under the resource management act 1991 (the act) in the ... · docdm-1038877 - andrew baxter nzks...

UNDER THE Resource Management Act 1991 (the Act)

IN THE MATTER OF A Board of Inquiry appointed under section 149J of the Act to consider The New Zealand King Salmon Co. Limited’s private plan change requests to the Marlborough Sounds Resource Management Plan and resource consent applications for marine farming at nine sites in the Marlborough Sounds

STATEMENT OF EVIDENCE IN CHIEF OF ANDREW STEPHEN BAXTER FOR THE MINISTER OF CONSERVATION IN RELATION TO

MARINE MAMMALS

9 August 2012

CROWN LAW TE TARI TURE O TE KARAUNA

PO Box 2858 WELLINGTON 6140

Tel: 04 472 1719 Fax: 04 473 3482

Contact Person: Kristina Muller

Email: [email protected]

In-house counsel for the Minister:

Shona Bradley [email protected] Telephone: 04 471 3022

Eleanor Jamieson [email protected] Telephone: 04 496 1915

DOCDM-1038877 - ANDREW BAXTER NZKS MARINE MAMMALS FINAL VERSION

TABLE OF CONTENTS

EXECUTIVE SUMMARY .................................................................................................................1

INTRODUCTION.............................................................................................................................3

CODE OF CONDUCT......................................................................................................................5

SCOPE OF EVIDENCE ....................................................................................................................5

MARINE MAMMAL SPECIES ..........................................................................................................6

MANAGEMENT OF MARINE MAMMAL INTERACTIONS .............................................................7

EFFECTS OF FARMS ON MARINE MAMMALS ...............................................................................9

ENTANGLEMENT AND ENTRAPMENT .............................................................................9

HABITAT DISPLACEMENT/EXCLUSION ........................................................................ 14

SOUND/NOISE................................................................................................................. 15

MARINE DEBRIS............................................................................................................... 18

CONDITIONS............................................................................................................................... 19

APPENDICES ................................................................................................................................ 23

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EXECUTIVE SUMMARY

1. I have over 30 years experience in coastal and marine management, specialising

in marine (including marine mammal) ecology.

2. This evidence addresses issues raised by the New Zealand King Salmon

Company Limited (NZ King Salmon) applications for the welfare of marine

mammals.

3. The Marlborough Sounds have a diverse marine mammal fauna including

orca/killer whale (Nationally Critical), bottlenose dolphin, Hector's dolphin

and southern right whale (Nationally Endangered), humpback whale (migrant),

and dusky dolphin and fur seal (not threatened). Any human-induced

mortality of nationally critical or endangered species must be considered with a

high degree of concern.

4. NZ King Salmon has a permit under the Marine Mammals Protection Act

1978 to manage but not harm seals at its Marlborough Sounds salmon farms.

5. There are several records of dolphins or seals drowning in NZ King Salmon’s

farms due to entanglement or entrapment. For many years these were

relatively infrequent and improvements in net design and management have

helped reduce the likelihood of serious harm. However, there have been five

juvenile fur seal deaths in the last year and juvenile seals are likely to be

attracted to salmon farms in increasing numbers in the future. In addition,

there have been four dolphin deaths (two dusky dolphins and two (probably)

bottlenose dolphins) in the last two years. Different predator net construction

used in Crail Bay may have contributed to the three dolphin incidents recorded

there (one of these was prior to NZ King Salmon purchasing the Crail Bay

farms).

6. While I recommend various conditions which would help reduce the

possibility of seal and dolphin deaths at salmon farms, I do not believe it will

be possible to eliminate marine mammal mortality at salmon farms.

7. Depending on frequency and intensity, noise can be a significant issue for

cetaceans. While NZ King Salmon’s activities will contribute more noise into

the Marlborough Sounds’ marine environment, for several reasons I believe

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the additional noise is likely to have no more than a minor additional effect on

marine mammals relative to other existing noise sources in the Marlborough

Sounds.

8. I discuss particular draft consent conditions in relation to marine mammals at

the end of my evidence. I understand I will be involved in caucusing on these

matters.

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INTRODUCTION

9. My full name is Andrew Stephen Baxter. I graduated from the University of

Canterbury in 1981 with a BSc with First Class Honours in Zoology. I have

over 30 years experience in coastal and marine management, specialising in

marine (including marine mammal) ecology. I am a member of the New

Zealand Marine Sciences Society.

