UNDER THE Resource Management Act 1991

Transcription

1 BEFORE HEARING COMMISSIONERS AT CHRISTCHURCH UNDER THE Resource Management Act 1991 IN THE MATTER OF Applications by Lyttelton Port Company Limited for consents to reclaim land and construct a wharf in Te Awaparahi Bay, Lyttelton Harbour STATEMENT OF EVIDENCE OF ANDREW STEPHEN BAXTER ON BEHALF OF DIRECTOR-GENERAL OF CONSERVATION REGARDING MARINE MAMMALS 11 September 2017 Department of Conservation Private Bag 4715, Christchurch 8011 Solicitor: Susan Newell Tel: ; snewell@doc.govt.nz

2 Page 2 INTRODUCTION 1. My full name is Andrew Stephen Baxter. I am a Technical Advisor (Marine) in the Marine Species and Threats team, a science and technical team in the Department of Conservation s Biodiversity Group. I am based in the Department s Nelson office. 2. I graduated from the University of Canterbury in 1981 with a BSc with First Class Honours in Zoology. 3. I have 35 years experience in coastal and marine science and management, specialising in marine ecology including marine mammals. In 1982 and 1983 I was employed by the Taranaki Catchment Commission as a marine biologist. From early 1984 until October 1987 I worked as a fisheries management scientist for MAF-Fisheries based in Wellington. Since October 1987 I have been employed as a marine ecologist in various roles by the Department of Conservation, all in Nelson. 4. I present this evidence as a marine ecologist with a broad range of experience in coastal and marine resource management. Marine mammal management is a significant area of my work and has included: a) Development of the Marine Mammals Protection Regulations 1990 and 1992; b) Assessing applications for marine mammal watching permits; c) Investigation and implementation of moratoria on new commercial marine mammal watching permits; d) Commissioning and assessing research and scientific advice on the impacts of commercial marine mammal watching operations; e) Assessing applications to take marine mammals (as defined under the Marine Mammals Protection Act 1978) including permits to conduct scientific research; f) Marine mammal strandings; g) Working with the Ministry for Primary Industries on fisheries by-catch issues; h) Providing specialist input to consent and planning processes under the Resource Management Act and the Exclusive Economic Zone and Continental Shelf (Environmental Effects) Act; i) Input to the Code of Conduct for Minimising Acoustic Disturbance to Marine Mammals from Seismic Survey Operations. 5. I have presented evidence at various hearings relating to the impacts of marine developments on marine mammals including most recently:

3 Page 3 a) Trans Tasman Resources Ltd seabed mining (first TTRL application; EPA Board of Enquiry); b) New Zealand King Salmon application to establish nine new salmon farms in the Marlborough Sounds (EPA Board of Enquiry); c) Admiralty Bay Consortium marine farming (Environment Court). 6. I have authored or co-authored presentations on marine mammal management at two national conferences and eight international conferences/workshops. I coauthored a chapter entitled Human interactions with dusky dolphins: a management perspective (Childerhouse and Baxter 2010) in a book published in 2010 on the ecology and management of dusky dolphins. 7. I confirm that I have read and agree to comply with the Code of Conduct for Expert Witnesses (set out in the Environment Court s Consolidated Practice Note, 2011). This evidence is within my area of expertise, except where I state that I am relying on what I have been told by another person. I have not omitted to consider material facts known to me that might alter or detract from the opinions that I express. SCOPE OF EVIDENCE 8. Lyttelton Port Company Limited (LPC) proposes to build a new wharf involving ~350 piles to be driven 100 m into the sea floor. I have been asked to give evidence on the effects of noise from pile driving on marine mammals. 9. I have visited Lyttelton Harbour on several occasions dating back as far as 1981 when I undertook field work there for my Honours thesis. I have not visited the area recently and not in relation to this LPC application. 10. I have read the evidence or Dr Deanna Clement (marine mammals) and Mr Darran Humpheson (underwater noise modelling). In my opinion, both sets of evidence address the various matters that are relevant for consideration by the hearing committee in terms of effects (including noise) on marine mammals. I largely concur with these witness statements. 11. Other relevant documentation I have read (apart from the scientific literature) includes: a) The Assessment of Environmental Effects as it relates to marine mammals. b) Brough et al. (2014): Marine Mammals and the Port Lyttelton Development. An Environmental Impact Assessment. c) Leunissen and Dawson (2017): Recommendations for managing the impact of pile driving noise on Hector s dolphins in Lyttelton Harbour.

