Appendix G. Ecology Assessment

Notice of Requirement, Resource Consent Application and Assessment of Environmental Effects

Assessment of Ecological Effects: Tūhonohono ki Tai / Matakana Link Project October 2018

DOCUMENT APPROVAL

Assessment of Ecological Effects: Tūhonohono ki Tai / Matakana Link Document title: Project Prepared for: Auckland Transport Version: Draft 5 Date: 9 October 2018 Document name: 22074358_5.docx

Mark Delaney M.Sc. (Hons) Authors: Senior Freshwater

Sarah Killick M.Sc. (Hons) Botany

Chris Wedding M.Sc. (Hons) Senior Terrestrial

Graham Don M.Sc. (Hons) Reviewer: Senior Consulting Ecologist

Chris Wedding M.Sc. (Hons) Approved for Release: Manager – Ecological Services/Business Unit

REVISION HISTORY

Rev. No. Date Description December 1 Draft 1 2017 December 2 Draft 2 2017 3 January 2018 Draft 3 02 March 4 Draft 4 2018 18 October 5 Draft 5 2018

Reference: Bioresearches (2018). Assessment of Ecological Effects: Tūhonohono ki Tai / Matakana Link Project. Report for Auckland Transport. pp 79

Cover Illustration: Canopy and sub canopy vegetation, 245 Matakana Road, Warkworth.

Contents 1. Introduction ...... 4 Staged Approach ...... 4 Project Area and Assessments ...... 4 2. Terrestrial Ecology ...... 6 2.1 Assessment Methodology ...... 6 2.2 Existing Terrestrial Environment and Values ...... 11 2.3 Assessment of Effects ...... 21 2.4 Mitigation Measures ...... 26 3. Freshwater Ecology ...... 29 3.1 Assessment Methodology ...... 29 3.2 Existing Freshwater Environments and Values ...... 32 3.3 Assessment of Effects ...... 50 3.4 Mitigation Measures and Recommendations ...... 53 4. Summary ...... 55 5. REFERENCES ...... 58 6. APPENDICES ...... 61

1. INTRODUCTION

Auckland Transport (AT) has commissioned Bioresearches to prepare an assessment of ecological effects of the proposed alignment and designation for the staged construction, operation and maintenance of a new road known as the Tūhonohono ki Tai / the Matakana Link Road Project (the Project). The Project provides a Warkworth bypass for traffic between the State Highway 1 (SH1) motorway) and Matakana and beyond.

Staged Approach AT are seeking a designation for the construction of the entire Project, which will occur in stages. Generally speaking, Stage 1 will provide two general traffic lanes and a shared path on one side of the road. Stage 1 is proposed to be implemented to align with the opening of NZTA’s P2Wk project.

Stage 2 is currently anticipated to be implemented between 2036 and 2046, when traffic demand exceeds Stage 1’s capacity. This will involve the widening of the road to accommodate four general traffic lanes and upgrading the berm to separated walking and cycling facilities on both sides of the road.

It is understood that the majority vegetation removal and earthworks, to accommodate Stage 2 would be undertaken in Stage 1.

Project Area and Assessments

1.1.1 Previous assessments and Options analysis Previous assessments of eight long list and four short list route options favoured the proposed route from an ecological basis, considering both terrestrial and freshwater values. The proposed Project Area avoids kauri trees, as well as a Significant Ecological Area (SEA) and QEII covenant to the south. It also avoids a greater number of watercourse crossings to the north of the proposed construction boundary.

1.1.2 Proposed Project Area The Project area generally covers an area of managed pasture grass and a block of riparian vegetation associated with the main Mahurangi tributary to the north-east (Project Area, Figure 1).

Freshwater and terrestrial ecological assessments were undertaken within the Project Area and these included complete, targeted surveys associated with terrestrial flora and fauna, as well as Stream Ecological Valuations (SEVs). Terrestrial ecology assessments generally focused on the riparian vegetation of the main Mahurangi tributary, where flora and fauna habitat values were considered to be greatest. Managed pasture may provide some terrestrial habitat values and entire site walkovers were undertaken over the course of the assessment to ensure a complete assessment of the Project Area.

Figure 1. Overview of Project Area – Supplied by Jacobs.

2. TERRESTRIAL ECOLOGY

2.1 Assessment Methodology 2.1.1 Vegetation A preliminary site assessment was undertaken on 26 April 2017 to provide an overview of the potential site options for the Project. Following this, a detailed vegetation assessment was conducted on 30 October 2017, to assess the vegetation present within the Project Area.

Vegetation was inventoried using a qualitative walk-through (Rapid Assessment) method (Rose, 2012) and categorized by ecosystem type using the national (Singers & Rogers, 2014) and Auckland-specific (Singers et al., 2017) terrestrial classification systems.

Canopy trees within the Project Area were measured at diameter at breast height (DBH). Where such trees had a DBH greater than 20 cm, these were recorded and georeferenced to assist with any mitigation calculations, where appropriate.

2.1.1.1 Kauri Dieback Species known to show potential susceptibility to kauri dieback (PTA) were checked for symptoms. Any symptomatic trees and all kauri (including non-symptomatic trees) present within the proposed area were sampled for PTA presence. Sampling used soil taken from 1m uphill of the tree trunk, as per the methods described by Singh et al. (2017) and tested by SCION laboratories using the baiting method.

2.1.2 Fauna Targeted fauna surveys were undertaken for indigenous lizards and long-tailed bats while opportunistic surveys were undertaken for native invertebrates and avifauna. Eight site visits were undertaken to service survey equipment and undertake fauna searches and observations. Specific survey methods are described in this section and mapped in Figure 2. All fauna surveys were undertaken over November-December, to coincide with the summer period within which lizards and bats are considered most conspicuous.

Figure 2. Survey equipment and search areas within Tūhonohono ki Tai / the Matakana Link Project Area.

2.1.2.1 Invertebrates The site was visited on eight occasions by a terrestrial ecologist, during which time opportunistic habitat searches were undertaken for native invertebrates. Searches were undertaken within the main

Mahurangi riparian vegetation (including two night-time visits) and involved lifting logs and leaf litter, where invertebrates are likely to be found.

2.1.2.2 Frogs Desktop investigations involved a review of the Department of Conservation’s Amphibian and Reptile Distribution Scheme (ARDS) database (accessed March 2017), and as well as an analysis of aerial and topographic imagery for the presence of first and second order streams, where potential habitat is most likely.

Streams where potential habitat was potentially present were surveyed for frog presence. All frog habitat assessments and searches were undertaken by an experienced herpetologist (WA 37604-FAU). All footwear and equipment was sanitised using Trigene prior to survey.

2.1.2.3 Lizards Desktop investigations involved a review of the Department of Conservation’s ARDS database (accessed November 2016), as well as an analysis of aerial and topographic imagery for the presence of tracks and vegetation cover to plan survey design and spatial coverage.

All vegetated areas that were identified as potentially supporting habitat for indigenous lizards were visited to undertake a qualitative habitat description. Where potential habitats supported logs or other debris that could be lifted, searches of these habitats were undertaken.

Pitfall trap survey A survey was undertaken using twenty live-capture, baited pitfall traps, in accordance with the Department of Conservation best practice (Hare 2012). Pitfall traps are suitable for capturing terrestrial skinks, although are unlikely to detect the gecko species identified in Table 2. Traps were installed within native forest vegetation, its interfaces with scrub or open edges and baited with fish- based cat food to maximise encounter opportunities with skinks. All traps were furnished with native leaf litter, covered to provide shelter for any lizards confined during capture and checked daily. All traps were active over five consecutive days.

Nocturnal Visual Encounter Surveys (VES) Nocturnal VES was undertaken on 13 November 2017 and repeated on 16 November 2017. Focused headlamps (LED Lenser XEO 19R) aided by 8 x 42 Monarch binoculars were used to search for geckos on the ground, on tree branches and in foliage. Searches involved walking slowly along the track edges where a greater profile of the forest edge was more visible. Particular attention was placed on scanning kanuka trees and epiphytes, where gecko encounters were considered most likely. A total of 10 person-search hours were conducted over 886 m of track edge.

2.1.2.4 Birds The site was visited on eight occasions by a terrestrial ecologist, during which time a full site walkover was undertaken, in addition to all other visits to the main Mahurangi riparian vegetation (including

two night visits). Birds observed were recorded opportunistically on all occasions, given the relatively small area affected (> 0.1 ha of forest and scrub).

2.1.2.5 Bats Long-tailed bat (LTBs; Chalinolobus tuberculatus) surveys were undertaken using one fixed-location Automatic Bat Monitoring (ABM) detector and hand-held recorders. These methods are detailed below.

Automatic Bat Monitoring (ABM) detectors ABMs are used to record ultrasonic echolocation calls that are produced by bats during their navigation and foraging behaviours. An ABM records the ultrasonic echolocation calls emitted by bats and converts them to frequencies that are audible to humans (Parsons & Szewczak, 2009).

An ABM is comprised of two ultrasound sensors and microphones, a sound-activated recording device, a timer to turn the system on and off each day, and a rain-noise detector that turns the system off in the event of heavy, persistent rainfall. ABMs record and store data passively and remotely and have the capacity to record both long-tailed (40 kHz) and lesser short-tailed (28 kHz) bat calls.

The ABM used for this study was fixed on the northern most edge of the main Mahurangi tributary riparian margin to record any bat passes along the riparian edge where potential bat passes or potential roosting habitat were considered most likely (Figure 2). The ABMs were set to begin recording 30 minutes before sunset and turn off 30 minutes after sunrise, for 14 nights through November 2017, when bats are considered most active (October-February, O’Donnell & Sedgeley 2001).

Data Analysis ABM data were downloaded and the waveforms analysed using Bat Box 1.0 software (Department of Conservation, 2008). The total number of ‘usable nights’ (UNs) was determined using climate data (CliFlo, New Zealand’s National Climate Database, NIWA) and recording analyses (e.g. when the recorder log indicated a noise switch pause for a period of more than half the night). Nights were considered ‘useable’ if the temperature remained above 5°C and more than half the night was free of rain or insect noise.

Each echolocation pass was time (hour/minute/second) and date stamped (year/month/day) providing timing information for activity.

Line Transects A handheld recorder was carried opportunistically during two nocturnal spotlight searches of the riparian forest edge on 13 November and repeated on 16 November 2017. A total of five hours of live recording was captured at the forest edge between 2100 and 1200, and the route walked is mapped in Figure 2.

2.1.3 Terrestrial Ecological Descriptors Ecological values are described in this report as being “high”, “moderate”, “low” or “very low”.

Table 1 provides generalised ecological descriptions for these simplified terrestrial ecological values. In this report assessments of effects are described as high, moderate (more than minor), minor and less than minor (taking into account both the habitat/values affected and the extent or severity of the effect).

Generally, any minor ecological effects of activities can be adequately mitigated or remedied through reinstatement of any disturbed areas of native vegetation. Moderate effects would require greater consideration of mitigation and compensation for lost ecological values (such as fauna relocation). Where adverse effects are high, it is expected that methods would be adopted, where practicable, to avoid those values, with compensation to address any residual effects. Adverse effects that are less than minor would not require mitigation.

Table 1. Generalised Terrestrial Ecological Descriptors and Corresponding Valuations used in this Report.

Ecological Value Habitat Description Descriptor Vegetation Entirely or predominantly exotic pest plants; may have some scattered common natives. Fauna May support some habitat value to common Very Low native fauna (birds and lizards), though potential habitats are largely occupied by introduced fauna. Vegetation Planted young (<20 years) native vegetation comprising common species. Vegetation is generally of small size (<15m tall). Low Fauna Potential habitat likely to support some common native fauna (birds and lizards). Vegetation Naturally regenerating kanuka/ broadleaf forest with understorey. Fauna Potential habitat likely to support common Moderate native fauna. Some Nationally 'At Risk' species may potentially occur. Vegetation Naturally regenerating podocarp or broadleaved forest with mature trees. High Fauna Potential habitat likely to support common native and Nationally 'At Risk' or 'Threatened' fauna.

2.2 Existing Terrestrial Environment and Values 2.2.1 Vegetation In general, the vegetation within the Project Area consists of pasture grasses, and an area of exotic- dominated scrub and regenerating native forest (Figure 3) associated with the main Mahurangi River tributary.

The most abundant vegetation type within the Project area was grazed exotic pasture, which covers most of the Project Area. This vegetation is of low ecological value.

Other vegetation types with ecological value are associated with the main Mahurangi tributary riparian margin. This vegetation is protected where it occurs within the 10 m riparian margin. Beyond this margin, vegetation removal within the Project Area is considered to be a permitted activity (under the AUP(OP) given its location within the FUZ).

2.2.1.1 Anthropogenic Forest Anthropogenic forests are highly modified forest ecosystems, driven largely by agriculture (Singers et al., 2017). They typically consist of canopy trees and may transition to a more natural forest (with a more diverse sub-canopy and understorey) through protection from browsing, although they are also associated with cattle-caused soil compaction and pugging, which may delay the regeneration of other taxa.

There is one Anthropic Tōtara (AVS1) forest fragment within the Project Area, on the eastern side of the main Mahurangi tributary (Figure 3).

Anthropogenic forests in the Auckland region are characterised by a dominance of tōtara (Podocarpus totara var. totara), and often have an open understory due to browsing.

The Anthropogenic Tōtara forest within the Project Area has been fenced, and supported small numbers of native plants, including drooping spleenwort (Asplenium flaccidum), karamū (Coprosma robusta), silver fern (Cyathea dealbata), and māpou (Myrsine australis). Exotic weeds were occasional throughout and included gorse (Ulex europaeus), tree privet (Ligustrum lucidum), Chinese privet (Ligustrum sinense), and arum lily (Zantedeschia aethiopica).