10. 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.

11. Since October 1987 I have been employed as a marine ecologist by the

Department of Conservation in Nelson. My current position is Technical

Advisor (Marine) in the Science and Technical Group.

12. My duties with the Department have included:

12.1 technical oversight and co-ordination of the Department’s coastal and

marine responsibilities in Nelson and Marlborough, including marine

survey and monitoring;

12.2 marine reserve implementation, management and monitoring;

12.3 technical input on Resource Management Act matters; and

12.4 marine mammal research and management.

13. I present this evidence as a marine ecologist with a broad range of experience

in coastal and marine resource management especially in the Marlborough

Sounds. I have had a close involvement with a number of significant coastal

issues and developments, including:

13.1 marine farming;

13.2 various major port developments;

13.3 major roading proposals;

13.4 various coastal discharges;

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13.5 commercial fishing issues;

13.6 coastal shipping issues;

13.7 marine mammal management, including tourism; and

13.8 marine biosecurity.

14. Marine mammal management is a significant area of work within Nelson and

Marlborough. My marine mammal management work has included:

14.1 development of the Marine Mammals Protection Regulations 1990

and 1992. I was a technical adviser in the development of these

regulations;

14.2 assessing applications for marine mammal watching permits;

14.3 investigation and implementation of moratoria on new commercial

marine mammal watching permits at Kaikoura and along the Abel

Tasman National Park coast;

14.4 commissioning and assessing research and scientific advice on the

impacts of commercial marine mammal watching operations;

14.5 assessing applications to “take” marine mammals (as defined under

the Marine Mammals Protection Act 1978) including permits to

conduct scientific research;

14.6 oversight of the conservancy’s response to marine mammal

strandings;

14.7 working on the Hector’s dolphin threat management plan process;

14.8 working with the Ministry for Primary Industries (formerly the

Ministry of Fisheries) on fisheries by-catch issues;

14.9 providing specialist input in Resource Management Act consent and

planning processes relating to marine mammal issues.

15. I have authored or co-authored presentations on marine mammal management

at two national and eight international conferences/workshops. I have co-

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authored a chapter entitled “Human interactions with dusky dolphins: a

management perspective” in a recently published book on the ecology and

management of dusky dolphins (Childerhouse and Baxter 2010).

16. I have visited various parts of the Marlborough Sounds many times over my

career including all of the sites applied for by NZ King Salmon. I last visited

all the sites on 29 May 2012.

CODE OF CONDUCT

17. 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

18. My evidence addresses the potential effects of the proposed salmon farms on

the welfare of marine mammals. I discuss in particular:

18.1 marine mammal species and their threat status;

18.2 the management of marine mammal – salmon farm interactions; and

18.3 the effects of entanglement, habitat displacement, noise and marine

debris.

19. I discuss particular draft consent conditions in relation to marine mammals at

the end of my evidence.

20. In preparing this evidence I have read the following reports and statements of

evidence:

20.1 Statement of Evidence of Mr Martin William Cawthorn in relation to

Marine Mammals for the New Zealand King Salmon Co. Limited;

20.2 Statement of Evidence of Mr Michael Miklin Halstead in relation to

noise effects for the New Zealand King Salmon Co. Limited;

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20.3 The draft consent conditions proposed by Ms Sarah Dawson for the

New Zealand King Salmon Co. Limited;

20.4 Cawthorn, M. Marine Mammals and Salmon Farms. Report prepared

for The New Zealand King Salmon Co. Ltd. Undated (Cawthorn

Marine Mammals Report);

20.5 Marshall Day Acoustics. New Zealand King Salmon New Water

Space Project. Assessment of Noise Effects. 9 August 2011.

21. I refer to these documents and statements of evidence where relevant in

various sections of my evidence. Other relevant references are noted

throughout my evidence and are listed in Appendix 1.

MARINE MAMMAL SPECIES

22. In the Cawthorn Marine Mammals Report, Mr Cawthorn provides a review of

the main marine mammal species which occur in and around the Marlborough

Sounds (refer Sections 7-9 of this report). Of particular note are New Zealand

fur seals, bottlenose dolphins, dusky dolphins, Hector's dolphins, killer whales

(orca), humpback whales and southern right whales. I largely agree with Mr

Cawthorn’s summary but note the following additional key points of

difference.