4 Page 4 d) Leunissen (2017): Underwater noise from pile driving and its impact on Hector s dolphins in Lyttelton Harbour, New Zealand. Submitted MSc thesis. e) Childerhouse (2017): Technical review of proposed LPC Te Awaparahi Bay reclamation project. Appendix 6 of the Section 42A Officers Report. 12. In my evidence, I focus on several key areas which I believe the hearing committee needs to be particularly mindful of when considering the effects of the proposed wharf construction. My evidence is presented under the following general headings and topics: a) Marine mammals, distribution and threat status. b) Effects of noise on marine mammals. c) Noise limits. d) Noise from proposed pile driving. e) Monitoring. f) Acoustic dampening. g) Other research and new information. h) Summary and recommendations. MARINE MAMMALS, DISTRIBUTION AND THREAT STATUS 13. New Zealand has a rich marine mammal fauna including three endemic taxa (Hector s and Maui s dolphin (two subspecies) and New Zealand sea lion). Almost half the world's cetaceans (whales, dolphins and porpoises) have been reported in our waters. 14. All marine mammals are protected species under the Marine Mammals Protection Act 1978 (MMPA). The Minister of Conservation has declared Hector s dolphin a threatened species under Section 2(3) of the MMPA. 15. The Marine Mammals Protection Regulations 1992 were established under the MMPA to regulate human encounters with marine mammals. These regulations establish a permit regime for commercial marine mammal watching operators and prescribe appropriate behaviour by commercial tourism operators and other persons operating boats or otherwise coming into contact with marine mammals. 16. The current threat classification 1 for marine mammals in New Zealand was undertaken in 2013 (Baker et al 2016). The threat categories used by Baker et al (2010) are: a) Nationally critical 1 The New Zealand threat classifications for marine mammals is to be reviewed in 2018.

5 Page 5 b) Nationally endangered c) Data deficient d) Not threatened e) Migrant f) Vagrant. 17. The International Union for Conservation of Nature (IUCN) provides a separate threat classification based on a global threat assessment. The IUCN threat classification categories ( Red List ) which apply to New Zealand marine mammals are: a) Critically endangered b) Endangered c) Vulnerable d) Data deficient e) Least concern 18. The New Zealand fur seal is not threatened and has a growing and expanding population. Banks Peninsula supports large numbers of fur seals but haul-outs and breeding colonies are well distant from Lyttelton Harbour, the closest near Little Akaloa (Derek Cox, DOC Ranger Akaroa, pers. comm.). Although individual seals will visit Lyttelton Harbour, provided adequate mitigation is incorporated with piledriving start-ups, I do not have any significant concerns for this species given their non-threatened status, current distribution at Banks Peninsula, and ability to swim with their heads above the water if need be. 19. The key cetacean taxa that I believe are most relevant for the LPC application, and their threat classifications, are listed in Table 1. Table 1. Threat classification for specified cetacean species Taxa (Species or subspecies) Hector s dolphin Cephalorhynchus hectori hectori Killer whale (orca) Orcinus orca (type A) Southern right whale Eubalaena australis Humpback whale Megaptera novaeangliae NZ threat classification; Baker et al (2010) Nationally endangered Nationally critical Nationally vulnerable Migrant IUCN threat classification (Red List) Endangered Data deficient Least concern Endangered (Oceania subpopulation)

6 Page The New Zealand threat classification system is New Zealand centric; it does not address global status. Under this system, migrant taxa such as humpback whale are those which predictably and cyclically visit New Zealand waters as part of their normal life cycle, but do not breed here. This migrant classification does not consider the threat status of these migrant taxa in their wider (beyond New Zealand) population context. In my view, for migrant species, the IUCN threat classification provides a better indication of the actual threat status of the wider population. 21. Humpback whales migrating up the east coast of the South Island are considered part of the Oceania subpopulation (Steel et al 2013), the least abundant breeding stock in the southern hemisphere (Constantine et al 2012). The Oceania subpopulation is classified as endangered in the IUCN red list. This subpopulation has shown a modest rate of recovery in recent years (Constantine et al 2012) and increasing humpback whale sightings in Cook Strait over the last decade during the Cook Strait whale survey suggest numbers passing through New Zealand waters are increasing. 22. Southern right whales are classified as nationally vulnerable in New Zealand waters under the New Zealand threat classification system but least concern by the IUCN due to their healthier population levels elsewhere in the southern hemisphere. Southern Right Whale has demonstrated a strong recovering trend in Sub-Antarctic waters but numbers around the New Zealand mainland remain low and sightings are relatively infrequent. 23. Killer whale (orca; Type A) has three separate inshore groups and is classified as nationally critical owing to its very small total population size (117; 95% CI ; Visser 2000). 24. Hector s dolphin is classified as nationally endangered. Recent aerial surveys of Hector s dolphins around the South Island indicate that the total overall population size is close to 15,000 individuals (MacKenzie and Clement 2014, 2016), higher than the previous estimate of over 7,000 animals. The east coast South Island Population is estimated to be near 9,000 dolphins (MacKenzie and Clement 2014). 25. Sightings and incidents involving killer whale, humpback whale and southern right whale are depicted in Figure 1. These data include all records on the DOC database; these particular sightings/incidents date back to The database is normally a few months out of date as there is typically a lag between receiving reports and inputting the data.

