A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment

Maurice Duncan Peter Wilkins

Prepared for Ministry of Agriculture and Forestry Biosecurity New Zealand

NIWA Client Report: CHC2006-071 June 2006 NIWA Project: MAF06508

AgriQuality Ltd 14 Sir William Pickering Drive, Private Bag 4718 Christchurch Phone +64-3-358 1842, Fax +64-3-358 6222 www.agriquality.com

National Institute of Water & Atmospheric Research Ltd 10 Kyle Street, Riccarton, Christchurch P O Box 8602, Christchurch, New Zealand Phone +64-3-348 8987, Fax +64-3-348 5548 www.niwa.co.New Zealand

Contents

Executive Summary i 1. Introduction. 1 2. Ongoing passive surveillance 2 3. Nationwide survey April -May 2006 6 4. Summary and conclusions 18 5. Acknowledgements. 19 6. References. 20 Appendix 1: Ongoing passive surveillance summary of samples 22 Appendix 2: Criteria for ranking of sites 28 Appendix 3: Briefing Report for the delimiting survey 58 Appendix 4: Field Sample Form 67 Appendix 5: Summary of suvery results 69

Reviewed by: Approved for release by:

Cathy Kilroy Murray Towler

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites likelymost for its introduction and establishment ii

Executive Summary

1. The introduced invasive diatom Didymosphenia geminata (didymo) was first identified in the Mararoa and lower Waiau Rivers, Southland, in October 2004. An initial delimiting survey in December 2004 found no evidence of D. geminata in adjacent rivers.

2. Ongoing passive surveillance by Fish and Game Councils, Regional/District Councils, Department of Conservation and Crown Research Institutes who had been provided D. geminata identification sheets by Biosecurity New Zealand in December 2004 have resulted in the submission of multiple suspect samples from around New Zealand. All of these suspect samples had been negative until 27 September 2005, when a NIWA – Fish & Game team discovered D. geminata blooming in the Buller River. This spurred the rapid discovery of further occurrences reported within days from the Hawea and upper Clutha Rivers in Otago and the upper Waiau and Oreti Rivers in Southland.

3. Given the wide geographical spread of the new infestations, priority was given to determine quickly whether the distribution of D. geminata had extended to elsewhere in New Zealand. A second delimiting survey, originally planned for spring 2005 in Otago and Southland, was expanded to cover high-risk sites nationwide.

4. The objective of the October 2005 nationwide survey was to detect the presence of D. geminata in high-risk sites where it was likely to have been introduced by human activity and where it was likely to have established due to environmental suitability. That survey of 492 sites found D. geminata in samples from seven sites from four rivers in the nationwide survey. The Von River, Southland, was the only one from which D. geminata had not been previously identified from the ongoing passive surveillance.

5. Biosecurity New Zealand has planned quarterly D. geminata delimiting surveys, at least for 2006, with smaller surveys alternating with larger ones. The survey reported here is the third survey in the series and is one of the larger surveys.

6. The 400 site survey reported here was mainly a subset of the sites for October 2005 survey. Sites for the nationwide survey were distributed between the North (139 sites, 35%) and South (261 sites, 65%) Islands. South Island sites were selected according to a ranking system that used the following criteria:

(a) Numbers of people visiting sites, such as those with high value in terms of recreation, tourism, and natural heritage (biodiversity), and therefore having the highest likelihood of introduction of D. geminata by humans. (b) Risk of establishment and growth of D. geminata according to the NIWA likely environments risk stratification.

(c) Ease of access, e.g., main road, short unsealed road, foot track, etc.

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment iii

(d) Risk activity, e.g., angling, boating, swimming, picnicking, etc. (e) Likelihood of transfer from infected rivers.

(f) Social/cultural value of the site.

Stakeholders were given the opportunity to comment on the list of sites before they were ranked. As Biosecurity New Zealand operations would be more affected by discovery of D. geminata in the North Island, all North Island sites were selected and the above criteria used to select the balance of the survey sites within the fiscal cap of about 400 sites. 7. River sampling was conducted during the period 8-19 May 2006 and D. geminata was found in the Gowan River one kilometre upstream from the confluence with the Buller river, the Twizel River at SH8, the Ohau River downstream of its confluence with the Twizel River, and the Upukerora River near Lake Te Anau township.

8. No D. geminata was found in the North Island in the 139 sites on rivers where experts considered that it was most likely to have been introduced and to have established.

9. In common with previous finds, the latest discoveries of D. geminata were at popular fishing spots on rivers well suited to D. geminata establishment and this vindicates the site sampling strategy.

10. As the 400 sites and rivers in the survey were those considered to be the most likely to be infected and to allow establishment, it is unlikely that D. geminata was more widespread, or at least established, at the time of the survey, at other than within its known range before sampling began.

11. The efficiency of detection for this survey may have been affected by widespread flooding before the survey. Flooding has the potential to move bed material and abraid D. geminata from the bed material. However, if D. geminata is present in large quantities it is usually caught on branches and exposed riverbeds and there was no such evidence seen during the survey.

12. Ongoing passive surveillance between 24 November 2005 and 17 May 2006 resulted in 109 samples being sent to NIWA for analysis. Six samples contained D. geminata. Rivers where D. geminata has been previously found were not considered for the survey so that resources could be deployed to areas not known to contain D. geminata.

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment iv

1. Introduction The introduced invasive diatom (alga) Didymosphenia geminata (didymo) was first identified in the Mararoa and lower Waiau Rivers, Southland, in October 2004. Over the summer of 2004/05, the species formed thick growths throughout a 150-km stretch of river, which persisted over the following autumn and winter. D. geminata was declared an “unwanted organism” by Biosecurity New Zealand in November 2004 and measures were put in place to prevent its spread into other river systems. A delimiting survey undertaken in mid-December 2004 found no evidence of D. geminata growth in other major Southland Rivers (Kilroy 2004b). Therefore, it was assumed that there was a strong likelihood that the organism had not yet spread to these systems. Biosecurity New Zealand also set up a system of ongoing passive surveillance (OPS) that enabled local, regional and national agencies (Fish and Game Councils, Regional/District Councils, Department of Conservation and Crown Research Institutes) undertaking activities in rivers to report any sightings of suspicious algal growths. Samples are collected by AgriQuality staff, or by the person reporting the growth, and sent to NIWA, Christchurch, for microscopic examination.

A series of investigations was commissioned by Biosecurity New Zealand to improve understanding of this invasive, but poorly studied organism. These included a review of the biology, distribution, effects and potential risks of D. geminata for New Zealand (Kilroy 2004a), tests to determine the effectiveness of methods for sanitising material contaminated with D. geminata (Kilroy 2005), and an analysis of the ecological suitability of rivers for colonisation by D. geminata, assuming it could disperse throughout the country (Kilroy et al. 2005a). In addition, Meridian Energy, who has funded ecological studies in the lower Waiau River since 1993, contributed substantial baseline information on the development and effects of the infestation (Kilroy et al. 2005b, c). A further delimiting survey was planned for spring 2005, to coincide with the time when benthic algae generally bloom; in other words, this was the time when D. geminata, if present in a river, would be expected to become obvious.

However, on 27 September 2005, before the second delimiting survey, D. geminata was discovered blooming in the Buller River, with the infestation starting some 3 km downstream from the Lake Rotoiti outlet. Within a few days, further occurrences of D. geminata were reported from the Hawea and upper Clutha Rivers in Otago and the upper Waiau and Oreti Rivers in Southland.

Given the wide geographical spread of the new infestations, a priority was to quickly determine whether D. geminata had spread to other New Zealand rivers. A nationwide delimiting survey to determine the distribution of D. geminata was therefore initiated by Biosecurity New Zealand. Of the 492 sites surveyed in October 2005, the Von River was the only one from which D. geminata had not been previously identified from the ongoing passive surveillance (Duncan et al. 2005).

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 1

An important outcome of the October 2005 survey was the detection by microscopic analysis of D. geminata where it was not visible to the naked eye at the site. Detection of D. geminata in the Oreti River more than 80 km downstream of the most visible growths serves to raise confidence that the sampling and analytical method were adequately detecting the presence of D. geminata. This ability to detect D. geminata well downstream of visible growths increases the confidence that the sampling strategy employed in this survey of sampling the downstream extents of tributaries and rivers, will detect D. geminata if it is established upstream.

A limited nation-wide survey of 119 sites in January 2006 found D. geminata in only one river, the Waitaki where it had been found about 40 km upstream from the sampling site (see above) only a few days before sampling for that survey was to begin.

The survey described in this report is one of a series of surveys planned by Biosecurity New Zealand. Surveys are scheduled to be undertaken at approximately 3-monthly intervals with full detailed surveys (~400 sites) alternating with smaller scale operations covering ~100 highest risk sites. The present survey, undertaken in May 2006, is in the former category.

Like the previous delimitation surveys, the present survey aimed to address the following question: To what extent is D. geminata present in sites where it is likely to have been introduced and become established? Two important assumptions underlie this question. The first is that the principal means by which D. geminata can be spread from river to river is via human vectors. The second is that some sites provide much more suitable environments for D. geminata establishment than others. Both these assumptions were central to the selection of sites for inclusion in the survey, and emphasis is placed on their justification. They form the basis for a sampling survey design that is commonly used as a means of maximising the information gained with the available resources (Biggs & Malthus 1983).

2. Ongoing passive surveillance: November 2005 to May 2006 As part of Biosecurity New Zealand’s initial incursion response, a D. geminata query service was incorporated into Biosecurity New Zealand’s Exotic Pest and Disease Emergency hotline (0800 80 99 66). The number was advertised on brochures and public notices concerning D. geminata, as a source of further information (along with the Biosecurity New Zealand website), and as the place to report finds of suspected D. geminata. Messages could also be emailed to Biosecurity New Zealand via a link on their website. The 0800 number system was managed by staff from AgriQuality Limited, who received all calls concerning D. geminata and determined the appropriate follow-up action. Some suspected finds were also reported direct to AgriQuality or Biosecurity New Zealand staff. In cases of suspected D. geminata,

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 2

AgriQuality staff collected a sample (if one had not already been collected), and arranged for dispatch to NIWA, Christchurch, for microscopic examination. From 3 October 2005, all calls were prioritised using the scale: 1 = low risk, 2 = medium risk, 3 = high risk. Low-risk calls included those deemed extremely unlikely to be D. geminata sightings, on the basis of a description that did not correspond with D. geminata, and/or a habitat unsuitable for D. geminata. High risk calls were those deemed very likely to be D. geminata sightings, and samples were collected for further investigation. Medium risk reports were generally not thought to be D. geminata, but were usually checked to confirm this.

In addition to suspected D. geminata samples arising from the 0800 number system NIWA also directly receives suspected D. geminata samples from organisations such as Regional/District Councils, Fish and Game Council staff and the public.

Details of samples microscopically examined as a result of ongoing passive surveillance (OPS) for 16 December 2004 to 14 November 2005 are in Duncan et al. (2005). OPS between 15 November 2006 and 17 May 2006 resulted in 109 samples being sent to NIWA for analysis. Of these, the seven samples from the North Island were negative. Details are given in Appendix 1 where positive findings are highlighted in bold font. Six samples from the southern half of the South Island were positive for D. geminata. New discoveries of D. geminata were made at about monthly intervals. The rivers (with confirmation dates) where positive samples were found were: Whitestone at Glen Echo Station (21 December 2005), Waitaki at Kurow (25 January 2006), Ahuriri at Birchfield Road (21 February 2006), Von at the outlet to Lake Whakatipu (2 March 2006), Aparima at Dunrobin Station (28 March 2006) and the Fraser at Marshall Road (Central Otago) (4 May 2006).

The OPS has been crucial to Biosecurity New Zealand’s incursion response programme because it has highlighted the appearance of new growths of D. geminata, in some cases before the growth reached bloom proportions (e.g., in the upper Waiau), including in downstream areas of river systems already affected. Figures 1 and 2 show the locations of all sites sampled as part of OPS for which map coordinates are currently available.

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 3

Figure 1: North Island and top of the South Island showing locations of sites sampled as part of the ongoing passive surveillance response to the D. geminata incursion. Samples positive for D. geminata (South Island only) are shown as red triangles, and negative samples as green dots.

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 4

Figure 2: South Island showing locations of sites sampled as part of the ongoing passive surveillance response to the D. geminata incursion. Samples positive for D. geminata (South Island only) are shown as red triangles, and negative samples as green dots.

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 5

3. Nationwide survey, April and May 2006

3.1. Logistics and organisation The survey was managed by AriQuality which provided the mapping systems, administration, logistics and coordination of staff resources. The survey was managed centrally and through ten Area Coordinators who were responsible for the site sampling and sampling teams within their respective areas. All samples were couriered to a sample reception facility at AgriQuality’s Christchurch office for logging and verification of supporting sample submission documentation. Processed samples were then delivered to NIWA Christchurch for analysis. AgriQuality provided all sampling equiment, maps, uniquely numbered sample submission forms, briefing and training documentation. Field staff was sourced from AgriQuality, NIWA, Fish and Game, DOC and Regional councils, with numbers varying between areas. NIWA was sub-contracted to coordinate site selection, and to provide technical training, field staff and analytical services.

3.2. Site selection Site selection was done in two main stages. First, a list of over 500 sites was developed based on environmental data and information about human activities on rivers throughout New Zealand. The sites on this list were then ranked and the highest ranking sites selected for the May 2006 survey. The site selection and ranking processes are detailed below.

3.2.1. Criteria for selecting sites Rivers where D. geminata had been detected were not included in this survey. Using the site list from the October 2005 survey as a starting point, locations were selected based on the following criteria:

1. Sites where D. geminata is likely to have been introduced We make a single crucial assumption for this condition, viz., that the spread of D. geminata within New Zealand is entirely or almost entirely attributable to transfer by humans. The robustness of this assumption is discussed in Duncan et al. (2005). Therefore selected sites were at river access points that are visited regularly by people (fishermen, kayakers, trampers, tourists, scientists, swimmers etc.), and therefore have the highest likelihood of inter-waterway D. geminata transfer. Particular emphasis was placed on usage by highly mobile international anglers. The spread of the incursion suggests that mobile anglers are the most likely vectors. The Ministry for the Environment document “Water Bodies of National Importance” (MfE 2004) was used as a reference to locate popular sites.

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 6

A key addition for this survey was use of angling survey data (Unwin and Image 2003). Their study produced a list of fishing rivers and fishing pressure in terms of angler days. This data was supplemented with data from the Taupo region (John Gibbs, Department of Conservation, Turangi (pers. comm)). This survey (Unwin and Image 2003) may have underestimated angling pressure by overseas anglers. All rivers with more than 348 angler days that were not in previous surveys were added to the list of potential rivers for sampling.

2. Sites where D. geminata is likely to have become established The assumption here is that specific environmental conditions exist under which D. geminata will establish and grow, and in the absence of these conditions, the likelihood of establishment/growth decreases. These conditions are detailed in Duncan et al. (2005). Sites available for selection were categorised for their suitability for the establishment and growth of D. geminata according to the NIWA likely environments analysis (Kilroy et al. 2005a).

3.2.2. Number of sites The number of sites for this survey was prescribed by Biosecurity New Zealand to be in the region of 400 sites for fiscal reasons. Their main interest was to see if D. geminata had reached the North Island. Starting with the list of sites from the October 2005 and the January 2006 surveys, sites were added or culled for a variety of reasons including:

• Sites on rivers where D. geminata was known to be present were culled. • Sites on rivers with a poor likelihood of establishment (normally unsuitable substrate) were culled.

• Sites close to others on the same tributary were culled. • Sites with high fishing pressure were added.

• Sites with high risk of establishment not previously sampled were added.

• Sites of particular interest to DOC or other stakeholders were added.

3.2.3. Site ranking

Biosecurity New Zealand required the site selection process to be quantifiable, transparent and consistent across New Zealand. A ranking system was devised to justify the inclusion/exclusion of sites from the survey.

The ranking critieria included:

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 7

• Visitor numbers as indicated by the anglers usage study of Unwin and Image (2003), data supplied for the Taupo region by John Gibb of DOC, Turangi and anecdotal evidence where site visitors were not anglers.

• Risk activity based on the most likely activities at the site. Data on site activities gathered during the October 2005 survey (Duncan et al. 2005) was a useful reference for site activity. Where there was a mix of activities at a site it was scored according to the highest risk activity. Activities where there is a lot of water contact, such as angling, were considered to be a higher risk than more passive activities such as picnicking.

• Accessibility. Each site was located on 1:50,000 scale topography maps to determine their ease of access. Sites with easy helicopter access were ranked highly based on the assumption that anglers at these sites are likely to fish several catchments over a few days.

• Likelihood of transfer of didymo from another river to the site. Sites of highest risk of transfer were judged to be those with high angler and/or tourist angler usage and adjacent to rivers currently infected with didymo. Those with lowest risk of transfer were those with low fishing pressure or no fishing pressure, and low visitor numbers.

• Favourable environmental conditions for establishment of didymo. This criterion was based on the model described in the likely environments analysis by Kilroy et al. (2005a). Within a GIS environment, each site was located on the favourable environments map and given a risk of establishment weighting. The range of weights was divided into four equal classes and each river assigned a risk of establishment according to class. As the October 2005 survey site list, (on which the potential sites for this survey was predominantly based), was initially determined partly on the favourable environments model, the sites were not evenly distributed among the classes, but were predominantly in the two classes most favourable for establishment.

• Social or cultural value. This criterion was not necessarily a risk of infection or establishment. It reflected the importance of the site to the nation, e.g., iconic sites like Pupu Springs in Nelson, the Tongariro River, Lake Taupo tributaries, or sites with endangered fish or bird species would rank high, whereas small rivers, fished by local fishermen, in highly modified environments would rank low.

• North Island/South Island. The greatest influence on the Biosecurity New Zealand didymo response will be the detection of didymo in the North Island, as the South Island has already been declared a controlled area. Biosecurity New Zealand

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 8

decided that all North Island sites on the ranked site list would be sampled, thus, while all sites were ranked the ranking was only used to select South Island sites.

All criteria were given equal weight in the ranking of South Island sites. All sites ranking 15 or less were selected for sampling. Refer to Appendix 2 for details of the ranking system.

3.2.4 Stakeholder involvement in site selection and ranking

An initial list of sites, their weighting for the ranking criteria, their overall ranking and likelihood of being selected among the ~400 sites was sent to Fish and Game Councils, Regional/District Councils and Department of Conservation offices for their comment and input. Many responses were received with advice on site additions, deletions, relocations, and alterations to ranking of the various criteria. Almost all these suggestions were incorporated in a revised list. In addition a few sites were added to fill in gaps where rivers with a high likelihood of establishment did not have sites.

The revised list was reranked and submitted to Biosecurity New Zealand for approval. The list was approved subject to minor changes.

The process resulted in selection of 400 sites, of which 139 (35%) were North Island and 261 (65%) were in South Island from a total of 513 sites available for selection The weightings of the ranking criteria and the list of all sites considered for selection, their rankings and those selected for the survey are shown in Appendix 2.

3.3. Survey procedures Appendix 3 is the brief used to manage the survey. It contains details of the purpose, scope of the survey, a description of D. geminata, copies of field sample forms (Appendix 4), sampling and decontamination instructions, and other logistical matters.

3.3.1. Briefing/training for field surveys

Training sessions were conducted for ten AgriQuality Survey Area Coordinators at training sessions held in Hamilton and Christchurch. They were given direction on logistical and procedural aspects of the survey by the AgriQuality Ltd Operations Manager and Logistics Manager, and on sampling and disinfection procedures by NIWA staff. The AgriQuality staff in turn instructed staff in the regions. Many of the staff used for sampling had been trained for the October 2005 survey, however refresher training was provided to update personnel on the specific aspects of this survey.

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 9

All teams were supplied with a full set of equipment required for sampling and decontamination, including sampling forms, sampling containers, buckets, sample scrapers and pipettes, chilly bin(s), and protective gloves, with the rest of the sampling equipment and bleach being sourced locally. Refer to Appendix 3 for a listing of equipment. Each team also carried a GPS unit for locating the position of each sampling site.

3.3.2. Sampling method Teams were instructed to access river sites as close as possible to the locations defined during the site selection exercise, and to work within a reach of up to ~50 m length (or more if practical). The reach would generally be downstream of public access to the river. Areas surveyed were, for safety reasons, wadeable, but any growths of interest in deeper, faster-flowing areas were to be noted. The survey protocol had two aims:

1. To inspect the entire site for presence of visible D. geminata and to sample suspected colonies.

2. To collect a representative (random) sample of algae growing at each site from a 25 stone pooled sample from 5 transects at a site.

For site inspections, teams were instructed to scan the substrate of the entire reach for algal growth and to take samples of any growth that resembled colonies of D. geminata. After the site inspection, representative samples of algae growing at the site were collected along transects. At each site, five transects were positioned at right angles to the bank, downstream of public access points to the river. The location of the first (most upstream) transect was assigned randomly, and the remaining transects were generally 0.5 to one channel width apart with a maximum distance apart of 50 m. Where different habitat types (riffles, runs and pools) were present within the sampling reach, transects were located in proportion to these habitat types. Coarse, periphyton-covered bed material (usually stones/rocks) was removed from the bed at five equally spaced locations along each transect. Samples of each colony type on each sample clast were scraped off with a disposable wooden scraper into a container. Where samples were sparse, scrapings were washed off with a disposable water-filled pipette. Samples were normally consolidated into one sampling container. Generally one or two sampling containers were collected from one site, e.g., one from transects and one from suspected D. geminata colonies.

Apart from location, the only additional information collected at each site was information of water clarity and habitat type (riffle, run or pool) sampled. This information may be used to examine sampling efficiency, e.g. if water was very turbid it might be difficult to see early stages of didymo infection. Recording habitat type might indicate the most likely sites for initial establishment. Notes were also made on

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 10

the amount of visible D. geminata coverage (if any), other algae present and suitability of the site.