23. The threat classification for marine mammals in New Zealand has been

updated since that of Hitchmough et al (2007) referred to in the Cawthorn

Marine Mammals Report. Baker et al (2010) provides the most up to date

threat rankings. Importantly for the current hearing, the threat statuses for

bottlenose dolphins and killer whales (orca) (type A) have been changed.

24. Killer whales are now listed as “Nationally Critical”, the highest threat

classification in New Zealand (the same as Maui’s dolphins). This ranking

reflects the very small population size for inshore killer whales in New

Zealand, estimated to number only 117 individuals (95% CI 64-167) (Baker et

al 2009). The population is also listed as being stable with no known threat or

evidence of decline. Note, however, this latter assessment was made before

two killer whales were found entangled in and rescued from rocklobster pot

lines in two separate incidents at Kaikoura in 2011 and Coromandel earlier this

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year. Entanglement in fishing gear (specifically lobster pot lines) is, therefore, a

newly documented threat for this species. Mr Cawthorn’s statement that killer

whales have never been recorded entangled in New Zealand (Cawthorn Marine

Mammals Report, Section 9.1) is therefore also incorrect.

25. Bottlenose dolphins are now listed as “Nationally Endangered” (the second

highest threat classification; the same as Hector’s dolphins). This ranking

reflects the small size of three genetically isolated coastal populations

(Fiordland, Marlborough Sounds – Westport, and north-east Northland) and

the reported decline or probability of decline in Doubtful Sound and the Bay

of Islands.

MANAGEMENT OF MARINE MAMMAL INTERACTIONS

26. Mr Cawthorn provides a good summary of the methods that have been trialled

and used internationally and in New Zealand to address seal predation

(reference Section 7.1.4, Cawthorn Marine Mammals Report).

27. As also noted by Mr Cawthorn, NZ King Salmon has a permit issued under

the Marine Mammals Protection Act 1978 which allows it to “take” marine

mammals at its Marlborough Sounds salmon farms. I have attached a copy of

this permit as Appendix 2.

28. Key aspects of NZ King Salmon’s permit are as follows:

28.1 “Take” means “catch and release seals which have entered salmon cages; harass

seals while attempting to deter them from entering salmon cages; and injure,

attract, herd, disturb and possess seals in association with the above actions.”

28.2 Killing of any seal (or any other marine mammal) is not authorised.

28.3 All actions undertaken under the permit are to be carried out in

accordance with a seal handling protocol attached to the permit.

28.4 Acoustic seal scarers, tuna bombs or seal bombs are not permitted.

28.5 Reporting, monitoring, auditing and training requirements.

29. In 2007, NZ King Salmon applied to the Department of Conservation for a

permit to use a Lofitech Acoustic Harassment Device (AHD) at its

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Marlborough Sounds salmon farms. The purpose of this device was to scare

seals (and indirectly dolphins) away from the salmon farms while the predator

nets were being installed or maintained, or during cage transfers between

farms. AHDs typically only have short term deterrent effects on New Zealand

fur seals as seals can get used to AHDs or find ways to “get around them”.

30. The Department assessed the application at the time (Nelson-Marlborough

Conservancy 2008) and concluded:

The use of a Lofitech AHD is likely to displace seals and dolphins while the unit is in operation out to varying distances from the cages depending on the different sensitivities of the marine mammals to sound. Beyond this exclusion area, there will be a zone of decreasing influence extending away from the transducer. Based on theoretical modelling of sound transmission loss in shallow coastal waters and the reported hearing sensitivities of bottlenose dolphins and orca, it is predicted the AHD will disturb cetaceans out to several kilometres from the sound source. Seals probably will not be as affected as much because of their less sensitive hearing, their ability to swim with their heads above the water and capacity to relocate to natural haul-outs more remote from the salmon farms.

The consequences of AHD use on cetaceans can be much greater due to impacts on favoured foraging areas and especially migratory routes. In particular, AHD use at the Tory Channel, Ruakaka Bay and outer Pelorus farms are likely to have significant impacts on dolphin and orca movements into and out of the Sounds while the device is operational.