7 Page 7 Figure 1. Sightings and incidents (e.g. strandings) of selected species at Banks Peninsula. Source: Department of Conservation data base; extract dated 1 Sept In interpreting these data, especially the sightings data, it is important to be cognizant of several important caveats: a) The data are from a variety of sources; b) Details (e.g. species identification, precise location) cannot always be verified and may be estimated; c) Most data have not been collected or recorded systematically nor consistently; d) Sightings records represent a combination of species presence, observer presence (usually where there is greatest boating and tourism activity), and whether people record and forward the details to DOC; e) Recorded sightings are influenced by public perception of importance. 27. Therefore, these data are only indicative and interpretation can only be very general in nature. Importantly, the absence of sightings records for a species at any given location is not proof this species does not occur there. 28. With these important caveats in mind, killer whale, humpback whale and southern right whale have been reported all around Banks Peninsula. 29. There are two records of southern right whale at the entrance to Lyttelton Harbour and given the very coastal habits of this species, I see no reason why southern right whales would not occasionally venture further into the harbour.

8 Page Although I would not expect migrating humpback whales to enter the harbour, with increasing numbers in New Zealand waters this possibility will increase, especially with respect to juvenile humpbacks. A juvenile humpback whale remained for several days in inner Queen Charlotte Sound in July Killer whale records show they occur all around Banks Peninsula and, given this species is known to hunt stingrays in shallow waters in New Zealand, I would not be surprised to hear of them venturing into Lyttelton Harbour at least occasionally. Killer whales sometimes strand; e.g. when hunting in shallow waters. 32. More information is available for sightings of Hector s dolphin around Banks Peninsula. Brough et al. (2014) mapped the distribution of Hector s dolphin for sightings near Lyttelton Harbour between 1991 and 2014, which I have reproduced below as Figures 2, 3 and Hector s dolphins (including groups with calves) utilise much of Lyttelton Harbour but mostly from the port area out to and beyond the heads. There is also a clear seasonal pattern, reflecting general season trends for this species, with more sightings over summer, fewer in spring and autumn, and least in winter. These temporal patterns offer opportunities for mitigating adverse effects through seasonal staging of development (I address this matter again later in my evidence). Figure 2. Distribution of all Hector s dolphin sightings near Lyttelton Harbour Source Brough et al

9 Page 9 Figure 3. Distribution of Hector s dolphin sightings with calves near Lyttelton Harbour Source Brough et al Figure 4. Distribution of Hector s dolphin sightings (survey effort adjusted) near Lyttelton Harbour during (a) summer, (b) autumn, (c) winter and (d) spring. Source Brough et al Several aspects of the ecology of Hector s dolphins make them vulnerable to disturbance. They are a very small dolphin, are not strong or fast swimmers, and have a low reproductive potential. In addition, Hector s dolphins show high site fidelity, with relatively small home ranges compared to other dolphins (alongshore movements average around 30 km at Banks Peninsula). They are a coastal species, frequenting near-shore waters particularly over the summer months when recreational and tourism boating activity is highest. The peak in boating activity (December to February) also coincides with the calving period for this species. 35. Lyttelton Harbour is within the Banks Peninsula Marine Mammal Sanctuary (Figure 5). This sanctuary recognises the significance of the wider Banks Peninsula area for Hector s dolphin conservation and is specifically aimed at managing the effects of noise from seismic surveys (e.g. for oil and gas exploration).