During the October 2005 survey there was some concern that floods would slough off periphyton, including didymo, and that sampling after flooding may fail to detect didymo. However, during the October 2005 survey, didymo was detected in the Von River, even though the stones sampled appeared periphyton free and the nearest visible colony was several kilometres upstream. This result gave confidence that there was a high probability of detection of didymo if it was there, even though river bed disturbance by flooding may have caused loss of periphyton by sloughing or abrasion. Thus, for this survey, field staff was instructed to sample rivers for didymo, regardless of previous flow conditions and apparent periphyton cover on the river bed.

3.3.3. Decontamination Field staff was required to start the sampling at the most upstream site to avoid contamination of an upstream site from downstream, and to work from an upstream to downstream direction within each site. They were also required to decontaminate before moving to tributaries or different rivers. Decontamination consisted of collecting disposable materials used at each site (e.g., scrapers, pipettes, rubber gloves) into a rubbish bag, and subjecting all other equipment exposed to river water or periphyton scrapings to a 2% solution of bleach for one minute. Staff stood in their waders in a tray of bleach solution while the waders were washed down with the solution.

3.3.4. Microscopic examination of samples Samples were couriered directly to AgriQuality’s Christchurch sample reception for data recording and sample tracking. Samples were delivered to NIWA’s Christchurch laboratory during the second half of each day for assessment of D. geminata presence/absence. Samples were refrigerated while awaiting consolidation at AgriQuality and while awaiting analysis at NIWA. Samples were generally analysed the day they arrived at NIWA or the next day depending on the time of the delivery and quantity of samples.

Samples were concentrated as necessary by pipetting or pouring off excess water, following a settling period of up to eight hours. Aliquots of approximately 1 ml of the algal suspensions were transferred to the well of an inverted microscope and allowed to settle briefly (30 s). Entire sub-samples were then scanned at magnifications of 100x to 200x. At least three aliquots from each sample were examined in order to increase the chances of finding D. geminata in a sample, even if it was very rare.

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 11

Samples were not stained. Cells with intact, green chloroplasts were asummed to be alive and cells with diminished and distorted chloroplasts or no chloroplasts were assumed to be dead.

Precautions were taken in the laboratory to prevent cross-contamination of samples and to eliminate any chance of D. geminata entering the local environment. The microscope well was rinsed twice between each sub-sample and thoroughly cleaned after examining samples from each site. A new disposable pipette was used for samples from each site, or from each sub-sample if D. geminata was found. Excess water was pipetted into a waste container and was not washed into the drainage system. All sub-samples examined were rinsed into the waste container.

After examination of each sample the remaining algal material was frozen (–20ºC). The material will be kept until this report and its results have been accepted by Biosecurity New Zealand. It will then be disposed of as detailed in the next paragraph.

All liquid waste material was treated with bleach (to a concentration of at least 5%) then disposed of into the sewerage system. All solid waste was autoclaved for 20 min at 15 psi before disposal.

3.4. Data analysis This survey had two possible outcomes:

1. Cells or other traces of D. geminata would be detected in one or more samples outside its known range. This result would imply that the species had spread from the existing infection sites.

2. No traces of D. geminata would be detected in any of the samples. This would imply either that the species was not present in the rivers at the time of sampling or that the sampling was not sufficiently effective to detect it.

For the second outcome, the question to be answered would be: how confident can we be that the survey would have detected the species if, in fact, it was present? This issue is addressed in Duncan et al. (2005). Assuming the sites are independent, a detection efficiency of 100%, and there is a 1% probability of D. geminata being present at any one site then the probability of detection is 98.2% based on sampling 400 sites (Figure 3, equation 1). In this survey few sites are on the same river and those sites are sufficiently far apart to be considered independent.

α = (1-(1-ρ) n )× 100……………………………………………Equation 1

where α is the percent probability of detecting D.geminata in the survey,

ρ is the percent probability of D. geminata occurring at any one site ,

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 12

n is the number of independent sites.

The red, blue and black lines on Figure 3 show the percent probability of detection of D.geminata in the survey for probabilities of 0.25%, 0.5% and 1% probability of occurrence of D.geminata respectively.

100

D. 90 80 70 60 50 in the survey) 40 400 sites 30

geminata 20 (% probability of detecting (% probability

α 10 0 012345 p (% probability of D. geminata occurring at any one site)

Figure 3: Abundance of D. geminata (p, as %) at low levels plotted against the probability (α, as %) of finding the species at a single site during a survey of multiple sites. A curve is shown for a 400 site survey. See text for reference to the red and blue and black intersects.

3.5. Hydrological conditions before and during sampling Flood flows with high velocity water, bed movement and abrasion have the potential to slough or abrade periphyton (including D. geminata) from bed material. Periphyton needs about 14 days of stable flows to establish sufficient biomass to sample (Biggs 2000). Thus floods or freshes with peak flows more than about three times the preceding median flow, 14 days before, or during, sampling are likely to leave insufficient material to adequately sample the river, and may result in false negative samples. However, D geminata adheres very strongly to the substrate. Floods peaking at up to 15 times the pre-existing median flow in some sites in the lower Waiau River did not appear to reduce D. geminata biomass whereas at other sites floods peaking at 7.5 to 9 times the pre-existing median flow (Kilroy et al. 2005c) did reduce D. geminata biomass. Our experience to date indicates that floods have to be strong enough to disturb the bed (turn over the rocks) before D. geminata is removed from them. The propensity for bed material to move depends on the water depth and velocity, the size of the bed material, the water surface slope and the degree of

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 13

imbrication (layering) of the bed material. This propensity varies between and along rivers.

To determine whether bed disturbance may have occurred at any sites such that periphyton may have been removed, 40 hydrographs of rivers representative of sub- regions were examined and analysed. The median flow from 15 February 2006 to the end of sampling (19 May 2006) was calculated and the ratio between that and the highest flood peak from 15 February to the end of sampling was calculated. Values >20 indicate likelihood of insufficient sample material to provide a reliable sample. Figure 4 shows an example hydrograph and the full set is available from the authors. The hydrographs to be analysed were selected from a much larger data set that showed the selected hydrographs to be typical of the regions/flow regimes they represent. The locations of the sites for which hydrographs were analysed are shown in Figure 4 of Duncan et al. 2005.

80 Largest prec. flood 10 x median March April May

50

median 0 15-Feb-2006 7-Mar 17-Mar 27-Mar 6-Apr 16-Apr 26-Apr 6-May site 1043461 Tongariro at Upper Dam Flow m3/s

Figure 4: An example hydrograph. The vertical red lines show the duration of sampling. In the top left the ratio between the highest flood peak and the median flow is shown. The flow unit for the vertical axis is cumecs.

3.6. Sample tracing Each sample site was given a unique site number, printed sample form and accompanying site map. Both the sample form and site map contained the same unique site number. On collection of a sample, this unique site number was written on the consolidated sample jar (pottle) together with a sample date. Where there was more than one sample per site, the type of sample was identified on the container and corresponding site sample form. The sample jar(s), completed sample form and sample map were double bagged and couriered to AgriQuality Christchurch for data collection and tracking. A master spreadsheet was updated daily as samples were received at Christchurch. Consolidated samples were delivered daily to NIWA for analysis and on completion of the results section of the form, the form was returned to AgriQuality. Negative or positive results were then entered in the spreadsheet. This spreadsheet was included with a daily report to Biosecurity New Zealand during the sampling period and until completion of all analytical results.

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 14

3.7. Results

3.7.1. Sites and samples The 400 sites identified for the survey were visited in 10 working days (8-19 May 2006). Samples were taken at 386 sites, yielding 395 samples of algae scraped from the surfaces of river stones. The remaining sites were not sampled because: river was too high (3 sites: 1253, 1307, 1626), bedrock or muddy subtrate (4 sites: 64, 1265, 1161, 1402), river dry (1 site: 1382), poor access/dangerous (1 site: 1123), site unsuitable but no reason given and site 1625 nearby (site 1472), no reason given (1 site 1150), didymo present (1 site 1584). A further two sites were deleted from the list because of duplication. See Appendix 5 for site details.

Figure 5 shows the locations of sites selected for the survey, and Table 1 lists the numbers of sites selected in each Fish and Game Council region for the May 2006 survey. Site and sample details are listed in Appendix 5. While many sites were at the general location of the October sampling sites, the precise location is given by the GPS co-ordinates many of which are marginally different from those of the October survey. Substrate composition, channel width, shading and water clarity information were recorded for most of the sites during previous sites and these measurements, apart from water clarity, were not duplicated for this survey. The sites where D. geminata was found are shown in bold font.

3.7.2. Microscope analysis D. geminata was found in samples from four sites as a result of the survey, and from one site shortly before the survey. All positive sites were in the South Island (Table 2, Figure 5).

D. geminata colonies were not visible in the Upukerora River at Te Anau, but 2-3 live cells were seen per field of view in the laboratory, suggesting that D. geminata was not established at the site and that there was an established colony upstream or that D. geminata was newly established at this site.

At the Gowan River 1 km upstream of the Buller River confluence D. geminata was visible on some cobbles in the river and was abundant in the microscope sample. It was not found in the sample from the Gowan River immediately downstream of the Lake Rotoroa outlet.

At the Twizel River at SH8 D. geminata was not visible and only dead cells were found under the microscope, suggesting colony establishment well upstream. No D. geminata was found in the sample taken about 6 km upstream in the Fraser River, a substantial tributary of the Twizel River.

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 15

Figure 5: North Island and South Island locations of the D. geminata sampling sites for the May 2006 survey with those where D. geminata is confirmed present (South Island only) shown as red triangles and those where samples tested negative shown as green dots.

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 16

Table 1: D. geminata selected sites by Fish and Game Council region

Selected sites Sampled sites Region Auckland 21 22 Eastern 31 29 Hawke's Bay 25 25 Taranaki 17 17 Taupo 11 10 Wellington 34 33 NORTH ISLAND TOTAL 139 136 Central South Island 36 34 Nelson/Marlborough 49 47 North Canterbury 27 26 Otago 71 67 Southland 41 39 Westcoast 48 37 SOUTH ISLAND TOTAL 261 250 NEW ZEALAND TOTAL 400 386

Table 2: List of sites where D. geminata was found during the May 2006 survey

Status Site no. River Location Notes

Known before survey 1584 Fraser Marshall Road Not visible at site. Rare in sample 1573 Gowan 1 km U/S of Buller confluence Visible at site. Abundant in sample. 1228 Upukerora Te Anau Not visible at site. Rare in sample. Not visible at site. Dead cells in 1385 Twizel SH8 sample 1578 Ohau D/S Twizel confluence Not visible at site. Live cells in sample,

Approximately 12 live cells per cm3 of benthic material were found in the sample from the Ohau River between the Twizel River confluence and Lake Benmore, where the flow is predominantly from the Twizel River. D. geminata was not visible at this site.

North Island survey

All 136 North Island sites sampled returned negative results, i.e., no D. geminata was identified at those sites.

3.8. Hydrolological analysis. Seventeen of the 40 hydrographs had peak flows >20 times the median flow from 15 February until the end of sampling. The largest flood relative to the median flow was

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 17

in the Shag River, North Otago where flood peak was 1130 times the median flow. The areas with large floods were Coromandel (Ohinemuri River), Northern Hawkes Bay (Wairoa River), Wairarapa (Mangatainoka River), Golden Bay, Nelson, Marlborough, Coastal Otago, Southland and South Westland. There were many comments about there being little algae or the rocks being clean for rivers where there had been large floods. About 26 April there was a storm that brought flooding to many of the areas mentioned above. If D. geminata had been present in the storm affected areas then it is likely that it was flushed or abraided away and it is unlikely to have re- established in the short time between the floods and sampling.

Flooding was experienced during the sampling period in the Wellington/Wairarapa, Canterbury foothills, and Central Otago regions and in the Mataura River catchment, Southland.

3.9. Discussion

3.9.1. Confidence in sample analysis and site selection method In this survey D. geminata was found in four rivers. In three of those cases the sampling team reported that the river was free of visible D. geminata at the site. This shows that the sampling and analysis methods used were capable of detecting low levels of D. geminata.

In the previous nationwide survey (Duncan et al. 2005) there was discussion on the site selection strategy, i.e., selection of popular river access points where river conditions favour establishment. If this strategy was wrong the likelihood of detecting D. geminata, if present, would be lower than ideal. The discovery of D. geminata at popular fishing sites on rivers providing ideal conditions, according to the NIWA classification (Kilroy et al. 2005a), for D. geminata vindicates the site selection strategy used for this and the previous surveys. That D. geminata has been found at yet more popular fishing sites suggests that the primary vectors are anglers.

4. Summary and conclusions 1. Since the initial discovery of the invasive alien diatom Didymosphenia geminata in the Mararoa and lower Waiau Rivers in October 2004, and a local delimiting survey in December 2004, limited passive surveillance showed no evidence that the alga had spread from these rivers until late September 2005. Passive surveillance refers to reports from the public and local organisations to the Biosecurity New Zealand emergency 0800 number or website, or direct to Biosecurity New Zealand or AgriQuality Limited staff, of suspected D. geminata growths.

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 18

2. Discovery of D. geminata in locations beyond its previously known range in September 2005 brought forward a planned second delimiting survey and expanded it to cover high risk sites nationwide.

3. In October 2005, 492 sites nationwide were systematically sampled for D. geminata. The sites were chosen on the basis of having a suitable environment for D. geminata, and a high level of human activity. In that survey D. geminata was found at seven sites on four rivers, of which one site was beyond its previous range. At that site on the Von River, D. geminata was present in microscopic quantities.

4. In January 2006 119 sites nationwide were systematically sampled for D. geminata. The sites were chosen on the same basis as for the October 2005 survey. In this survey D. geminata was found at one site on one river, where it had been discovered beyond its previous range a few days before the survey. At the sampling site on the Waitaki River, 40 km downstream of the discovery, D. geminata was present in microscopic quantities. No D. geminata was found in the North Island.

5. In the nationwide 400 site survey reported here D. geminata was found at four locations during the survey and at one location immediately before the survey as a result of passive surveillance. None were found in the North Island. All sites where D. geminata was found were sampled at locations in the vicinity of popular (angling) access points where river conditions were estimated to be suitable for D. geminata's establishment and growth.

6. Ongoing passive surveillance between 24 November 2005 and 17 May 2006 resulted in 109 samples being sent to NIWA for analysis. Six samples from the South Island contained D. geminata.

5. Acknowledgements A large team of people from AgriQuality and NIWA has been involved and our thanks to all of them for their hard work. Special thanks go to Fish and Game Council, Regional/District Council staff and Department of Concervation staff who volunteered to collect samples. The NIWA laboratory team consisting of Cathy Kilroy, Donna Sutherland, Karen Robinson, Amy Lagerstedt and Phil Jellyman are thanked for efficiently analysing the samples for presence of D. geminata. Sampling sites were selected using the invaluable local knowledge of staff of the Department of Conservation, Fish and Game Councils and Regional/District Councils. Melissa Doyle of AgriQuality and Helen Hurren of NIWA compiled the maps.

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 19

We would like to thank the following orgainsations for permitting access to hydrological data to see if floods may have affected the efficiency of the sampling: Contact Energy, Environment Canterbury, Environment Southland, Environment Waikato, FRST, Genesis Power, Horizons Regional Council, Otago Regional Council and TrustPower. Roddy Henderson analysed and presented the hydrology data.

6. References Biggs, B.J.F. 2000. New Zealand periphyton guidelines: detecting, monoitoring, and managing enrichment in steams: Background and guidelines. Ministry for the Environment, Wellington.

Biggs, B.J.F.; Malthus, T.J. 1983. Biological studies for power development impact assessment – upper Clutha valley. In: Design of water quality surveys: proceedings of a symposium. Hoare R.A. (Ed.). Water and Soil Division, Ministry of Works and Development for the National Water and Soil Conservation Organisation, Wellington. Water and Soil Miscellaneous Publication No. 63.

Duncan M.J. 2006. A New Zealand-wide survey for the presence of the non- indigenous freshwater diatom D. geminata in sites most likely for its introduction and establishment. NIWA Client Report CHC2006-023. For Biosecurity New Zealand. 29 p.

Duncan M.J.; Kilroy, C.; McBride, G.; Burnip, G.; Bullians, M. 2005. A New Zealand-wide survey in October 2005 for the presence of the non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment. NIWA Client Report CHC2005-141. For Biosecurity New Zealand. 52 p.

Kilroy, C. 2004a. A new alien diatom Didymosphenia geminata (Lyngbye) Schmidt: its biology, distribution, effects and potential risks for New Zealand fresh waters. NIWA Client Report CHC2004-128. For Environment Southland. 40 p.

Kilroy, C. 2004b. A survey to investigate the presence or absence of Didymosphenia geminata in selected Southland rivers. NIWA Consultancy Report CHC 2004-133. For Biosecurity New Zealand. 12 p.

Kilroy, C. 2005. Tests to determine the effectiveness of methods for decontaminating material contaminated with Didymosphenia geminata. NIWA Consultancy Report CHC2005-04. For Biosecurity New Zealand. 30 p.

Kilroy, S; Snelder, T; Sykes, J. 2005a. Likely environments in which the non- indigenous freshwater diatom, Didymosphenia geminata, can survive, in New

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 20

Zealand. NIWA Consultancy Report 2005-043. For Biosecurity New Zealand. 43 p.

Kilroy, C.; Lambert, P.; Robinson, K.; Blair, N. 2005b. Periphyton and invertebrate monitoring programme, lower Waiau River. Results of the 2005 survey and a commentary on the ecological effects of Didymosphenia geminata. NIWA Consultancy Report 2005-032. For Meridian Energy. 45 p.

Kilroy, C.; Jarvie, B.; Sutherland, S. 2005c. Nuisance growths of periphyton in the lower Waiau River in relation to flow: a summer monitoring programme with a focus on Didymosphenia geminata. NIWA Consultancy Report 2005-059. For Meridian Energy. 51 p.

Ministry for the Environment 2004. Potential Water Bodies of National Importance. Ministry for the Environment, Wellington. Technical Working Paper. (http://www.mfe.govt.nz/publications/water/national-importance-rec-dec04/index.html).

Unwin, M.; Deans, N. 2003. Travel distance as an index of angling value: a preliminary study based on the 2001/02 National Angling Survey. NIWA Client Report : CHC2003-113. For Fish and Game New Zealand. 24p.

Unwin, M.; Image, K. 2003. Angler useage of lake and river fisheries managed by Fish & Game New Zealand: results from the 2001/02 National Angling Survey. NIWA Client Report : CHC2003-114. For Fish and Game New Zealand. 48p.

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 21

Appendix 1. Ongoing passive surveillance: Summary of samples received by NIWA for microscope examination, 24 November 2005 to 17 May 2006. Samples positive for D. geminata are highlighted in bold font and heavy shading.

Date Sampling Sampling Date Didymo NZMG NZMG collected team 1 team 2 Organisation analysed River Site location Analyst positive Map ref. easting northing 24-Nov-05 Jason DOC Kauaeranga 5 Magotahi Rd, Tauranga (stream in property) Roxburgh 06-Dec-05 Susan Marks DOC Alpine Stream Mt Richmond Forest Park N28 093 509 Karen 7-Dec-05 Tengawai Pleasant Point ckilroy no 2358620 5660340 Philpott 03-Dec-05 Wayne DoC 7-Dec-05 Awakino River Middle Gorge, dsutherland no Hutchins Bexley Stream Phone call Simon Bayley DoC Motueka Hackett Stream no ?7 Dec 05 Brian Butcher AgriQuality 8-Dec-05 Lower Waiau Clifden Bridge ckilroy no 13-Dec-05 Andrew Cade AgriQuality 14-Dec-05 Morley Creek Mt Linton, Ohai, krobinson no D45 121 621 Southland ? Martin Abel DoC Buller 15-Dec-05 Lewis River rest area just of ckilroy no 2459610 5857061 SH7, north of the Boyle River ? Martin Abel DoC Buller 15-Dec-05 Elford Creek trib of Karamea ckilroy no 2441940 5993582 River 10-Dec-05 Leith Rhynd Winifred Rhynd for DoC? 16-Dec-05 Mohaka Kaimanawa Forest ckilroy no U19 933 314 Park 10-Dec-05 Leith Rhynd Winifred Rhynd for DoC? 16-Dec-05 Mohaka Kaimanawa Forest ckilroy no U19 933 314 Park 10-Dec-05 Leith Rhynd Winifred Rhynd for DoC? 16-Dec-05 Mohaka Kaimanawa Forest ckilroy no U19 933 314 Park 10-Dec-05 Leith Rhynd Winifred Rhynd for DoC? 16-Dec-05 Mohaka Kaimanawa Forest ckilroy no U19 933 314 Park 18-Dec-05 Ross Steve Dolan Meridian Energy 19-Dec-05 Lake Ohau Port Dyson, Boat krobinson no 2264836 5655399 Hamilton ramp 18-Dec-05 Ross Steve Dolan Meridian Energy 19-Dec-05 Ohau canal ckilroy no 2266012 5655191 Hamilton 18-Dec-05 Ross Steve Dolan Meridian Energy 19-Dec-05 Ohau canal u/s confluence ckilroy no 2273184 5657548