Landowners have planted an area to the immediate north of the tōtara forest, providing a buffer and linking this stand to the existing older kauri podocarp forest present in the main forest body. Both areas have low-moderate ecological value at present, but a high potential future value.

A small area (0.00048 ha) of this is within the proposed construction boundary and consent is required for its removal under the AUP(OP) because it is located within a riparian margin.

2.2.1.2 Exotic-dominated Scrub Within the Project Area, the riparian margin of the main Mahurangi tributary has become severely infested with exotic scrub, dominated by gorse and pampas (Cortaderia selloana), with low numbers of pine scattered throughout. There are also a small number of native species that have established here, including bracken (Pteridium esculentum), kumeraho (Pomaderris kumeraho), and small isolated patches of Nertera dichondrifolia and Microsorum pustulatum.

Pinus species are exotic, commercially cultivated trees, which have become weedy in many parts of New Zealand. However, they can also provide favourable habitat and microclimate for 118 threatened New Zealand species, including 78 species of vascular plants, 9 species of bird, 2 species of bats, 10 herpetofauna species, and at least 6 endangered invertebrate species (Pawson et al., 2010).

There are young wilding pines dotted throughout the exotic scrub, and large mature specimens on the southern and western outer exotic scrub edges.

Within the Project Area, areas of pine and the exotic scrub outside of the riparian margin (10m) are of low botanical value and are not protected (AUP(OP)).

Two areas of this scrub are within the riparian margin (0.057 ha within the proposed designation boundary) and are of moderate value due to the ecological functions they provide for freshwater habitat (e.g. shading, filtration and organic input).

2.2.1.3 Native forest Native forest bisects the northern end of the Project Area and continues south along the riparian margin of the main Mahurangi tributary. Based on the species present, described below, this forest aligns best with indigenous ecosystem type WF11: Kauri, podocarp, broadleaved forest (Singers et al., 2017). This forest type has been greatly reduced from its historic range due to logging and is now classified as an ‘Endangered’ ecosystem under the IUCN classification system. Commonly, only the gully component remains, and no kauri are present within the Project Area. In regard to the Project Area, kauri were not observed, although there are many pole-sized kauri beyond the dripline of the Project Area, none were observed within three times the radius of their canopy drip line of the proposed designation boundary.

Within the Project Area, the canopy of the native forest is comprised of tanekaha (Phyllocladus trichomanoides – many of which have died), rimu (Dacrydium cupressinum), tōtara, and kānuka (Kunzea robusta). Some of these trees, particularly the tōtara, are large individuals with trunk diameters exceeding 70 cm DBH.

There is an abundance of native epiphytes growing on the canopy trees, including large Astelia hastata, drooping spleenwort, Hound’s tongue fern (Microsorum pustulatum), mokimoki (Microsorum scandens), bush lawyer (Rubus cissoides), bamboo orchid (Earina sp.), leath fern (Pyrrosia eleagnifolia) and sickle spleenwort (Asplenium polyodon). There are also a number of corticolous lichens, including Usnea rubicunda, Usnea angulata, Menegazzia sp., and Ramalina sp.

In the understory, silver fern is the most prevalent species, but is joined by turepo (Rhabdothamnus solandri), putaputaweta (Carpodetus serratus), lancewood (Pseudopanax crassifolious), hangehange (Geniostoma ligustifolium var. ligustrifolium), māhoe (Melicytus ramiflorus), rangiora (Brachyglottis repanda), native broom (Carmichaelia australis), cabbage tree (Cordyline australis), nīkau (Rhopalostylis sapida), pate (Schefflera digitata), and kiekie (Freycinetia banksii).

The forest floor has a diverse range of seedlings, including pigeonwood (Hedycarya arborea), rewarewa (Knightia excelsa), and kahikatea (Dacrycarpus dacrydiodes), as well as native ground cover bead plant (Nertera dichondrifolia), ground ferns Austroblechnum lanceolatum, Doodia australis, Blechnum discolour, and Pneumatopteris pennigera, and near the water’s edge, the native herbaceous ground cover parataniwha (Elatostema rugosum).

This forest type has a regional IUCN threat status of “Endangered” and is of high ecological value. Although the area within the Project Area characterised as WF11 forest is small, and no kauri were observed, the species present remain representative of this ecosystem type. Due to the representativeness, rarity, and ecological function of the areas of WF11 forest, they are considered to be of high ecological value.

Approximately 0.431 ha of this forest type occurs within the riparian margin of the proposed designation boundary (Table2) and is protected (AUP(OP). The removal of this forest type beyond the riparian margin is a permitted activity.

Table 2. Estimated areas (ha) of vegetation types within the proposed designation and construction boundaries.

Proposed Proposed Proposed Road Proposed Road Vegetation type Construction Construction Footprint Footprint Boundary Boundary (all) (Riparian Yard) (all) (Riparian Yard) WF11 / kauri forest 0.999 0.431 0.397 0.095

Anthropogenic totara forest 0.31348 0.00048 0.121 0

Exotic- dominated 0.646 0.057 0.575 0.0523 scrub

Total (ha) 1.95848 0.48848 1.093 0.1473

Figure 3: Vegetation types within the Project.

2.2.1.4 Kauri Dieback Presence No kauri were observed within the Project Area. However, Phytophthora agathidicida (the causal agent of kauri dieback disease) has been shown to infect other species, including tanekaha (Ryder, Waipara, & Burns, 2016). Soil samples taken from the base of kauri near the Project Area boundaries

(< 20m) and from the base of deceased tanekaha within the Project Area were found to contain no Phytophthora species (Peter Scott, Scion, Pers. comm., 28 November 2017).

These results strongly suggest that the forest is currently free from PTA. With PTA infection spreading throughout Auckland and Northland and no cure for trees affected, healthy kauri forests are invaluable. Further, other species are may also be affected by PTA, including tanekaha, which is present within the proposed construction and designation boundaries. Movement of vehicles and equipment into this forest significantly increases the risk of PTA infection. The Kauri Dieback Standard Operating Procedure (Bioresearches Ltd., 2017) must be strictly adhered to at all times to reduce this risk.

Figure 4: Stand of dead tanekaha. Soil samples were taken from near the base of these trees to test for PTA presence, but results have shown no Phytophthora presence.

Figure 5: From top left clock-wise: Asplenium flaccidum, wax-gill mushroom, pate (Schefflera digitata), and Nertera dichondrifolia, all from within the WF11 forest within the Project Area.

2.2.2 Fauna 2.2.2.1 Invertebrates Most native invertebrates are not legally protected under the Wildlife Act 1953. Protected invertebrates are listed in Schedule 7 of the Act and include a small number of large or threatened species, including the kauri snail (Paryphanta busbyii) and wetapunga (Deinacrida heteracantha). Both of these species occur in the Auckland Region, although the wetapunga is restricted to offshore islands. However, the Project Area is within the natural range of the kauri snail.

Other invertebrate species that are not listed as protected may also contribute to the identification of valuable habitats by their presence. In particular, the rhytid snail (Amborhytida dunniae), a medium sized carnivorous land snail is classified as Nationally At-Risk (Mahlfeld et al., 2012).

The peripatus or velvet worm, (Phylum: Onychophora) is widely regarded as important from an evolutionary perspective, with characteristics of both worms and arthropods. They are poorly understood, however, there is some recent clarification of their taxonomy and conservation status. Specifically, two species may be present within the Project Area, namely Peripatus aurobis and P. sympatrica (Department of Conservation, 2014). Both species have a conservation status of ‘Not Threatened’ (Trewick et al. 2018).

Rhytid snails and peripatus require cool, moist areas of leaf litter in native forest and scrub. They can be found in deep leaf litter and in association with rotten logs and fallen nikau fronds.

Results and Discussion

The invertebrate searches did not identify the presence of any threatened or At-Risk species and it was noted that the forest floor supported only a few logs that could be searched (around and under). This may be a result of historic grazing and clearance. For this reason, the Project Area is not considered to be important habitat for either the rhytid snail, peripatus or kauri snail and the overall value of the habitats to native invertebrates is low.

2.2.2.2 Frogs Hochstetter’s frog (Leiopelma hochstetteri) is a small, endemic frog that occurs in scattered, fragmented populations throughout the northern half of the North Island and on Great Barrier Island (Green and Tessier, 1990). It is listed as “At Risk - Declining” by the Department of Conservation (Newman et al., 2013) and is regarded as “Vulnerable” on the IUCN Red List 2009 (Bell et al., 2009).

Frog populations in the Auckland Region form three genetically distinct groups, of which populations in the Waipu-Brynderwyn-Warkworth areas are considered most at risk by the Auckland Council, due to habitat fragmentation, ongoing and future land use changes (Boffa Miskell, 2012). These populations are also the closest to the Project Area.

The frog is most commonly associated with shaded streambeds or seepages under mature native forest. However, it is capable of tolerating modified habitats, such as exotic forest (Douglas, 1999, Bell et al., 2009, Stephenson and Stephenson, 1957). Hochstetter’s frogs are sensitive and vulnerable to environmental disturbances, such as floods and sedimentation (Najera-Hillman 2009) and because they tend to occur in small and localised populations (Newman, 1996).

Results and Discussion No frogs were recorded from searches of the main stream or smaller side tributaries within the main Mahurangi tributary in the Project Area. The potential habitats within the Project Area were of very low value for Hochstetter’s frogs because they were highly channelized, had high volumes of water moving through or were particularly silty (Figure 8).

Figure 6. Examples of the main stem stream channels from within the Project Area.

2.2.2.3 Lizards The survey aspect of this assessment was completed by a herpetologist, acting under Wildlife Act Authority WA-37604-FAU.

New Zealand has two major groups of terrestrial reptiles: lizards (Order Squamata) and tuatara (Order Rhynchocephalia). Tuatara are not present on mainland New Zealand outside wildlife sanctuaries, and therefore are not considered in this assessment. Seven species of native lizards are considered potentially present (Table 2) and six of these are classified as Nationally “At-Risk” by the Department

of Conservation (Hitchmough et al., 2016). Strictly coastal species, such as the shore skink (Oligosoma smithi), are excluded from this list.

One introduced species, the rainbow skink (Lampropholis delicata), is classified as an “Unwanted Organism” by the Ministry of Agriculture and Fisheries (MAF) under the Biosecurity Act 1993 and was not considered in this assessment, other than noting its presence when observed.

Table 3- Threat classification of potentially present native lizards in the Auckland Region.

Species Threat Category Threat Status Copper skink (Oligosoma aeneum) Not Threatened - Ornate skink (Oligosoma ornatum) At Risk Declining Moko skink (Oligosoma moco) At Risk Relict Striped skink (Oligosoma striatum) At Risk Declining Forest gecko (Mokopirirakau granulatus) At Risk Declining Pacific gecko (Dactylocnemis pacificus) At Risk Relict Elegant gecko (Naultinus elegans) At Risk Declining Threat category as per Hitchmough et al. (2016).

Results and discussion No skinks or geckos were recorded from any of the survey methods.

The vegetation within the main Mahurangi tributary riparian vegetation provides the best potential habitat for native skinks and geckos and appeared suitable for both skinks and geckos during the survey period, however, the ground was particularly dry and ground cover, such as thick leaf litter and logs, was patchy throughout. This was particularly so through areas where the vegetation was much younger and exotic species dominated. These factors may have reduced activity or population capacity of native lizards within the Project Area. However, it cannot be discounted that some species of native skink or gecko are present at low or less than detectable densities. Copper skink and forest gecko are fairly widespread throughout the Auckland Region and likely to be present within some parts of the riparian vegetation at low density. Other species, such as pacific gecko, green gecko and ornate skink have been recorded throughout the north Auckland region and relict individuals or small populations are occasionally recorded where intense searching or long-term monitoring identifies them over a period of time. Therefore, while it is unlikely that the Project Area supports significant habitat for native lizard species, it is possible that some species may still be present. Therefore, the value of the riparian vegetation within the Project Area to native lizards is low-moderate. This value anticipates that a low abundance or diversity of native or ‘At Risk’ species may be present.

Beyond the main Mahurangi tributary riparian, suitable potential habitat was either absent (open managed pasture) or degraded to marginal value (cattle grazed totara forest).

2.2.2.4 Birds Results and Discussion Thirteen native species were recorded from the Project Area’s open pasture and riparian habitats. None of those species are classed as At-Risk or Threatened. However, a potentially high diversity of intermittent native species to the Project Area is likely to include Australasian harrier (Circus

approximans); bellbird (Anthornis melanura); kaka (Nestor meridionalis); red crowned parakeet (Cyanoramphus novaezelandiae); and tomtit (Petroica macrocephala). Kaka and red crowned parakeet are both classified as Nationally At-Risk (recovering and relict, respectively) whereas bellbird and tomtit are not threatened. Although not threatened, bellbird and tomtit are generally not considered to be common native species in the Auckland region. This potential diversity is relatively high due to the relatively close proximity of the potential habitats to Dome Forest and Tawharanui Wildlife Sanctuary.

The value of habitats to native birds within and around the main Mahurangi riparian margin in the Project Area is considered to be moderate, given the presence of some mature native trees and regenerating native scrub that provides roosting, nesting and foraging habitat to at least 10 native species, and potentially including less common or At-Risk species. The habitats beyond the riparian margin, within the Project Area (open pasture and surrounds) support a lower diversity of common native species and the value of these habitats is low.