10 Page While the sanctuary previously used to control set netting (alongside parallel provisions under the Fisheries Act), set netting in this area is now entirely managed under fisheries legislation. There is a total set net ban around Banks Peninsula apart from flatfish netting (using specified nets between 1 April - 30 September) in some inner harbour areas including the upper reaches of Lyttelton Harbour (Figure 6). 37. A full review of the government s Hector s dolphin threat management plan is due to commence in Figure 5. Banks Peninsula Marine Mammal Sanctuary. Inner cross-hatched area was the previous extent of the sanctuary before it was extended in Source: DOC website, 4 Sept Figure 6. Banks Peninsula set net restrictions. Source: MPI website, 4 Sept

11 Page 11 EFFECTS OF NOISE ON MARINE MAMMALS 38. Water is an excellent medium for transmitting sound. Cetaceans rely on sound for a host of important interrelated behaviours including: foraging/feeding; sensing predators and other dangers; social interactions; breeding; rearing young; and general communication. It is within this important context that the LPC application needs to be assessed. 39. There is a growing body of scientific research that has investigated the impacts of noise on marine mammals. Southall et al. (2007) was a pivotal paper in terms of synthesising the available research at the time and proposing noise exposure criteria for marine mammal injury and behaviour changes. In a more recent paper, Gomez et al. (2016) reviews the literature relating to the behavioural responses of marine mammals to noise. 40. Noise can affect cetaceans in several general ways (Figure 7) (Richardson 1995; Southall et al. 2007; Hildebrand 2012; Gomez et al. 2016): a) A marine mammal close to a very loud noise may experience permanent hearing loss (permanent threshold shift; PTS); b) Exposure to noise further away may cause a temporary threshold shift (TTS; i.e. temporary hearing loss where hearing will recover with time) depending on noise characteristics and duration. c) Within and beyond the PTS/TTS zone, cetaceans may be disturbed by noise. That disturbance may lead to changed behaviours such as increased travelling, reduced foraging, reduced resting, changed vocal behaviours, stress responses, and displacement; d) Noise may mask important sound cues throughout the PTS/TTS and behavioural response zones. For example, noise can mask the vocalisations of an approaching predator or the sounds of another threat, or interfere with echolocation or communication; e) Beyond, noise may be detected by marine mammals, but with no obvious behavioural implications. Further afield the noise becomes inaudible.

12 Page 12 Figure 7. Marine mammal responses to noise. Source: Gomez et al. (2016) 41. The effects of noise on marine mammals will depend on (Southall et al. 2007; Gomez et al. 2016): a) The noise characteristics including received levels (db), sound frequency (Hz), onset, duration, and whether the noise is pulsed (single or multiple) or continuous; b) The species characteristics. 42. In terms of species characteristics, there is reasonable agreement in the literature (see Southall et al. 2007; Gomez et al. 2016) that cetaceans can be broadly grouped into species that are: a) Low frequency (7 Hz 30 khz); baleen whales such as humpback, southern right, minke and blue whales; b) Mid frequency (150 Hz 160 khz); e.g. sperm whale, beaked whales and most dolphins (including orca); c) High frequency (200 Hz 180 khz); e.g. porpoises and Hector s dolphin. 43. These species groupings have been based on a combination of experimental research, anatomical characteristics (e.g. size, morphology), and for many species their vocalisation characteristics (the assumption being animals are likely to be most sensitive to the sound frequencies they produce). Audiograms for cetaceans are limited to a small number of species which have been held and experimented with in captivity. 44. Gomez et al. (2016) also found in their review of numerous studies that noise and species characteristics alone were not good predictors of cetacean behavioural response to noise, and that context of exposure plays a critical and complex role

13 Page 13 in modulating severity of behavioural response. In other words, bundling species into like-frequency groups alone may be too simple and other factors (e.g. age, sex, presence of calves, previous exposure, existing behavioural state, onset of noise, duration of exposure, ambient noise, depth, topography, etc.) may have significant roles to play. Thus, a cautious approach is needed when considering the effects of noise on cetaceans and possible mitigation options. NOISE LIMITS 45. There are no New Zealand standards for managing noise impacts on marine mammals apart from the Code of Conduct for Minimising Acoustic Disturbance to Marine Mammals from Seismic Survey Operations 2. The seismic code applies to all New Zealand fisheries waters, but is currently only given regulatory effect in the EEZ. It applies to seismic surveying, but not other activities involving anthropogenic noise such as pile driving. 46. The seismic code requires adherence to certain operational and monitoring procedures including soft starts and delaying or shutting down operations when specified marine mammals are within monitored zones around the acoustic source. The code requires dedicated trained observers to help ensure marine mammals are detected within these mitigation zones. For a Level 1 acoustic source (i.e. as used for oil and gas exploration), there are three mitigation zones where start up is delayed or the source shut down and not reactivated if defined species are detected: a) 1 km for species of concern ; b) 1.5 km for species of concern with a calf; c) 200 m for other marine mammal species; 47. The seismic code does not require adherence to noise thresholds during operations at sea, but there is a requirement for sound transmission loss modelling during the impact assessment process to predict sound levels within the various mitigation zones and potential impacts on species present. The code states that If sound levels are predicted to exceed either 171 db re 1 μpa2-s at distances corresponding to the relevant mitigation zones for Species of Concern or 186 db re 1 μpa2-s at 200 m, consideration will be given to either extending the radius of the mitigation zone or limiting acoustic source power accordingly. 48. In the absence of any other noise standards for marine mammal protection in New Zealand, each proposal needs to be assessed on its own merits using the best 2