…given the much wider consequences of AHD use on cetacean movement patterns throughout the Marlborough Sounds, it is concluded that the effects do not meet the requirements of the Marine Mammals Protection Act 1978 to conserve, protect, or manage marine mammals.

31. This particular application was declined.

32. I note that the current applications by NZ King Salmon do not include any

reference to the use of AHDs. In my view predator nets currently remain the

only effective method for keeping seals away from the salmon pens.

33. I am aware the Department of Conservation has a good working relationship

with NZ King Salmon at all levels in relation to marine mammal interactions

with existing salmon farms, from management staff in Nelson and Picton

through to individual farm managers and their staff out in the Marlborough

Sounds. Incidents involving marine mammals are reported to the Department

quickly and from my experience NZ King Salmon is very good at investigating

issues and looking at ways to improve their management and technology to

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address issues that arise. Mr Cawthorn’s evidence (paragraph 28) gives an

example of this, with NZ King Salmon investigating ways to increase tension

on newly installed predator netting which has not been anti-fouled and has no

bio-fouling growth on it.

EFFECTS OF FARMS ON MARINE MAMMALS

Entanglement and entrapment

34. Mr Cawthorn includes in his evidence (pages 8-11) a summary of reported

incidents involving interactions between marine mammals and NZ King

Salmon’s existing salmon farms in the Marlborough Sounds. His summary

largely accords with the Department of Conservation records which I have

reviewed.

35. In his evidence, Mr Cawthorn reports on several reported dolphin deaths in

salmon farms over the years (paragraph 31): two dusky dolphins at Ruakaka in

1999, a dead Hector’s dolphin at Ruakaka in 2005, two dusky dolphins in Crail

Bay in 2011 and one dusky dolphin at Wahinau in 2012.

36. The Department of Conservation’s records differ in that one of the 2011 Crail

Bay dolphins is thought to be a bottlenose dolphin rather than a dusky dolphin

(based on the advice of NZ King Salmon worker Mr Jade McCartney to Mr

Mike Aviss, Sounds Area Office, Department of Conservation). Unfortunately

due to a misunderstanding the carcass was not recovered for a positive

identification or a post mortem. The Department also has a separate record

(also from Mr McCartney) of another bottlenose dolphin drowning in a loose

half removed predator net in Crail Bay about 12-18 months ago, prior to this

farm being taken over by NZ King Salmon.

37. Post mortem analyses for the two recovered dusky dolphins (one from Crail

Bay and one from Waihinau) undertaken by Massey University both concluded

asphyxia/drowning due to entanglement as the most likely cause of death.

38. There seem to be three main themes with these dolphin incidents.

39. The earlier incidents (1999) involved earlier predator net designs where

dolphins became entrapped between adjoining nets. Net designs used

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currently should avoid this happening again as I understand they now form a

complete envelope around the cages.

40. Some of the later incidents involved entanglement or entrapment when

predator nets were being maintained or replaced; e.g. the nets were open, loose

or pulled up to form potential entrapment pockets.

41. Thirdly, the predator nets which were in use at the Crail Bay farms were made

of much lighter mesh (Mr Mark Gillard, NZ King Salmon, pers. comm.) which

could have contributed to the entanglement.

42. Mr Cawthorn’s evidence (paragraphs 27-28) also reports on a number of

incidents at the Waihinau salmon farm where seals have:

42.1 managed to get past the predator net and gained entry into the

salmon farm. These have been later caught and released by NZ King

Salmon staff;

42.2 become entangled in the predator netting and subsequently released

alive by NZ King Salmon staff;

42.3 become entangled in the predator netting and subsequently drowned.

These drownings involved juvenile seals (five in total) that had either

pushed their heads through the predator net mesh and/or had

become entangled in netting.

43. These records accord with those held by the Department of Conservation.

44. In addition to the recent seal deaths at Waihinau, the Department was also

notified by NZ King Salmon of a juvenile seal having drowned in the predator

net at Te Pangu in April 2012.

45. As a general rule, seal deaths have tended to be relatively infrequent. The spate

of seal drownings over the past few months at Waihinau and Te Pangu has

been very unusual because of the number of seals involved and their small size

(juveniles). The small seals were found with their heads through the mesh

and/or enveloped in loose netting (i.e. not under tension). Despite their

agility, it would have been very difficult for these young seals to have dislodged

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their heads due to the backward facing direction of their fur, especially if the

netting was loose.

