey University, Palmerston North.

Joy, M. K. 1999. Freshwater fish survey of the Manawatu dune lakes. A Report to the Manawatu-Wanganui Regional Council Massey University, Palmerston North.

Joy, M. K. 1999. Native Fish Diversity and Distribution in Selected Tributaries of the Oroua River: a contribution to a Study of the Life Supporting Capacity of the Oroua River. A Report to the Manawatu-Wanganui Regional Council Massey University, Palmerston North.

Joy, M. K. 1998. Freshwater fish diversity and distribution in the Ohakune area: a contribution to a study of the environmental impact of vegetable washing. A report to the Manawatu-Wanganui Regional Council Massey University, Palmerston North.

Joy, M. K. 1998. Native fish diversity in the Oroua River and tributaries: a contribution to a study of the life supporting capacity of the Oroua River. A report to the Department of Conservation and the Manawatu-Wanganui Regional Council.


Joy, M.K. (2005) A Fish Index of Biotic Integrity (IBI) for the Wellington Region, Bioassessment software, Massey University Palmerston North.

Joy, M.K. and 2005 Point-click-fish. GIS predictive software for the Hawkes Bay Region New Zealand.

Joy, M.K. (2004) A Fish Index of Biotic Integrity (IBI) for the Auckland Region, Bioassessment software, Massey University Palmerston North.

Joy, M.K. and 2003 Point-click-fish. GIS predictive software for the Wellington Region Massey University New Zealand.

Selected addresses to professional bodies

Joy, M. K. 2008. State of the environment or state of denial; freshwaters in crisis. At  Sustainable New Zealand: Rhetoric or Reality? ECO 2008 conference, Wellington.

Joy, M. K. 2007. Using Predictive models to assess the extent of freshwater fish  habitat and biodiversity loss. At  Water: an inconvenient truth; joint meeting of the New Zealand and Australian Freshwater Sciences Societies.

Joy, M.K. & Death, R.G. (2004) Using GIS and neural networks to create fish habitat suitability maps. Presented at: Fourth International Workshop on Environmental Applications of Machine Learning and the Fourth European Conference on Ecological Modelling, Bled, Slovenia

Joy, M.K. & Death, R.G. (2004) Application of the Index of Biotic Integrity to New Zealand freshwater fish communities. In 38th Annual Conference of the New Zealand Limnological Society, Waiheke Island, Auckland

Death, R.G. & Joy, M.K. (2004) Mapping distribution of freshwater fish and decapods in GIS: extending point samples to regional coverage. Presented at: Annual Conference of the North American Benthological Society, Vancouver, Canada

Joy, M. K., and R. G. Death. 2003. Using neural networks and GIS to predict the spatial occurrence of freshwater fish and decapods. Presented at: Ecological Society of Australia Conference. Armidale, NSW, Australia

Joy, M.K. & Death, R.G. (2003) Point-click-fish a predictive bioassessment modelling tool. Presented at The Australian Society for Fish Biology annual conference, Victoria University, Wellington New Zealand

Joy, M.K. & Death, R.G. (2002) Neural network modelling of freshwater fish and macro-crustacean assemblages for biological assessment in New Zealand. Presented at: 3rd Conference of the International Society for Ecological Informatics, Rome, Italy