14 Page 14 species- and situation-specific information available at the time. For example, in the recent decision on the Trans Tasman Resources Ltd seabed mining application in the South Taranaki Bight, the Decision Making Committee set the following noise standards: a) The overall combined noise level at 500 m shall not exceed 130 db re 1μPa RMS linear in any of the following frequency ranges: low frequency Hz, mid-frequency ,000 Hz, and high frequency >10,000 Hz; b) The overall combined noise level at a nominal depth of ten (10) m below the sea surface and 500 m from the IMV, across all frequencies shall not exceed a sound pressure level of 135 db re 1μPa RMS linear. c) The Consent Holder shall design and construct the crawler and IMV to achieve a total combined noise source level (measured in water), when operating at full production, of not more than 171 db re 1μPa RMS linear at one (1) metre. 49. These noise thresholds were set to help manage the risk of noise impacts on marine mammals, including behavioural changes. The consent conditions also require: a) testing and certification of the equipment prior to the commencement of operations; b) Soft starts during start-up procedures; c) Validation of sound modelling; d) Ongoing noise monitoring; e) Marine mammal monitoring; and f) Any observer engaged by the Consent Holder shall be a qualified observer as defined in the 2013 Department of Conservation Code of Conduct for Minimising Acoustic Disturbance to Marine Mammals from Seismic Survey Operations (or any subsequent updated Code of Conduct) 50. I support the above as a general approach for managing the adverse effects of noise on marine mammals. From my experience, the effects of noise and steps that can be taken to manage them are sufficiently well known for many of these matters to be addressed up-front as consent conditions, thus providing measurable and certain outcomes, rather than being included in a future management planning process. 51. Leunissen and Dawson (2017) and Leunisen (2017) refer to overseas studies on the impacts of pile driving noise on Harbour porpoise, notably: a) Kastelein et al. (2015): cumulative exposure resulting in TTS at a sound exposure level (SEL) of 146 db re 1μPa 2 s;

15 Page 15 b) Kastelein et al. (2013): behavioural change at a single strike SEL of 133 db re 1μPa 2 s. 52. There has been no similar experimental research on Hector s dolphins. Given the similarities between Harbour porpoise and Hector s dolphin in morphology and vocalisations, a roughly similar response by Hector s dolphins is a reasonable assumption in the circumstances. However, it is also important to recognise the limitations of the available research. The studies by Kastelein et al. (2013; 2015) involved a single, trained, captive, male porpoise in an enclosed pool, using recordings of pile driving noise. Different species, individuals and sexes may have different responses. Captive trained individuals may respond quite differently to wild animals. Responses may vary in a pool versus open natural waters where ambient noise levels will also be higher. Recordings may not capture the entire frequency bandwidth. These are totally understandable limitations in the circumstances, but may have a significant bearing in terms of the real-world response of wild Harbour porpoise (and by extension Hector s dolphin) to pile driving noise. Having said that, Kastelein et al. (2013) noted their results generally aligned with observations of wild Harbour porpoise behaviour in the vicinity of pile driving activities at sea. 53. Leunissen and Dawson (2017) adopted Kastelein et al s (2013; 2015) 146 db re 1μPa 2 s and 133 db re 1μPa 2 s sound exposure levels for TTS and behavioural responses respectively. Given the research limitations outlined in the preceding paragraph, I recommend erring on the side of caution when considering noise threshold criteria for Hector s dolphins. NOISE FROM PROPOSED PILE DRIVING 54. Pile driving is a well-known source of anthropogenic noise that can have a significant adverse effect on marine mammals including hearing loss, behavioural changes and avoidance/displacement (Richardson 1995; Southall et al. 2007). For this LPC application, I understand the piling will comprise multiple strikes (>1 second apart) over a 15-minute on/off duty cycle. 55. Leunissen and Dawson (2017) and Leunisen (2017) reported an average source SEL of 182 db re 1μPa 2 s and a maximum source SEL of 192 db re 1μPa 2 s. The proposed new wharf involves around 350 piles which I understand are significantly larger than those used for the reconstruction of Cashin Quay. Mr Humpheson has modelled sound transmission loss within the harbour using a larger assumed source level of 193 db re 1μPa at 1m to account for the larger piles (note this is a different sound metric from that used by Leunissen and Dawson (2017). Not surprisingly,