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 22

Date Sampling Sampling Date Didymo NZMG NZMG collected team 1 team 2 Organisation analysed River Site location Analyst positive Map ref. easting northing Hamilton Ohau/Pukaki 18-Dec-05 Ross Steve Dolan Meridian Energy 19-Dec-05 Ohau River above entrance to krobinson no 2272581 5655450 Hamilton RTH 18-Dec-05 Ross Steve Dolan Meridian Energy 19-Dec-05 L. Ruataniwha Boat ramp krobinson no 2274536 5655429 Hamilton 18-Dec-05 Ross Steve Dolan Meridian Energy 19-Dec-05 Ruataniwha SH8 bridge, true left ckilroy no 2277517 5658620 Hamilton 18-Dec-05 Ross Steve Dolan Meridian Energy 19-Dec-05 Ohau canal 10 m from Slamon ckilroy no 2281121 5652135 Hamilton Farm Ross Steve Dolan Meridian Energy 19-Dec-05 Ohau canal tailrace, 500 m from ckilroy no 2285711 5647861 18-Dec-05 Hamilton Lake Benmore Ross Steve Dolan Meridian Energy 19-Dec-05 Ohau canal Boatramp ckilroy no 2286240 5647387 18-Dec-05 Hamilton Ross Steve Dolan Meridian Energy 19-Dec-05 Tekapo canal 500 m below TKA at ckilroy no 2306019 5684513 18-Dec-05 Hamilton bridge Ross Steve Dolan Meridian Energy 19-Dec-05 Tekapo canal Mt Cook Salmon krobinson no 2288972 5675287 18-Dec-05 Hamilton Ross Steve Dolan Meridian Energy 19-Dec-05 Pukaki canal Pukaki Canal Rd, ckilroy no 2279885 5663781 18-Dec-05 Hamilton SH8 bridge Bill Jarvie Southland Fish 21-Dec-05 Whitestone Glen Echo Station krobinson yes D43 165 255 19-Dec-05 & Game Peter AgriQuality 11-Jan-06 Blenheim? krobinson no Brunsden 16-Jan-06 Ross Martin Peter Mark DoC 17-Jan-06 Tongariro Turangi ckilroy no 2755190 6236010 16-Jan-06 Ross Martin Peter Mark DoC 17-Jan-06 Tongariro Turangi ckilroy no 2755190 6236010 16-Jan-06 Ross Martin Peter Mark DoC 17-Jan-06 Tongariro Turangi ckilroy no 2755190 6236010 16-Jan-06 Ross Martin Peter Mark DoC 17-Jan-06 Tongariro Turangi ckilroy no 2755190 6236010 17-Dec-05 Andrew Willsman NIWA 17-Jan-06 Monowai below gates ckilroy no Richard Simpson AgriQuality 20-Jan-06 Lake Stream Prospect Hill krobinson no Peter AgriQuality 24-Jan-05 Boulder River Leatham Valley krobinson no Brunsden 21-Jan-06 Fisherman ? 25-Jan-06 Waitaki Kurow ckilroy yes I40 219 960

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 23

Date Sampling Sampling Date Didymo NZMG NZMG collected team 1 team 2 Organisation analysed River Site location Analyst positive Map ref. easting northing Clare Pascoe Env. Bay of 27-Jan-06 Waioeka River Waioeka Gorge krobinson no 2886675 6324065 24-Jan-06 Plenty ? Johlene Kelly Env. Waikato 3-Feb-06 Waikato River? ckilroy no Scott Bowie DOC 13-Feb-06 Hakataramea Hakataramea Pass krobinson no 2315814 5653769 03-Feb-06 Rd 10-Feb-06 15-Feb-06 Arnold Blair Rd bridge no. 2 krobinson no Stu F&G 17-Feb-06 Waikaia Canton Bridge ckilroy no 2204855 5517165 16-Feb-06 Sutherland 17-Feb-06 Doc Twizel? DoC 21-Feb-06 Ahuriri Birchwood Road ckilroy yes 2247429 5635358 12-Feb-06 Chris Tonkin F&G 21-Feb-06 Lake Mapourika nboustead no M Rutledge DOC 24-Feb-06 Duncan Bay Duncan Bay map ref krobinson no 2573770 6009260 15-Feb-06 Stream P27 738093 Davor Bejakovich F&G 28-Feb-06 Hurunui from several spots ckilroy no ~500 m to 1 km 23-Feb-06 below Lake Sumner braid/channel flowing into Rakaia Lagoon, between N 23-Feb-06 Davor Bejakovich F&G 28-Feb-06 Rakaia & S Rakaia huts ckilroy no 28-Feb-06 Lindsay Tasman District 2-Mar-06 Motueka ckilroy no 2507000 6009760 Grueber Council 23-Feb-06 Rob NIWA Nelson 24-Feb-06 Wairau above branch nboustead no Merrilees confluence, Manuka Island 01-Mar-06 Mike Ogle DoC 2-Mar-06 Anatoki krobinson no 2488770 6035581 28-Feb-06 Mike Ogle DoC 2-Mar-06 Dry River Packard Road krobinson no 2497290 6036720 28-Feb-06 Mike Ogle DoC 2-Mar-06 Anatoki McCallum road krobinson no 28-Feb-06 Murray Knowles Fishing guide 2-Mar-06 Von River outlet to L. Rex yes 2150770 5558930 Wakatipu Lowe/Max Bothwell 02-Mar-06 Heather DoC 6-Mar-06 Tasman River Acklands Lagoon dsutherland no 2278454 5703938 Purdie 02-Mar-06 Heather DoC 6-Mar-06 Tasman River Acklands Lagoon dsutherland no 2278452 5703920 Purdie

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 24

Date Sampling Sampling Date Didymo NZMG NZMG collected team 1 team 2 Organisation analysed River Site location Analyst positive Map ref. easting northing 02-Mar-06 Heather DoC 6-Mar-06 Tasman River Acklands Lagoon dsutherland no 2278436 5703858 Purdie 09-Mar-06 Sue Doc 14-Mar-06 Ohau Creek Near Ohau lodge krobinson no 2255436 5659655 Anderson 14-Mar-06 Matt Dale NIWA 23-Mar-06 Waimakariri 200m ds of gorge n.boustead no 2433346 5760311 bridge 14-Mar-06 Matt Dale NIWA 23-Mar-06 Waimakariri 200m ds of gorge n.boustead no 2433346 5760311 bridge 09-Mar-06 Matt Dale NIWA 23-Mar-06 Waimakariri Gooseberry stream n.boustead no 2416957 5792972 confluence 09-Mar-06 Matt Dale NIWA 23-Mar-06 Waimakariri Gooseberry stream n.boustead no 2416957 5792972 confluence 14-Mar-06 Matt Dale NIWA 23-Mar-06 Waimakariri Rockford rd us of n.boustead no 2427806 5764173 gorge 14-Mar-06 Matt Dale NIWA 23-Mar-06 Waimakariri Rockford rd us of n.boustead no 2427806 5764173 gorge 14-Mar-06 Matt Dale NIWA 23-Mar-06 Waimakariri Weedons Ross Rd n.boustead no 2461035 5749689 14-Mar-06 Matt Dale NIWA 23-Mar-06 Waimakariri Weedons Ross Rd n.boustead no 2461035 5749689 09-Mar-06 Matt Dale NIWA 23-Mar-06 Waimakariri 50 m ds of SH73 n.boustead no 2395651 5797687 bridge 09-Mar-06 Matt Dale NIWA 23-Mar-06 Waimakariri 50 m ds of SH73 n.boustead no 2395651 5797687 bridge 14-Mar-06 Matt Dale NIWA 23-Mar-06 Waimakariri 500 us of intake rd n.boustead no 2451998 5749039 14-Mar-06 Matt Dale NIWA 23-Mar-06 Waimakariri 500 us of intake rd n.boustead no 2451998 5749039 14-Mar-06 Matt Dale NIWA 23-Mar-06 Waimakariri Bleakhouse cnr n.boustead no 2439350 5753719 14-Mar-06 Matt Dale NIWA 23-Mar-06 Waimakariri Bleakhouse cnr n.boustead no 2439350 5753719 09-Mar-06 Matt Dale NIWA 23-Mar-06 Waimakariri 100m ds of Mt white n.boustead no 2407949 5799432 bridge 09-Mar-06 Matt Dale NIWA 23-Mar-06 Waimakariri 100m ds of Mt white n.boustead no 2407949 5799432 bridge 14-Mar-06 Matt Dale NIWA 23-Mar-06 Waimakariri 150m ds of sh1 n.boustead no 2481507 5754716 bridge

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 25

Date Sampling Sampling Date Didymo NZMG NZMG collected team 1 team 2 Organisation analysed River Site location Analyst positive Map ref. easting northing 14-Mar-06 Matt Dale NIWA 23-Mar-06 Waimakariri 150m ds of sh1 n.boustead no 2481507 5754716 bridge 14-Mar-06 Matt Dale NIWA 23-Mar-06 Waimakariri Haul Rd n.boustead no 2470117 5751111 14-Mar-06 Matt Dale NIWA 23-Mar-06 Waimakariri Haul Rd n.boustead no 2470117 5751111 17-Mar-06 Boustead NIWA 22-Aug-06 Waitaki canals Ohau canal nboustead no 2280830E, 5652080N 17-Mar-06 Boustead NIWA 22-Aug-06 Waitaki canals Tekapo canal nboustead no 2288820E, 5674750N 17-Mar-06 Boustead NIWA 22-Aug-06 Waitaki canals Wairepo arm nboustead no 2277310E 5653190N 27-Mar-06 Peter Hamill Marlborough 28-Mar-06 Waiau River Kowhai Point ckilroy no 2519487 5944077 District Council 26-Mar-06 Stu F&G 28-Mar-06 Aparima River Dunrobin Station ckilroy yes 2130293 5485471 Sutherland 31-Mar-06 Davor Bejakovich F&Game 6-Apr-06 Lillian Burn? Road Culvert krobinson no 31-Mar-06 Davor Bejakovich F&Game 6-Apr-06 Lillian Burn? Low______? krobinson no 31-Mar-06 Davor Bejakovich F&Game 6-Apr-06 Lillian Burn? Harper Valley? krobinson no 31-Mar-06 Davor Bejakovich F&Game 6-Apr-06 Lillian Burn? Below krobinson no accomodation 31-Mar-06 Davor Bejakovich F&Game 6-Apr-06 Lillian Burn? At accommodation krobinson no 04-Apr-06 salmon Meridian Energy 7-Apr-06 Waitaki canals Wairepo Arm krobinson no farmers 03-Apr-06 salmon Meridian Energy 7-Apr-06 Waitaki canals Tekapo Canal krobinson no farmers 03-Apr-06 salmon Meridian Energy 7-Apr-06 Waitaki canals Ohau canal krobinson no farmers 19-Apr-06 Ross Pannell 21-Apr-06 100m above ckilroy no Glenorchy rd, 30m d/s of bridge 19-Apr-06 Ross Pannell 21-Apr-06 12 Mile Creek ckilroy no 11-Apr-06 Salmon Sandfords 13-Apr-06 Clutha U/s of Salmon Farm krobinson no farmers Kaitangata intake Salmon 11-Apr-06 Salmon Sandfords 13-Apr-06 Clutha d/s salmon outfall krobinson no farmers Kaitangata

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 26

Date Sampling Sampling Date Didymo NZMG NZMG collected team 1 team 2 Organisation analysed River Site location Analyst positive Map ref. easting northing Salmon Karen 12-Apr-06 Robinson NIWA 12-Apr-06 Salmon Farm Tentburn krobinson no 18-Apr-06 Grant Barnes Marcus Auckland 21-Apr-06 Anderson Didymo 2 krobinson no 2645020 6479337 Cameron Regional Council Stream 18-Apr-06 Grant Barnes Marcus Auckland 21-Apr-06 Anderson Didymo 3 krobinson no 2645043 6479207 Cameron Regional Council Stream 18-Apr-06 salmon Meridian Energy 24-Apr-06 Waitaki canals Ohau canal nboustead no farmers 18-Apr-06 salmon Meridian Energy 24-Apr-06 Waitaki canals Wairepo Arm nboustead no farmers 18-Apr-06 DOC ranger (for Hamish Angus) DoC, Te Anau 28-Apr-06 Pyke d/s Lake Alabaster, ckilroy no 2123580 5616740 next to Pyke Lodge 03-May-06 orc Otago Regional 4-May-06 Earnscleugh Marshall Road ckilroy yes 2223977 5544823 Council (Fraser) River 01-May-06 salmon Meridian Energy 5-May-06 Waitaki canals Ohau canal nboustead no 2280830 5652080 farmers 02-May-06 salmon Meridian Energy 5-May-06 Waitaki canals Wairepo arm nboustead no 2277310 5653190 farmers 01-May-06 salmon Meridian Energy 5-May-06 Waitaki canals Tekapo canal nboustead no 2288820 5674750 farmers 05-May-06 Alison Beath Petra Specht 11-May-06 Mangatepopo Stream dsutherland no 2730900 6236100 11-May-06 ECan 11-May-06 Conway River above Ferniehurst, ckilroy no 2537460 5842598 below bridge 11-May-06 ECan 11-May-06 Conway River at SH1 ckilroy no 2544350 5845250 16-May-06 salmon Meridian Energy 18-May-06 Waitaki canals Ohau canal nboustead no 2280830 5652080 farmers 16-May-06 salmon Meridian Energy 18-May-06 Waitaki canals Wairepo arm nboustead no 2277310 5653190 farmers 16-May-06 salmon Meridian Energy 18-May-06 Waitaki canals Tekapo canal nboustead no 2288820 5674750 farmers 17-May-06 R. Warren N. Fallows Agriquality 19-May-06 Arawhata ckilroy no 2154285 5642703 National Survey

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 27

Appendix 2. Criteria for ranking of sites and list of sites eligible for ranking. Sites not selected for sampling are shown in italic font. The sites are sorted in island, region and site number order.

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score 1264 North Auck/Waik Waimakariri Stm SH 5 Bridge 2758940 6352622 2 1 1 3 3 3 13 1265 North Auck/Waik Pokaiwhenua Arapuni Rd 2750090 6345730 3 1 1 3 2 4 14 Ngakoaohia 1266 North Auck/Waik Stm Puketotara 2700262 6348096 3 1 1 3 3 4 15 off Lime Works 1267 North Auck/Waik Kaniwhaniwha Loop Rd 2694089 6365470 3 1 2 4 3 4 17 1268 North Auck/Waik Ohinemuri Karangahake 2751016 6416326 1 1 1 3 3 4 13 1269 North Auck/Waik Waitawheta end of Franklin Rd 2756185 6411448 2 1 2 3 3 4 15 1270 North Auck/Waik Kaueranga Coromandel 2743534 6449687 3 1 1 3 3 3 14 1271 North Auck/Waik Mangatapopo Mangatapopo 2728978 6239551 5 1 1 4 4 4 19 1272 North Auck/Waik Whanganui Wanganui 2732258 6240671 1 1 4 4 4 4 18 1341 North Auck/Waik Whanganui Motor camp 2710191 6255498 1 1 3 4 4 3 16 1391 North Auck/Waik Awakino SH 83 2307164 5608752 2 1 1 2 4 2 12 1604 North Auck/Waik Mangauika Te Tahi Road 2697800 6350300 3 1 1 4 3 4 16 1618 North Auck/Waik Matarawa Paraonui Rd 2759530 6330780 2 1 1 3 2 4 13 1622 North Auck/Waik Waiomou Tauranga Rd 2762300 6368110 3 1 1 4 3 4 16 1665 North Auck/Waik Whakapapa Kakahi 2718874 6248775 1 1 2 3 1 3 11 1296 North Eastern Taharua Poronui Stn Track 2794260 6237705 1 1 3 1 4 4 14

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 28

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score 1307 North Eastern Wairoa Frasertown 2891830 6239390 3 1 1 3 3 4 15 1321 North Eastern Ruakitiri Morere 2886553 6274745 1 1 3 3 4 4 16 1322 North Eastern Ruakituri Erepeti 2888499 6263152 1 1 3 2 4 4 15 1323 North Eastern Waioeka Wairata 2888784 6313053 1 1 3 3 4 4 16 1324 North Eastern Waioeka River gauge& C/w 2887736 6321798 1 1 1 3 3 4 13 1325 North Eastern Whakatane Ruatoki North 2860818 6332293 1 1 1 3 3 4 13 Waimana Ranger 1326 North Eastern Tauranga Station 2869573 6315169 5 1 3 3 1 4 17 1328 North Eastern Whirinaki River Rd, Minginui 2832570 6275870 2 1 3 3 4 4 17 1331 North Eastern Horomanga Nat Park base hut 2844300 6303380 3 1 1 1 1 2 9 Te Awa camp 1332 North Eastern Rangitaiki ground 2812086 6275521 1 1 1 2 3 4 12 Hatchery Stream 1333 North Eastern Waimataa Stm Walk bridge 2788667 6340319 4 1 1 3 1 4 14 Ngongotaha above Valley 1334 North Eastern Stm Fishing Lodge 2788317 6340515 1 1 1 2 3 4 12 Tahunaatara SH 30 South of 1343 North Eastern Stm Rotorua 2783830 6318290 3 1 3 3 3 4 17 1344 North Eastern Pokaitu Stm Horohoro 2786340 6327850 5 5 2 4 4 4 24 1568 North Eastern Rangitaiki Rimu Road 2832490 6294850 1 1 1 3 3 2 11 1571 North Eastern Whakatane Grace Rd 2859973 6340595 1 1 1 3 3 3 12 1572 North Eastern Motu Haupotu 2917657 6360611 1 1 1 3 3 3 12 1593 North Eastern Kaituna Trout pool Rd 2803490 6349740 1 1 1 1 2 1 7

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 29

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score 1594 North Eastern Hamurana Hamurana Rd 2796250 6346910 1 1 1 1 1 2 7 1596 North Eastern Awahou Stm Hamurana Rd Br 2792220 6345390 1 1 1 2 1 3 9 1598 North Eastern Ruruanga sh34 br, Kawarau 2833840 6340020 1 1 1 3 1 3 10 1601 North Eastern Ngamuwahine SH29 Br 2775680 6371720 1 1 1 3 1 4 11 Main Rd Br 1602 North Eastern Wainuiomata Wainuiomata 2673720 5990690 2 1 1 4 3 4 15 1621 North Eastern Waimana Waimana Rd 2868540 6331840 2 1 1 4 3 4 15 1626 North Eastern Hangaroa Te Reinga 2902610 6254840 3 1 1 4 3 4 16 1630 North Eastern Wairata Redpath rd end 2888120 6312240 3 1 4 4 1 4 17 Ngahinga 1631 North Eastern Wheao Crossing 2827250 6286830 3 1 3 3 3 4 17 1661 North Eastern Rangitaiki Dry Fly Rd Br 2802770 6267700 1 1 2 3 3 3 13 Whirinaki Rd 1662 North Eastern Whirinaki Murapara 2837030 6295890 2 1 1 3 4 4 15 2003 North Eastern Otara Tutaetoka bridge 2892337 6337634 4 1 2 3 3 4 17 1289 North Hawkes Bay Ngaruroro 2km u/s Gold Ck 2784996 6220347 1 1 1 2 4 4 13 Harkness Stream 1290 North Hawkes Bay Ngaruroro and Main river 2790447 6213870 1 1 1 2 3 4 12 Kiwi mouth 1291 North Hawkes Bay Ngaruroro helipad 2792556 6203524 1 1 1 1 4 4 12 1292 North Hawkes Bay Ngaruroro Kuripapango 2796652 6195868 1 1 2 3 4 4 15 Napier-Taihape 1293 North Hawkes Bay Taruarau Rd 2787373 6191844 3 1 3 2 4 4 17 1294 North Hawkes Bay Taruarau near L Horotea 2782016 6206602 3 1 1 2 4 4 15

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 30

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score 1295 North Hawkes Bay Mohaka Taharua confl. 2795840 6230620 1 1 1 2 4 4 13 1297 North Hawkes Bay Mohaka Te Puia Lodge 2804779 6220060 1 1 1 2 4 4 13 Mohaka/Ripia 1298 North Hawkes Bay Confluence Pakaututu 2813658 6215866 1 1 3 3 4 4 16 1299 North Hawkes Bay Mohaka McVicar Road 2823922 6217900 1 1 1 3 4 4 14 1304 North Hawkes Bay Mohaka Willow Flat 2851910 6237090 1 1 3 3 4 4 16 Cental Te Hoe 1306 North Hawkes Bay Te Hoe Hoe Hut 2836821 6252835 4 1 1 1 1 4 12 1308 North Hawkes Bay Waipunga Opoto Falls 2817006 6239001 3 1 1 3 3 4 15 Walker Rd 1335 North Hawkes Bay Tukituki ,Waipawa 2820967 6130152 1 1 1 3 3 4 13 Tutaekuri, Puketapu- 1336 North Hawkes Bay Puketapu Sherenden 2835724 6181149 1 1 1 3 3 4 13 u/s Chesterhope 1567 North Hawkes Bay Ngaruroro bridge 2840620 6171740 1 1 1 3 4 3 13 1597 North Hawkes Bay Waipawa SH2 br,, Waipawa 2816280 6133650 1 1 1 3 3 3 12 1599 North Hawkes Bay Ngaruroro Main River 2790615 6213827 1 1 1 1 3 4 11 1600 North Hawkes Bay Tukipo Road Bridge 2794780 6132460 1 1 1 3 3 4 13 1619 North Hawkes Bay Mangaonuku Tikokino Rd 2811320 6138410 2 1 1 4 3 4 15 1633 North Hawkes Bay Mangaone Dartmore 2828010 6185020 3 1 3 4 2 4 17 1635 North Hawkes Bay Waikoau Tutira 2843700 6213920 3 1 3 4 2 4 17 1636 North Hawkes Bay Taruarua Pohakura 2789430 6184220 3 1 3 4 4 4 19 2001 North Hawkes Bay O'Hara Stm Kereru 2800340 6171670 3 1 1 3 2 4 14

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 31

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score Confluence of Donald river and 2002 North Hawkes Bay Donald Jap Creek 2805900 6200610 4 1 1 1 3 4 14 273 North Taranaki Waingongoro Ohawe Beach 2612600 6179300 1 1 1 3 3 4 13 275 North Taranaki Kaupokonui Glenn Rd br u/s 2603217 6184443 3 1 1 3 3 4 15 at Tarata Rd. d/s 281 North Taranaki Maketawa of bridge 2618885 6226974 4 1 1 3 3 3 15 282 North Taranaki Patea at Skinner Rd 2625919 6206428 2 1 1 3 3 4 14 283 North Taranaki Waingongoro Eltham 2620755 6196587 1 1 1 3 3 4 13 Manganui-a-te- 1254 North Taranaki ao Ruatiki Rd bridge 2700144 6208154 2 1 3 3 4 4 17 Mangawhero- 1255 North Taranaki Mangawhero Pakahi Rd Bridge 2710035 6194503 4 1 1 2 4 4 16 1256 North Taranaki Retaruke Matuku 2704373 6230179 4 1 1 3 3 4 16 1276 North Taranaki Stony Mangatete Rd Br 2587510 6219619 3 1 1 3 4 4 16 1277 North Taranaki Waiwhakaiho SH3 Br,Taranaki 2608305 6228799 3 1 1 3 4 4 16 1278 North Taranaki Waiwhakaiho Constance Rd Br 2606052 6239049 3 1 1 3 3 3 14 1279 North Taranaki Mangaoraka Corbett Rd 2612659 6238072 4 1 1 3 3 4 16 Bristol Road, 60m d/s from bridge at 1280 North Taranaki Manganui trib 2621319 6229715 1 1 1 3 3 4 13 Whangaehu 1337 North Taranaki Whangaehu valley, Rd bridge 2723234 6186838 4 1 1 2 4 4 16 1603 North Taranaki Kapuni at Skeet Road 2610865 6190687 3 1 1 3 4 4 16