46. I cannot explain the recent spate of seal drowning incidents. Fur seals have

been breeding in the outer Sounds for many years, primarily on Stephen’s

Island (Takapourewa) but also in the last few years on the Trio Islands (Kuri

Pongi). The increase in seal pups at the Trio Islands (Kuri Pongi) could be a

factor (especially given its proximity to the outer Pelorus); however, there has

been a large rookery on Stephen’s Island (Takapourewa) for many years and it

is still relatively close to the Waihinau farm and well within swimming distance

of young seals.

47. New Zealand fur seals will be attracted to salmon farms because of the

foraging opportunities present both outside (e.g. yellow eyed mullet, garfish)

and inside the salmon pens. They can be opportunistic feeders and are very

adept at finding ways to get into salmon farms. Any gap in the predator net

defence – a hole or ripped seam – will be taken advantage of and based on the

recent seal deaths referred to above smaller seals now appear to be trying to

force themselves through intact mesh.

48. Fur seals learn quickly and given the recent incidents involving juvenile seals I

would not be surprised to see more of these sorts of problems in the future,

especially in the outer Pelorus Sound, as young seals learn there is a convenient

food source nearby.

49. Dolphins may also target baitfish around salmon farms or sometimes heard

baitfish up against the farms. Dolphins may accidentally get caught in the

mesh while chasing fish. For one of the dolphins which drowned at Crail Bay

last year, NZ King Salmon reported that the animal was found caught by its

teeth. Thus despite their size and obvious agility and power, dolphins can get

caught in predator nets simply by getting their mouths caught in the mesh.

50. Mr Cawthorn concludes that seal and dolphin deaths due to entanglements are

unlikely to have an adverse effect on seal and dolphin populations. I agree

with his conclusion with respect to seals and dusky dolphins. Both these

species are not threatened. Seals are abundant and expanding their geographic

range.

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51. However, the potential effects on killer whales, Hector’s dolphins and

bottlenose dolphins are a different matter. Killer whales are listed as “Critically

Endangered” in New Zealand waters and both Hector’s dolphins and

bottlenose dolphins are listed as “Nationally Endangered” (refer paragraphs

23-25 of my evidence). Any human-induced mortality of these three species

must be considered with a high degree of concern.

52. The most comprehensive and recent study on bottlenose dolphins in the

Marlborough Sounds is that reported in Merriman et al (2009). This study

found that bottlenose dolphins in the Sounds are part of a larger top-of-the

south coastal population consisting of 385 individuals, with 211 (95% CI = 195

– 232) dolphins utilising the Sounds per annum. Bottlenose dolphins are slow

breeders (one calf approximately every four years) and long lived (around 50

years) (Wells and Scott 2002), attributes which make them susceptible to

human impact. These attributes, along with the small population size and

reasonable site fidelity (i.e. attachment to a certain area) mean any human-

induced mortality is a big concern. As noted in paragraph 36 of my evidence,

there have been two probable mortalities of bottlenose dolphins in salmon

farming predator netting in the Marlborough Sounds over the past two years.

53. There has been a single incident involving a dead Hector’s dolphin in a salmon

farm (refer paragraph 31(b) of Mr Cawthorn’s evidence).

54. There is no known entanglement of a killer whale in a salmon farm, though the

entanglement of two killer whales in lobster pot lines over the last two years

(refer paragraph 24 above) shows they are not immune to entanglement

threats. However, their larger body size and more robust rounded head should

mean that entanglement in well maintained and tensioned predator nets should

be unlikely. The most vulnerable time would be when predator nets might be

left partially open or slack during maintenance work, or if the nets were

allowed to fall into disrepair.

55. A common theme with entanglements/entrapments (seals and dolphins) is that

they often occur when the predator nets are not under tension; e.g. during

installation/removal or when new predator netting has been installed.

Furthermore, as noted earlier the predator nets which were used on the

Polarcirkel cages in Crail Bay were made of a lighter grade of mesh than at NZ

13


King Salmon’s other farms. A lighter grade mesh would be more susceptible

to folding inwards under pressure and this may well have contributed to the

three dolphin entanglements which have been reported at Crail Bay. I am

aware that all the salmon farms in Crail Bay are currently not operational and

all the netting has been removed (Mr Mark Gillard, NZ King Salmon, pers

comm.).