16 Page 16 Mr Humpheson s matching noise contours are significantly larger than those reported previously by Leunissen and Dawson (2017). I would expect impacts on Hector s dolphins (e.g. displacement) to be correspondingly greater than those recorded during the Cashin Quay project. 56. Leunisen (2017) also reported vibro-hammer noise was usually much louder than pile driving noise at close range. Pile driving was 10 db less than vibro noise. I have reproduced Figure A. 8 from Leunisen (2017) below (Figure 8). This being the case, it will be important to include vibro-piling noise within any definition of active pile driving. Figure 8. Pile driving and vibro noise pressure wave form. Source: Leunisen (2017) 57. Dr Clement and Mr Humpheson in their respective briefs adopt the same noise threshold criteria for Hector s dolphins as used by Leunissen and Dawson (2017), which I also support; i.e.: a) 133 db re 1μPa 2 s SEL as a limit for behavioural responses; b) 146 db re 1μPa 2 s SEL as a TTS limit; and for defining a zone where pile driving should be delayed or shut down should Hector s dolphins (or any other marine mammal) be detected. 58. Mr Humpheson s Figure 3 shows the 146 db re 1μPa 2 s SELcum contour extending out 600 from the source, and the 133 db re 1μPa 2 s SELcum contour an additional 570 metres. These are big distances and may pose a barrier for any marine mammals in the inner harbour when operations commence each day. Levels of disturbance will decrease with distance from the source and theoretically the corridor between the 146 db re 1μPa 2 s SEL contour and the Diamond Harbour shoreline may provide an escape route for cetaceans to access the outer harbour

17 Page 17 and beyond. This corridor includes a narrower 230 metre zone closer to the Diamond Harbour shore which is beyond the 133 db re 1μPa 2 s SEL contour. It will be important to monitor and maintain the effectiveness of this corridor during operations to allow for continued cetacean movements. 59. I understand there will be two piling rigs in operation, but only one will be driving piles at any one time. If the two rigs were to operate simultaneously the amount of noise entering the water at any given time would be greater. This possibility has obvious implications for noise impacts on marine mammals and I believe it is essential there is no possibility of this situation happening. I support a consent condition along these lines. 60. I also understand the operation will spread over two stages potentially several years apart. As noted earlier in my evidence, Hector s dolphins are most common within Lyttelton Harbour during the summer and to a lesser extent spring and autumn. Calving occurs mostly over summer. Few Hector's dolphins are present over winter. Because of this seasonality, I would support: a) Any effort to reduce pile driving noise during at least the peak summer period of Hector s dolphin (including calf) occurrence; b) Commencing each stage of the operation after summer to reduce the possibility of pile driving occurring over two consecutive summers (should either stage of pile driving take longer than 12 months). 61. Soft starts are proposed to gradually increase power (and therefore noise) during initial start-ups. I support this approach as theoretically it would allow marine mammals to detect and subsequently move away from the noise before the noise ramps up to full power levels. In this regard, sufficient time would be needed to allow marine mammals to move through and out of the safety mitigation zone. Given the size of this zone (~600 metres in radius) and Hector s dolphins being relatively slow swimmers, I recommend a soft start period of at least minutes. 62. The risk of hearing loss will increase with duration of exposure to the noise. Although Hector s dolphins may leave the area before significant harm occurs, how long they might also tolerate a noise due to other reasons to stay (e.g. avoidance of predators; food availability) is unknown. Thus, I would caution against assuming dolphins will always move out of harm s way. 63. Aside from the risk of hearing loss, significant Hector s dolphin behavioural changes would be expected closer than the 146 db re 1μPa 2 s SEL contour.