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 32

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score 1642 North Taranaki Mangawhero side rd off SH2 2708840 6158270 5 1 1 4 2 4 17 2004 North Taranaki Manganui near York Rdi 2614191 6212136 4 1 1 3 3 4 16 1244 North Taupo Waitahanui Waitahanui Bridge 2777460 6264031 1 1 1 1 3 1 8 1245 North Taupo Hinemaiaia Hinemaiaia 2772257 6256600 1 1 1 1 3 1 8 Tauranga First exit point on 1246 North Taupo Taupo river 2761657 6249494 1 1 1 1 4 1 9 1247 North Taupo Tongariro Lonely Pool 2754444 6242474 1 1 1 1 4 1 9 1248 North Taupo Tongariro Blue Pool 2755258 6235954 1 1 1 1 4 1 9 1249 North Taupo Tongariro d/s Poutu Dam 2754029 6226906 1 1 1 1 4 1 9 1253 North Taupo Waikato Reids Farm 2778229 6277721 1 1 1 2 4 2 11 1257 North Taupo Wairehu Canal outlet to L Rotoira 2742944 6237378 5 1 2 2 4 1 15 1595 North Taupo Waiotaka R rd to airstrip Br 2757860 6240170 1 1 1 1 3 4 11 1637 North Taupo Waimarino Kepa Rd Br 2761070 6242550 3 1 2 2 3 2 13 1285 North Wellington Rangitikei d/s Oturua stream 2771733 6201381 1 1 1 2 4 4 13 1286 North Wellington Rangitikei Mangamaire confl. 2769236 6209180 1 1 1 2 3 4 12 Ecology Stream 1287 North Wellington Rangitikei Confluence 2769097 6217541 1 1 1 2 3 4 12 1288 North Wellington Rangitikei Springvale 2770968 6186395 1 1 2 2 4 4 14 1300 North Wellington Moawhango Whitikaupeka Pa 2755650 6176230 4 1 3 3 4 4 19 1301 North Wellington Hautapu Mataroa 2742430 6169760 5 1 3 3 3 4 19 Pukeokahu, River 1302 North Wellington Rangitikei Valley Lodge 2771342 6170801 1 1 2 2 4 4 14

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 33

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score 1303 North Wellington Pourangaki Upper Kawhatau 2763530 6150760 5 1 3 2 4 4 19 Hawkes Bay- 1305 North Wellington Hautapu Maungataniwha 2837641 6240305 4 1 3 3 4 4 19 Kumeroa, 1309 North Wellington Manawatu Jacksons Road 2761959 6091514 1 1 1 3 3 3 12 1310 North Wellington Mangatinoka SH@ B 2752884 6083196 1 1 1 3 4 3 13 1311 North Wellington Manawatu Ashurst 2744382 6096410 1 1 1 3 3 3 12 at Masterton, u/s 1312 North Wellington Ruamahanga Waipoua confl. 2736302 6025092 1 1 1 3 4 3 13 Gladstone Rd,10 1313 North Wellington Ruamahanga km d/s Masterton 2731010 6011730 1 1 1 3 3 4 13 d/s Atiwhakatu 1314 North Wellington Waingawa confl. 2723316 6031666 3 1 1 3 4 4 16 1315 North Wellington Waiohine near road end 2711025 6020432 2 1 2 3 4 4 16 Akatarawa Road Junction 1316 North Wellington Hutt (Birchville) 2686228 6010786 1 1 1 3 4 3 13 1317 North Wellington Hutt at Upper Hutt 2679631 6006344 1 1 1 3 4 3 13 1318 North Wellington Waikanae d/s SH1 Br. 2683294 6033941 3 1 1 3 3 2 13 1319 North Wellington Otaki at SH1 Br. 2691060 6046096 3 1 1 3 4 3 15 1320 North Wellington Makuri Makuri 2765421 6070597 2 1 1 4 4 4 16 Toe Toe Rd Br, 1338 North Wellington Rangitikei Utiku 2752950 6157340 1 1 1 2 4 4 13 1339 North Wellington Pakuratahi WaterworksRd Br 2694786 6013131 4 1 1 3 3 3 15

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 34

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score 1569 North Wellington Rangitikei Mangaweka 2750381 6151246 1 1 1 2 4 3 12 1570 North Wellington Manawatu Teachers College 2732707 6089240 1 3 1 3 1 3 12 1616 North Wellington Oroua London Ford Rd 2750320 6125410 2 1 1 4 2 4 14 1620 North Wellington Kopuaranga Donovans Rd 2735860 6037180 2 1 1 4 4 4 16 1638 North Wellington Pohangina Camping Ground 2753160 6116790 2 1 1 4 2 4 14 Saddle Rd, 1639 North Wellington Pohangina Ashurst 2745560 6099060 2 1 1 4 2 4 14 1658 North Wellington Mangahao Mangahao 2746880 6082080 2 1 1 3 4 3 14 Vinegar Hill, 1 km 1659 North Wellington Rangitikei u/s br 2736182 6138000 1 1 1 2 4 4 13 1660 North Wellington Rangitikei Bulls, d/s SH1 Br 2713160 6110240 1 1 1 2 4 4 13 1664 North Wellington Tauherenikau Underhill Rd 2708715 6011317 3 1 1 2 3 3 13 1666 North Wellington Oroua Boness Rd 2726100 6101600 2 1 1 4 4 4 16 Uxbridge Road, 1170 South CSI Awamoko Waitaki District 2339674 5586963 4 1 1 1 3 4 14 1172 South CSI Hakataramea 1.3 km from SH82 2311372 5607180 1 1 1 1 4 2 10 Ashburton 1375 South CSI South branch Gorge Road 2364264 5730284 1 1 3 3 4 3 15 1376 South CSI Ashburton Smalls Rd 2412470 5688930 1 1 2 3 4 3 14 just above lagoon 1377 South CSI Rangitata in flowing reach 2390712 5668261 1 1 1 2 4 2 11 1379 South CSI Opihi d/s Raincliff Rd Br 2349290 5668499 1 1 1 3 4 3 13 1380 South CSI Opuha below Skiptons Br 2348127 5678828 1 1 1 3 4 3 13

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 35

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score 1381 South CSI Tengawai Cave 2346751 5653580 2 1 1 3 4 3 14 1382 South CSI Tekapo d/s kayak course 2306972 5684583 1 1 2 2 4 2 12 1383 South CSI Mary Burn at crossing 2296138 5658218 3 1 3 3 3 3 16 1384 South CSI Irishman Ck U/s Tekapo Canal 2297383 5678250 4 1 3 3 4 3 18 1385 South CSI Twizel Twizel at SH 8 2279268 5657308 1 1 1 1 4 1 9 300 m u/s L 1386 South CSI Ohau Ruataniwha 2272795 5655434 3 1 2 1 4 2 13 500 m u/s SH72 1519 South CSI North Ashburton Br 2391439 5732805 1 1 1 3 4 3 13 Deep Creek 2km 1520 South CSI Upper Rangitata sw 2341800 5734745 1 1 2 3 4 1 12 main access point d/s water intake rantiata tce Rd 1521 South CSI Rangitata end 2371273 5700790 1 1 3 3 4 3 15 1522 South CSI Opihi Grassy Banks 2373366 5659022 1 1 1 2 4 3 12 1523 South CSI Te Moana At toilet block 2356982 5683421 4 1 2 3 4 3 17 u/s of Gorge Rd 1524 South CSI Pareora Br 2340342 5650753 2 1 1 3 4 3 14 at river access sign. End Orari R 1525 South CSI Orari Rd 2364755 5696127 1 1 2 3 4 3 14 1528 South CSI Otamatapaio 1.5km from SH83 2278620 5621470 4 1 3 3 3 4 18 1530 South CSI Tasman Glentanner Stn 2280154 5696373 2 1 2 1 2 1 9 1560 South CSI Tekapo Canal 2288920 5675066 1 1 1 1 2 1 7

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 36

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score 1578 South CSI Ohau D/s Twizel confl 2286225 5648320 1 1 1 1 4 2 10 150 m d/s Kapu 1610 South CSI Waihao Rd Br 2350130 5598990 1 1 2 3 4 4 15 1611 South CSI Timaru d/s bridge 2217485 5623470 3 1 2 1 2 2 11 1614 South CSI Waihi Te Awa rd Br 2371520 5664790 2 1 1 4 3 4 15 1643 South CSI Cass delta 2308960 5700190 5 1 4 4 1 1 16 ford to Lillybank 1644 South CSI Mcaulay Stn 2314490 5717990 3 1 3 2 1 2 12 1645 South CSI Snow Haldon Rd br 2309190 5662670 5 5 3 3 3 1 20 1646 South CSI Edward SH8 br 2309960 5680170 4 3 3 3 2 1 16 1647 South CSI Fraser stm u/s Pukaki canal 2274130 5660840 2 5 2 3 2 1 15 1648 South CSI Tasman u/s Fred Stm confl 2278220 5705100 3 1 3 1 1 1 10 1 km u/s Huxley 1649 South CSI Hopkins Lodge 2257140 5675180 3 1 3 2 1 1 11 u/s Hopkins 1650 South CSI Dobson confluence 2261230 5677320 3 1 3 1 1 3 12 1651 South CSI Fork Braemar Rd Br 2301720 5688360 5 5 2 4 2 1 19 1652 South CSI Tekapo u/s Maryburn confl 2296310 5658020 1 1 3 1 1 1 8 1653 South CSI Waihao Crowes Rd ford 2362153 5599509 1 1 1 4 2 4 13 1654 South CSI Waikakahi Tawai Rd Br 2357930 5586820 5 1 1 1 2 4 14 1655 South CSI Welcome Stm u/s waitaki confl 2357620 5584650 5 5 4 4 3 4 25 car park near Blue 1656 South CSI Blue stm Lakes 2281400 5719500 5 3 3 4 2 1 18

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 37

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score 1657 South CSI Maitland R Lake Ohau R Br 2255472 5667546 4 3 2 2 1 3 15 Ohau, unnamed 2013 South CSI tributary Weir Board 2280067 5653286 3 1 2 2 1 4 13 2015 South CSI Tekapo Tekapo Delta 2287026 5648287 1 1 3 2 4 2 13 1 South Nel/Marl Maitai Hardy St 2534400 5992630 3 1 1 3 3 2 13 2 South Nel/Marl Motueka Blue Gum Corner 2507241 6011265 1 1 1 2 4 3 12 Moss Bush 3 South Nel/Marl Riwaka Reserve 2503515 6017577 2 1 1 3 4 2 13 Rugby Ground 4 South Nel/Marl Riwaka SH60 2508739 6015645 2 1 1 3 4 2 13 5 South Nel/Marl Pelorus Tinline River 2552096 5988027 1 1 3 3 4 4 16 6 South Nel/Marl Pelorus Pelorus Bridge 2557934 5989711 1 1 1 2 3 2 10 7 South Nel/Marl Pelorus Fishermans Flat 2569697 5991520 1 1 1 3 4 2 12 8 South Nel/Marl Kaituna Reading Road 2574877 5988160 4 1 1 3 3 3 15 9 South Nel/Marl Wakamarina State Highway Br. 2566006 5990396 4 1 1 3 4 3 16 10 South Nel/Marl Tunakino Rai Valley 2562294 5999190 4 1 1 3 3 4 16 Just above Brown 11 South Nel/Marl Rai River 2559483 5998765 2 1 1 3 3 3 13 12 South Nel/Marl Rai Rai Falls 2558017 5990942 2 1 1 3 3 3 13 50m South of Fox 13 South Nel/Marl Wai-iti hill Wai-iti Bridge 2509227 5975360 4 1 1 3 3 4 16 14 South Nel/Marl Motueka Jackson Bridge 2501055 5958204 1 1 1 2 1 3 9 15 South Nel/Marl Motueka Kohatu Bridge 2496080 5972977 1 1 1 2 4 3 12

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 38

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score 16 South Nel/Marl Baton Top, above bridge 2485283 5988665 3 1 3 3 4 4 18 17 South Nel/Marl Baton half-way 2490802 5991987 3 1 3 3 4 4 18 By old toilet, 2km 18 South Nel/Marl Pearce from Mot River 2492973 5996671 4 1 2 2 3 4 16 19 South Nel/Marl Graham Graham School 2496294 6000010 4 1 3 3 4 4 19 20 South Nel/Marl Sherry Matipiko Bridge 2487073 5976490 5 1 3 2 4 4 19 21 South Nel/Marl Whangapeka Walters Peak 2490947 5985974 2 1 2 2 4 3 14 22 South Nel/Marl Motueka Whangapeka 2492662 5985262 1 1 2 2 4 3 13 23 South Nel/Marl Roding Roding Bridge 2523177 5980150 4 1 1 4 4 4 18 24 South Nel/Marl Waimea/Lee SH6 Bridge 2520065 5981166 3 1 1 2 4 3 14 Upstream of 25 South Nel/Marl Wai-iti Brightwater bridge 2518204 5982098 4 1 1 3 3 4 16 Highway Bridge 26 South Nel/Marl Waimea Appleby 2520903 5988612 3 1 1 3 4 3 15 Picnic site near 27 South Nel/Marl Motupiko Kikiwa 2500502 5944729 3 1 1 2 4 3 14 just u/s Motopiki 28 South Nel/Marl Rainy confl 2492752 5954771 3 1 2 3 3 4 16 29 South Nel/Marl Motupiko Murry Airwacker 2492025 5959233 3 1 1 3 4 4 16 30 South Nel/Marl Motupiko Kohatu Bridge 2495996 5972903 3 1 1 3 4 4 16 400m u/s Rolling 31 South Nel/Marl Wangapeka R confluence 2474795 5973738 2 1 3 2 4 4 16 50 m u/s from 32 South Nel/Marl Rolling swingbridge 2474890 5973520 4 1 3 3 3 4 18

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 39

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score 33 South Nel/Marl Wangapeka ~1.5 km d/s Dart 2481508 5976692 2 1 3 2 4 4 16 34 South Nel/Marl Owen 8 km us SH6 2468827 5951907 3 1 3 1 4 4 16 35 South Nel/Marl Owen 1 km us SH6 2465118 5947481 3 1 2 1 4 4 15 37 South Nel/Marl Howard Buller tributary 2483907 5942686 4 1 1 1 4 2 13 38 South Nel/Marl Homestead Ck Ford 2493290 5935010 5 1 3 1 4 4 18 39 South Nel/Marl Speargrass Ck Buller tributary 2493287 5934984 5 2 3 1 4 4 19 trib. Frying Pan 40 South Nel/Marl Owen Ck 2469792 5954159 3 1 4 1 4 4 17 ~1.5 km past 41 South Nel/Marl Leatham cableway 2524161 5941619 5 1 3 3 4 4 20 Leathem 42 South Nel/Marl Branch confluence (u/s) 2523520 5942745 4 1 2 3 4 3 17 1 km upstream 43 South Nel/Marl Branch from bridge 2525766 5947453 4 1 2 3 4 3 17 44 South Nel/Marl Wairau Kowhai Flat 2519400 5943800 1 1 1 2 4 3 12 near ford u/s from cableway before 45 South Nel/Marl Glenroy bridge 2455258 5905315 4 1 3 3 3 4 18 off end of farm 46 South Nel/Marl Matakitaki track 2455504 5911435 2 1 3 1 4 3 14 47 South Nel/Marl Six Mile Ck Power house 2454180 5924866 5 1 1 3 4 4 18 Tutaui Valley 2k u/s Buller 48 South Nel/Marl Mangles confluence 2459103 5934263 3 1 1 1 4 3 13 49 South Nel/Marl Matakitaki Mt Ella 36 2468548 5911949 2 1 3 1 4 3 14

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 40

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score 50 South Nel/Marl Tutaki East Branch 2466350 5923348 4 1 3 1 4 4 17 51 South Nel/Marl Mangles Tutaki Rd North 2467235 5933267 3 1 2 1 4 4 15 52 South Nel/Marl Mangles footbridge 2464304 5931833 3 1 2 1 4 4 15 2.5km u/s Awapiri 53 South Nel/Marl Maruia Bridge 2481499 5976690 1 1 1 1 4 2 10 54 South Nel/Marl Matakitaki 1km u/s SH 6 2453446 5933182 2 1 1 1 4 2 11 300m u/s west 55 South Nel/Marl Matiri branch 2453550 5946993 4 1 3 1 4 3 16 56 South Nel/Marl Matiri 1.5km d/s bridge 2454210 5937667 4 1 2 1 4 3 15 57 South Nel/Marl Wairau Below SH1 bridge 2591015 5973368 1 1 1 2 2 3 10 61 South Nel/Marl Coldwater 200m u/s L.Rotoiti 2494733 5926091 4 1 4 2 3 2 16 62 South Nel/Marl Travers 200m u/s L Rotoiti 2495080 5926089 3 1 6 2 4 1 17 63 South Nel/Marl L. Rotoiti trib 3/4 way up lake 2496180 5927818 4 1 4 3 4 4 20 64 South Nel/Marl Walkers Stm Church Lane 2555050 5961149 4 1 1 3 1 4 14 65 South Nel/Marl Wairau The Narrows 2568465 5965043 1 1 1 2 2 3 10 Waihopai Bridge 66 South Nel/Marl Waihopai SH63 2571064 5964024 4 1 1 3 4 4 17 67 South Nel/Marl Waihopai Quaildale 2567943 5955053 4 1 1 3 4 4 17 1 km u/s L 68 South Nel/Marl Durville Rotoroa 2480615 5921544 3 1 4 2 4 1 15 69 South Nel/Marl Sabine At hut 2483958 5921974 3 1 4 2 3 1 14 70 South Nel/Marl Lake Rotoroa Gowan River 2475814 5934945 3 1 2 1 1 1 9

71 South Nel/Marl Waikoropupu downstream of 2491385 6040577 1 4 1 3 2 1 12

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 41

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score Pupu Springs u/s Carters Road 73 South Nel/Marl Kaituna bridge 2474553 6054098 4 1 3 3 4 4 19 d/s from heaphy 74 South Nel/Marl Aorere track car park 2463832 6040474 3 1 3 4 4 4 19 u/s Cobb Dam. 75 South Nel/Marl Cobb Camping ground. 2477512 6008725 3 1 3 3 4 3 17 1km d/s of Cobb 76 South Nel/Marl Takaka power station 2487952 6014027 1 1 2 3 3 3 13 77 South Nel/Marl Takaka 100m u/s of Rd Br 2492232 6018442 1 1 1 3 4 3 13 u/s Tasman Drive 78 South Nel/Marl Motupipi road bridge 2496459 6039689 5 1 1 4 3 4 18 u/s of One Spec 79 South Nel/Marl Anatoki road bridge 2493067 6037954 5 1 1 3 3 3 16 80 South Nel/Marl Alfred Springs Junction 2446205 5873393 4 1 3 3 3 3 17 81 South Nel/Marl Rahu Springs Junction 2443107 5878379 5 1 1 3 4 4 18 82 South Nel/Marl Station Ck Maruia 2445569 5890929 5 1 1 4 4 4 19 83 South Nel/Marl Maruia Creighton Rd Br 2444686 5900320 1 1 1 1 3 2 9 84 South Nel/Marl Rappahannock Maruia 2447462 5902771 5 1 1 3 3 4 17 u/s 500m from Larrys creek 88 South Nel/Marl Larrys Ck bridge 2418778 5911407 5 1 1 2 4 4 17 90 South Nel/Marl Goulter Lower River 2527226 5951466 4 1 3 3 4 4 19 91 South Nel/Marl Awatere Muller Station 2541107 5906797 3 1 4 3 4 4 19

92 South Nel/Marl Castle Middlehurst 2546752 5914290 3 1 3 3 2 4 16

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 42

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score Station Awatere Valley Upcot Stream 93 South Nel/Marl Grey Awatere Valley 2558612 5923590 5 1 3 4 4 4 21 Gladstone Street Upcot Stream 94 South Nel/Marl Awatere Bridge 2559672 5923285 3 1 4 3 4 4 19 Seddon rail/road 95 South Nel/Marl Awatere bridge 2599004 5949029 3 1 1 3 4 3 15 SH 1 under road 97 South Nel/Marl Clarence bridge 2585075 5893686 2 1 1 2 4 4 14 Upper Bridge 98 South Nel/Marl Clarence (D?S L Tennyson 2489981 5886503 2 1 3 2 4 4 16 99 South Nel/Marl Clarence Above Ackeron 2506495 5867666 2 1 3 2 4 4 16 Above Alma River 100 South Nel/Marl Island Lake u/s 2506306 5891346 5 1 3 2 4 4 19 101 South Nel/Marl Alma Airstrip Crossing 2506317 5891107 4 1 6 3 4 3 21 1 km above 103 South Nel/Marl Severne Acheron 2517235 5894852 4 1 3 2 4 2 16 104 South Nel/Marl Acheron Clarence 2507088 5869907 4 1 3 3 4 2 17 107 South Nel/Marl Rainbow at cableway 2501059 5908717 4 1 3 3 4 3 18 100 m u/s Wairau 108 South Nel/Marl Coldwater CK confl 2503586 5905067 3 1 1 3 4 3 15 109 South Nel/Marl Wairau above Rainbow 2501765 5908280 1 1 3 2 4 2 13 110 South Nel/Marl Wairau Dip Flat 2503564 5925767 2 1 3 2 4 2 14