56. Some of these entanglement issues could be mitigated by ensuring predator

nets are maintained as taut as possible (e.g. through additional weighting) so

that if a seal or dolphin pushes into the net there is little scope for the net to

fold or collapse inwards.

57. Minimum mesh size and twine thickness should also be set to reduce the risk

of entanglement. I understand the current NZ King Salmon farms use either

204mm or 240mm mesh (the internal measurement when the net is stretched

in the direction of the long diagonal of the meshes) and that NZ King Salmon

is moving towards a smaller mesh size of 200mm (Mr Mark Gillard, NZ King

Salmon, pers. comm.). I have been advised that four of the young seals drowned

earlier this year (refer paragraph 42) were caught in 240mm mesh and two were

caught in 204mm mesh (Mr Mark Preece, NZ King Salmon, pers. comm.). A

reduction in mesh size to 200mm should help reduce the likelihood of marine

mammals becoming entangled.

58. Requiring visual surface marine mammal surveys prior to net maintenance

work and ensuring nets are not opened, removed or shifted if dolphins are

observed in the general area of the farms would also be a good precautionary

measure. Leaving predator nets open for any long length of time, including

over night, should also be avoided.

59. These various matters could be addressed with appropriate provisions of a

Marine Mammal Management Plan required as a condition of consent and

ensuring all NZ King Salmon staff have a high level of awareness of the issues

and receive full and appropriate training (I make some suggestions regarding

conditions at the end of my evidence). However, I do not believe it will be

possible to eliminate seal and dolphin deaths at salmon farms that use predator

nets. Even if predator nets were removed (e.g. through the introduction of

predator-proof fish pen technology), there could still be a risk of entrapment

14


of seals or dolphins between adjoining pens depending on net design and

layout. Other than not having salmon farms at all, presently all that can be

done in my view is to progressively improve management and technology to

reduce the risk.

60. I agree with Mr Cawthorn that entanglement of larger whales (e.g. humpbacks

or southern right whales) is unlikely in a salmon farm, provided it is

surrounded by a well maintained and tensioned predator net.

61. The risk of entanglement for all marine mammal species would be greatly

elevated if a salmon farm was ever abandoned or left derelict with nets left in

place.

62. The risk of marine mammal entanglement and/or entrapment also needs to be

placed into context with other similar threats in the marine environment,

notably those posed by set nets. Commercial and recreational set netting is a

permitted activity under the Fisheries Act 1996 in various parts of the

Marlborough Sounds. The areas which are open or closed to different forms

of set netting are shown in Appendix 3 (Source: Mr Alex Thompson, Ministry

for Primary Industries, Nelson, 20 July 2012). From these maps it is clear that

a large proportion of the Marlborough Sounds (i.e. Pelorus Sound and the

outer Sounds) is open to set netting. Set netting is prohibited in Queen

Charlotte Sound and Tory Channel to protect the small population of Hector's

dolphins present there.

63. Set nets are made of monofilament nylon and are very difficult to detect

(visually and acoustically) underwater. They can be set in the same general

areas where marine mammals may also be foraging or transiting from time to

time. In my view, set nets pose a much larger entanglement threat to marine

mammals in the Marlborough Sounds than well constructed and well managed

salmon farm predator nets.

Habitat displacement/exclusion

64. Mr Cawthorn has commented on and discounted habitat displacement as a

likely adverse effect of the proposed salmon farms on dolphins (see paragraph

33 of his evidence). He states displacement from feeding areas “is unlikely as the

area taken up by existing and proposed farm sites in the Marlborough Sounds is very small

15


in the context of the Sounds as a whole”. While I agree that the actual farm sites are

small in the wider Sounds context, and direct habitat exclusion will be minimal,

the effects of the salmon farms, including displacement effects, could extend

well beyond the farm boundaries due to hydrodynamics and the effects of

nutrient discharges and dispersal.

65. Marine mammals are higher order predators within the broader marine

ecosystem and any effects of nutrients on this ecosystem could also adversely

affect them (e.g. through effects on the distribution and abundance of prey,

and effects of algal blooms). I am unable to comment further on this matter as

it is beyond my particular expertise.