18 Page 18 Behavioural impacts should theoretically reduce with increasing distance out to the 133 db re 1μPa 2 s SEL contour. 64. Hector s dolphin is within the grouping of high frequency cetaceans with an estimated auditory range between 200 Hz and 180 khz. Some of the broadband noise from pile driving may, therefore, be less of a concern for this species, particularly the lower frequencies. This frequency-effect may help mitigate the effects of the piling to some degree. 65. Mr Humpheson maps frequency-weighted sound pressure level contours (SEL) in figures 4-6 of his evidence. Although it might be tempting to see the SEL contours for high frequency cetaceans as indicating pile driving will not disturb Hector s dolphin to a significant degree, I would caution against such a broad assumption. Leunissen and Dawson (2017) and Leunisen (2017) report Hector s dolphins responding negatively to pile driving noise during the reconstruction of Cashin Quay. Acoustic detections reduced at the researchers closest T-POD site as piling duration and SEL increased, which Leunissen and Dawson (2017) concluded was an indication of decreased abundance. Although reduced detection rates could also have been due, at least in part, to reduced vocalisation, detection rates increased concurrently at the mid-harbour site supporting the hypothesis that Hector s dolphins were most likely displaced by the pile driving nearer the port to the middle of the harbour. Overseas studies on Harbour porpoise also show this high frequency cetacean demonstrates strong avoidance to pile driving noise (Tougaard et al. 2009; Kastelein et al. (2013) and discussion therein; paragraph 32 of Dr Clement s evidence). Tougaard et al. (2015) also suggest Harbour porpoise is more sensitive to noise than previously reported. In addition, it is important to remember that reduced vocalisation is still a significant behavioural change for dolphins as it indicates, amongst other things, reduced levels of communication, social behaviour and foraging. 66. Although there is a low likelihood of a southern right whale, humpback whale, or killer whale being in the harbour, especially in the inner harbour, the consequences could be very high if pile driving work commences and continues if/when they are there. The inner harbour has very shallow shelving waters and there is a risk of whales panicking and stranding should they be exposed to high noise levels. I recommend pile driving be curtailed should there be any confirmed reports of these species in the harbour, especially inside from about Camp Bay.

19 Page 19 MONITORING 67. Monitoring will be needed to: a) Validate the noise transmission loss modelling. Mr Humpheson s modelled noise contours are a prediction and their accuracy should be verified before or soon after works commence; b) Periodically measure underwater noise levels to ensure continued compliance with noise conditions (e.g. at the beginning of the operation and if operating procedures change in a way that could increase noise levels); c) Search for and report on Hector s dolphins within the 146 db re 1μPa 2 s SEL mitigation zone; and d) Report on southern right whale, humpback whale, and killer whale presence in the harbour. 68. The 146 db re 1μPa 2 s SEL mitigation zone is large, much larger than the one I understand was required for reconstruction of Cashin Quay. As such, monitoring will need to be able to detect Hector s dolphins (and other marine mammals) throughout the larger zone especially during start-ups (e.g. at the beginning of the day) and following any significant break (e.g. for maintenance reasons) when the risks will be greater. Hector s dolphins can be difficult to detect; thus shore-based methods will need to be augmented with monitoring by boats and/or drones (UAV, RPAS). The latter could be programmed to fly and video pre-set transects at suitable speeds to detect dolphins. 69. Monitoring should be undertaken throughout the day to ensure there are no marine mammals within the cetacean mitigation zone. 70. Monitoring for the presence of marine mammals will only be possible during daylight hours. Thus, pile driving should be limited to daylight hours. Sufficient time will need to be allotted to allow for adequate search coverage depending on the method (e.g. boat or drone) and visibility (e.g. longer periods when visibility is poor due to fog, sun glare and sea state > Beaufort 3). Timing requirements could be set out in the piling management plan. ACOUSTIC DAMPENING 71. The Director-General s submission sought the use of effective acoustic dampening technology (e.g. bubble/air curtains) when pile driving is in operation. Bubble curtains have been trialled and used overseas with some success at reducing noise energy by up to several db (e.g. Würsig et al 2000; Lucke et al 2011). Bubble