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 43

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score 1 km u/s Buller 1573 South Nel/Marl Gowan confluence 2473430 5943000 3 1 1 1 4 3 13 1574 South Nel/Marl Maruia 200 m d/s Falls 2447782 5927380 1 1 1 1 1 2 7 1575 South Nel/Marl Grey Dobson 2365160 5860037 1 1 1 2 3 3 11 1586 South Nel/Marl Takaka Kotinga Bridge 2493940 6037340 1 1 1 2 4 3 12 1587 South Nel/Marl Aorere Lecomte 2479606 6059765 3 1 1 3 3 4 15 1592 South Nel/Marl Maruia above Buller confl 2444670 5934570 1 1 1 1 4 2 10 1605 South Nel/Marl Matakitaki 200m d/s SH 6 2453467 5934388 2 1 1 1 4 2 11 1356 South North Canty Boyle 50m above bridge 2459493 5854515 3 1 1 2 4 2.5 13.5 1361 South North Canty Conway SH 1 2544391 5845197 4 1 1 3 4 3 16 1362 South North Canty Hurunui 500m d/s SH 1 Br 2518547 5812096 1 1 1 2 4 2.5 11.5 1364 South North Canty Hurunui Mandamus 2474062 5823186 1 1 2 2 4 2 12 1365 South North Canty Hurunui South Branch 2456163 5819785 1 1 2 2 4 1 11 Sth Branch 1366 South North Canty Hurunui confluence 2456897 5820161 1 1 3 2 4 1 12 Double Corner 1367 South North Canty Waipara road bridge 2492083 5786479 4 4 2 4 3 3 20 1368 South North Canty Ashley SH 1 below bridge 2484985 5769959 1 1 1 1 4 2 10 1370 South North Canty Ryton Mt Olympus Rd Br 2392948 5772362 4 1 3 2 2 2 14 1371 South North Canty Selwyn Whitecliffs, u/s Br 2420439 5748987 1 1 1 1 4 2 10 1372 South North Canty Selwyn Coes Ford 2462258 5723406 1 1 1 3 3 3 12 1396 South North Canty Ashley at Gorge rd bridge 2447442 5775013 1 1 1 2 4 2 11

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 44

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score 5km Nth Shaggy 1532 South North Canty Lake Stm Hill 2358739 5762740 3 1 4 3 3 4 18 Double Hill Run 1533 South North Canty Glenariffe Rd Br 2377996 5764866 3 1 3 3 3 4 17 1 km nth of 1534 South North Canty Double Hill flats Glenarriffe 2377369 5765942 4 1 4 4 4 4 21 1535 South North Canty Manuka Point access Rd 2367140 5768257 5 1 4 4 4 4 22 2 km west of Mt 1536 South North Canty Titan Stm Algidus Stn 2375584 5770128 5 1 4 4 4 4 22 d/s of Avoca 1537 South North Canty Harper Confluence 2391622 5778871 3 1 4 4 4 4 20 300 m d/s Gorge 1538 South North Canty Rakaia Br 2401482 5742214 1 1 1 2 4 3 12 1539 South North Canty Rakaia sh1 2432624 5716719 1 1 1 3 2 4 12 1540 South North Canty Waimakariri Trib Paddys' Bend 2403195 5797008 1 1 1 2 3 4 12 1541 South North Canty Waimakariri Mt White bridge 2407882 5799461 1 1 1 2 4 4 13 d/s Slovens Stm 1542 South North Canty Broken confl 2419963 5778779 3 1 3 3 3 4 17 1543 South North Canty Porter d/s sh73 Br 2406649 5772881 3 1 1 3 2 4 14 1544 South North Canty Winding Ck at Hut 2414519 5782345 4 1 3 3 4 4 19 1545 South North Canty Waimakariri d/s Gorge bridge 2433140 5760390 1 1 1 2 4 2 11 50m below jetboat 1546 South North Canty Waimakariri ramp 2481435 5754707 1 1 1 1 4 2 10 1548 South North Canty Kaiapoi Mabers Rd 2478497 5755162 1 1 1 3 2 4 12

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 45

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score Fishers Road d/s 1550 South North Canty Okuku Br 2466829 5773216 4 1 1 3 4 4 17 foot bridge u/s 1551 South North Canty Hurunui Lake Sumner 2437324 5833097 1 1 3 2 4 2 13 Below Lake 1552 South North Canty Hurunui Sumner 2451118 5831207 1 1 4 2 4 2 14 500m down SH 7 1553 South North Canty Lewis from NZDA lodge 2460124 5859050 3 1 1 2 4 3 14 down walking track at Bus 1554 South North Canty Boyle shelter 2458867 5846574 3 1 3 2 4 3 16 1555 South North Canty Hope at SH7 bridge 2465120 5846442 3 1 1 3 4 3 15 at confluence of Waiau and 1557 South North Canty Percival Hanmer 2492117 5847438 5 1 1 3 4 4 18 1558 South North Canty Waiau Leslie Hills Rd Br 2493724 5835261 4 1 1 3 2 4 15 1559 South North Canty Conway SH 70 2532697 5860392 4 1 1 4 3 4 17 1576 South North Canty Otukaikino Ck d/s Dickies Rd Br 2480470 5752410 3 1 1 2 3 3 13 1613 South North Canty Avon Armagh St 2480540 5990690 2 1 1 4 2 2 12 Leeston and 1624 South North Canty Harts Ck Lakes Rd 2455770 5711900 3 1 1 4 3 4 16 2010 South North Canty Hurunui 250 m u/s SH 1 Br 2517860 5812110 1 1 1 2 4 3 12 1119 South Otago Dingle near homestead 2223040 5635082 3 1 1 2 2 2 11 1122 South Otago Nevis u/s of crossing 2195309 5551005 3 1 3 3 1 2 13 1123 South Otago Kawarau Scrubby Creek 2203460 5568055 1 2 1 1 4 1 10

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 46

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score 1126 South Otago Lochy Long Burn 2167565 5550076 3 1 1 1 1 1 8 1127 South Otago Wye Ck u/s mouth by lake 2176076 5554814 5 1 1 3 3 3 16 1129 South Otago Greenstone above Hut 2134835 5569809 3 1 4 2 2 1 13 Mid section, Old 1130 South Otago Caples Homestead 2138307 5579519 3 1 1 1 1 3 10 Lake Sylvan 1133 South Otago Route Burn footbridge 2139067 5598724 3 1 2 4 2 2 14 between fishtrap 1134 South Otago Diamond Ck and creek 2145189 5592156 3 1 1 1 2 3 11 1142 South Otago Dunstan Ck Beatie Rd Br 2254694 5580329 4 1 2 3 2 2 14 1144 South Otago Manuherikia Galloway Road 2229717 5547379 1 1 1 2 2 2 9 1145 South Otago Pool Burn Poolburn Br. (d/s) 2253850 5565830 3 1 2 4 4 3 17 1146 South Otago Ida Burn Auripi Rd Br 2254900 5566540 3 1 2 2 2 1 11 1147 South Otago Kye Burn SOE site 2294650 5558520 4 1 2 3 3 1 14 1150 South Otago Taieri at Outram 2295682 5480758 1 1 1 2 4 2 11 1151 South Otago Taieri d/s Harcus Rd Br 2285959 5510688 1 1 1 2 4 2 11 1153 South Otago Waipori Scenic reserve 2279591 5471613 2 1 3 3 3 4 16 d/s Roxburgh east 1155 South Otago Teviot bridge 2222608 5512523 3 1 2 1 2 3 12 1156 South Otago Tuapeka 200 m us Clutha 2239730 5460368 3 1 1 1 4 4 14 300 m d/s Blach 1158 South Otago Pomahaka Bridge 2241508 5446528 1 1 2 2 3 4 13 Queens hill Rd, 1159 South Otago Waitahuna Clydevale 2245914 5448718 2 1 2 1 3 4 13

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 47

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score 1161 South Otago L. Tuakitoto Outlet 2266163 5434519 5 1 1 3 4 1 15 1165 South Otago Water of Leith Dunedin 2316134 5480891 4 1 1 3 4 3 16 Danseys Pass 1169 South Otago Maerewhenua Motor Camp 2318113 5582042 3 1 2 1 4 2 13 Upper Taieri- 1177 South Otago Logan Burn Paerau Rd. 2266800 5523613 5 1 3 3 4 4 20 Loganburn Ford 1178 South Otago Taieri Rd 2266271 5525157 1 1 3 3 4 4 16 1183 South Otago Mataura Fairlight Station 2171519 5522724 1 1 1 1 4 1 9 Brightwater 1184 South Otago Spring Fairlight 2172416 5521182 4 1 1 1 3 3 13 1193 South Otago Waimea SH 94, Mandeville 2184599 5460728 2 1 1 1 4 4 13 u/s Wyndham- 1201 South Otago Mokoreta Stm Letterbox Rd 2190665 5420209 1 1 1 1 4 4 12 Sth Hillend Dipton 1214 South Otago Dipton Stm Rd 2146830 5458894 4 1 1 1 4 4 15 1222 South Otago Otautau Stm Main Street Br 2123395 5440033 3 1 1 1 4 3 13 1389 South Otago Omarama Stm Omarama 2268690 5631370 3 1 1 1 4 1 11 1390 South Otago Otematata SH 83, d/s bridge 2288031 5618826 3 1 1 2 4 2 13 East Branch d/s 1397 South Otago Matukituki footbridge 2174943 5626216 2 1 2 2 1 1 9 1401 South Otago Kakanui Dunrobin Rd Br 2332748 5572684 3 1 1 1 3 3 12 1402 South Otago Waiareka Ck Teschmakers Rd 2343460 5559410 4 1 1 1 1 1 9 1403 South Otago Shag Palmerston 2334383 5523460 2 1 1 3 4 3 14

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 48

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score 1409 South Otago SilverStm 3 Mile Hill Road 2308029 5481421 5 1 1 3 4 4 18 Tokomairiro 1410 South Otago West Branch Mt Stuart 2266266 5453744 1 1 1 3 3 1 10 1412 South Otago Kaihiku Stm Clifton Rd Br 2249080 5441542 5 1 1 1 4 3 15 1413 South Otago Waiwera SH1 br 2239746 5439526 3 1 1 3 4 3 15 1414 South Otago Pomahaka Burning Plain Rd 2231446 5454891 1 1 3 3 3 3 14 1415 South Otago Wairuna Stm Miller Rd Br 2225443 5449781 5 1 1 4 4 3 18 1418 South Otago Pomahaka below picnic area 2210051 5475619 1 1 2 3 2 3 12 1420 South Otago Heriot Burn SH 90 2225557 5480951 5 1 1 3 4 3 17 1422 South Otago Pomahaka Hamilton flat 2212037 5498701 1 1 3 4 4 3 16 1424 South Otago Teviot Bridge Huts Rd 2234040 5513010 3 1 2 3 2 3 14 150 u/s Long 1429 South Otago Manuherikia Gully Rd Br 2256653 5576168 1 1 1 2 2 2 9 400m d/s of Runs 1431 South Otago Manuherikia Rd Br 2265929 5598499 1 1 2 2 2 2 10 1435 South Otago Lindis d/s Elliots bridge 2233748 5600810 3 1 1 2 2 2 11 1436 South Otago Hunter Ferguson Flat 2234664 5671099 1 1 1 1 2 1 7 1437 South Otago Hunter Cascade creek 2228118 5656288 1 1 1 1 1 1 6 1438 South Otago Dingle at Cotters Hut 2232410 5644295 3 1 1 1 1 2 9 1440 South Otago Makarora Camerons Flat 2213515 5665574 1 1 1 2 1 2 8 1441 South Otago Young Ram Flat 2207508 5660665 3 1 1 3 2 2 12 Nth Br. U/s Sth Br 1442 South Otago Young confl 2201845 5662943 3 1 1 3 1 2 11

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 49

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score 1443 South Otago Wilkin Keiran Forks 2194294 5655758 3 1 1 2 1 2 10 1445 South Otago Motatapu d/s main rd bridge 2189393 5609370 4 1 2 3 2 3 15 at water leve gauge, 400m u/s 1451 South Otago Lake Hayes Stm of lake 2179774 5573847 5 1 2 3 4 2 17 Willow Park below 1452 South Otago Kawarau Kawarau bridge 2174255 5566520 1 1 1 2 4 2 11 Shotover/Kawarau 1453 South Otago Shotover confl 2176581 5568061 1 1 3 3 4 3 15 1456 South Otago Rees at Muddy Creek 2150814 5601714 3 1 2 2 2 3 13 1462 South Otago Ettrick Burn 150 u/s from lake 2095569 5537587 5 1 1 1 4 2 14 Nth Makarewa 1478 South Otago Makarewa Grove Bush Rd 2157831 5425327 1 1 1 2 4 3 12 1479 South Otago Owaka 2251844 5413998 3 1 2 4 3 3 16 Tawanui Rd, SOE 1481 South Otago Catlins Site 2244813 5410722 2 1 2 3 3 3 14 Cairn Peak, 1482 South Otago Waipahi Kurawai 2219352 5429354 1 1 3 3 3 3 14 1483 South Otago Waipahi Waipahi 2220182 5449060 1 1 2 3 4 3 14 Mossburn Five 1487 South Otago Cromel Stm Rivers Rd 2150595 5499501 4 1 1 1 4 2 13 Mossburn Five 1488 South Otago Irthing Rivers Rd 2153688 5500826 3 1 1 1 4 2 12 Danseys Pass 1526 South Otago Maerewhenua Road 2311181 5580492 3 1 2 1 2 4 13

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 50

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score 1577 South Otago Kakanui Mill Dam 2340090 5559200 3 1 1 2 4 1 12 1581 South Otago Lindis Ardgour 2228786 5589302 3 1 1 1 2 3 11 1582 South Otago Cardrona Mt Barker 2202763 5599188 5 1 1 2 2 1 12 1583 South Otago Taieri Waipiata 2286310 5552960 1 1 1 2 4 1 10 1584 South Otago Fraser Marshall Rd 2223987 5544926 2 1 1 1 2 3 10 1585 South Otago Makarora d/s Wilkin confl 2205616 5652285 1 1 1 1 1 1 6 1607 South Otago Kauru Kakanui Valley Rd 2336310 5567470 4 1 1 1 3 1 11 Bucklands 1608 South Otago Waikouaiti Crossing 2321530 5508710 1 1 2 3 3 2 12 br 5 km u/s lower 1627 South Otago Manor Burn dam 2235720 5544960 3 1 2 3 2 2 13 1632 South Otago Spey Bridge 2062420 5504670 3 1 1 2 4 1 12 1634 South Otago Tautuku end rewcastle rd 2230030 5397490 3 1 3 3 4 3 17 1640 South Otago Clutha Clyde 2221960 5549500 1 1 1 1 1 1 6 1641 South Otago Clutha Beaumont 2239950 5481440 1 1 1 1 1 1 6 d/s Hyde Macraes 1667 South Otago Filly Burn Road 2296312 5537730 5 5 2 5 3 1 21 D/s L. Hayes @ 2012 South Otago Hayes Ck road culvert 2178844 5570596 5 1 1 2 3 4 16 200m below Moke 1668+A253 South Otago Moke Ck Lake 2160956 5569896 5 1 2 4 2 4 18 1185 South Southland Mataura Garston 2172584 5518325 1 1 1 1 4 1 9 d/s Black bridge 1186 South Southland Mataura SH 6 2167374 5512053 1 1 1 1 4 2 10

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 51

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score 1187 South Southland Mataura u/s Fiery Creek Br 2164631 5507454 1 1 2 1 4 3 12 u/s Nokomai/ 1188 South Southland Nokomai Mataura Confl. 2170274 5507758 3 1 1 1 4 3 13 1189 South Southland Mataura u/s Nokomai confl 2169570 5507720 1 1 3 1 4 3 13 North end of 1190 South Southland Mataura Cattle Flat Rd 2169428 5495808 1 1 3 1 4 4 14 1191 South Southland Mataura d/s SRC Station 2172845 5489725 1 1 2 1 4 4 13 150m d/s 1192 South Southland Mataura Bridge/gravel pit 2180937 5473434 1 1 1 1 4 4 12 1194 South Southland Mataura Dillon Road 2186862 5461144 1 1 2 1 4 4 13 u/s of bridge SH 1195 South Southland Otamita Stm 94 2186488 5459560 2 1 1 1 4 4 13 Gore, Surrey 1196 South Southland Mataura Street 2196841 5443711 1 1 1 1 4 3 11 1197 South Southland Waikaka Stm River Road, Gore 2197130 5447949 1 1 1 1 4 3 11 d/s of Mataura. 1198 South Southland Waimumu Stm SH 1 2189928 5437165 5 1 1 1 4 4 16 1199 South Southland Mataura Coal Pit Road. 2188607 5426347 1 1 1 1 4 3 11 d/s Br., Mimihau 1200 South Southland Mimihau School Rd 2191591 5424439 1 1 1 1 4 4 12 u/s Mataura Island 1202 South Southland Mataura Bridge 2185153 5416060 1 1 1 1 4 3 11 Southland. By Piano Flat DOC 1203 South Southland Waikaia sign & Cattle stop 2198539 5508188 1 1 3 2 4 4 15

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 52

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score 1204 South Southland Waikaia u/s Waikaia bridge 2186395 5490219 1 1 1 1 4 3 11 d/s Waipounamu 1205 South Southland Waikaia Bridge 2183222 5475599 1 1 1 1 4 3 11 Waimahaka- 1206 South Southland Waimahaka Stm Mataura Rd Br 2187953 5402350 5 1 1 2 4 4 17 d/s of bridge, by Scrubby Hill 1207 South Southland Waikawa corner 2213131 5402642 2 1 1 2 4 4 14 1219 South Southland Hamilton Burn Hamilton Burn Br. 2134980 5480730 1 1 1 1 4 2 10 1228 South Southland Upukerora Te Anau 2098352 5520201 1 1 1 1 4 1 9 1231 South Southland Eglinton Knobs Flat 2116850 5569488 1 2 1 2 4 2 12 1232 South Southland Hollyford road end 2123876 5601399 3 1 1 1 2 1 9 1235 South Southland Clinton Glade House 2109626 5574986 4 1 1 1 4 2 13 Te Anau, 300m 1236 South Southland Worsley u/s from lake 2101510 5572600 3 1 1 1 4 1 11 600 m u/s from 1238 South Southland Iris Burn river mouth. 2086685 5511523 5 1 4 1 4 1 16 1327 South Southland Borland Borland Burn 2089361 5479288 4 1 3 1 3 3 15 u/s Cascade 1458 South Southland Eglinton confluence 2121177 5578826 1 1 1 2 4 2 11 Lillburn Monowai 1471 South Southland Lill Burn Road 2097170 5453930 4 1 2 1 4 2 14 Cliffden 1472 South Southland Wairaki Blackmount Road 2098971 5461559 3 1 1 1 4 2 12 1473 South Southland Orauea Feldwick Road 2108766 5451356 2 1 1 1 4 2 11

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 53

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score Otapiri Gorge Rd 1474 South Southland Otapiri Br 2158212 5451866 2 1 1 1 4 2 11 1475 South Southland Orauea Birchwood 2111459 5461692 2 1 1 1 4 2 11 1477 South Southland Wairaurahiri Lake Hauroko 2067202 5442776 4 1 4 3 4 3 19 1484 South Southland Mataura Keowns Bridge 2172028 5480327 1 1 1 1 4 2 10 1485 South Southland Garvie Burn McDonald Rd 2180936 5486404 5 1 1 3 4 3 17 Mossburn Five 1486 South Southland Acton Rivers Rd 2147172 5497847 3 1 1 1 4 2 12 1489 South Southland Mataura u/s Cainard Rd Br. 2164137 5525610 1 1 2 1 4 2 11 U/s of lake 1492 South Southland Electric Monowai 2071442 5466965 3 1 1 1 4 2 12 1623 South Southland Waimatuku Waimatuku 2138030 5423340 3 1 1 4 4 4 17 rd br 1.7km us 1625 South Southland Wairaki Waiau confl 2099470 5461580 3 1 1 1 4 3 13 2006 South Southland Eyre Ck u/s Eyre Creek Br 2162971 5512855 4 1 1 1 4 3 14 Mill Road 2007 South Southland Waihopai Invercargill 2157279 5414856 3 1 1 2 4 4 15 2008 South Southland Rata Burn Lake Hauroko 2067140 5443303 5 1 6 1 3 4 20 North Mavora 2014 South Southland Mararoa Lake 2129400 5547400 1 1 6 1 1 1 11 1065 South W Coast Otututu (Rough) Atarau Rd Br 2399111 5881500 3 5 1 3 4 3 19 1346 South W Coast Arahura Milltown 2363791 5821665 2 5 3 4 3 4 21 1350 South W Coast Ellis Ck Ferry Road 2322768 5799685 5 1 3 4 1 4 18

1355 South W Coast Hall Lake Paringa 2222057 5715843 4 2 6 4 1 4 21

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 54

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score outlet 1513 South W Coast Crooked Bell Hill Rd Br 2394867 5840933 2 1 3 3 4 3 16 Evans Rd, Hari 1515 South W Coast Evans Ck Hari 2315571 5788981 5 1 3 3 1 3 16 1517 South W Coast Okuru Nolan Road end 2185964 5691529 4 1 2 3 4 3 17 2 km u/s Okuru 1518 South W Coast Turnbull Sth Turnbull Rd 2181318 5690087 3 1 2 3 4 3 16 confluence with 1561 South W Coast Paringa Otoko 2229727 5709619 4 1 1 2 4 4 16 Jacobs d/s Kini crekk 1566 South W Coast (Makawhio) confluence 2243305 5726553 5 1 3 2 4 4 19 1612 South W Coast Robinson Palmer Road 2428843 5858796 3 1 3 3 4 4 18 Higgins Road 36 South W. Coast Buller trib Ford 2482698 5945192 1 1 1 1 3 4 11 opposite Garveys 85 South W. Coast Inangahua Mine Road 2421649 5891760 1 1 1 3 4 3 13 O'Gradys Road – 86 South W. Coast Inangahua end 2412808 5902352 1 1 2 2 4 4 14 50m d/s Waitahu 87 South W. Coast Waitahu Bridge 2414307 5903354 3 1 1 2 4 3 14 Roundhill Farm 89 South W. Coast Inangahua (Landing) 2422425 5926103 1 1 1 1 1 3 8 Flats d/s Saddle 165 South W. Coast Cascade Creek 2145583 5658196 4 1 1 1 4 2 13 1052 South W. Coast Grey Phil Bell Farm 2429904 5860506 1 1 3 3 3 4 15