Sound/noise

66. In the case of salmon farms, noise will be produced by vessels servicing the

farms, as well as farm work associated with cleaning nets, feeding and

harvesting. Mr Cawthorn has discounted noise as a potential concern

(reference Section 10, Cawthorn Marine Mammals Report, and paragraphs 34-

35 of his evidence).

67. Increasing noise is a growing concern in the world’s oceans for cetaceans

which rely heavily on sound for communication, social cohesion, predator

avoidance and (for toothed whales and dolphins) foraging (i.e. detection of

prey using echolocation). Interference with the detection of acoustic signals

(i.e. “masking”) is therefore a particular problem for cetaceans (Morton and

Symonds 2002). In other words, too much noise may mask some of these

mechanisms.

68. In the absence of experimentally validated audiograms (which is the case for

most marine mammals), it is generally accepted that a marine mammal will be,

at the very least, sensitive to frequencies matching those of its own sounds

(Reeves 1992).

69. Most whistles of dolphins are relatively high frequency, centred around 7-15

kHz (Frankel 2002). Bottlenose dolphins, arguably the most studied cetacean

in terms of acoustics, are known to produce and hear a very broad frequency

of sounds ranging from <1 to 150 kHz; however, their peak sensitivity (the

range that the dolphins hear the best) is 40 to 100 kHz (reported in David

16


2006). Based on the anatomy of Hector’s dolphin, this species is thought to

have good frequency hearing with peak sensitivity greater than 80 kHz (Stone

et al 2000). Killer whales are thought to have the most sensitive hearing of any

toothed whale (Szymanski et al 1999) and are most sensitive to sound between

15 to 30 kHz (Au 1993).

70. Looking across all these data, it would appear that frequencies greater than

about 5 kHz are the most significant for dolphins (including killer whales).

71. I am very familiar with the issue of vessel noise from my work connected with

managing marine mammal tourism. The amount and frequency of noise

entering the water can be highly variable between boats depending on matters

such as size, hull design, speed, engine type/size, noise insulation, muffling

systems, propulsion systems, maintenance, and the skill and behaviour of the

skipper. As a generalised rule, jet propelled vessels are much quieter under

water than propeller driven craft.

72. While vessels produce underwater noise across a broad range of frequencies

(<10 Hz to > 60 kHz), most is at frequencies less than 5 kHz (e.g. refer Trial

Analysis Unit 1992; Marrett 1992). In contrast, and as noted above, dolphins

are likely to be most sensitive to frequencies greater than 5 kHz. This

frequency separation provides a degree of protection for dolphins and other

toothed cetaceans.

73. The sea’s surface can also act as a partial “sound refuge” due to the countering

effect of sound waves approaching and reflecting off the sea surface onto each

other. The result is that received sound levels can be significantly less near the

surface, thus allowing some refuge for cetaceans at the surface (The Ocean

Ecology Institute 2007; Marrett 1992). Marrett (1992) estimated that vessel

noise intensity at 1 kHz would be approximately halved (i.e. reduced by 3 dB)

near the surface compared to measurements at depth (75m), and that lower

frequency sounds would be dampened by a hundred times (20 dB) or more

under the same conditions. This sound dampening effect will therefore reduce

the noise disturbance caused by vessels for marine mammals near the surface.

74. All vessels are required to adhere to Part III of the Marine Mammals

Protection Regulations 1992 (MMPR) which includes inter alia regulations

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limiting: approach distances (>50 to whales; >200m to baleen whales with

calves), speeds (idle or “no wake” speed within 300m), the number of vessels

around marine mammals (a maximum of three within 300m), and general

vessel “behaviour” around marine mammals (e.g. no sudden or repeated

changes in speed or direction). NZ King Salmon’s vessels are equally required

to adhere to these Part III regulations. Commercial marine mammal watching

vessels (as defined in the MMPR) are also required to have a permit issued

pursuant to the regulations.

75. The rules under Part III of the MMPR are aimed at reducing the effects of

boating activity around marine mammals, though they do not address all the

effects of marine mammal watching (e.g. cumulative impacts including effects

of repetitive encounters). Of direct relevance with respect to the issue of

noise, these rules when adhered to will reduce the amount of noise entering the

water around marine mammals.