Table 3. Native bird species recorded in the Project Area. Open pasture Mahurangi Species and surrounds tributary riparian Fantail / piwakawaka (Rhipidura fuliginosa placabilis) ✓ ✓ Grey warbler / riroriro (Gerygone igata) ✓ New Zealand pigeon / kereru (Hemiphaga novaeseelandiae ✓ Kingfisher / kotare (Todiramphus sanctus vagans) ✓ Morepork / ruru (Ninox novaeseelandiae) ✓ Paradise shelduck / putangitangi (Tardorna variegata) ✓ Pukeko (Porphyrio melanotus) ✓ ✓ Shining cuckoo ✓ Silvereye / tauhou (Zosterops lateralis lateralis) ✓ Spur-winged plover (Vanellus miles novaehollandiae) ✓ Tui (Prosthemadera novaeseelandiae) ✓ ✓ Welcome swallow (Hirundo tahitica neoxena) ✓ ✓ White faced heron / matuku moana (Ardea novaehollandiae) ✓ Total Native Avifauna Diversity Recorded 13

2.2.2.5 Bats LTB are classified as ‘Nationally Vulnerable’ in the North Island (O’Donnell et al., 2013). This classification is given the qualifier “Data Poor” which indicates that there is low confidence in the rating due to poor data available on the species populations and distribution (Townsend et al., 2008). LTBs are known to occur at several sites across the Auckland Region with scattered records through the Rodney District and including Dome Forest, 2 km to the north. The Project Area is well within the flight range of LTBs.

Results and Discussion No bats were recorded from either the fixed ABM or from handheld night searches.

Some of the larger trees along the riparian edge, including totara and exotic pine support cavities or epiphytes within which bats could potentially roost.

The large home ranges of LTBs (up to 5629 ha; O’Donnell 2001); nearby records (Dome Forest) and lack of detection during the survey period suggest that the species may pass through or roost onsite intermittently. The results indicate that the site was not important habitat to the species at the time of survey and that although the site may provide some intermittent habitat for bats these potential habitats are of low value.

2.3 Assessment of Effects

2.3.1 Vegetation Areas of assessed and protected (riparian only) vegetation types are shown in Table 4 below. The assessment of effects of the project are discussed below.

Table 4. Estimated areas (ha) of vegetation types within the proposed designation and construction boundaries.

Anthropogenic totara forest 0.31348 0.00048 0.121 0

Exotic-dominated scrub 0.646 0.057 0.575 0.0523

Total (ha) 1.95848 0.48848 1.093 0.1473

2.3.1.1 Anthropogenic Forest A small area of anthropogenic totara forest occurs within the proposed designation boundary. It is estimated that a 0.12 ha fragment of anthropogenic tōtara forest would be removed for construction of the carriageway, including approximately 0.00048ha of this vegetation within the riparian margin. Outside of the riparian margin the removal of this totara forest is a permitted activity. The fragment within the carriageway footprint has low-moderate botanic value, but given it supports mature canopy trees, its connectivity to the main riparian forest through restoration planting and the native scrub regenerating beneath the canopy, its loss would be a moderate adverse effect.

2.3.1.2 Exotic-dominated scrub Approximately 0.64 ha of exotic-dominated scrub is within the proposed designation boundary, of which 0.57 ha would be removed as a result of the construction of the carriageway and of which only 0.057ha is located within the riparian margin. The vegetation itself is of a low botanic value and its loss beyond riparian margins would be a minor adverse effect. Within riparian margins, loss of this vegetation type would be a moderate effect as a result of loss of riparian function. This could be mitigated through compensation plantings as discussed in Section 3.4.

2.3.1.3 Native Forest Approximately 1 ha of kauri, podocarp and broadleaf forest (WF11) is within the proposed designation boundary, including 0.4 ha within the proposed carriageway and 0.431ha within the riparian margin. It is estimated that some of the trees within the development footprint are between 80 - 100 years old. Removal of the riparian vegetation requires consent, however the remainder of this forest can be removed as a permitted activity under the AUP(OP). The proposed bridge would not support canopy trees beneath the structure, due to the effects of shading or potentially ‘topping’ to accommodate the bridge, therefore this forest type will not be present below the bridge following construction.

Given this forest type (WF11) is endangered (Singers et al. 2017), we consider the effect of its loss would be high, however it can be removed as a permitted activity under the AUP-OP. It is acknowledged, however, that the affected forest type within the footprint of the Project Area has been avoided to the greatest extent possible, and in particular kauri trees are avoided as a result of refinements during earlier design stages.

2.3.1.4 Edge Effects Edge effects describe a range of effects that increased proximity to an edge have on the outer parts of a forest patch. These include factors such as increased light, wind, temperature fluctuations and other microclimates including reduced humidity. They may also increase weed and pest animal invasion. Removing edge vegetation therefore results in degradation of the newly created edge of a forest patch. Assuming the edge effect reaches 50 metres into the forest interior (Young & Mitchell, 1994), the resulting edge effect from the bisection of the forest for the carriageway would result in some increase in wind, light, vehicle emissions and exotic weed spread. These effects would likely result in some degradation at the newly created edge, including loss of habitat for some forest floor dwelling plant species including parataniwha (Elatostema rugosum) and maidenhair fern (Adiantum cunninghamii). These are common plant species and currently, almost all of the riparian forest is within 50 m of an edge. Historic aerial imagery (2010-2011, Geomaps) indicates that the riparian vegetation was no more than 30 m wide less than 10 years ago. Edge effects created by the Project are therefore considered to be minor.

2.3.1.5 Shading Effects A bridge will be constructed over the watercourse, running approximately west-east. The bridge’s height has the potential to allow some lower stature vegetation to remain.

It is expected that, due to the aspect of the bridge, little direct sunlight or rainfall will reach the vegetation beneath, however, there will be some indirect light reflectance from adjacent areas. The resulting lower level of light and water availability will affect the photosynthetic abilities and growth of vegetation present and this would likely alter the community composition and structure away from WF11 forest in the future. The adverse effect of an altered plant community from WF11 forest to a lower value, shade and potentially drought tolerant species community would be moderate, if vegetation survives or re-establishes. Mitigation planting for loss of WF 11 forest, as described in section 3.4, would reduce these effects of loss to minor.

2.3.1.6 Loss of connectivity Fragmentation impacts the movement of organisms and resources, disrupts species interactions, and can result in smaller, less rich populations (Ibáñez et al., 2014). The vegetation present in this site forms an important ecological corridor and bisecting the forest will result in the loss of connectivity between the two remaining patches. This effect would be minor.

2.3.1.7 Potential for PTA Infection and Spread The forest at present is asymptomatic for PTA infection, and laboratory soil testing found no Phytophthora presence in soil samples. Phytophthora agathidicida is a soil-borne pathogen; therefore, movement of potentially contaminated vehicles and equipment into this forest increases the risk of loss to the remaining forest outside of the Project Area.

If PTA was introduced into this area, it would likely infect the adjacent kauri forest to the south) and could potentially kill a large number of kauri and other species here. This loss would be significant, as kauri forests are classified as endangered. Recommendations for minimizing this risk are supplied in the Kauri Dieback Standard Operating Procedures document, supplied separately (Bioresearches 2017).

Figure 7. Significant and protected vegetation types that would be mitigated.

2.3.2 Fauna The Project Area is a highly modified environment with naturally occurring vegetation generally restricted to the riparian vegetation of the main Mahurangi tributary. Within this vegetation, potential habitats for invertebrates, lizards, birds and bats were surveyed and no species of conservation concern were recorded.

2.3.2.1 Invertebrates No significant or notable invertebrates were found and the Project Area is not considered to support important habitats for invertebrates. The removal of vegetation within the Project Area would result in the loss of habitat for common invertebrates, however the potential effects of the Project on invertebrates are considered to be less than minor as they would be expected to recolonise newly planted areas from adjacent habitats rapidly.

2.3.2.2 Frogs No frogs were found and the Project Area is not considered to support native frogs. The potential effects of the Project on frogs are considered to be negligible.

2.3.2.3 Lizards Although no native lizards were identified from survey, the Project Area may still support cryptic species of native lizard, including some with a conservation rating of nationally ‘At Risk’, albeit in low abundance. Removal of potential habitats would represent a low-moderate adverse effect, although a greater diversity of species at low abundance would represent a moderate level effect that would require mitigation.

2.3.2.4 Birds The Project Area supports foraging, roosting and probably nesting habitat for a suite of common native birds and this habitat may also be visited intermittently by a greater diversity of species than recorded, including some that are uncommon in the Auckland Region or nationally “At Risk”, due to close proximity of the Project Area to Dome Forest and Tawharanui Wildlife Sanctuary. Therefore, the value of the habitat to the range of potential bird species is of moderate ecological value and clearance of their habitats would similarly be a moderate adverse effect at a local scale. This effect could be avoided through managed vegetation clearance as described in Section 3.4 below and through implementation of a mitigation planting plan and legal protection of planted and retained areas of vegetation within the designation boundary.

2.3.2.5 Bats Although bats were not recorded within the Project Area, it is well within the flight range of known habitats within Dome Forest. The vegetation within the Project Area was not used by bats during the survey period and is not considered to be important for them. However, bats may use vegetation within the Project Area intermittently and given their conservation rating of ‘Nationally Critical”, any mortality caused by felling a tree that supports an active roost would be a significant adverse effect. This effect can be avoided through implementation of tree-felling protocols as agreed with the Department of Conservation through a Wildlife Act Authority.

2.3.3 Haul Road As part of the construction methodology a subgrade improvement layer (Haul Road) will be constructed immediately behind the advancing earthworks excavations. The Haul Road footprint will be confined to within the operational boundary. Accordingly, it is considered that the construction of

the Haul Road will have no additional adverse terrestrial ecological effects beyond those already discussed.

2.3.4 Staged Approach

While AT are seeking a designation for the construction of the entire Project, it is proposed to construct the Project in two stages. Generally speaking, Stage 1 will provide two general traffic lanes and a shared path on one side of the road. Stage 1 is proposed to be implemented to align with the opening of NZTA’s P2Wk project.

Stage 2 is currently anticipated to be implemented in 2036 - 2046, when traffic demand exceeds capacity. This will involve the widening of the road to accommodate four general traffic lanes and upgrading the berm to separated walking and cycling facilities on both sides of the road.

It is understood that the majority of vegetation removal and the majority of earthworks to accommodate Stage 2, would be undertaken in Stage 1. Therefore, the staged approach would not have any adverse effects on ecology as they pertain to vegetation clearance.

2.4 Mitigation Measures As identified in Section 2.3.1 of this assessment and within the Project’s Assessment of Environmental Effects, the majority of vegetation present within the Project corridor is not subject to protection under the AUP(OP) given its location within the FUZ. The following mitigation measures are recommended for the removal of riparian vegetation.

2.4.1 Avoidance The Project Area avoids larger areas of higher ecological value to the north and south (SEA), and the bridge may avoid loss of some of understory riparian vegetation beneath it. The storm water wetland has been positioned as to avoid further vegetation clearance.

2.4.2 Vegetation The Project Area avoids kauri trees and SEA T 6985; and minimises overall vegetation loss through construction of a bridge. The location of the crossing further minimises loss of higher value WF11 forest to the north and south of the proposed designation boundary.

2.4.2.1 Mitigation for the removal of protected riparian vegetation

Approximately 0.48 ha of native and exotic vegetation occurs within the riparian margin within the proposed designation boundary and removal of any of this would require consent under the requirements of the AUP(OP), and mitigation of assessed effects.

2.4.2.2 Edge Effects Buffer planting should be undertaken along all newly created edges of remaining riparian vegetation to minimise resulting edge effects, including wind, light, vehicle emissions and exotic weed spread. Planting for edge effects could be undertaken in part through the mitigation planting identified in section 2.4.2.1.

2.4.2.3 Shading The effect of shading and potential drought by the proposed bridge would alter the existing vegetation communities, including WF11 forest. The resulting change from WF11 forest to lower value vegetation below the bridge would be a moderate effect if vegetation survives or establishes.

The loss of native forest from below the bridge would be sufficiently mitigated in accordance with 2.4.2.1 (above).

2.4.2.4 Summary In summary, we recommend native replanting to mitigate loss of any riparian vegetation. Removal of other vegetation is considered a permitted activity.

Plantings should be undertaken in two stages, providing first for planting mixes that represent early successional forest and followed by enrichment with later successional species within the same area.

Due to constraints of the Project, like-for-like on-site or off-site planting in close vicinity of the Project Area is considered appropriate mitigation for loss of riparian vegetation. Such areas should provide for any off-site mitigation plantings to achieve similar outcomes as on-site plantings, including reduced edge effects enhanced connectivity for nearby forest fragments and riparian buffer function.

A Planting, Weed and Pest Management plan, for all areas of mitigation planting to be undertaken as well as along the edges of all retained vegetation, should be prepared by a qualified ecologist and the Kauri Dieback Operating Procedure (Bioresearches 2017 (Appendix VIII)) should be adhered to at all times.

2.4.3 Fauna 2.4.3.1 Invertebrates The Project Area was not considered to support important habitat for significant invertebrates. Consequently, the actual effects of the Project are considered to be less than minor and no specific mitigation is recommended. However, invertebrate communities are expected to benefit from revegetation and habitat enhancement measures undertaken for lizard management.

2.4.3.2 Frogs The Project Area was not considered to support native frog habitat. Consequently, the actual and potential effects of the Project are considered to be negligible and no mitigation is recommended.

2.4.3.3 Lizards The Project may have a moderate adverse effect on native lizards and their habitat. This effect would be reduced to less than minor by way of the following mitigation measures: ● Preparation and implementation of a Lizard Management Plan to relocate potentially present lizards into adjacent habitats prior to and during vegetation clearance; and ● Requiring animal-pest management and utilizing felled material for habitat enhancement within or alongside planting areas. Retaining felled material onsite would provide additional retreats for fauna (lizards and invertebrates) and foster nutrient cycling by providing organic material to the forest floor for decomposition by invertebrates. Invertebrates are crucial for ecosystem functioning and provide an important food source to lizards and birds.

The Lizard Management Plan should include details of animal-pest management, mitigation planting and habitat enhancement, specific to habitat requirements, to minimise potential adverse effects on lizard populations and compensate for habitat loss. The Lizard Management Plan should be prepared by a DOC-permitted herpetologist and approved by Auckland Council prior to works commencing.