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 55

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score sh7- Waipuna 1063 South W. Coast Grey corner 2400523 5878935 1 1 1 2 4 4 13 1066 South W. Coast Mokihinui 200m d/s bridge 2423802 5963749 3 1 1 3 3 3 14 1097 South W. Coast Karamea d/s kelly Creek 2442897 5995138 3 1 2 2 4 3 15 1340 South W. Coast Arnold Blair Rd Br 2376543 5857022 1 1 1 3 4 3 13 1342 South W. Coast Haupiri d/s of bridge 2404461 5847232 3 1 2 3 4 2 15 1345 South W. Coast Taramakau Otira 2383365 5829049 1 1 1 3 3 4 13 1349 South W. Coast Harris Ck Hokitika Valley 2347473 5815199 3 1 2 2 1 2 11 1351 South W. Coast Waitangitaona White Heron Jetty 2293567 5779372 3 1 2 3 1 3 13 1353 South W. Coast Haast Clarke Bluff 2222872 5686617 3 2 1 2 2 4 14 1494 South W. Coast Moeraki Lake outlet 2209253 5714550 4 1 1 2 1 3 12 Lake Mapourika 1495 South W. Coast Okarito outlet 2285511 5765478 3 1 1 3 3 3 14 500m u/s 1503 South W. Coast Roaring Lion Karamea confl. 2462280 6000690 4 1 1 1 3 2 12 1504 South W. Coast Karamea Lesley confluence 2468677 5996921 3 1 1 1 3 2 11 1505 South W. Coast Karamea Ugly 2453085 6000894 3 1 1 1 4 2 12 1506 South W. Coast Mokihinui North branch 2441470 5962450 3 1 1 1 1 2 9 1507 South W. Coast Mokihinui opposite hut 2441582 5961866 3 1 1 1 4 2 12 800m up walking 1509 South W. Coast Porarari track 2372873 5898503 4 1 1 2 3 3 14 1.5 km upstream 1510 South W. Coast Punakaiki from road 2373207 5896544 4 1 1 2 3 3 14

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 56

Visitors per year Accesibility 1. Risk activity 1. Easy, >1000 1. Angling helicopter Likeli- Social/ 2. 500- 2. Kayak 2. Unsealed road hood of Favourable cultural 1000 3. Jetboat, raft 3. Remote road transfer environment 1. New New 3. 100- 4. 4WD 4. Private access 1. Very to establish National Zealand Zealand 499 5. Swim, tramp 5. No roads high 1. Very high 2. Map Map 4. <100 6. Sightsee, 6. Long walk 2. High 2. High Regional Site Grid Grid 5. no picnic 7. Very 3. Mod. 3. Mod. 3. Local Total No. Island Region River Site Location Easting Northing record 7. Other inaccessible 4 Low 4. Low 4. Low score 1511 South W. Coast Fox 1 km from road 2376458 5906691 4 1 1 2 4 3 15 1512 South W. Coast Grey McDonnells farm 2422856 5871780 1 1 3 3 4 3 15 2km u/s Lake 1514 South W. Coast Bruce Stm Brunner 2383089 5836349 4 1 2 3 1 3 14 1516 South W. Coast La Fontaine Stm Hari Hari 2310829 5787869 2 1 1 3 1 3 11 2.5 km d/s Horseshoe Flat 1562 South W. Coast Moeraki hut 2219092 5704458 4 1 1 1 3 4 14 end of walking track (u/s Bob 1563 South W. Coast Thomas Creek) 2205566 5695456 3 1 1 1 1 4 11 1564 South W. Coast Waiatoto Drake Flats 2173122 5660580 3 1 1 1 3 4 13 1579 South W. Coast Inangahua Landing 2418611 5921403 1 1 1 1 4 4 12 Woodstock sports 1606 South W. Coast Hokitika ground 2346750 5824610 1 1 1 3 3 4 13 1609 South W. Coast Taramakau Kumara 2362180 5840490 1 1 1 3 4 4 14 1617 South W. Coast Ahaura Ahaura 2389490 5871900 2 1 1 3 4 4 15 1629 South W. Coast Orangipuku Br 2381760 5836070 3 1 2 3 3 4 16 Stillwater -Coal Ck rd br d/s Arnold 1663 South W. Coast Grey conflu 2373902 5862135 1 1 2 3 3 3 13

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 57

Appendix 3: Briefing for the survey

Briefing Report: New Zealand delimiting survey brief and sampling procedures for Didymosphenia geminata Briefing report: Didymo Report Number: 7 Operations Manager: Peter Wilkins Technical : NIWA Date of report: 1/5/2006

Table of Contents 1. Purpose 58 2. Scope 58 3. Introduction 58 4. Timeline and coverage 59 5. Sampling and samples 59 6. Mapping 59 7. Logistics 60 8. Communications 60 9. Site selection 60 10. Briefings 60 11. Contacts 60 12. Sampling procedures 62

1. Purpose The purpose of this survey is to detect if D. geminata is present, in selected South Island and North Island tributaries and rivers to provide short term containment options and longer term response options.

2. Scope The rivers selected for the survey include sites that have ‘high use’ and/or ‘high value’. These include catchments, tributaries and rivers that provide suitable habitat and/or are used for various recreational and commercial activities.

The NIWA Likely Environments model will be overlaid with ‘high use/value’ sites as determined by information provided by Councils.

3. Introduction Absence of an algal species in a river can never be absolutely established because it is generally only possible to sample a small proportion of the places where the alga might grow. Therefore, to ensure that a negative survey result has a high chance of reflecting the absence of the species from the river, it is

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 58

necessary to maximize the chance of finding the alga. This can be achieved by: (1) sampling many sites, (2) targeting the sampling at points where the alga is most likely to have been introduced, and (3) sampling the habitats that the alga is most likely to colonise first.

This delimiting survey will cover selected ‘high use/value’ sites in the North Island, and South Island. The focus will be to detect if D. geminata is present, in selected North Island and South Island land catchments, tributaries and rivers where the alga is currently not known to be present.

High use sites will be prioritised including kayaking, fishing and jet boating as high risk activities.

4. Timeline and coverage 400 selected sites will be sampled throughout New Zealand. Theses sites will be divided into areas and each area will have an AgriQuality Area Co-ordinator responsible for organising the field teams. Teams will be made up of trained staff from AgriQuality, NIWA, Fish and Game, Regional Councils and DOC as available. All survey sites will be completed by the 19 May 2006.

• A list of site names and GPS locations for each site to be sampled will be issued at the start of the survey. Each site will have a unique site number, printed sample form sample form and accompanying site map. All will contain the unique sute number. • Equipment required includes; • Waders • GPS units • Vehicle (some sites require helicopter access) • Mobile phones • Disinfection kits • Sample methods and specifications and Safety, Health and Environment (SH&E) information.

5. Sampling and samples Refer to Datasheet BioNZ for sampling procedures for D. geminata

All samples together with sample sheets should be couriered to the following address and made attention to:

AgriQuality Ltd, 14 Sir William Pickering Drive, Christchurch

6. Mapping All mapping of sites, overview maps, and location maps will be undertaken by AgriQuality’s Geospatial Services team.

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 59

Overlay of D. geminate likely environments model and ‘high use/value’ sites, undertaken by NIWA, for Biosecurity New Zealand approval of site selection prior to the start of the survey.

Data-entry of site localities and results into a GIS overlay at completion of survey.

7. Logistics AgriQuality will provide all equipment, maps, survey forms and other resources. AgriQuality will provide co-ordination of sampling within areas.

8. Communications Refer members of the public with suspected findings of D. geminata to 0800 80 99 66. Refer members of the public requesting information on D. geminata to: www.biosecurity.govt.nz/didymo

All media enquires shall be referred to Phillip Barclay of Biosecurity New Zealand.

Confidentiality should be maintained at all times.

9. Site Selection Sites have been based on those of the October 2005 delimiting survey. The sites have been selected by Maurice Duncan of NIWA in consultation with Regional Councils, Fish and Game Councils and DOC offices.

10. Briefings

There will be two briefings for AgriQuality Area Co-ordinators.These will be held in Hamilton on the 2 May 2006 and in Christchurch on 4 May 2006. NIWA staff will attend to provide technical training on sampling methodology. Subsequent staff training and briefing will be conducted by the Area Co- ordinators and will be given to all staff working on the survey irrespective of whether prior training has been received. (This will cover any variation to procedures from prior surveys).

11. Contacts Operations Manager Peter Wilkins AgriQuality Ltd.

Didymo Survey Site Selection and Technical Maurice Duncan NIWA

Didymo Survey Diagnostics & Technical

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 60

Cathy Kilroy NIWA

MAF Communications Phillip Barclay

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 61 WARNING DECONTAMINATE

______Survey of New Zealand catchments for macroscopic/microscopic presence of Didymosphenia geminata (didymo)

1. Sampling sites A “site” is any river reach. Reach length is variable, but should encompass areas with stony substrate within reasonably easy reach of the access point. Up to 25 – 50 m length is suggested, depending on river conditions. We assume highest chance of infestation by didymo is at public access points. In each river, sample from upstream to downstream (to eliminate any chance of transferring didymo, if it is present, upstream in a system).

2. Field procedure The sampling has two aims: 1. to inspect the site, looking for any algae that resembles didymo, especially young colonies (Figure 1), which are brown/pinkish-brown round bobbles. Collect samples, if found; 2. to collect a representative sample of algae growing at each site. It is important to sample the typical algae from a site – as well anything that looks suspiciously like didymo (Figure 2) – because didymo cells may be mixed with other algae. For the first aim, look for small round algal colonies, particularly in the habitats listed below, but also check edge areas, and algae growing on/amongst aquatic plants, submerged wood, etc. Take samples of any suspicious-looking growths.

Figure 1: Small didymo colonies

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 62 WARNING DECONTAMINATE

______

Figure 2: Colonies of a red alga that look a bit like didymo. For the second aim, as you inspect the site, take samples along transects across the river, following the method described overleaf. Good habitat for didymo is: 1. Moderate velocity waters (i.e., not in very still waters, not in very fast flowing waters more than ~1 m/s). The species may be present in backwaters of rivers (out of direct flow, but subject to constant water movement) so these also need to be inspected/sampled. Virtually all places where didymo has been sighted in the Mararoa/lower Waiau catchments have been wadeable, though the alga may occur on the margins of faster-flowing, deeper areas. In the early stages of colonization it is likely that didymo will not be in fast-flowing areas (> 1 m/s). 2. Well-lit stream bed (but this does not preclude areas that are in shade for part of the day); 3. Stable substrates: i.e. most likely to occur on substrate of cobble-size or larger (>150 mm diam.), but smaller rocks may be examined in areas of very stable flow In other words, look for stable cobbles in open, wadeable areas with moderately flowing water. Particularly look for rocks with small, tightly adhering light brownish bumps (see photos), but include rocks, plants and other substrates with all types of algae. 3. Equipment:

• Wooden scrapers (disposable ice-cream sticks) (dispose of after use at one site) • A metal knife may also be useful – anything that can be wiped thoroughly clean (spray and soak for at least one minute and wipe down with bleach after each site, rinse out with river water at the next site) • Disposable pipetters for rinsing or sampling from bedrock (dispose of after use at one site) • Bucket – for collecting rocks etc. during visual survey (spray and soak for at least one minute and wipe down with bleach after each site, rinse out with river water at the next site) • Paper towels

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 63 WARNING DECONTAMINATE

______• Containers for samples (e.g., 110 ml stackable “Elkays”, 100 ml bottles) • Pens/pencils/markers • Chilly bins for holding samples • Data sheets • Disposable gloves (for use with bleach) • Rubbish bags for used scrapers, pipetters, towels, gloves, etc. • 10L bottle of bleach • A large plastic bin (for soaking waters and equipment in bleach solution) • GPS unit • Water containers • Maps

4. Method • Complete site information on data sheet (GPS is very important, and/or supply an accurate 1:50 000 map reference). Also please write your full names (not just initials). Site location is very important.

• Before starting your inspection of the site, determine the approximate locations of five transects from which you’ll collect samples. Space every few metres (depending on reach length) but if the site contains different habitat (runs, riffles, pools – see definitions on sampling form), make sure that the transects include each habitat type, e.g., three transects in runs, two in riffles.

• Depending on river size, transects will extend across to the opposite bank, or to water up to about 0.7 m deep (as long as it is flowing at a safe velocity). STAY IN SAFE DEPTHS/VELOCITIES AT ALL TIMES. • Start inspecting the site at the upstream end. At each transect walk across the reach and collect rocks from 5 points, roughly equally spaced.

• Pool the five rocks from the transect into a bucket. These can be pooled with rocks from other transects.

• For each set of pooled stones, scrape a sub-sample of algae from each stone and transfer to a small sampling container. Try to include all types of algae present (distinguishing algae by colour and texture). Also pipette out some of the river water from the bottom of the bucket and add to the sample. If algal growth is very thin, use a metal blade, rather than the wooded scrapers provided.

• NB. Please sample all rivers and scrape all stones even if there appears to be no algae present. After scraping stones with little or no visible algae wash the scraped area of the stone with the pipette filled with water from the bottom of the bucket.

• If during your site inspection you see any suspicious algae colonies in areas other than the transects, also collect samples of these. Check submerged plants and wood, as well as stones.

• We expect to receive 1 or 2 samples per site. One from the scrapings and one from any suspicious algae colonies in areas other than the transects.

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 64 WARNING DECONTAMINATE

______• Write sample numbers on the containers and datasheet and indicate habitat type against each sample. (There is space on the sheet for one sample per transect, but generally transects will be pooled.)

• Indicate the coverage of suspected didymo against the transects where it was noted; or add a note describing coverage at the whole site. Also note appearance, growth form.

• Complete extra information for each site (width, substrate type, shade, river use) if it is shown on the site list that it is a new site, i.e., that the site was not sampled in the October 2005 survey. Please always note water clarity.

• For new sites, take a water sample in a clean sampling container (label with river name and site no.) from a free flowing part of the river, for conductivity assessment at the lab. • Keep all samples cool and in the dark. Keep the datasheets with the samples, for microscope analysis and entry into master list.

5. Inspection and Sampling Hygiene • Samplers must take precautions to minimise the risk of unintentional transfer of D. geminata from affected to non-affected sites.

• Specific hygiene instructions are outlined in bold italics in the text above.

• Use a new set of equipment in each river or tributary.

• Start inspection and sampling at the clean, upstream end of a river or tributary and work downstream.

• Remove all macro material from hands, boots/waders, clothing, equipment, etc, before leaving each sampling and inspection site.

• Spray and soak all potentially contaminated boots/waders and equipment, etc for at least one minute after completing sampling on a single river or tributary, before leaving the last site.

• Samplers should carry sufficient bleach solution made up for a day’s sampling, i.e. 10 litres. Disinfection using the bleach solution should be carried out in a place where splashing and/or disposal of the used solution will not cause environmental damage.

• At the end of each sampling day, visually check all potentially contaminated boots/waders, clothing and equipment to ensure they are cleaned, disinfected, dry and ready for the next inspection and sampling cycle.

Any questions or issues to should be directed to:

Peter Wilkins AgriQuality Ltd Maurice Duncan NIWA Refer all media enquiries to Phillip Barclay of Biosecurity New Zealand.

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 65 WARNING DECONTAMINATE

______Important

NEW FOR THE 2006 SURVEYS

1. If possible pool all the periphyton scrapings into one sample container. 2. MOST IMPORTANT. Please take samples even if the stones appear to be algae free. See the bold section in methods above. In the October survey didymo was found on one such sample. 3. Record extra information for each site (width, substrate type, shade, water use) and take a water sample for conductivity ONLY if it is shown on the site list that it is a new site, i.e., that the site was not sampled in the October 2005 survey. 4. Always take a GPS reading and note water clarity. 5. Please note site location as well as river name, e.g., River name: Otaki Site location: 50m downstream of State Highway One Bridge

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 66

Appendix 4. Field Sample Form Sample Site Number………

Survey of New Zealand catchments for macroscopic/microscopic presence of Didymosphenia geminata: April-May 2006.

Sample site number:……………………………………. River:……………………………………….

Site location description:………………………………………………………………………….……..

GPS: NZMG E……………………… NZMG N……………………or. Map ref.…………...……… . GPS Field reading(if differs from above): NZMG E…………………. NZMG N………......

Date: ………………………………... Time:……………….……………………………………….….

Sampling team leader:………………………………..……………………………….………………....

Sampling officer:………………………………..……………………………….……………………….

Samples: label with site no., river name, site location., date, team leader..

Sample Habitat types Didymo visible % Didymo Notes (e.g. other algae Sample type no. (run, riffle, pool) ? (yes/no) cover if visible present, suitability of site) Pooled sample from 25 stones

Suspected didymo

Other

Water clarity Clear Slightly turbid Very turbid

Include this form with the samples and courier to: DIDYMO SURVEY SAMPLES. AgriQuality Ltd, 14 Sir William Pickering Drive, Christchurch. Ph 03 358 1830.

Lab only: Results Positive Negative Comments on sample Pooled sample Suspected didymo Other

NIWA Analysist: Name:………………………………………Date:…………………………………..

On completion of results, Lab to fax a copy of this form to: AgriQuality Ltd. Fax 03 358 6222

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 67

Range of substrate sizes Boulders are broader than 25 cm

Large cobbles: 12 – 25 cm wide

Small cobbles: 6 – 12 cm wide

Gravels: 2 mm to 6 cm wide

Sand, mud and silt are finer than 2 mm. Sand feels “gritty”.

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 68

Appendix 5. Selected survey results from May 2006. Samples positive for D. geminata in bold font and heavy shading. Sites not sampled in italics and light shading.

Water clarity Class Description NZMG New Zealand Map Grid C Clear S Slightly turbid V Very turbid

% Lab Result Didymo Water Positive/ Sample NZMG NZMG Habitat Didymo cover if Clarity Site_No River_name Site_Description Negative Date Easting Northing Types Visible Y/N visible C/S/V 1 Maitai Hardy St Negative 11/05/2006 2534568 5992453 riffle No N/A C 2 Motueka Blue Gum Corner Negative 08/05/2006 2507241 6011265 riffle No N/A C 3 Riwaka Moss Bush Reserve Negative 08/05/2006 2503546 6017590 riffle, run No N/A C 4 Riwaka Rugby Ground SH60 Negative 08/05/2006 2508720 6015653 riffle No N/A C 6 Pelorus Pelorus Bridge Negative 15/05/2006 2557955 5989615 pool No N/A C 7 Pelorus Fishermans Flat Negative 15/05/2006 2569513 5991636 run No N/A C 8 Kaituna Reading Road Negative 15/05/2006 2574837 5988117 run No N/A C 11 Rai Valle Just above Brown River Negative 15/05/2006 2559495 5998786 run No N/A C 12 Rai River Rai Falls Negative 15/05/2006 2557987 5990944 run No N/A C 14 Motueka Jackson Bridge Negative 10/05/2006 2501012 5958368 riffle No N/A C 15 Motueka Kohatu Bridge Negative 12/05/2006 2496024 5973059 run No N/A C 17 Avon Armagh St Site change 15/05/2006 2490802 5991987 run, riffle No N/A C 21 Whangapeka Walters Peak Negative 15/05/2006 2490956 5985950 run, riffle No N/A C 22 Motueka Whangapeka Negative 15/05/2006 2492585 5986012 run, riffle No N/A C 24 Waimea/Lee SH6 Bridge Negative 10/05/2006 2519962 5981183 riffle No N/A C 26 Waimea Highway Bridge Appleby Negative 10/05/2006 2520776 5988648 run No N/A C 27 Motupiko Picnic site near Kikiwa Negative 10/05/2006 2500498 5944789 riffle No N/A C

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 69

% Lab Result Didymo Water Positive/ Sample NZMG NZMG Habitat Didymo cover if Clarity Site_No River_name Site_Description Negative Date Easting Northing Types Visible Y/N visible C/S/V 35 Owen River 1 km us SH6 Negative 11/05/2006 2465628 5948667 pool, riffle No N/A C 36 Buller tributary Higgins Road Ford Negative 10/05/2006 2482698 5945192 run, riffle No N/A C 37 Howard Buller tributary Negative 10/05/2006 2483892 5942702 riffle No N/A C 44 Wairau Kowhai Flat Negative 15/05/2006 2519400 5943800 run, riffle No N/A C 46 Matakitaki off end of farm track Negative 11/05/2006 2455643 5911372 run No N/A C 48 Mangles Tutaui Valley 2k u/s Buller confluence Negative 12/05/2006 2459204 5934286 riffle No N/A C 49 Matakitaki Mt Ella 36 Negative 12/05/2006 2468574 5911999 run No N/A C 51 Mangles Tutaki Rd North Negative 12/05/2006 2467320 5933743 riffle No N/A C 52 Mangles footbridge Negative 12/05/2006 2464411 5931842 run No N/A C 53 Maruia 2.5km u/s Awapiri Bridge Site change 2481499 5976690 54 Matakitaki 1km u/s SH 6 Negative 11/05/2006 2453537 5933244 run No N/A C 56 Matiri 1.5km d/s bridge Negative 11/05/2006 2454280 5937986 riffle No N/A C 57 Wairau Below SH1 bridge Negative 16/05/2006 2591187 5973216 run, riffle No N/A C 64 Walkers Church Lane No sample 17/05/2006 2555050 5961149 65 Wairau The Narrows Negative 16/05/2006 2568745 5965244 run, riffle No N/A C 68 Durville River 1 km u/s L Rotoroa Negative 17/05/2006 2480720 5921658 riffle No N/A C 69 Sabine At hut Negative 17/05/2006 2483949 5921979 run, riffle No N/A C 70 Lake Rotoroa Gowan River Negativex2 10/05/2006 2475760 5935221 run Yes? Possible C 71 Waikoropupu d/s of Pupu Springs Negative 18/05/2006 2491389 6040573 riffle No N/A C 76 Takaka River 1km d/s of Cobb power stn. Negative 18/05/2006 2488032 6013829 riffle No N/A C 77 Takaka River 100m u/s of road Bridge Negative 18/05/2006 2492263 6018411 riffle No N/A C 83 Maruia River Creighton road river bridge Negative 15/05/2006 2444694 5900339 run, riffle No N/A C 85 Inangahua opposite Garveys Mine Rd Negative 11/05/2006 2421649 5891751 all No N/A C 86 Inangahua O'Gradys Road - end Negative 11/05/2006 2412760 5902403 all No N/A C