20 Page 20 curtain technology is available commercially 3. However, there appears to have been limited uptake of this technology which I presume is due to logistical difficulties (e.g. due to depth and currents) and noise escapement via the substrate. 72. Mr Humpheson s evidence discusses the utility of bubble curtains and notes the practicality issues they have. He also mentions the possibility of using pile sleeves to reduce acoustic transmission, though appears to discount this method too. 73. This is an area that is mostly outside my expertise but given the potential for acoustic dampening technology to reduce noise levels during pile driving, I support the investigation and trialling of options. If successful, noise dampening could reduce the size of the mitigation zone and reduce monitoring costs. 74. I understand the wharf construction is not to be undertaken for many years (commencing later next decade). This delay would allow for: a) opportunities to undertake experimental trials of acoustic dampening technology well in advance of construction; and b) new technologies to become available and incorporated into the construction programme. 75. The value/need of acoustic dampening will also depend on the actual size of the mitigation zone once validated by field-based monitoring. If the mitigation zone is larger than currently predicted, then the need for additional mitigation will be greater. Conversely, if the mitigation zone is smaller, the need for additional mitigation may be reduced. 76. I support the inclusion of these matters in the proposed piling management plan, as this approach would allow for the flexibility to test and assess acoustic dampening technology and respond to new information and technologies as they come to hand. OTHER RESEARCH AND NEW INFORMATION 77. Dr Clement (paragraphs 46.6(c) and (d)) recommends further research on the response of Hector s dolphins to pile driving noise, including to test the appropriateness of the noise thresholds and the effectiveness of the escape route on the opposite coast. I agree with Dr Clement s suggestions. 78. As noted above, I understand the wharf construction is not to be undertaken for many years. This delay poses issues in terms of predicting impacts on marine mammals in the future. Numbers, distribution and behaviour of marine mammals 3

21 Page 21 may change over time. For example, fur seals may establish a colony nearby or southern right whales may become more common and start to breed around mainland New Zealand. Due to this uncertainty, the piling management plan needs to be responsive to these potential changes. SUMMARY AND RECOMENDATIONS 79. Hector s dolphin is a critical species in terms of minimising the impacts of pile driving noise on marine mammals in Lyttelton Harbour. Other species of concern are southern right whale, killer whale and possibly humpback whale. 80. Cetaceans rely on sound for important life behaviours, from communication and social interactions to sensing predators/hazards and foraging. 81. Anthropogenic noise, including from pile driving (and vibro-piling), can have a significant effect on marine mammals ranging from permanent and temporary hearing loss to behavioural changes and displacement. 82. I support the following limits for managing the effects of noise on marine mammals in Lyttelton Harbour: a) 133 db re 1μPa 2 s SEL as a limit for behavioural responses; b) 146 db re 1μPa 2 s SEL as the TTS limit, and to be used for defining a zone where pile driving should be delayed or shut down should Hector s dolphins (or any other marine mammal) be detected. 83. Sound propagation modelling and the mapped noise contours should be validated by noise monitoring in situ before or at the beginning of the piling programme. 84. For the proposed wharf construction at Port Lyttelton, there are several measures which I believe can help mitigate the effects of noise on marine mammals; specifically: a) Ensuring active pile driving and associated marine mammal monitoring occurs during daylight hours, and monitoring is responsive to visibility issues; b) Using a soft start procedure for least minutes. c) Ensuring there are no marine mammals within the 146 db re 1μPa 2 s SEL mitigation zone during active pile driving; d) Ceasing operations if a southern right whale, killer whale or humpback whale is reported and confirmed to be in the harbour; e) Implementing an effective monitoring regime to detect marine mammals in the harbour and especially within the 146 db re 1μPa 2 s SEL mitigation zone.

22 Page 22 Given the size of the mitigation zone and the difficulties in detecting Hector s dolphins, monitoring will need to include the use of vessels or possibly drones; f) Ensuring the two piling rigs are never operated simultaneously; g) Staging construction to avoid as far as practicable pile driving over the peak summer period for Hector s dolphin occurrence. In this regard, I also recommend commencing pile driving after summer (i.e. after 1 March) to avoid the possibility of two summers being included in either of the two stages. 85. Marine mammal distribution and movements in the harbour should be monitored, especially in relation to the 146 db re 1μPa 2 s SEL mitigation zone and to ensure there is an adequate and effective corridor for marine mammals to transit between the inner and mid/outer harbour; 86. Further opportunities to mitigate the effects of noise on marine mammals through the piling management plan process include: a) Setting strict operational requirements for marine mammal monitoring, including methodologies, timing, flexibility (e.g. to account for visibility issues), training, and reporting. b) Testing and where applicable implementing noise dampening technologies; c) Responding to changed circumstances (e.g. new and innovative technology, and changes in the distribution and abundance of marine mammals) between now and when construction begins. Andrew Stephen Baxter 11 September 2017

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