2.4.3.4 Birds The value of the habitats to the range of potential bird species within the Project Area is of moderate ecological value, and therefore the clearance and subsequent loss of their habitats would have a moderate adverse effect at a local scale. These effects would be suitably minimised by way of the following mitigation measures: ● Where possible, clearance of habitats should be undertaken outside the main bird breeding season (September- December inclusive). Where this is not practicable, vegetation clearance should follow immediately after a nesting native bird survey can confirm there are no nesting native birds present in affected vegetation. In the case of the latter, nesting native birds, where identified, should be allowed to fledge their chicks undisturbed immediately prior to tree removal. ● Requiring animal-pest management and utilizing felled material for habitat enhancement within or alongside planting areas. Retaining felled material onsite would foster nutrient cycling by providing organic material to the forest floor for decomposition by invertebrates. Invertebrates are crucial for ecosystem functioning and provide an important food source to birds and lizards. Provision of animal pest control should aim to maximise native bird breeding success for a minimum five years.

2.4.3.5 Bats The area was not used by bats during the survey period and is not considered to be important for them. However, bats may use vegetation within the Project Area intermittently, and given their conservation rating of ‘Nationally Critical”, any mortality caused by felling a tree that supports an active roost would be a significant adverse effect. This effect can be avoided through implementation of tree-felling protocols as agreed with the Department of Conservation through a Wildlife Act Authority.

3. FRESHWATER ECOLOGY

3.1 Assessment Methodology Prior to an onsite assessment, a map of the site was created using the overland flow paths and contours from the Auckland Council GIS viewer to determine where potential watercourses may exist, and to develop a preliminary classification of the watercourses (as ephemeral, intermittent, or permanent in nature). An initial walkover of all the aquatic habitats and potential watercourses was undertaken on 26 April 2017, by an experienced freshwater ecologist.

3.1.1 Stream Ecological Evaluation Detailed assessments of four representative reaches (Figure 9), one permanent and three intermittent, were undertaken using the Stream Ecological Valuation (SEV) methodology (Auckland Council Technical Report 2011/009 and 2016/023) by two experienced freshwater ecologists. The SEV methodology (Storey et al., 2011) enables the overall function of the stream to be assessed and compared to the quality of other streams in the Auckland Region. The SEV assessment involves the collection of habitat data (e.g. stream depth, substrate type, riparian cover), and sampling of fish communities and macroinvertebrates (e.g. insect larvae, snails), the latter being recognised indicators of habitat quality. The SEV method gives a score between 0 (low quality) and 1 (high quality) for each of a number of attributes which are weighted in terms of their contribution to overall stream value. These attributes are then combined to give an overall SEV score, also on a scale of 0 to 1.

The SEV assessments were undertaken on 30 October and 6 November 2017, over a representative 50m or 100m section1. The SEV reach was marked at the upstream and downstream boundaries with a handheld GPS. Photographs were taken and notes made on any evident habitat limiting factors, such as barriers to fish passage, or permanence of flows. SEV scores for the permanent and intermittent watercourses were calculated using the SEV Data Analysis Spreadsheet Version 2.3 (Auckland Council; October 2013) and the Intermittent SEV Data Analysis Spreadsheet (Auckland Council; June 2016), respectively. Summary SEV data are presented in Appendix II.

1 The length of the SEV reach was dependent upon the watercourse type and the length within the Project Area.

Figure 8: Project Area with the impacted watercourses labelled A-F. Yellow highlighted sections represent SEV reaches.

3.1.2 Macroinvertebrates Macroinvertebrates were sampled from instream habitats to obtain semi-quantitative data in accordance with the Ministry for the Environment’s current “Protocols for Sampling Macroinvertebrates in Wadeable Streams” (Stark et al., 2001). Sampling was undertaken along all four SEV reaches, using protocol ‘C2: soft-bottomed, semi-quantitative’ as the streams were soft bottomed. The macroinvertebrate sample was preserved in 70% ethyl alcohol (ethanol), returned to the laboratory and sorted (using protocol ‘P3: full count with sub-sampling option’ (Stark et al., 2001)). Macroinvertebrates were then identified to the lowest practicable level and counted to enable biotic indices to be calculated. Three biotic indices were calculated, namely the number of taxa, the percentage of Ephemeroptera (mayflies); Plecoptera (stoneflies) and Trichoptera (caddisflies) recorded in a sample (%EPT) and the Macroinvertebrate Community Index (MCI). EPT are three orders of insects that are generally sensitive to organic or nutrient enrichment, but exclude Oxyethira and Paroxyethira as these taxa are not sensitive and can proliferate in degraded habitats. The MCI is based on the average sensitivity score for individual taxa recorded within a sample. MCI scores of >120 are indicative of excellent habitat quality, 100 - 119 are indicative of good habitat quality, 80 – 99 are indicative of fair habitat quality and < 80 are indicative of poor habitat quality (Stark & Maxted, 2007b). Raw macroinvertebrate data are presented in Appendix III. 3.1.3 Fish To sample fish communities, electric fishing was carried out over all four SEV survey reaches using an EFM300 backpack electric fishing machine. The electric fishing machine temporarily stuns the fish, allowing them to be captured. All fish captured were identified, their size estimated and counted before being returned to their habitats. New Zealand Freshwater Fish Database forms were completed and are presented in Appendix IV. An Index of Biotic Integrity (IBI) was calculated for each site based on fish species present, altitude and distance inland (Joy & Henderson, 2004). 3.1.4 Water Quality In situ spot measurements of basic water quality parameters (temperature, dissolved oxygen and conductivity) were undertaken at a representative site within each SEV reach. Measurements were undertaken using a Yellow Springs Instruments (YSI) Professional Series combined dissolved oxygen/temperature/conductivity meter. Water quality data are presented in Table 5. 3.1.5 Stream Classification Streams were classified on 26 April 2017, under the AUP, to determine, in accordance with the definitions in these plans, the ephemeral, intermittent, or permanent status of these watercourses. 3.1.6 Aquatic Ecological Descriptors Aquatic ecological values are described in this report as being “high”, “moderate”, “low” or “very low”. Table 4 provides generalised ecological descriptions for these simplified aquatic ecological values.

In this report the assessment of effects have been described as less than minor, minor, moderate (more than minor) or high. These assessments take into account both the nature of the environment that is affected (in terms of the ecological values) and the severity or extent of the effect.

Table 4: Generalised Freshwater Ecological Descriptors and Corresponding Valuations used in this Report Ecological Value Habitat Description Descriptor

Aquatic habitats have a combination of very low levels of: shading, hydrologic heterogeneity, aquatic habitat diversity, and riparian Very Low integrity. They also have potentially high levels of anaerobic processes.

Aquatic habitats have a combination of low levels of: shading, hydrologic heterogeneity, aquatic habitat diversity, and riparian Low integrity. They also have potentially moderate to high levels of anaerobic processes.

Aquatic habitats have a combination of moderate levels of: shading, hydrologic heterogeneity, aquatic habitat diversity, and riparian Moderate integrity. They also have potentially moderate to low levels of anaerobic processes.

Aquatic habitats have high levels of shading, low levels of suspended sediments and high hydrologic heterogeneity, such as pools, riffles, runs, chutes and cascades. Aquatic habitats likely to support (or has High records for) a high diversity of fish species, including Nationally 'At Risk' species.

3.2 Existing Freshwater Environments and Values A review of the New Zealand Fresh Database showed that a number of native freshwater species have been identified within the larger catchment area of the project. These species include: shortfin eel (Anguilla australis), longfin eel (Anguilla dieffenbachii), common bully (Gobiomorphus cotidianus), Crans bully (G. basalis), redfin bully (G. huttoni), inanga (Galaxias maculatus), freshwater mussels (Hyridella menziesii) and koura (Paranephrops spp.). It is also highly likely that banded kokopu (Galaxias fasciatus) are present within the catchment. Of these species the longfin eel, inanga and redfin bully are listed as ‘At Risk; Declining’ on the national threatened species list (Goodman et al., 2014). While the watercourses within the immediate Project Area would typically provide habitat for a range of common native fish and macroinvertebrates, most of the instream habitats are likely to have been adversely impacted to some extent by the existing catchment land use. Additionally, the weir within the Mahurangi River, located close to the Warkworth town centre, significantly impedes migratory fish passage.

Rainfall over the winter months, prior to the site assessments, was at a sustained moderate to high level, well above the average for this time of year (Auckland Council Environmental Monitoring Site: Mahurangi @ Satellite Dish) (Figure 10). During the month preceding the site assessments, rainfall was at a sustained moderate level. No rainfall was recorded within 48hrs immediately prior to the site assessments.

Figure 9: Totalled daily rainfall depth (mm) from the Mahurangi Satellite Dish monitoring site between 01/05/17 – 06/11/17.

Six watercourses were identified within the proposed designation boundary (Watercourses A-F, Figure 9). Four SEVs were undertaken within Watercourse A, C, D and E. No SEVs were undertaken within Watercourses B and F as Watercourse B had no flowing water at the time of the survey and no stream works are proposed within Watercourse F. The summarised stream characteristics and the results of the SEV are presented in Table 5.

3.2.1 Watercourse A Watercourse A is a minor tributary of the Mahurangi River catchment (Figure 9). The watercourse originated within Lot 3 DP 155679 and flowed in a southerly direction for approximately 700m before entering a culvert under SH1. Within the assessed reach the watercourse had an average width and depth of 1.3m and 0.15m, respectively. Watercourse A was considered to have an overall low current aquatic ecological value, as detailed below.

3.2.1.1 Watercourse Classification At the time of the site assessment flowing water was evident throughout the reach of Watercourse A 48 hours after a rain event. But considering the sustained rain over the prior months (Figure 10) and the shallow average depth of the watercourse (0.15m), Watercourse A was considered an intermittent stream under the AUP(OP) criteria.

3.2.1.2 SEV Assessment The SEV assessment for Watercourse A calculated an overall low score of 0.38. This indicates that the stream is highly modified due to farming practices. The highest function score, 1.00, was for ‘connectivity for migrations’ due to the absence of a fish barrier within the SEV reach. The lowest scoring functions were ‘organic matter input’, ‘fish spawning habitat’, ‘fish fauna intactness’ and ‘riparian vegetation intactness’ all with a function under 0.2 due to the limited shading, the lack of native fish and the absence of suitable fish spawning habitat.

Figure 10: Watercourse A (images above and below).

3.2.1.3 Riparian Vegetation The riparian margin along Watercourse A consisted almost entirely of open grazed pasture with some scattered rushes. Stock had unimpeded access to the watercourse.

3.2.1.4 Water Quality The dissolved oxygen concentrations and saturation within Watercourse A were low (DO 52.9%; 5.12 mg/L) indicating moderate stress on aquatic organisms (Davies-Colley et al., 2013). The water temperatures were moderate, at around 17.1oC, and within the temperature range of ‘good’, which is considered to be suitable for most invertebrates (Biggs et al., 2002). Conductivity was ‘good’ at 131µS/cm, indicating nutrient enrichment is unlikely (Biggs et al., 2002). Water clarity was poor where exposed banks and cattle access has resulted in excess sediment being introduced to the stream. Once macrophytes or the stream bed were disturbed the water became brown and turbid.

3.2.1.5 Aquatic Plants Macrophytes were found abundantly throughout Watercourse A which choked the watercourse and inhibited flow. Macrophyte species included starwort (Callitriche stagnalis), water purslane (Ludwigia palustris), water pepper (Persicaria hydropiper), watercress (Nasturtium sp.) and fools water cress (Apium nodiflorum).

3.2.1.6 Freshwater Fauna Habitat The substrate of the watercourse was entirely mud and silt. Hydrologic heterogeneity was low with the watercourses characterised by slow flowing runs. The watercourse was unfenced from stock and extensive pugging was evident.

3.2.1.7 Macroinvertebrates Macroinvertebrate diversity was moderate to low with 13 taxa recorded from the site. Taxa typically tolerant of degraded habitat quality dominated the communities, with the freshwater amphipod crustaceans (Paracalliope fluviatilis) numerically dominating the sample (71% of sample abundance). One EPT taxa which was also the only sensitive taxa (with individual MCI scores >8) was found; the caddisfly (Polyplectropus puerilis). This was reflected in the MCI scores of 89 and a ranking of ‘fair’ macroinvertebrate habitat (Stark & Maxted, 2007a).

3.2.1.8 Fish Communities Twelve shortfin eel were found within the watercourse ranging from 180-450mm. The Auckland Index of Biotic Integrity (IBI) score was 14 for each site, indicating ‘Very Poor’ species diversity in comparison to other Auckland streams, given the altitude and distance from the sea (Joy & Henderson, 2004).

3.2.1.9 Aquatic Ecological Potential The aquatic ecological potential for the assessed reach was considered moderate. The ecological potential of the watercourse is restricted by the limited base flow, the current availability of native fish habitat and its association with SH1.

3.2.2 Watercourse B Watercourse B is a very minor tributary within the Mahurangi River catchment which has been highly modified through straightening and deepening (Figure 9). The watercourse originated within Pt Lot 1 DP 61693 and flowed in a southerly direction for approximately 140m before joining a network of

swales and concrete lined drainage channels, approximately 140m long, associated with the Warkworth sports grounds. Within the Warkworth sports grounds the watercourse drains into a grated manhole and the reaming downstream length appears to be appears to be piped (<420m). At the very upper extent of the watercourse a heavily degraded headwater seepage was present, measuring approximately 300m2. Only a very low volume of water appeared to be seeping through the ground within this area. This area was not considered a wetland as no animals adapted to wetland conditions were observed. Additionally, no obligate wetland plants and only one facultative wetland plant (Juncus effuses) was recorded, comprising of less than 15% of the site.