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 70

% Lab Result Didymo Water Positive/ Sample NZMG NZMG Habitat Didymo cover if Clarity Site_No River_name Site_Description Negative Date Easting Northing Types Visible Y/N visible C/S/V 87 Waitahu 50m d/s Waitahu Bridge Negative 11/05/2006 2414307 5903357 all No N/A C 89 Inangahua Roundhill Farm (Landing) Negative 11/05/2006 2422421 5926112 all No N/A C 95 Awatere Seddon rail/road bridge Negative 16/05/2006 2598799 5949116 run No N/A V 97 Clarence SH 1 under road bridge Negative 16/05/2006 2585094 5893681 run No N/A V 108 Coldwater 100 m u/s Wairau confl Negative 15/05/2006 2503586 5905067 riffle No N/A C 109 Wairau above Rainbow Negativex2 15/05/2006 2501765 5908280 riffle, run Unsure 1% C 110 Wairau Dip Flat Negative 15/05/2006 2503564 5925767 run, riffle No N/A C 165 Cascade Flats d/s Saddle Creek Negative 17/05/2006 2145583 5658196 all No N/A C 273 Waingongoro Ohawe Beach Negative 08/05/2006 2612600 6179300 riffle No N/A S 275 Kaupokonui Glenn Rd bridge u/s Negative 08/05/2006 2603217 6184443 run, riffle No N/A S 281 Maketawa at Tarata Rd. d/s of bridge Negative 08/05/2006 2618885 6226974 riffle No N/A S 282 Patea River at Skinner Rd Negative 08/05/2006 2625919 6206428 riffle No N/A S 283 Waingongoro Eltham Negative 08/05/2006 2620755 6196587 riffle No N/A C 1052 Grey Phil Bell Farm Negative 08/05/2006 2429880 5860528 run, pool No N/A C 1063 Grey sh7- Waipuna corner Negative 08/05/2006 2400524 5878934 pool, riffle No N/A C 1066 Mokihinui river 200m d/s bridge Negative 10/05/2006 2423806 5963796 run, riffle No N/A S 1097 Karamea d/s kelly Creek Negative 10/05/2006 2442743 5995170 all No N/A C 1119 Dingle River near homestead Negative 19/05/2006 2223040 5635082 run, riffle No N/A C 1122 Nevis River u/s of crossing Negative 10/05/2006 2195309 5551005 riffle No N/A C 1123 Kawarau River Scrubby Creek No sample 10/05/2006 2203460 5568055 1126 Lochy River Long Burn Negative 17/05/2006 2167372 5549853 all No N/A C 1129 Greenstone above Hut Negative 17/05/2006 2134656 5569838 run, riffle No N/A C 1130 Caples Mid section, Old Homestead Negative 17/05/2006 2138294 5579510 run, riffle No N/A C 1133 Route Burn Lake Sylvan footbridge Negative 11/05/2006 2139067 5598724 riffle No N/A C

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 71

% Lab Result Didymo Water Positive/ Sample NZMG NZMG Habitat Didymo cover if Clarity Site_No River_name Site_Description Negative Date Easting Northing Types Visible Y/N visible C/S/V 1134 Diamond between fishtrap and creek Negative 11/05/2006 2145189 5592156 riffle No N/A C 1142 Dunstan Beatie Rd Br Negative 10/05/2006 2254694 5580329 run No N/A S 1144 Manuherikia Galloway Road Negative 10/05/2006 2229717 5547379 riffle No N/A C 1146 Ida Burn Auripi Rd Br Negative 10/05/2006 2254900 5566540 riffle No N/A C 1147 Kye Burn SOE site Negative 19/05/2006 2294618 5558517 riffle No N/A S 1150 Taieri at Outram No sample 19/05/2006 2295682 5480758 1151 Taieri below Harcus Road bridge Negative 19/05/2006 2285988 5510669 run No N/A S 1155 Teviot Below Roxburgh east bridge Negative 15/05/2006 2222608 5512523 run No N/A C 1156 Tuapeka 200 m us Clutha Negative 10/05/2006 2239730 5460368 pool No N/A C 1158 Pomahaka 300 m d/s Blach Bridge Negative 10/05/2006 2241508 5446528 run, pool No N/A C 1159 Waitahuna queens hil Rd, Clydevale Negative 10/05/2006 2245914 5448718 run No N/A C 1161 Lake Tuakitoto Outlet No sample 17/05/2006 2266163 5434519 1169 Maerewhenua Danseys Pass Motor Camp Negative 15/05/2006 2318119 5582056 run No N/A C 1170 Awamoko Uxbridge Road Negative 15/05/2006 2339550 5586979 pool No N/A C 1172 Hakataramea 1.3 km from SH82 Negative 15/05/2006 2311228 5607316 riffle No N/A C 1183 Mataura River Fairlight Station Negative 09/05/2006 2171519 5522724 run, pool No N/A C 1184 Brightwater Spring Fairlight Negative 09/05/2006 2172857 5521492 all No N/A C 1185 Mataura River Garston Negative 09/05/2006 2172151 5518024 all No N/A C 1186 Mataura River d/s Black bridge SH 6 Negative 09/05/2006 2167374 5512053 all No N/A C 1187 Mataura River u/s Fiery creek bridge Negative 09/05/2006 2164631 5507454 all No N/A C 1188 Nokomai u/s Nokomai/Mataura confl. Negative 09/05/2006 2170164 5507619 run, pool No N/A C 1189 Mataura River u/s Nokomai confl Negative 09/05/2006 2169570 5507720 run, pool No N/A S 1190 Mataura River North end of Cattle Flat Rd Negative 09/05/2006 2169428 5495808 run No N/A C 1191 Mataura River d/s SRC Station Negative 09/05/2006 2172845 5489725 run No N/A C

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 72

% Lab Result Didymo Water Positive/ Sample NZMG NZMG Habitat Didymo cover if Clarity Site_No River_name Site_Description Negative Date Easting Northing Types Visible Y/N visible C/S/V 1192 Mataura River 150m d/s Bridge/gravel pit Negative 09/05/2006 2180937 5473434 run, riffle No N/A C 1193 Waimea River SH 94, Mandeville Negative 09/05/2006 2184599 5460728 run No N/A C 1194 Mataura River Dillon Road Negative 09/05/2006 2186862 5461144 run No N/A C 1195 Otamita Stream u/s of bridge SH 94 Negative 09/05/2006 2186488 5459560 run, pool No N/A C 1196 Mataura River Gore, Surrey Street Negative 09/05/2006 2196847 5449712 run, pool No N/A C 1197 Waikaka Stream River Road, Gore Negative 09/05/2006 2197130 5447949 run, riffle No N/A C 1199 Mataura River Coal Pit Road. Negative 19/05/2006 2188607 5426347 run No N/A S 1200 Mimihau River d/s Bridge, mimihau School Rd Negative 16/05/2006 2191591 5424439 run, riffle No N/A V 1201 Mokoreta Stream u/s Wyndham- Letterbox Rd Negative 19/05/2006 2190665 5420209 run No N/A S 1202 Mataura River u/s Mataura Island Bridge Negative 19/05/2006 2185153 5416060 run No N/A S 1203 Waikaia River By Piano Flat DOC sign Negativex2 09/05/2006 2198539 5508188 all No N/A C 1204 Waikaia River u/s Waikaia bridge Negative 09/05/2006 2186395 5490219 run No N/A C 1205 Waikaia River below Waipounamu Bridge Negative 09/05/2006 2183222 5475599 run No N/A C 1207 Waikawa d/s of br, by Scrubby Hill cnr Negative 16/05/2006 2213131 5402642 run No N/A V 1214 Dipton Stream Sth Hillend Dipton Rd Negative 18/05/2006 2146830 5458894 run No N/A S 1219 Hamilton Burn Hamilton Burn bridge Negative 18/05/2006 2136135 5480469 run No N/A S 1222 Otautau Stream Main Street Bridge Negative 18/05/2006 2123510 5440203 run No N/A S 1228 Upukerora Te Anau Positive 12/05/2006 2098458 5520612 all No N/A S 1231 Eglinton Knobs Flat Negative 19/05/2006 2116850 5569488 all No N/A C 1232 Hollyford road end Negative 19/05/2006 2123876 5601399 all No N/A C 1235 Clinton Glade House Negative 16/05/2006 2109626 5574986 all No N/A C 1236 Worsley Te Anau, 300m u/s from lake Negative 16/05/2006 2102692 5571714 run, pool No N/A C 1244 Waitahanui Waitahanui Bridge Negative 09/05/2006 2777477 6263921 run No N/A C 1245 Hinemaiaia Hinemaiaia Negative 09/05/2006 2772241 6256634 run, riffle No N/A C

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 73

% Lab Result Didymo Water Positive/ Sample NZMG NZMG Habitat Didymo cover if Clarity Site_No River_name Site_Description Negative Date Easting Northing Types Visible Y/N visible C/S/V 1246 Tauranga Taupo First exit point on river Negative 08/05/2006 2761657 6249494 all No N/A C 1247 Tongariro Lonely Pool Negative 08/05/2006 2754276 6242561 all No N/A C 1248 Tongariro Blue Pool Negative 08/05/2006 2755258 6235954 run, riffle No N/A C 1249 Tongariro d/s Poutu Dam Negative 08/05/2006 2754029 6226906 riffle, run No N/A C 1250 Whakapapa Whakapapa Negative 05/05/2006 2723265 6228891 riffle, run No N/A C 1251 Whakapapa Owhango-Ohinetonga Rd. Br. Negative 05/05/2006 2717800 6242700 run No N/A C 1252 Whanganui Whangapeki Negative 05/05/2006 2721103 6247658 riffle, run No N/A C 1253 Waikato Reids Farm No sample 19/05/2006 2778229 6277721 1254 Manganui-a-te-ao Ruatiki Rd bridge Negative 10/05/2006 2700148 6208156 all No N/A C 1255 Mangawhero Mangawhero-Pakahi Rd Br. Negative 10/05/2006 2710010 6194503 run, pool No N/A C 1256 Retaruke Matuku Negative 05/05/2006 2704378 6230174 all No N/A C 1257 Wairehu Canal outlet to L Rotoira Negative 05/05/2006 2742944 6237378 run No N/A C 1258 Ongarue Okauaka Rd junction Negative 10/05/2006 2718764 6286512 run No N/A C 1259 Awakino Mahoenui Negative 10/05/2006 2669236 6292899 run No N/A C 1260 Waipa Toa Bridge Negative 08/05/2006 2716016 6321839 run No N/A C 1261 Mangatutu Wharepuhunga Road Negative 08/05/2006 2725367 6331461 riffle No N/A C 1262 Puniu Bayley Road Negative 08/05/2006 2729901 6331834 run No N/A C 1263 Waihou Whites Road bridge Negative 09/05/2006 2757184 6349882 run No N/A C 1264 Waimakariri Stream SH 5 Bridge Negative 09/05/2006 2758940 6352622 run No N/A C 1265 Pokaiwhenua Arapuni Rd No sample 09/05/2006 2749026 6345843 1266 Ngakoaohia Stream Puketotara Negative 08/05/2006 2700262 6348096 riffle No N/A C 1267 Kaniwhaniwha off Lime Works Loop Rd Negative 08/05/2006 2694089 6365470 riffle No N/A C 1268 Ohinemuri Karangahake Negative 08/05/2006 2751016 6416326 run No N/A S 1269 Waitawheta end of Franklin Rd Negative 08/05/2006 2756185 6411448 riffle No N/A C

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 74

% Lab Result Didymo Water Positive/ Sample NZMG NZMG Habitat Didymo cover if Clarity Site_No River_name Site_Description Negative Date Easting Northing Types Visible Y/N visible C/S/V 1270 Kaueranga Coromandel Negative 08/05/2006 2743534 6449687 riffle No N/A C 1271 Mangatapopo Mangatapopo Negative 05/05/2006 2728978 6239551 riffle, run No N/A C 1272 Whanganui Wanganui Negative 05/05/2006 2732258 6240671 all No N/A C 1276 Stony River Mangatete rd brTaranaki Negative 09/05/2006 2587510 6219619 riffle No N/A C 1277 Waiwhakaiho SH3 br,Taranaki Negative 09/05/2006 2608305 6228799 riffle No N/A S 1278 Waiwhakaiho Constance Rd BrTaranaki Negative 09/05/2006 2606052 6239049 riffle No N/A S 1279 Mangaoraka Corbett Rd, Taranaki Negative 09/05/2006 2612659 6238072 riffle No N/A S Bristol Road, 60m d/s from bridge at 1280 Manganui trib Negative 09/05/2006 2621319 6229715 riffle No N/A S 1285 Rangitikei d/s Oturua stream Negative 18/05/2006 2771733 6201381 run, riffle No N/A C 1286 Rangitikei Mangamaire confluence Negative 18/05/2006 2769236 6209180 run, riffle Unsure 1% C 1287 Rangitikei Ecology Stream Confluence Negative 18/05/2006 2769109 6217938 run, riffle No N/A C 1288 Rangitikei Springvale Negative 10/05/2006 2770948 6186394 all No N/A C 1289 Ngaruroro 2km u/s Gold Ck Negative 18/05/2006 2784996 6220347 run, riffle No N/A C 1290 Ngaruroro Harkness Stm. & Main river Negative 18/05/2006 2790469 6213882 run, riffle No N/A C 1291 Ngaruroro Kiwi mouth helipad Negative 18/05/2006 2792653 6203582 Run, riffle No N/A C 1292 Ngaruroro Kuripapango Negative 12/05/2006 2796652 6195870 all No N/A C 1293 Taruarau Napier - Taihape Rd Negative 12/05/2006 2787373 6191844 riffle, run No N/A C 1294 Taruarau near L Horotea Negative 18/05/2006 2782016 6206602 run No N/A C 1295 Mohaka River Taharua confluence Negative 08/05/2006 2795958 6230583 riffle, run No N/A C 1296 Taharua Poronui Stn Track Negative 08/05/2006 2794176 6237748 run No N/A C 1297 Mohaka River Te Puia Lodge Negative 18/05/2006 2804767 6220060 run, riffle No N/A C 1298 Mohaka/Ripia Confl. Pakaututu Negative 16/05/2006 2813658 6215866 pool, riffle No N/A C 1299 Mohaka McVicar Road Negative 10/05/2006 2823774 6217900 riffle, run No N/A S

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 75

% Lab Result Didymo Water Positive/ Sample NZMG NZMG Habitat Didymo cover if Clarity Site_No River_name Site_Description Negative Date Easting Northing Types Visible Y/N visible C/S/V 1300 Moawhango Whitikaupeka Pa Negative 10/05/2006 2755707 6176185 pool, run No N/A S 1301 Hautapu River Mataroa Negative 10/05/2006 2742491 6169718 run, pool No N/A S 1302 Rangitikei Pukeokahu, River Valley Lodge Negative 10/05/2006 2771333 6170802 all No N/A C 1303 Pourangaki River Upper Kawhatau Negative 11/05/2006 2763500 6150788 all No N/A C 1304 Mohaka River Willow Flat Negative 17/05/2006 2851910 6237090 pool No N/A V 1305 Hautapu River Hawkes Bay-Maungataniwha Negative 17/05/2006 2837641 6240305 run, riffle No N/A C 1306 Te Hoe Hoe Cental Te Hoe Hut Negative 18/05/2006 2836821 6252835 run, riffle No N/A C 1307 Wairoa Frasertown No sample 19/05/2006 2891830 6239390 1308 Waipunga Opoto Falls Negative 10/05/2006 2816844 6238834 riffle No N/A C 1309 Manawatu Kumeroa, Jacksons Road Negative 08/05/2006 2761913 6091411 riffle No N/A S 1310 Mangatinoka SH@ Br, Mangatainoka Negative 08/05/2006 2752884 6083226 run No N/A C ruffle, run, 1311 Manawatu Ashurst Negative 08/05/2006 2744460 6096355 backwater No N/A S 1312 Ruamahanga at Masterton, u/s Waipoua confl. Negative 09/05/2006 2736294 6025077 all No N/A C 1313 Ruamahanga Gladstone Rd,10 km d/s Masterton Negative 09/05/2006 2731055 6011738 all No N/A S 1314 Waingawa d/s Atiwhakatu confl. Negative 09/05/2006 2723302 6031663 all No N/A C 1315 Waiohine near road end Negative 09/05/2006 2710869 6020627 all No N/A C 1316 Hutt Akatarawa Rd Jctn (Birchville) Negative 09/05/2006 2686211 6010769 all No N/A C 1317 Hutt at Upper Hutt Negative 10/05/2006 2679638 6006344 all No N/A C 1318 Waikanae d/s SH1 Br. Negative 09/05/2006 2683294 6033860 all No N/A C 1319 Otaki at SH1 Br. Negative 09/05/2006 2691060 6046096 all No N/A C 1320 Makuri Makuri Negative 08/05/2006 2765391 6070597 riffle, run No N/A C 1321 Ruakitiri Morere Negative 11/05/2006 2886553 6274745 all No N/A S 1322 Ruakituri Erepeti Negative 11/05/2006 2888499 6263152 all No N/A S

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 76

% Lab Result Didymo Water Positive/ Sample NZMG NZMG Habitat Didymo cover if Clarity Site_No River_name Site_Description Negative Date Easting Northing Types Visible Y/N visible C/S/V 1323 Waioeka Wairata Negative 18/05/2006 2888784 6313053 run, riffle No N/A C 1324 Waioeka River gauge& C/w Negative 18/05/2006 2887736 6321798 run No N/A C 1325 Whakatane Ruatoki North Negative 18/05/2006 2860818 6332293 run No N/A S 1326 Tauranga Waimana Ranger Station Negative 18/05/2006 2869573 6315169 run, riffle No N/A C 1327 Borland Borland Burn Negative 18/05/2006 2089361 5479288 run No N/A C 1328 Whirinaki River River Rd, Minginui Negative 17/05/2006 2832645 6275894 riffle No N/A C 1331 Horomanga Nat Park base hut Negative 17/05/2006 2844300 6303380 riffle No N/A C 1332 Rangitaiki Te Awa camp ground Negative 09/05/2006 2812209 6275364 run No N/A C 1333 Waimataa Stream Hatchery Stream Walk Br Negative 09/05/2006 2788667 6340319 riffle No N/A C 1334 Ngongotaha Stream above Valley Fishing Lodge Negative 09/05/2006 2788317 6340515 riffle No N/A C 1335 Tukituki Walker Rd ,Waipawa Negative 15/05/2006 2820967 6130160 run, riffle No N/A S 1336 Tutaekuri, Puketapu Puketapu-Sherenden Negative 16/05/2006 2835636 6181150 run No N/A S 1337 Whangaehu Whangaehu valley, Rd Br Negativex2 10/05/2006 2723225 6186857 run, riffle No N/A V 1338 Rangitikei Toe Toe Rd Br, Utiku Negative 10/05/2006 2752952 6157315 all No N/A C 1339 Pakuratahi WaterworksRd Br Negative 09/05/2006 2694778 6012910 run, riffle No N/A C 1340 Arnold Blair Rd Br Negative 09/05/2006 2376536 5857010 run No N/A C 1341 Whanganui River Motor camp Negative 05/05/2006 2710191 6255504 ruffle, run No N/A C 1342 Haupiri d/s of bridge Negative 09/05/2006 2404461 5847232 all No N/A C 1343 Tahunaatara Stream SH 30 South of Rotorua Negative 09/05/2006 2783940 6317341 run No N/A C 1344 Pokaitu Stream Horohoro Negative 09/05/2006 2786340 6327850 riffle No N/A C 1345 Taramakau Otira Negative 09/05/2006 2383365 5829049 run No N/A C 1349 Harris creek Hokitika Valley Negative 16/05/2006 2347483 5815168 run, pool No N/A S 1351 Waitangitaona River White Heron Jetty Negative 09/05/2006 2293573 5779373 run, riffle No N/A C 1353 Haast Clarke Bluff Negative 17/05/2006 2222862 5686645 all No N/A C

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 77

% Lab Result Didymo Water Positive/ Sample NZMG NZMG Habitat Didymo cover if Clarity Site_No River_name Site_Description Negative Date Easting Northing Types Visible Y/N visible C/S/V 1356 Boyle 50m above bridge Negative 19/05/2006 2459493 5854515 run, riffle No N/A C 1362 Hurunui 500m below SH 1 bridge Negative 19/05/2006 2518547 5812096 run No N/A S 1364 Hurunui mandamus Negative 19/05/2006 2474198 5823196 run No N/A S 1365 Hurunui South branch Negative 18/05/2006 2456395 5819652 run, riffle No N/A C 1366 Hurunui Sth Branch confluence Negative 18/05/2006 2456897 5820161 all No N/A C 1368 Ashley River at SH 1 below bridge Negative 17/05/2006 2484985 5769959 all No N/A S 1370 Ryton River Mt Olympus Rd Br Negative 17/05/2006 2392942 5772367 riffle, pool No N/A C 1371 Selwyn Whitecliffs, above bridge Negative 08/05/2006 2420439 5749010 run, pool Unsure N/A S 1372 Selwyn Coes Ford Negative 08/05/2006 2462247 5723408 run, pool Unsure N/A S 1375 Ashburton Sth branch Gorge Road Negative 11/05/2006 2364279 5730266 run No N/A C 1376 Ashburton River Smalls Rd Negative 09/05/2006 2412470 5688930 run No N/A S 1377 Rangitata u/s of lagoon in flowing reach Negative 12/05/2006 2390722 5668302 run No N/A S 1379 Opihi d/s Raincliff road bridge Negative 16/05/2006 2349291 5668499 riffle No N/A C 1380 Opuha below skiptons bridge Negative 16/05/2006 2348127 5678828 riffle No N/A S 1381 Tengawai Cave Negative 16/05/2006 2346740 5653570 riffle No N/A C 1382 Tekapo River below kayak course No sample 17/05/2006 2306972 5684583 River Dry 1385 Twizel River Twizel at SH 8 Positive 16/05/2006 2279272 5657308 riffle No N/A C 1386 Ohau River 300 m u/s L Ruataniwha Negative 16/05/2006 2272672 5655311 run No N/A C 1389 Omarama Stream Omarama Negative 16/05/2006 2268690 5631370 run No N/A C 1390 Otematata SH 83, below bridge Negative 16/05/2006 2287974 5618845 run, riffle No N/A C 1391 Awakino SH 83 Negative 16/05/2006 2307164 5608752 run, riffle No N/A C 1396 Ashley at Gorge rd bridge Negative 08/05/2006 2447442 5775013 run No N/A S 1397 Matukituki River East Branch d/s footbridge Negative 10/05/2006 2174943 5626216 riffle, run No N/A C 1401 Kakanui Dunrobin Rd Br Negative 12/05/2006 2332733 5572660 run, riffle No N/A S

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 78

% Lab Result Didymo Water Positive/ Sample NZMG NZMG Habitat Didymo cover if Clarity Site_No River_name Site_Description Negative Date Easting Northing Types Visible Y/N visible C/S/V 1402 Waiareka Creek Teschmakers Rd No sample 16/05/2006 2343460 5559410 1403 Shag River Palmerston Negative 12/05/2006 2334420 5523406 riffle No N/A C Tokomairiro West 1410 Branch Mt Stuart Negative 17/05/2006 2266260 5453714 run No N/A S 1412 Kaihiku Stream Clifton Rd Br Negative 10/05/2006 2249080 5441542 run, pool N N C 1413 Waiwera SH1 br Negative 10/05/2006 2239746 5439526 run, pool No N/A S 1414 Pomahaka Burning Plain Rd Negative 10/05/2006 2231446 5454891 pool, run No N/A C 1418 Pomahaka below picnic area Negative 08/05/2006 2209465 5475958 all No N/A C 1424 Teviot Bridge Huts Rd Negative 15/05/2006 2234040 5513010 run, riffle No N/A C 1429 Manuherikia River 150 u/s Long Gully Rd Br Negative 10/05/2006 2256653 5576168 run No N/A S 1431 Manuherikia River 400m d/s of Runs Rd Br Negative 10/05/2006 2265929 5598499 run No N/A C 1435 Lindis River d/s Elliots bridge Negative 10/05/2006 2233748 5600810 riffle No N/A C 1436 Hunter Ferguson Flat Negative 19/05/2006 2234664 5671099 run, riffle No N/A C 1437 Hunter River Cascade creek Negative 19/05/2006 2228057 5656011 run, riffle No N/A C 1438 Dingle River at Cotters Hut Negative 19/05/2006 2232410 5644295 run, riffle No N/A C 1440 Makarora Camerons Flat Negative 10/05/2006 2213515 5665574 run No N/A C 1441 Young River Ram Flat Negative 19/05/2006 2207508 5660665 run, riffle No N/A C 1442 Young River Nth Br. U/s Sth Br confl Negative 19/05/2006 2201845 5662943 riffle No N/A C 1443 Wilkin Keiran Forks Negative 19/05/2006 2194294 5655758 riffle No N/A C 1445 Motatapu River d/s main road bridge Negative 10/05/2006 2189393 5609370 riffle No N/A C 1452 Kawarau Willow Park d/s Kawarau Br Negative 11/05/2006 2174255 5566520 run No N/A C 1453 Shotover Shotover/Kawarau confl Negative 11/05/2006 2176581 5568061 run, riffle No N/A C 1456 Rees river at Muddy Creek Negative 11/05/2006 2150814 5601714 riffle, rapid No N/A V 1458 Eglinton u/s Cascade confluence Negativex2 19/05/2006 2120881 5578646 all Yes? 60% C

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 79

% Lab Result Didymo Water Positive/ Sample NZMG NZMG Habitat Didymo cover if Clarity Site_No River_name Site_Description Negative Date Easting Northing Types Visible Y/N visible C/S/V 1462 Ettrick Burn 150 u/s from lake Negative 16/05/2006 2095569 5537587 all No N/A C 1471 Lill Burn Lillburn Monowai Road Negative 18/05/2006 2097170 5453930 run No N/A S 1472 Wairaki Cliffden Blackmount Road No sample 18/05/2006 2098971 5461559 1473 Orauea Feldwick Road Negative 11/05/2006 2108766 5451356 all No N/A S 1474 Otapiri Otapiri Gorge Rd Br Negative 18/05/2006 2158212 5451866 run No N/A S 1475 Orauea Birchwood Negative 18/05/2006 2111459 5461692 run No N/A S 1478 Makarewa Nth Makarewa Grove Bush Rd Negative 19/05/2006 2157831 5425327 pool, run No N/A S 1481 Catlins River Tawanui Rd, SOE Site Negative 18/05/2006 2244813 5410722 run No N/A S 1482 Waipahi Cairn Peak, Kurawai Negative 10/05/2006 2219352 5429354 run, riffle No N/A C 1483 Waipahi Waipahi Negativex2 10/05/2006 2220182 5449060 run, riffle No N/A C 1484 Mataura River Keowns Bridge Negative 09/05/2006 2172028 5480327 run No N/A C 1486 Acton Mossburn Five Rivers Rd Negative 10/05/2006 2147172 5497847 all No N/A C 1487 Cromel Stream Mossburn Five Rivers Rd Negative 10/05/2006 2150595 5499501 all No N/A C 1488 Irthing Mossburn Five Rivers Rd Negative 10/05/2006 2153688 5500826 run, pool No N/A C 1489 Mataura River u/s Cainard Rd bridge Negative 09/05/2006 2164137 5525610 all Suspicious 1% C 1492 Electric River U/s of lake Monowai Negative 15/05/2006 2071442 5466965 all No N/A C 1494 Moeraki Lake outlet Negative 17/05/2006 2209250 5714552 all No N/A S 1495 Okarito River Lake Mapourika outlet Negative 09/05/2006 2285545 5765513 all No N/A C 1503 Roaring Lion 500m above Karamea confl. Negative 09/05/2006 2462283 6000757 riffle,run No N/A C 1504 Karamea Lesley confluence Negative 09/05/2006 2468796 5997013 all No N/A C 1505 Karamea Ugly Negativex2 09/05/2006 2453121 6000940 riffle, run No N/A C 1506 Mokihinui river North branch Negative 09/05/2006 2441468 5962495 riffle, run No N/A C 1507 Mokihinui River opposite hut Negative 09/05/2006 2441604 5961933 riffle, run No N/A C 1509 Porarari River 800m up walking track Negative 09/05/2006 2372873 5898503 pool, run No N/A C

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 80

% Lab Result Didymo Water Positive/ Sample NZMG NZMG Habitat Didymo cover if Clarity Site_No River_name Site_Description Negative Date Easting Northing Types Visible Y/N visible C/S/V 1510 Punakaiki 1.5 km upstream from road Negative 09/05/2006 2373207 5896544 pool, run No N/A C 1511 Fox 1 km from road Negative 09/05/2006 2376458 5906691 run No N/A C 1512 Grey McDonnells farm Negative 08/05/2006 2422852 5871779 run, riffle No N/A C 1514 Bruce Stream 2km u/s Lake Brunner Negative 09/05/2006 2383089 5836349 run No N/A C 1516 La Fontaine Stream Hari Hari Negative 09/05/2006 2310820 5787533 all No N/A C 1519 North Ashburton 500 m u/s SH72 Br Negative 09/05/2006 2391375 5732717 run No N/A S 1520 Upper Rangitata Deep Creek 2km sw Negative 11/05/2006 2341798 5734748 run No N/A C main access point d/s water intake 1521 Rangitata rantiata Negative 11/05/2006 2371262 5700851 run No N/A C 1522 Opihi Grassy Banks Negative 12/05/2006 2373374 5659024 run, pool Unsure N/A V 1524 Pareora u/s of gorge road bridge Negative 16/05/2006 2340342 5650753 riffle No N/A C 1525 Orari at river access sign. End Orari R RD Negative 12/05/2006 2364755 5696127 run No N/A V 1526 Maerewhenua Danseys Pass Road Negative 15/05/2006 2311181 5580492 riffle No N/A C 1530 Tasman Glentanner Stn Negative 16/05/2006 2280226 5696165 riffle No N/A C 1538 Rakaia 300 m d/s Gorge Br Negative 09/05/2006 2401483 5742260 run No N/A C 1539 Rakaia sh1 Negative 09/05/2006 2432983 5716668 riffle No N/A C 1540 Waimakariri Trib Paddys' Bend Negative 17/05/2006 2403222 5797009 riffle No N/A C 1541 Waimakariri Mt White bridge Negative 17/05/2006 2407882 5799461 riffle, pool No N/A C 1543 Porter River d/s sh73 Br Negative 17/05/2006 2406649 5772881 riffle No N/A C 1545 Waimakariri d/s Gorge bridge Negative 08/05/2006 2433307 5760329 run No N/A S 1546 Waimakariri 50m below jetboat ramp Negative 19/05/2006 2481435 5754707 run, riffle No N/A S 1548 Kaiapoi Mabers Rd Negative 17/05/2006 2478497 5755162 run, pool No N/A C 1551 Hurunui foot bridge u/s Lake Sumner Negative 16/05/2006 2437353 5833110 run, riffle No N/A C 1552 Hurunui Below Lake Sumner Negativex2 18/05/2006 2451440 5830376 run, riffle No N/A C

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 81

% Lab Result Didymo Water Positive/ Sample NZMG NZMG Habitat Didymo cover if Clarity Site_No River_name Site_Description Negative Date Easting Northing Types Visible Y/N visible C/S/V 1553 Lewis 500m down SH 7 from NZDA lodge Negative 19/05/2006 2460124 5859050 run, riffle No N/A C 1555 Hope River at SH7 bridge Negative 19/05/2006 2465120 5846442 run, riffle No N/A C 1558 Waiau Leslie Hills Rd Br Negative 19/05/2006 2493724 5835261 run, pool No N/A S 1560 Tekapo Canal Negative 15/05/2006 2288893 5675014 run No N/A S 1562 Moeraki 2.5 km d/s Horseshoe Flat hut Negative 17/05/2006 2220863 5704441 all No N/A C 1563 Thomas end of walking track (u/s Bob Creek) Negative 17/05/2006 2205560 5695451 all No N/A C 1564 Waiatoto Drake Flats Negative 17/05/2006 2173122 5660591 all No N/A C 1567 Ngaruroro u/s Chesterhope bridge Negative 16/05/2006 2840817 6171576 run, riffle No N/A V 1568 Rangitaiki Rimu Road Negative 17/05/2006 2832751 6298318 pool No N/A S 1569 Rangitikei Mangaweka Negative 10/05/2006 2750400 61501248 all No N/A C 1570 Manawatu Teachers College Negative 11/05/2006 2732700 6089248 all No N/A C 1571 Whakatane Grace Rd Negative 18/05/2006 2859973 6340595 run No N/A S 1572 Motu River Haupotu Negative 18/05/2006 2917657 6360611 run No N/A S 1573 Gowan 1 km u/s Buller confluence Positive 10/05/2006 2474357 5942976 riffle Yes? 10%? C 1574 Maruia River 200 m d/s Falls Negative 15/05/2006 2447878 5927370 run No N/A S 1575 Grey River Dobson Negative 09/05/2006 2365175 5860044 run, riffle No N/A C 1576 Otukaikino Creek d/s Dickies Rd Br Negative 17/05/2006 2480470 5752410 run, pool No N/A C 1577 Kakanui Mill Dam Negative 12/05/2006 2340301 5559298 riffle No N/A S 1578 Ohau D/s Twizel confl Positive 15/05/2006 2286211 5648031 riffle No N/A C 1579 Inangahua Landing Negative 11/05/2006 2418678 5921380 all No N/A C 1581 Lindis River Ardgour Negative 10/05/2006 2228786 5589302 riffle No N/A C 1582 Cardrona Mt Barker Negative 10/05/2006 2202763 5599188 riffle No N/A C 1583 Taieri Waipiata Negative 19/05/2006 2286347 5552959 run No N/A S 1584 Fraser River Marshall Rd No sample 10/05/2006 2223987 5544926

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 82

% Lab Result Didymo Water Positive/ Sample NZMG NZMG Habitat Didymo cover if Clarity Site_No River_name Site_Description Negative Date Easting Northing Types Visible Y/N visible C/S/V 1585 Makarora d/s Wilkin confl Negative 10/05/2006 2205616 5652285 run, riffle No N/A C 1586 Takaka River Kotinga Bridge Negative 18/05/2006 2493924 6037303 riffle No N/A C 1587 Aorere Lecomte Negative 18/05/2006 2478624 6058943 run, riffle No N/A C 1592 Maruia River above Buller confl Negative 15/05/2006 2445112 5932808 run, riffle No N/A S 1593 Kaituna River Trout pool Rd Negative 09/05/2006 2803490 6349740 run No N/A S 1594 Hamurana Hamurana Rd Negative 09/05/2006 2796250 6346910 pool No N/A C 1595 Waiotaka R rd to airstrip Br Negative 08/05/2006 2757860 6240170 run, riffle No N/A C 1596 Awahou Stm Hamurana Rd Br Negative 09/05/2006 2793002 6345212 pool No N/A C 1597 Waipawa SH2 br,, Waipawa Negative 15/05/2006 2816304 6133478 run, riffle No N/A S 1598 Ruruanga sh34 br, Kawarau Negative 17/05/2006 2833840 6340020 run No N/A C 1599 Ngaruroro Main River Negative 18/05/2006 2790614 6213769 run, riffle No N/A C 1600 Tukipo Road Bridge Negative 15/05/2006 2794780 6132460 run No N/A C 1601 Ngamuwahine SH29 Br Negative 09/05/2006 2775628 6371771 riffle No N/A S 1602 Wainuiomata Main Rd Br Wainuiomata Negative 10/05/2006 2673735 5990670 run, riffle No N/A C 1603 Kapuni at Skeet Road Negative 08/05/2006 2610865 6190687 riffle No N/A C 1604 Mangauika Te Tahi Road Negative 08/05/2006 2697800 6350300 riffle No N/A C 1605 Matakitaki River 200m d/s SH 6 Negative 11/05/2006 2453397 5933917 run No N/A C 1606 Hokitika Woodstock sports ground Negative 16/05/2006 2346871 5824498 run No N/A C 1607 Kauru Kakanui Valley Rd Negative 12/05/2006 2336211 5567424 riffle No N/A C 1608 Waikouaiti River Bucklands Crossing Negative 12/05/2006 2321588 5508777 riffle No N/A C 1609 Taramakau Kumara Negative 09/05/2006 2362180 5840490 run No N/A C 1610 Waihao 150 m d/s Kapu Rd Br Negative 16/05/2006 2349958 5598862 run No N/A C 1611 Timaru River d/s bridge Negative 10/05/2006 2217485 5623470 all No N/A C 1613 Avon Armagh St Site change 2480540 5990690

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 83

% Lab Result Didymo Water Positive/ Sample NZMG NZMG Habitat Didymo cover if Clarity Site_No River_name Site_Description Negative Date Easting Northing Types Visible Y/N visible C/S/V 1614 Waihi Te Awa rd Br Negative 12/05/2006 2371520 5664790 run Unsure N/A C 1616 Oroua London Ford Road Negative 11/05/2006 2750320 6125354 all No N/A C 1617 Ahaura Ahaura Negative 09/05/2006 2389510 5871856 run No N/A C 1618 Matarawa Paraonui Rd Negative 09/05/2006 2758804 6330124 riffle No N/A C 1619 Mangaonuku Tikokino Rd Negative 15/05/2006 2811320 6138410 riffle, run No N/A C 1620 Kopuaranga Donovans Rd Negative 09/05/2006 2735893 6037203 all No N/A S 1621 Waimana Waimana Rd Negative 18/05/2006 2868540 6331840 run, riffle No N/A S 1622 Waiomou Tauranga Rd Negative 09/05/2006 2762300 6368110 run No N/A S 1625 Wairaki rd br 1.7km us Waiau confl Negative 18/05/2006 2099470 5461580 run No N/A S 1626 Hangaroa Te Reinga No sample 19/05/2006 2902610 6254840 1627 Manor Burn br 5 km us lower dam Negative 10/05/2006 2235720 5544960 riffle No N/A C 1630 Wairata Redpath rd end Negative 18/05/2006 2888120 6312240 run, riffle No N/A C 1631 Wheao Ngahinga Crossing Negative 17/05/2006 2828848 6288571 run No N/A S 1632 Spey Bridge Negative 15/05/2006 2062420 5504670 all No N/A C 1633 Mangaone Dartmore Negative 16/05/2006 2828000 6184971 run No N/A S 1635 Waikoau Tutira Negative 17/05/2006 2843768 6213914 run No N/A C 1636 Taruarua Pohakura Negative 12/05/2006 2789430 6184220 run, riffle No N/A C 1637 Waimarino Kepa Rd Br Negative 08/05/2006 2761070 6242550 pool, riffle No N/A C 1638 Pohangina Camping Ground Negative 08/05/2006 2753150 6116840 riffle, run No N/A S 1639 Pohangina Saddle Rd, Asshurst Negative 08/05/2006 2745604 6098993 riffle, run No N/A S 1640 Clutha Clyde Negative 10/05/2006 2221960 5549500 run No N/A C 1641 Clutha Beaumont Negative 15/05/2006 2239935 5481951 run No N/A S 1642 Mangawhero side rd off SH2 Negative 10/05/2006 2708848 6158263 all No N/A S 1644 Mcaulay ford to Lillybank Stn Negative 15/05/2006 2314490 5717990 riffle No N/A C

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 84

% Lab Result Didymo Water Positive/ Sample NZMG NZMG Habitat Didymo cover if Clarity Site_No River_name Site_Description Negative Date Easting Northing Types Visible Y/N visible C/S/V 1647 Fraser stm u/s Pukaki canal Negative 17/05/2006 2274177 5660825 run No N/A C 1648 Tasman u/s Fred Stm confl Negative 16/05/2006 2278304 5705508 riffle No N/A C 1649 Hopkins 1 km u/s Huxley Lodge Negative 17/05/2006 2257188 5675234 riffle No N/A C 1650 Dobson u/s Hopkins confluence Negative 17/05/2006 2261230 5677320 run No N/A C 1652 Tekapo u/s Maryburn confl Negative 15/05/2006 2296081 5657775 run, riffle No N/A C 1653 Waihao Crowes Rd ford Negative 16/05/2006 2362153 5599509 run No N/A C 1654 Waikakahi Tawai Rd Br Negative 15/05/2006 2357930 5586820 run No N/A V 1657 Maitland R Lake Ohau R bridge Negative 17/05/2006 2255472 5667546 riffle No N/A C 1658 Mangahao Mangahao Negative 08/05/2006 2746900 6082081 run No N/A C 1659 Rangitikei Vinegar Hill, 1 km u/s br Negative 10/05/2006 2736082 6137965 run, riffle No N/A S 1660 Rangitikei Bulls, d/s SH1 br Negative 11/05/2006 2713060 6110294 all No N/A S 1661 Rangitaiki Dry Fly Rd Br Negative 09/05/2006 2802770 6267700 run No N/A C 1662 Whirinaki River Whirinaki Rd Murapara Negative 17/05/2006 2837030 6295890 riffle No N/A S Stillwater -Coal Ck rd br d/s Arnold 1663 Grey conflu Negative 09/05/2006 2373807 5862242 run No N/A C 1664 Tauherenikau Underhill Rd Negative 09/05/2006 2708738 6011349 all No N/A C 1665 Whakapapa Kakahi Negative 05/05/2006 2718874 6248775 riffle No N/A C 1666 Oroua Boness Rd Negative 11/05/2006 2726107 6101609 all No N/A C 2001 O'Hara Stream Kereru Negative 16/05/2006 2800328 6171560 riffle, run No N/A C 2002 Donald River Confl. Donald R. and Jap Ck. Negative 18/05/2006 2805968 6200567 run, riffle No N/A C 2003 Otara Tutaetoka bridge Negative 18/05/2006 2892337 6337634 riffle, run No N/A C 2004 Manganui near York Rd, Taranaki Negative 08/05/2006 2614191 6212136 riffle No N/A C 2006 Eyre Creek u/s Eyre creek bridge Negative 09/05/2006 2162971 5512855 all No N/A C 2007 Waihopai Mill Road Invercargill Negative 16/05/2006 2157279 5414856 run No N/A S

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 85

% Lab Result Didymo Water Positive/ Sample NZMG NZMG Habitat Didymo cover if Clarity Site_No River_name Site_Description Negative Date Easting Northing Types Visible Y/N visible C/S/V 2010 Hurunui 250 m above SH 1 bridge Negative 19/05/2006 2517879 5812182 run No N/A S 2013 Ohau, unnamed trib. Weir Board Negative 15/05/2006 2280223 5653038 riffle No N/A C 2014 Mararoa North Mavora Lake Negative 10/05/2006 2130064 5548417 all No N/A C 2015 Tekapo Tekapo Delta Negative 15/05/2006 2287674 5648565 riffle No N/A C

A New Zealand-wide survey in May 2006 for the presence of non-indigenous freshwater diatom Didymosphenia geminata in sites most likely for its introduction and establishment 86