Figure 11: Degraded headwater seepage associated with Watercourse B.

Within the defined section (detailed below) the watercourse had an average width and depth of 0.6m and 0.02m, respectively.

Overall Watercourse B was considered to have a very low current aquatic ecological value, due to the lack of water flow, shading, aquatic habitat and hydrologic heterogeneity, as detailed below.

3.2.2.1 Watercourse Classification A reassessment of Watercourse B was undertaken on August 13th 2018, following moderate sustained rain within the month prior. Additionally, rainfall (4mm) occurred within 24hrs of the site visit. At the time of the site assessment only a short reach (20m) contained a trickle of flowing water. This occurred in a section of the watercourse which had been deepened and straightened the most significantly. This flow is believed to be due to the channel being artificially deepened to a level where the watercourse bed is periodically below the water table. Outside of this section, Watercourse B did

not have a defined channel or flowing water. Some surface water (stagnant) was present which was likely due to the extensive pugging within the area.

Furthermore, at the time of the site assessment, Watercourse B contained no natural pools, contained rooted terrestrial vegetation and no evidence of substrate sorting or flood debris was present. Watercourse B was classified as ephemeral under the AUP(OP) criteria. The short section within the defined channel and trickle flow was considered artificial in nature.

3.2.2.2 Riparian Vegetation The riparian margin along Watercourse B consisted almost entirely of open grazed pasture with some scattered rushes. Stock had unimpeded access to the upper reach of the watercourse.

3.2.2.3 Water quality The dissolved oxygen concentrations and saturation within Watercourse B were low (DO47.6%; 4.87 mg/L) indicating moderate stress on aquatic organisms (Davies-Colley et al., 2013). The water temperatures were moderate, at around 17.6oC, and within the temperature range of ‘good’, which is considered to be suitable for most invertebrates (Biggs et al., 2002). Conductivity was ‘good’ at 112µS/cm, indicating nutrient enrichment is unlikely (Biggs et al., 2002). Water clarity was poor where cattle access had resulted in excess sediment being introduced to the stream.

3.2.2.4 Aquatic Plants Macrophytes within Watercourse B were limited to a very small patches of water celery. Terrestrial vegetation was established throughout much of the watercourse channel.

3.2.2.5 Freshwater Fauna Habitat The substrate of the watercourse was entirely mud and silt. Hydrologic heterogeneity was very low and limited to runs. At the time of the assessment limited flowing water was evident. Surface water was present, with a few small puddles evident. The watercourse was unfenced from stock and extensive pugging was evident. Fish habitat was negligible and connectivity downstream was completely disconnected, due the presence of dry swales, drainage channels and extensive piping. Freshwater macroinvertebrate habitat was marginal and would only be present intermittently. Freshwater macroinvertebrates, likely to be present, would be limited to common, ‘pollutant tolerant’ species that are good disperses, such as Chironomis.

3.2.2.6 Ecological Valuation Due to the insufficient amount of flowing water, an SEV or fauna surveys were not undertaken within Watercourse B.

Figure 12: Watercourse B with degraded headwater seepage in background.

3.2.2.7 Aquatic Ecological Potential The aquatic ecological potential for the assessed reach was considered very low. This is due to the following: the location of the impacted reach at the very top of the watercourse/catchment (no upstream connectivity); no current or potential downstream connectivity, limited base water flow; and the lack of potential native fish habitat.

3.2.3 Watercourse C Watercourse C is a minor tributary of the Mahurangi River (Figure 9). The watercourse originated within PT Allot 97 PSH of Mahurangi and flowed in a southerly direction for approximately 200m before joining a confluence with Watercourse D. At the very upper extent of the watercourse a small heavily degraded headwater seepage was present, measuring approximately 70m2. Within the assessed reach the watercourse had an average width and depth of 0.26m and 0.01m, respectively. Watercourse C was considered to have an overall very low current aquatic ecological value, as detailed below.

3.2.3.1 Watercourse Classification At the time of the site assessment flowing water was evident throughout the reach of Watercourse C 48 hours after a rain event. But considering the sustained rain over the prior months (Figure 10) and the very shallow average depth of the watercourse (0.01m), Watercourse C was considered an intermittent stream under the AUP(OP) criteria. Furthermore, the intermittent watercourse was considered nearing ephemeral in nature.

3.2.3.2 SEV Assessment The SEV assessment for Watercourse C calculated an overall low score of 0.35. This indicates that the stream is highly modified due to farming practices. The highest function score, 0.83, was for both

‘natural flow regime’ and ‘natural connectivity to groundwater’ due to the natural nature of the stream channel. The lowest scoring functions were ‘organic matter input’, ‘fish spawning habitat’, ‘fish fauna intactness’ and ‘riparian vegetation intactness’ all with a function under 0.2 due to the limited shading, the lack of native fish and the absence of suitable fish spawning habitat.

Figure 13: Watercourse C.

3.2.3.3 Riparian Vegetation The riparian margin along Watercourse C consisted almost entirely of open grazed pasture with some scattered rushes. Stock had unimpeded access to the watercourse.

3.2.3.4 Water Quality The dissolved oxygen concentrations and saturation within Watercourse C were low (DO 56.5%; 5.23 mg/L) indicating moderate stress on aquatic organisms (Davies-Colley et al., 2013). The water temperatures were moderate, at around 18.1oC, and within the temperature range of ‘good’, which is considered to be suitable for most invertebrates (Biggs et al. 2002). Conductivity was ‘good’ at 87.5µS/cm, indicating nutrient enrichment is unlikely (Biggs et al. 2002). Water clarity was poor where exposed banks and cattle access had resulted in excess sediment being introduced to the stream. Once macrophytes or the stream bed were disturbed the water became brown and turbid.

3.2.3.5 Aquatic Plants Macrophytes within Watercourse C were limited to a few very small patches of starwort, water purslane and water pepper.

3.2.3.6 Freshwater Fauna Habitat The substrate of the watercourse was entirely mud and silt. Hydrologic heterogeneity was very low limited to slow flowing runs. The watercourse was unfenced from stock and extensive pugging was evident.

3.2.3.7 Macroinvertebrates Macroinvertebrate diversity was moderate to low with 13 taxa recorded from the site. Taxa typically tolerant of degraded habitat quality dominated the communities, with the freshwater crustaceans; Ostracoda and the Chironomid; Tanypodinae sp., numerically dominating the sample (46% and 31% of sample abundance, respectively). No EPT taxa were found and only one sensitive taxa (with individual MCI scores >8) was found; the midge larvae, Dixidae Paradixa sp.. This was reflected in the MCI scores of 87 and a ranking of ‘fair’ macroinvertebrate habitat (Stark &Maxted, 2007a). Freshwater macroinvertebrate habitat was a marginal and would only be present intermittently.

3.2.3.8 Fish Communities Although the stream was fished using the electric fishing machine, no fish were caught or observed, resulting in an Auckland Index of Biotic Integrity (IBI) score of zero, and ranking of ‘Very Poor’ species diversity in comparison to other Auckland streams, given the altitude and distance from the sea (Joy & Henderson, 2004). In addition, potential fish habitat was considered negligible, due to the current complete lack of aquatic habitat for fish.

3.2.3.9 Aquatic Ecological Potential The aquatic ecological potential for the assessed reach was considered low. This is due to the following: the location of the impacted reach at the very top of the watercourse/catchment (no upstream connectivity); limited base water flow; and the lack of native fish habitat.

3.2.4 Watercourse D Watercourse D is a minor tributary of the Mahurangi River (Figure 9). The watercourse originated within PT Allot 97 PSH of Mahurangi and flowed in a southerly direction for approximately 250m before joining a confluence with Watercourse C. Within the assessed reach the watercourse had an average width and depth of 0.26m and 0.03m, respectively. Watercourse D was considered to have an overall very low current aquatic ecological value, as detailed below.

3.2.4.1 Watercourse Classification At the time of the site assessment flowing water was evident throughout the reach of Watercourse D 48 hours after a rain event. But considering the sustained rain over the prior months (Figure 10) and the very shallow average depth of the watercourse (0.03m), Watercourse D was considered an intermittent stream under the AUP(OP) criteria.

3.2.4.2 SEV Assessment The SEV assessment for Watercourse D calculated an overall low score of 0.32. This indicates that the stream is highly modified due to farming practices. The highest function score, 0.83, was for ‘natural connectivity to groundwater’ due to the natural nature of the stream channel. The lowest scoring functions were ‘floodplain effectiveness’, ‘organic matter input’, ‘decontamination of pollutants’, ‘fish spawning habitat’, ‘fish fauna intactness’ and ‘riparian vegetation intactness’ all with a function under 0.2 due to the limited shading riparian zone, the lack of native fish and the absence of suitable fish spawning habitat.

Figure 14: Watercourse D.

3.2.4.3 Riparian Vegetation The riparian margin along Watercourse D, within the SEV reach, consisted entirely of open grazed pasture. Downstream of the SEV reach, a narrow riparian margin of willows (Salix sp.) and other exotic plants shaded the watercourse.

3.2.4.4 Water Quality The dissolved oxygen concentrations and saturation within Watercourse D were moderate (DO 79.4%; 7.6 mg/L) indicating occasional minor stress on aquatic organisms (Davies-Colley et al., 2013). The water temperatures were moderate, at around 17.5oC, and within the temperature range of ‘good’, which is considered to be suitable for most invertebrates and periphyton (Biggs et al. 2002). Conductivity was ‘good’ at 64.8µS/cm, indicating nutrient enrichment is unlikely (Biggs et al. 2002). Water clarity was poor where exposed banks and cattle access had resulted in excess sediment being introduced to the stream. Once the stream bed was disturbed the water became brown and turbid.

3.2.4.5 Aquatic Plants No macrophytes were observed within the SEV reach, although terrestrial bankside vegetation encroached into the stream channel in places.

3.2.4.6 Freshwater Fauna Habitat The substrate of the watercourse was entirely mud and silt. Hydrologic heterogeneity was very low and limited to runs. The watercourse was unfenced from stock and extensive pugging, erosion and slumps were evident, causing heavily incised banks.

3.2.4.7 Macroinvertebrates Macroinvertebrate diversity was low to moderate with 16 taxa recorded from the site. Taxa typically tolerant of degraded habitat quality dominated the communities, with the mosquito larvae; Culicidae, Culex sp.and the Chironomid; Orthcladiinae sp., numerically dominating the sample (30% and 15% of sample abundance, respectively). One EPT taxa was found (Hydrobiosidae, Psilochorema sp.) and no sensitive taxa (with individual MCI scores >8) were found. This was reflected in the MCI scores of 74 and a ranking of ‘poor’ macroinvertebrate habitat (Stark &Maxted, 2007a). Freshwater macroinvertebrate habitat was a marginal and would only be present intermittently.

3.2.4.8 Fish Communities Although the stream was fished using the electric fishing machine, no fish were caught or observed, resulting in an Auckland Index of Biotic Integrity (IBI) score of zero, and ranking of ‘Very Poor’ species diversity in comparison to other Auckland streams, given the altitude and distance from the sea (Joy & Henderson, 2004). In addition, potential fish habitat was also considered to be negligible within the reach, due to the lack of aquatic habitat for fish.

3.2.4.9 Aquatic Ecological Potential The aquatic ecological potential for the assessed reach was considered low. This is due to the following: the location of the impacted reach at the very top of the watercourse/catchment (no upstream connectivity); limited base water flow; and the lack of native fish habitat.

3.2.5 Watercourse E Watercourse E is a minor tributary of the Mahurangi River (Figure 9). The watercourse originated within PT Allot 97 PSH of Mahurangi and flowed in a south-easterly direction for approximately 300m before joining a confluence with Watercourse F, which forms a significant tributary of the Mahurangi tributary. Within the assessed reach the watercourse had an average width and depth of 0.67m and 0.1m, respectively. Watercourse E was considered to have an overall moderate current aquatic ecological value, as detailed below.

3.2.5.1 Watercourse Classification At the time of the site assessment a continuous flow of water was evident throughout the reach of the watercourse 48 hours after a rain event. Accordingly, Watercourse E was classified as a permanent stream under the AUP(OP) criteria.

3.2.5.2 SEV Assessment The SEV assessment for Watercourse E calculated an overall low to moderate score of 0.5. This indicates that the stream has been modified due to farming practices. The highest function score, 1.00, for ‘connectivity for migrations’ was due to the absence of a fish barrier within the SEV reach. The lowest scoring functions were ‘floodplain effectiveness’, ‘fish spawning habitat’ and ‘riparian vegetation intactness’ all with a function under 0.2 due to the limited shading and the absence of suitable fish spawning habitat.

Figure 15: Watercourse E (images above and below).

3.2.5.3 Riparian Vegetation The riparian margin along the upper reach of Watercourse E, consisted entirely of open grazed pasture and a thin margin of gorse. Further downstream the watercourse entered native forest (as described in Section 2.2.1.3) which provided high shading and organic input for the watercourse.

3.2.5.4 Water Quality The dissolved oxygen concentrations and saturation within Watercourse E were moderate-high (DO 81.6%; 7.88 mg/L) indicating that stress on aquatic organisms is unlikely (Davies-Colley et al., 2013). The water temperatures were moderate, at around 16.7oC, and within the temperature range of ‘good’, which is considered to be suitable for most invertebrates (Biggs et al. 2002). Conductivity was ‘good’ at 80.7µS/cm, indicating nutrient enrichment is unlikely (Biggs et al. 2002). Water clarity was poor where exposed banks and cattle access had resulted in excess sediment being introduced to the stream. Once macrophytes or the stream bed were disturbed the water became brown and turbid.

3.2.5.5 Aquatic Plants No macrophytes were observed within the lower reach of the SEV where shading was high. Along the upper reach isolated dense patches of water pepper were evident where shading was low.

3.2.5.6 Freshwater Fauna Habitat The substrate of the watercourse was entirely mud and silt. Hydrologic heterogeneity was low being limited to runs and a few small pools. The upper reach of the watercourse was unfenced from stock and extensive pugging was evident.

3.2.5.7 Macroinvertebrates Macroinvertebrate diversity was low with 14 taxa recorded from the site. The caddis fly, Polyplectropus puerilis numerically dominated the sample (43% of sample abundance) and was one of the two EPT taxa and sensitive taxa found. The other EPT taxa and sensitive taxa found were; Psilochorema sp. and Paranephrops planifrons, respectively. This was reflected in the MCI scores of 119 and a ranking of ‘good’ macroinvertebrate habitat (Stark &Maxted, 2007a).

3.2.5.8 Fish Communities Although the stream was fished using the electric fishing machine, no fish were caught or observed, resulting in an Auckland Index of Biotic Integrity (IBI) score of zero, and ranking of ‘Very Poor’ species diversity in comparison to other Auckland streams, given the altitude and distance from the sea (Joy & Henderson, 2004). Adequate fish habitat was present, so the lack of fish was considered to be from a potential downstream fish passage barrier. It should also be noted that koura (Paranephrops planifrons) were abundant throughout the reach.

3.2.5.9 Aquatic Ecological Potential The aquatic ecological potential for the assessed reach was considered moderate-high. With the upper reach having the highest potential for restoration. This is primarily due to the watercourse being permanent in nature and consequently able to support a higher degree of native fish communities.

3.2.6 Watercourse F Watercourse F is a significant tributary of the Mahurangi River catchment (Figure 9). The main stem originated within Lot 1 DP 101758 and flowed in a southerly direction for approximately 2km before draining directly into the Mahurangi River. Upstream of the main stem, four minor tributaries converge to form Watercourse F. Within the surveyed reach the watercourse had an average width and depth of 1m and 0.12m, respectively.

Overall Watercourse F was considered to have a high current aquatic ecological value due to the high shading, wide riparian margin, diverse aquatic habitat and high hydrologic heterogeneity, as detailed below.

3.2.6.1 Watercourse Classification At the time of the site assessment a continuous flow of water was evident throughout the reach of the watercourse 48 hours after a rain event. Accordingly, Watercourse F was classified as a permanent stream under the AUP(OP) criteria.

3.2.6.2 Riparian Vegetation The riparian margin of Watercourse F consisted of native forest (as described in Section 2.2.1.3) which provided high shading and organic input for the watercourse.

3.2.6.3 Water Quality The dissolved oxygen concentrations and saturation within Watercourse F were high (DO 92%; 9.36 mg/L) indicating that is there no stress on aquatic organisms (Davies-Colley et al., 2013). The water temperatures were moderate, at around 15.3oC, and within the temperature range of ‘good’, which is considered to be suitable for most invertebrates (Biggs et al. 2002). Conductivity was ‘good’ at 124µS/cm, indicating nutrient enrichment is unlikely (Biggs et al. 2002). Water clarity was good.

3.2.6.4 Aquatic Plants No macrophytes were observed within the watercourse as shading was high throughout.

3.2.6.5 Freshwater Fauna Habitat The substrate of the watercourse was predominantly mud and silt with some cobble and bedrock present in places. Hydrologic heterogeneity was moderate to high, with fairly diverse hydrologic conditions including runs, pools and cascades. Additional habitat included undercut banks and woody debris.

3.2.6.6 Ecological Valuation A SEV or fauna surveys were not undertaken within Watercourse F, as there are no proposed streamworks within the watercourse.

Figure 16: Watercourse F (images above and below).

3.2.7 Watercourse Characteristics Summary

Table 5: Watercourse characteristics and SEV results. Location Watercourse A Watercourse B Watercourse C Watercourse D Watercourse E Watercourse F End SEV Start SEV End SEV Start SEV Start SEV End SEV Start SEV End SEV E1747670 E1748269 E1748648 Map reference (NZTM) E1747837 E1747824 E1748288 E1748379 E1748356 E1748545 E1748508 N5971810 N597196 N5972150 N5971567 N5971614 N5971927 N5972026 N5972070 N5972154 N5972180 9 Average width (m) 1.30 0.6 0.26 0.26 0.67 1.00 Average depth (m) 0.15 0.02 0.01 0.03 0.1 0.12 Max depth (m) 0.47 0.04 0.04 0.06 0.29 0.62 Dominant Substrate Types Mud/Silt Mud/Silt Mud/Silt Mud/Silt Mud/Silt Silt/Clay Stream Classification Intermittent Ephemeral Intermittent Intermittent Permanent Permanent

Main Aquatic Plants Starwort, water celery Water celery Water pepper N/A Water pepper N/A Water Quality Time of Sampling (NZST 1000 1030 1230 1100 1045 0930 hours) Temperature (oC) 17.1 17.6 18.1 17.5 16.1 15.3 Oxygen saturation (%) 52.9 47.6 56.5 79.4 81.6 92 Dissolved oxygen (mg/L) 5.12 4.87 5.23 7.57 7.88 9.36 Conductivity (µS/cm) 131 112 87.5 64.8 80.7 124 Macroinvertebrates and Biota No. of taxa 13 - 13 16 14 - Dominant taxon Paracalliope fluviatilis - Ostracoda Culicidae Culex sp. Polyplectropus puerilis - No. of EPT taxa 1 - 0 2 2 - % EPT 2 - 0 1 44 - MCI – soft bottom 89 ‘fair’ - 87 ‘fair’ 74 ‘poor’ 119 ‘good’ -

Total fish recorded 12 - 0 0 0 - Species recorded: Shortfin eel - 0 0 0 - Fish IBI 14 ‘very poor’ - 0 ‘no natives’ 0 ‘no natives’ 0 ‘no natives’ - Stream Ecological Valuation SEV score 0.38 - 0.35 0.32 0.50 - Overall Ecological Value Low Very low Very low Very low Moderate High

3.3 Assessment of Effects 3.3.1 Watercourse A Watercourse A was considered to be of low aquatic ecological value. In-stream works are not proposed within the watercourse.

Consequently, the direct adverse effects of the project on Watercourse A are considered to be less than minor.

3.3.2 Watercourse B Adverse impacts on Watercourse B cannot be avoided due to the road alignment.

Watercourse B was considered to be ephemeral and of very low current and potential ecological value. It is proposed that Watercourse B and its associated headwater seepage is to be reclaimed. Adverse effects have been minimised by the use of a conveyance channel that redirects any overland flows from the upper catchment of Watercourse B to Watercourse A. Watercourse A is in close proximity and within the same catchment.

Due to the current and potential lack of fish habitat, the low restoration potential of the watercourse, the ephemeral nature of the watercourse and the fact that much of the hydrologic function of the watercourse will be retained through redirecting of overland flows, the direct adverse effects of the Project on Watercourse B and its associated headwater seepage are considered to be minor.

3.3.3 Watercourse C and D Adverse impacts on Watercourses C and D cannot be avoided due to the road alignment. Although the 70m2 degraded headwater seepage associated with Watercourse C will be avoided. Adverse effects on Watercourses C and D have been minimised by use of culverts rather than reclamation.

Watercourse C was considered to be of very low aquatic ecological value. In-stream works are proposed within the watercourse and approximately 70m of the watercourse is proposed to be culverted.

Watercourse D was considered to be of very low aquatic ecological value. In-stream works are proposed within the watercourse. Approximately 45m of the watercourse is proposed to be culverted of which, approximately 10m is considered to be ephemeral in nature.

It is important to recognise that the primary hydrologic function of Watercourses C and D will be retained through culverting and in this instance, there will be no loss in aquatic habitat for native fish

as there currently is none and no potential for any. Additionally, although it is hard to predict how the macroinvertebrate community will respond to the change in environment, there is an argument that the macroinvertebrate diversity will not change significantly in this instance. This is due to the current habitats being, poor, homogenous and intermittent and the fact that the culverts will be embedded (to promote natural streambed habitat and substrate) and cause an increase in shading (decrease water temperature). Nonetheless, the culverts will not inhibit macroinvertebrate dispersal.

Currently the filtering activity is very low around the watercourses due to the grazed vegetation and high soil compaction. Any further reduction in filtering activity, as well as any reduction in flow attenuation and dissipation, will be mitigated through stormwater devices as outlined within the Stormwater Management Report.

An additional adverse effect, as a result of the culverts would, be a reduction in organic input and connection to the riparian zone. Expected SEV values were determined for Watercourse C and D using predicted function scores assuming that the proposed culverting had been carried out. The assumptions took into account mitigation devices. SEV function score summaries and assumptions are provided in Appendix VI and VII.

Watercourse C and D had current SEV values of 0.353 and 0.323, respectively, while the predicted SEV values were 0.260 and 0.263. This equates to a decrease in SEV value of 0.093 and 0.06. A decrease of 0.093 and 0.06 are not considered to a have a significant effect on the aquatic ecology of the stream.

Consequently, due to the current and potential lack of fish habitat within the watercourses, the low restoration potential of the watercourses and the fact that much of the hydrologic function of the watercourses will be retained through culverting, the direct adverse effects of the Project on Watercourses C and D are considered to be minor.

3.3.4 Watercourse E Watercourse E was considered to be of moderate aquatic ecological value. In-stream works are proposed within the watercourse with approximately 70m of the watercourse proposed to be culverted.

Due to the permanent nature of the watercourse, the presence of aquatic habitat or fauna and the moderate-high restoration potential of the watercourse, the direct adverse effects of the Project on Watercourse E are considered to be moderate.

3.3.5 Watercourse F Watercourse F was considered to be of high ecological value. Approximately 45m of Watercourse F is located within the proposed road alignment.

In order to avoid reclamation or instream works within Watercourse F, a bridge is proposed to span the entire width of the watercourse. While AT are seeking designation for the full construction of the Project, it is likely that the bridged will be staged. The Stage 1 bridge will provide two general traffic

lanes with a shared path on one side. Support piles for the Stage 1 bridge will be located outside of the watercourse channel.

The Stage 1 bridge may require a temporary construction bridge. Any support piles required for the temporary construction bridge will be located outside of the watercourse channel.

The Stage 2 bridge will be constructed adjacent to the Stage 1 bridge and will provide two additional general traffic lanes with a shared path on one side. Support piles for the Stage 2 bridge will be located outside of the watercourse channel. No temporary construction bridge is required for the Stage 2 bridge.

It is understood that all vegetation removal and the majority of earthworks to accommodate Stage 2, would be undertaken in Stage 1.

No works are proposed within the streambed of Watercourse F for Stage 1 or 2 and consequently, the direct adverse effects of the project on Watercourse F are considered to be negligible.

The construction of the temporary staging bridge and the permanent bridge (Stage 1 and 2) would result in the loss of riparian vegetation which would in turn cause minor indirect adverse effects including reduced filtration activity and organic input.

3.3.6 Stormwater In the absence of adequate mitigation, there is a potential for adverse water quality effects arising from stormwater runoff from roads, including increased hydrocarbons and trace metals and an increase in erosion.

The Stormwater Management Report provides a detailed explanation of the design and capacity of the stormwater treatment for the operation of the Project. Three stormwater wetlands have been proposed that would discharge into Watercourses A, C and G (Figure 8). These wetlands have been designed in accordance with the Auckland Council Guideline Document 2017/001 Version 1.

In summary, the potential water quality effects of the stormwater and increased impervious surfaces from the Project on freshwater aquatic habitats will be mitigated appropriately by:

● Attenuating stormwater flows and not exacerbating existing flooding issues through efficient road drainage, preservation of existing overland flow paths, and runoff volume detention by wetlands. ● Minimising the effects of stormwater discharges on the receiving environments from newly formed impermeable surface by constructing treatment wetlands. ● Ensuring stream outfalls and culverts do not cause erosion and are designed using green infrastructure principles.

As a result of the stormwater mechanisms proposed, the adverse effects of stormwater runoff on freshwater aquatic habitats are considered to be minor.

3.3.7 Indirect Effects In the absence of adequate mitigation, there is the potential for moderate indirect adverse effects to occur, through sedimentation from works, on the aquatic habitat of the watercourses within the works designation, as well as the downstream catchment. This could include effects such as changes to water chemistry, reduction in clarity, temperature changes, increased turbidity, reduction in primary productivity, reduction in habitat, reduction in benthic densities and alterations to benthic communities, changes to fish communities, and conceivably the death of sensitive fish species. However, as discussed in the following section, with appropriate mitigation, such as sediment and erosion control, it is considered that the indirect effects of the Project on aquatic ecology will be less than minor.

3.3.8 Haul Road As part of the construction methodology a subgrade improvement layer (Haul Road) will be constructed immediately behind the advancing earthworks excavations. The Haul Road footprint will be confined to within the road corridor footprint. Additionally, the Haul Road will also extend across Watercourse F via a temporary staging bridge, but no instream works are proposed. Accordingly, it is considered that the construction of the Haul Road will have no additional adverse aquatic ecological effects.

3.3.9 Staged Approach It is understood that the majority of vegetation removal and the majority of earthworks to accommodate Stage 2, would be undertaken in Stage 1. A temporary construction bridge is not required for Stage 2 and the Stage 2 bridge will not require instream works. Therefore, the staged approach described above would not have any additional adverse effects on the freshwater ecology.

3.4 Mitigation Measures and Recommendations This assessment follows a multi criteria analysis of a long list of eight options (Bioresearches 2017a) and an assessment of ecological constraints associated with four short list options (Bioresearches 2017b). The long list and short list assessments identified ecological habitats of greatest value, which consequently were largely avoided through the planning process.

The bridge (including the Haul Road bridge) across Watercourse F will span the entire watercourse in order to avoid reclamation, culverting or instream works. Piles associated with the bridges should be positioned as to not impede flood flows or reduce bank stability. It is recommended that the works for the bridge take place during the summer (drier) months and be timed to avoid any predicted heavy rain in order to reduce the risk of adverse effects through sedimentation. Any works would be undertaken in accordance with a sediment control plan that would address timing to minimise potential adverse effects.

Adverse impacts on Watercourse A have also been avoided, following a redesign of the detention pond/wetland 1D-3.

Adverse impacts on the ephemeral Watercourse B cannot be avoided due to the road alignment. Adverse effects have been minimised by the use of a conveyance channel that redirects any overland flows from the upper catchment of Watercourse B to Watercourse A. While the Project proposes to reclaim Watercourse B and its associated wetland, the watercourse lacks current and potential fish habitat, has low restoration potential and is ephemeral. Additionally, much of the hydrologic function of the watercourse will be retained through redirecting overland flows. As such, the direct adverse effects of the Project on Watercourse B were considered to be minor and not significant. Accordingly, no mitigation or compensation is recommended.

Adverse impacts on Watercourses C and D cannot be avoided due to the road alignment. However, the headwater seepage associated with Watercourse C has been avoided and therefore no direct effects are anticipated. Adverse effects on Watercourses C and D have further been minimised by use of culverts rather than reclamation. The adverse effects, associated with the culverting of Watercourses C and D, are considered minor and not significant. Accordingly, no mitigation or compensation is recommended.

The adverse effects associated with the culverting of Watercourse E were considered moderate. Due to constraints of the Project and the limited amount of useable offset sites within the corridor, offset compensation will need to occur off-site. AT are exploring a range of off-site mitigation options. One potential option that AT are looking at is to formalise an agreement, with the Healthy Waters Department of Auckland Council, that outlines that appropriate compensation will occur for the culverting of Watercourse E in accordance with Section E3.3 (4) of the AUP.

Prior to stream works commencing a Native Fish Relocation Plan (NFRP) should be prepared and submitted to Auckland Council for approval.

Watercourses or part thereof that are within the Project Area but outside of the proposed road alignment should be avoided and protected during works. This can be achieved in accordance with a construction management plan which would be conditioned.

All watercourses within the site, or downstream of the site, will need to be stringently protected from sedimentation from works. The methodology for this protection should be outlined in an Erosion and Sediment Control Plan (ESCP) and submitted to Auckland Council for approval prior to earthworks commencing.

Provided that the above recommendations and mitigation measures are adhered to, the environmental effects on the aquatic ecology of the Project would be appropriately mitigated for, and any adverse effects would be largely avoided, so as to be no more than minor.

4. SUMMARY

The following table (Table 6) summarises the ecological areas assessed, the Project area’s existing ecological values, the potential adverse effects of the Project on those values, proposed mitigation measures and the potential adverse effects with mitigation.

As identified in Section 2.3.1 of this assessment and within the Project’s Assessment of Environmental Effects, all vegetation beyond the 10 m riparian margins within the Project area is not subject to protection under the AUP(OP) given its location within the FUZ. AT will seek to undertake mitigation measures and recommendations for the removal of vegetation within riparian margins.

Table 6: Summary of potential adverse ecological effects for the Project. Current Potential Adverse Potential Adverse Ecological Receiving Environment Ecological Effects without Proposed Mitigation Effects with Discipline Value Mitigation Mitigation Riparian Vegetation High High Replacement planting (1:1) Minor Anthropogenic Forests Low-Moderate Moderate None. Removal is considered a permitted activity Moderate Exotic and Native Scrub Low Minor None. Removal is considered a permitted activity Minor (outside riparian) Native WF11 Forest None. Removal considered is a permitted activity. High High High (outside riparian) Maintain vegetation below bridge (excepting canopy Edge Effects Low Minor Minor trees) Maintain vegetation below bridge (excepting canopy Shading Moderate Moderate Minor trees) Maintain vegetation below bridge (excepting canopy Loss of connectivity Low-moderate Minor Less than minor trees) High Kauri Dieback High Adherence to a Kauri Dieback Operating Procedure Less than Minor (Uninfected) None, but would benefit from lizard habitat Invertebrates Low Minor Less than Minor enhancement Terrestrial Frogs Very Low Negligible N/A Negligible Fauna Preparation of a Lizard Management Plan; pest Lizards Low-Moderate Moderate management and habitat enhancement Less than Minor

Clearance of habitats outside the main bird breeding Birds Low-Moderate Moderate season or a pre-clearance nesting native bird survey Less than Minor Pest Management and habitat enhancement Bats Low High Pre-clearance bat surveys Negligible Watercourse A Low Less than Minor Avoidance Less than Minor Watercourse B Very Low Minor Culverting and stormwater mechanisms Minor Watercourse C Very Low Minor Culverting and stormwater mechanisms Minor Watercourse D Very Low Minor Culverting and stormwater mechanisms Minor Culverting and stormwater mechanisms. Offset Compensation for any permanent degradation or Freshwater Watercourse E Moderate Moderate Minor loss of aquatic habitat in accordance with Section Habitat E3.3(4) of the AUP(OP) Watercourse F High Less than Minor Avoidance Less than Minor Indirect Effects Preparation of an Erosion and Sediment Control (Sedimentation, N/A Moderate Plan. Less than Minor Erosion and Reduction Stormwater mechanisms. in Filtration) *ECR = Environmental Compensation Ratio

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Northland Regional Council (2016) Consolidated Regional Water and Soil Plan as at 2014 – updated 2016. Northland Regional Council. https://www.nrc.govt.nz/resources/?url=/Resource-Library- Summary/Plans-and-Policies/Regional-plans/Regional-Water-and-Soil-Plan/

O’Donnell, C. F. J.; Sedgeley, J. A. (1994). An automatic monitoring system for recording bat activity. In: The Department of Conservation Technical Series. Wellington, NZ. The Department of Conservation.

O’Donnell, C. F. J.; Sedgeley, J. A. (2001). Guidelines for surveying and monitoring long-tailed bat populations using line transects. DOC Science Internal Series 12. Department of Conservation, Wellington, 20 p

O’Donnell, C.F.J. (2001). Advances in New Zealand mammalogy 1990-2000: Long-tailed bat. Journal of the Royal Society of New Zealand 31: 43-57.

O’Donnell, C. F. J; Christie, J.E., Lloyd, B., Parsons, S., Hitchmough, R.A. (2013). Conservation status of New Zealand bats, 2012. New Zealand Threat Classification Series 6. Department of Conservation, Wellington 8 p.

Ogden, J., Wardle, G. M., & Ahmed, M. (1987). Population dynamics of the emergent conifer Agathis australis (D. Don) Lindl. (Kauri) in New Zealand II. Seedling population sizes and gap-phase regeneration. New Zealand Journal of Botany, 25(2), 231–242. https://doi.org/10.1080/0028825X.1987.10410069

Parkyn, S. M., Davies-Colley, R. J., Halliday, N. J., Costley, K. J., Croker, G. F., (2003). Planted Riparian Buffer Zones in New Zealand: Do They Live Up to Expectations? Society of Ecological Restoration International 11(4):436-447.

Parsons, S., Szewczak, J. (2009). Detecting, recording and analyzing the vocalisations of bats. Ecological and Behavioral Methods for the Study of Bats [2nd. Ed.], 91-111

Trewick, S., Hitchmough, R, Rolfe, J., Stringer, I. (2018). Conservation status of New Zealand Onychophora (‘peripatus’ or velvet worm), 2018. New Zealand Threat Classification Series 26. Department of Conservation, Wellington 3 p.

Pawson, S. M., Ecroyd, C. E., Seaton, R., Shaw, W. B., & Brockerhoff, E. G. (2010). New Zealand’s exotic plantation forests as habitats for threatened indigenous species. New Zealand Journal of Ecology, 34(3), 342–355.

Rose, A. (2012). Introduction to vegetation monitoring. Wellington.

Ryder, J. M., Waipara, N. W., & Burns, B. R. (2016). What is the host range of Phytophthora agathidicida in New Zealand? New Zealand Plant Protection. University of Auckland.

Scott, P., & Williams, N. (2014). Phytophthora diseases in New Zealand forests. NZ Journal of Forestry, 59(2), 14–21.

Singers, N. J. D., Osborne, B., Lovegrove, T., Jamieson, A., Boow, J., Sawyer, J., Hill, K., Andrews, J., Hill, S.,Webb, C. (2017). Indigenous terrestrial and wetland ecosystems of Auckland. Auckland.

Singers, N. J. D., & Rogers, G. M. (2014). A classification of New Zealand’s terrestrial ecosystems. Science for Conservation 325. Wellington, N.Z. Retrieved from http://www.doc.govt.nz/documents/science-and-technical/sfc325entire.pdf

Singh, J., Curran-Cournane, F., Waipara, N., Schwendenmann, L., & Lear, G. (2017). Comparison of methods used to detect the organism responsible for kauri dieback, Phytophthora agathidicida, from soil samples.

Young, A., & Mitchell, N. (1994). Microclimate and vegetation edge effects in a fragmented podocarp- broadleaf forest in New Zealand. Biological Conservation, 67(1), 63–72. https://doi.org/10.1016/0006-3207(94)90010-8

5. APPENDICES

Appendix I ANZECC Interim Sediment Quality Guidelines

Table 3.5.1 Recommended sediment quality guidelines a ISQG- ISQG-Low Contaminant High (Trigger

value) METALS (mg/kg dry wt) Antimony 2 25 Cadmium 1.5 10 Chromium 80 370 Copper 65 270 Lead 50 220 Mercury 0.15 1 Nickel 21 52 Silver 1 3.7 Zinc 200 410 METALLOIDS (mg/kg dry wt) Arsenic 20 70 ORGANOMETALLICS Tributyltin (µg Sn/kg dry 5 70 wt.) ORGANICS (µg/kg dry wt) b Acenaphthene 16 500 Acenaphthalene 44 640 Anthracene 85 1100 Fluorene 19 540 Naphthalene 160 2100 Phenanthrene 240 1500 Low Molecular Weight PAHs 552 3160 c Benzo(a)anthracene 261 1600 Benzo(a)pyrene 430 1600 Dibenzo(a,h)anthracene 63 260 Chrysene 384 2800 Fluoranthene 600 5100 Pyrene 665 2600 High Molecular Weight 1700 9600 PAHs c Total PAHs 4000 45000 Total DDT 1.6 46 p.p’-DDE 2.2 27 o,p’- + p,p’-DDD 2 20 Chlordane 0.5 6 Dieldrin 0.02 8 Endrin 0.02 8 Lindane 0.32 1 Total PCBs 23 – a) Primarily adapted from Long et al. (1995); b) Normalised to 1% organic carbon;

c) Low molecular weight PAHs are the sum of concentrations of acenaphthene, acenaphthalene, anthracene, fluorene, 2- methylnaphthalene, naphthalene and phenanthrene; high molecular weight PAHs are the sum of concentrations of benzo(a)anthracene, benzo(a)pyrene, chrysene, dibenzo(a,h)anthracene, fluoranthene and pyrene

Appendix II SEV Summary Table

Appendix III Macroinvertebrate Data

Appendix IV Freshwater Fish Database Forms

Appendix VI Intermittent Impact SEV Summary

6. Appendix VII Intermittent SEV Assumption Table

Potential SEV Score – Assumptions Impact Stream

Function Category Variable Assumption

Hydraulic Vchann Reduction to 100% channel straightened Reduction to 100% banks and beds lined with impermeable Vlining surfaces Vpipe No change expected Vbank Changed to 100% no hydrological connectivity to floodplain Vrough Reduction to 100% artificial surfaces Vbarr No change expected Vchanshape No data entry required – populated from other variables Biogeochemical Vshade Increase to 100% ‘very high shading’ Vdod No change expected Vveloc No change as culverts will be embedded Vdepth No change expected as already shallow and fairly uniform Vripar No change expected as currently no trees or bushes present Vdecid No change expected Vmacro Reduction to ‘0’ for all macrophytes Vretain No data entry required – populated from other variables No change expected with substrate, but a reduction to ‘0’ for Vsurf organic material Uplift as livestock will be removed and swales will increase Vripfilt filtration Habitat provision Vgalspwn Reduction to ‘0m’ length of near flat slope. Vgalqual No change expected as spawning habitat already unsuitable No data entry required – populated from other variables. Vgobspawn Changed with increase in wood from Vsurf Reduction in ‘hydrologic heterogeneity’ and an increase in Vphyshab ‘channel shade’ Vwatqual No change expected Vimperv No change expected Biodiversity Vfish No change expected Vmci No change assumed Vept No data entry required – populated from other variables No data entry required – populated from other variables Vripcond Changed to reflect change in riparian margins. Vinvert No change expected Vripconn Changed to 100% no hydrological connectivity to riparian zone

Appendix VIII Kauri Dieback Standard Operating Procedure

KAURI DIEBACK OPERATING PROCEDURE:

TUHONOHONO KI TAI / MATAKANA LINK PROJECT

PREPARED BY: SARAH KILLICK BIORESEARCHES GROUP LTD 68 BEACH ROAD, AUCKLAND [email protected]

FOR: NEW ZEALAND TRANSPORT AUTHORITY (NZTA)

DATE: OCTOBER 25TH, 2017

REFERENCE: BIORESEARCHES (2017). KAURI DIEBACK OPERATING PROCEDURE: MATAKANA LINK PROJECT.

INTRODUCTION

Kauri dieback is a disease cause by a fungus-like organism, Phytophthora agathidicida (PTA). Unlike fungi, PTA is made of cellulose, rather than chitin, and forms a motile ‘tail’ which allows for movement. This motility increases the potential movement and spread risk of Phytophthora species. Although there are species of Phytophthora native to New Zealand, these have not been found to cause significant disease within New Zealand forests, despite having serious implications internationally (Scott & Williams, 2014). Conversely, PTA has been identified as a serious threat to kauri forests in New Zealand, and has been directly associated with the disease and death of kauri (Agathis australis). Kauri do not produce cones until the trees are 15 – 50 years old, depending on the tree, and cones produced by trees under 20 years old are often infertile (Ogden et al., 1987). Although kauri themselves are not a threatened species, this slow maturation process and the extent of historical logging has placed kauri forests as threatened under the IUCN threat classification system (Singers et al., 2017).

Infection of a kauri with PTA causes damage to the vascular tissues, preventing the tree from accessing the water and nutrients that it requires. Infected individuals may display symptoms of stress, including leaf yellowing and loss, branch loss, and eventually, death. There is no known cure for PTA, although there has been some success with extending tree life post-infection by injecting phosphorus directly into the tree trunk (Horner et al., 2015). Because of the high risk and cost of PTA to kauri and potentially other species across New Zealand, it is extremely important to minimize risk of spread.

This Operating Procedure has been written specifically for the Matakana Link Project (‘Project’) site in Rodney, Auckland, and has been adapted from Auckland Council’s Standard Operating Procedures (2017) and a recent review of PTA detection methods (Singh et al., 2017). The Project includes the construction of a highway, which is proposed to bisect a kauri forest. PTA infection has not yet been identified on site, however a nearby forest (c. 6.5 km) has confirmed PTA presence (www.kauridieback.co.nz). Although the proposed road design will result in the loss of kauri forest, it is of critical importance to limit the loss of kauri forests wherever possible by ensuring that PTA, if present, is not spread into healthy forests.

PTA is an unwanted organism under the Biosecurity Act 1993. In accordance with section 52 of

that act, no person shall knowingly communicate, cause to be communicated, release, cause to be released, or otherwise spread the organism.

IDENTIFICATION OF PTA-INFECTION

Symptoms of Infection

Figure 17: Signs of PTA infection include gummosis (left, photo credit Zoe Lyle), and branch dieback and eventual tree death (right, kauridieback.co.nz)

● Foliage yellowing or loss ● Branch dieback or loss ● Excessive exudation of gum (gummosis) on lower trunk ● Tree death. A lack of symptoms is not evidence of non-infection. Infected individuals may take a prolonged period to develop symptoms, and asymptomatic hosts that are not directly affected may still host the pathogen and spread it to other individuals (known as ‘silent hosts’). Data from preliminary pathogenicity trials strongly suggest other species (including tanekaha (Phyllocladus trichomanoides)) are also susceptible to PTA (Ryder, Waipara, & Burns, 2016). Although further research in this area is required, the precautionary principle should be applied and all vegetation should be assumed susceptible unless proven otherwise. Therefore, if any of the above symptoms are noticed in any species on site, follow through with soil testing and, if PTA is suspected, notify the Auckland Council. Any positive result from PTA testing must be reported to MPI immediately.

Soil Testing

To sample the soil for PTA testing, find a site 1 m away from the kauri trunk, on the uphill side. Using a clean metal soil corer, collect 1 kg of soil, and place in a sealable plastic bag. In a separate bag, place a 50 ml bottle of frozen water. Seal the bag containing the water bottle, and wrap the bag around the bottle several times to provide temperature protection. Place the wrapped bottle inside of the soil bag, and then place the sealed soil bag into a box cooler. Keep the cooler out of the sun as much as possible, and courier to Scion or another approved testing facility for testing immediately. Do not take samples at the end of the week or before a long weekend, as the samples may not be able to be processed before sample deterioration.

The most common form of soil testing is the baiting method, where the soil samples are dried fully and then moistened with distilled water to encourage zoospore production. The samples are then flooded, and then a bait (such as lupin radicals) are inserted. From the bait, the Phytophthora must be isolated and grown on a specific media. Because this process relies upon the colonization and growth of the organism, testing takes approximately 20 days. Recent research has also found that this method can provide an increased risk of a false-negative result, where PTA is present in soils but undetected, when compared to qPCR genetic analysis. Therefore, where possible, qPCR testing should be utilized.

PTA testing should be undertaken on site for preliminary testing prior to works commencing; following this, if PTA is suspected (i.e. kauri are presenting with PTA symptoms), Auckland Council should be notified immediately.

Notification

Phytophthora agathidicida is an Unwanted Organism under the Biosecurity Act 1993. You must notify Auckland Council and MPI immediately if PTA is found on or around the project site. Instructions given from the Auckland Council and/or MPI must be complied with by all personnel at all times.

SANITATION AND SPREAD PREVENTION

Sterigene

PTA spores can be removed by scrubbing thoroughly with warm water alone providing the equipment is allowed to dry completely afterward; however, the use of Sterigene (formerly known as Trigene) is preferred to more thoroughly disinfect shoes and equipment. Sterigene cannot be used to kill spores within soil.

Sterigene is purchased as a concentrate, and should be made up into a 2% solution. Whilst the concentrate has a shelf life of 3 years, the solution is only effective for six months, after which fresh solution will be required. Expired Sterigene can be returned to an Auckland Council or Department of Conservation office for disposal, or used as a general detergent (for non-PTA purposes). If necessary, it may be discarded on areas of lawn or gravel, but this should not occur during wet weather.

General Works

Works and vehicle movement within and in the areas immediately surrounding forest containing kauri should be avoided wherever practicable. Where not practicable, avoid undertaking works in wet weather where there is an increased risk of zoospore production and movement. If PTA is suspected, the Auckland Council should be notified, and works in the affected areas ceased until the Council has provided clearance for works re-commencement.

Footwear and Equipment

Upon entering and exiting the kauri forest, each person must scrub the soles of their footwear with a dry brush to loosen and remove soil, and then spray with a 2% solution of Sterigene. In addition, footwear should be re-brushed and sprayed when moving between areas of kauri, within the site.

Equipment that may come into contact with plant material or soil should also be sanitised upon entry to and exit from the site using the brush and Sterigene spray method. Equipment should be allowed to dry for at least 2 minutes, but preferably until completely dry, before transportation.

To assist with this, all on-site vehicles should hold a personal phytosanitary kit, including a 500ml spray bottle of 2% Sterigene solution and a scrubbing brush in a sealed plastic bag. At all site entries / sign in points, a scrubbing bush, 4 L jerry can of 2% Sterigene solution and a 1 L spray bottle of the Sterigene solution shall be kept and maintained in a suitable container. Signage instructing all visitors and workers passing this point to sanitize footwear and equipment that has or may come into contact with soil or vegetation should be visible at all times.

Vehicles and Heavy Equipment

Where possible, vehicles and heavy machinery should remain on-site for the duration of the project to limit spread risk. Operators are responsible for ensuring machinery and vehicles are free of mud and soil on tyres, mud flaps, body, and underbody when entering an area containing kauri and when moving from one area of kauri to another. Interior mats can also be a point of transfer, and should be cleaned regularly.

In addition to the personal Sterigene kit (Section 3.3), vehicles entering areas of kauri forest should hold tools to enable cleaning. Although these will vary depending on the vehicle, cleaning tools generally include scrubbing brushes and/or brooms to remove soil and plant material from the vehicles’ exterior, a steel rod for dislodging clumps of soil, and equipment for applying disinfectant.

Wash-down sites should be provided, and positioned on a concrete or gravel area with good drainage. After mud, soil, and vegetation has been removed by brush and/or rod, the vehicle should be sterilised with a 2% Sterigene solution. The vehicle should be as clean as possible before the Sterigene is applied to allow thoroughly decontamination. After the vehicle is cleaned, allow to dry for 1 – 10 minutes, and wash and sterilise tools (brushes and rods) used for vehicle cleaning. Do not allow water or Sterigene solution to pool on ground. For smaller vehicles, it is sufficient to dry brush of all visible mud, and then take the vehicle through a commercial car wash. Always undertake a final visual inspection of the vehicles and machinery to ensure there is no remaining soil, mud, or plant material before the vehicle is moved.

Felled Tree Disposal

Kauri and other native trees should be protected from felling wherever practicable. Where not practicable, the felled trees must not be disposed of in the remaining forest as doing so may spread PTA from potentially infected sites to the retained forested areas. Instead, all plant matter should be disposed of at a facility approved by the National Kauri Dieback Programme. Currently, the only

Auckland facility approved for receiving PTA-infected organic material is EnviroWaste Hampton Downs (136 Hampton Downs Road, Te Kauwhata). EnviroWaste will need to be provided with at least 24 hours’ notice to accept site waste, which can be done by calling (09) 622-8829. Vehicles used for transporting organic matter need to be securely covered as to prevent the release of potentially infected material en route. The vehicle should be thoroughly sanitized as per the methods outlined in Section 3.3 above.

Soil Movement

No soil or organic matter from the project site shall be moved into the remaining forested areas. Current testing methodologies have been found to under-report the presence of PTA (Singh et al. 2017). This means that a PTA-negative result should be treated as a non-positive, rather than a negative. At all times, the precautionary approach should be taken, and the soil within the forested area of the project shall be treated as potentially contaminated.

If any soil material cannot be left in situ, then it must be disposed off-site in a landfill approved by the National Kauri Dieback Programme. Currently, the two approved facilities within Auckland are:

● Ridge Road Quarries (for soil only), in Bombay; and ● EnviroWaste, Hampton Downs. For transportation off-site, the soil must be kept in a fully covered truck trailer, to prevent the dropping of contaminated soil during the commute. The truck should be sanitized thoroughly, as per Section 3.3 above.

SUMMARY AND RECOMMENDATIONS

The inclusion of a section of kauri podocarp broadleaved forest in the proposed Matakana Link Project increases risk of spreading the unwanted organism, Phytophthora agathidicida (PTA). Although PTA has not been recorded within the affected forest, there is a confirmed PTA-infected kauri forest nearby, increasing the need for vigilance. PTA is a pathogen spread by movement of soil, water, and vegetation. Once a kauri is infected with PTA, it is almost always fatal, and there is currently no known cure. Although kauri are not a threatened species, the ecosystem present (kauri podocarp broadleaved forest) is much reduced from its historic extent, and is classified as Endangered (Singers et al. 2017).

PTA is an unwanted organism under the Biosecurity Act 1993. In accordance with this Act, it is illegal to spread the organism. The best course of action is to avoid works within kauri forest. If this is not practicable, measures must be undertaken to ensure that PTA, if present, is not spread. Vehicles, machinery, and footwear should be sterilised before entering and exiting the site, as well as between areas of kauri. Soil and organic matter, if removed, must be disposed of at approved disposal facilities. At no point should soil, plant material, or any organic matter be disposed of in the retained forest. Kauri on site, and in the surrounding retained forest should be monitored for symptoms of infection. If PTA is suspected, the Auckland Council must be notified, and works in the area surrounding kauri should be halted until further notice. Any positive PTA test must also result in immediate MPI notification.

REFERENCES

Auckland Council. (2017). Standard Operating Procedures for Kauri Dieback (draft). Bioresearches Ltd. (2017). Kauri Dieback Operating Procedure. Horner, I. J., Hough, E. G., & Horner, M. B. (2015). Forest efficacy trials on phospite for control of kauri dieback. In New Zealand Plant Protection2 (pp. 7–12). Ibáñez, I., Katz, D. S. W., Peltier, D., Wolf, S. M., & Connor Barrie, B. T. (2014). Assessing the integrated effects of landscape fragmentation on plants and plant communities: The challenge of multiprocess-multiresponse dynamics. Journal of Ecology, 102(4), 882–895. https://doi.org/10.1111/1365-2745.12223 Ogden, J., Wardle, G. M., & Ahmed, M. (1987). Population dynamics of the emergent conifer Agathis australis (D. Don) Lindl. (Kauri) in New Zealand II. Seedling population sizes and gap-phase regeneration. New Zealand Journal of Botany, 25(2), 231–242. https://doi.org/10.1080/0028825X.1987.10410069 Pawson, S. M., Ecroyd, C. E., Seaton, R., Shaw, W. B., & Brockerhoff, E. G. (2010). New Zealand’s exotic plantation forests as habitats for threatened indigenous species. New Zealand Journal of Ecology, 34(3), 342–355. Rose, A. (2012). Introduction to vegetation monitoring. Wellington. Ryder, J. M., Waipara, N. W., & Burns, B. R. (2016). What is the host range of Phytophthora agathidicida in New Zealand? New Zealand Plant Protection. University of Auckland. Scott, P., & Williams, N. (2014). Phytophthora diseases in New Zealand forests. NZ Journal of Forestry, 59(2), 14–21. Singers, N. J. D., Osborne, B., Lovegrove, T., Jamieson, A., Boow, J., Sawyer, J., … Webb, C. (2017). Indigenous terrestrial and wetland ecosystems of Auckland. Auckland. Singers, N. J. D., & Rogers, G. M. (2014). A classification of New Zealand’s terrestrial ecosystems. Science for Conservation 325. Wellington, N.Z. Retrieved from http://www.doc.govt.nz/documents/science-and-technical/sfc325entire.pdf Singh, J., Curran-Cournane, F., Waipara, N., Schwendenmann, L., & Lear, G. (2017). Comparison of methods used to detect the organism responsible for kauri dieback, Phytophthora agathidicida, from soil samples. Young, A., & Mitchell, N. (1994). Microclimate and vegetation edge effects in a fragmented podocarp- broadleaf forest in New Zealand. Biological Conservation, 67(1), 63–72. https://doi.org/10.1016/0006-3207(94)90010-8

THE IMAGES USED ON THE FLIP SIDE OF THIS PAGE WERERETRIEVED FROM, OR ALTERED FROM, THOSE FOUND ON THE KAURI DIEBACK PROGRAMME’S WEBSITE

(www.kauridieback.co.nz). AS SUCH, THE IMAGES, OR WHERE ALTERED PARTS OF

IMAGES, BELONG THE INTELLECTUAL PROPERTY OF KEEP KAURI STANDING (2016).