76. While any additional vessels used by NZ King Salmon will add to the overall

underwater noise climate of the Marlborough Sounds, this also needs to be

considered within the context of the large numbers of vessels which use the

Sounds (especially over the peak holiday seasons). A huge variety of vessels

ply the Marlborough Sounds, from yachts to smaller recreational power boats,

to larger recreational and commercial vessels, to the Cook Strait ferries and

larger ships which enter Queen Charlotte Sound. Greatest activity will occur in

the busy holiday periods as holiday-makers flock to the Sounds. Other than

indirectly through the requirements of the MMPR (refer preceding two

paragraphs) or through general navigational speed restrictions, vessels which

are generally navigating through the Marlborough Sounds are, for all intents

and purposes, unregulated in terms of their underwater noise. Furthermore,

there is no effective limit on the total number of vessels which are allowed to

navigate through the Sounds.

77. I expect that much of the noise produced on a salmon farm (e.g. from

generators, above surface water blasters, etc) will be low frequency sound

generally lower than normal dolphin communication and echolocation. Much

of the sound will be produced above the water and, due to the particular

properties of sound transferral from air into water, only a portion will enter the

18


water column. The different densities of air and water mean much of the

sound produced in air is reflected off the sea’s surface; sound waves which are

greater than 13.2 degrees from the vertical are mostly reflected (Defence

Scientific Establishment 1992). Sound attenuation through simple spreading

loss from the source will mean that any sound that enters the water directly

under a farm will attenuate with distance, approximating a function of

10xLog(distance) for cylindrical spreading.

78. Some farm activities do result in noise being directly transferred into the water

column, notably water blasting and feed dispensing (refer Marshall Day

Acoustics 2011, Assessment of Noise Effects). That assessment found

underwater water blasting the noisiest but concluded it is “generally similar to the

exhaust burble from an outboard motor”. This being the case, I doubt underwater

noise from the farms would be much of a concern for marine mammals in the

vicinity, especially when you also account for sound propagation loss with

distance from the source.

79. The cumulative effect of noise from multiple sources is an issue for cetaceans

and NZ King Salmon’s proposed new activities (vessels and farm operations)

will result in additional noise entering the Marlborough Sounds’ marine

environment. I am unable to quantify the relative contributions from NZ

King Salmon’s proposed new activities and those from other sound sources

(notably existing and future vessel traffic through the Sounds). I am not aware

of any studies which have quantified the underwater noise climate of the

Marlborough Sounds. Nevertheless, based on my assessments above, I believe

the additional noise resulting from NZ King Salmon’s proposed new salmon

farms is likely to have no more than a minor additional effect on marine

mammals relative to other existing noise sources in the Marlborough Sounds.

Marine debris

80. Marine debris (plastics, strapping bands, net fragments, etc) is also a significant

threat to marine mammals through ingestion and entanglement, both of which

can be lethal. Marine debris can come from many sources including

aquaculture activities. I address this matter in the draft conditions of consent

below.

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CONDITIONS

81. I have reviewed the draft conditions of consent (dated 22 June 2012 and

attached to Ms Sarah Dawson’s evidence in chief) that are relevant to my areas

of expertise and provide preliminary comment on them below. I understand the

proposed conditions will be subject to further refinement following expert

conferencing (including myself) before the close of the hearing.

82. Draft condition 57 (attached to Ms Sarah Dawson’s evidence in chief) states:

“The consent holder shall prepare and implement a marine mammal management policy (developed in consultation with the Department of Conservation) to minimise the interactions of marine mammals with the farm, and to prescribe actions should marine mammals become a nuisance in relation to the farm or interact with the farm in a manner that could result in harm to the marine mammal. This policy shall include training for staff on the farm (including in the identification and safe handling of live seals and other marine mammals), a regular reporting system for farm managers and staff regarding interactions between the farm and marine mammals, and liaison, information sharing and notification procedures with the Department of Conservation.”

83. I believe this condition is imprecise and provides no certainty as to outcome.

There are no performance measures or standards.

84. I suggest the following alternative conditions:

1. The consent holder shall, in consultation with the Department of

Conservation, prepare a Marine Mammal Management Plan. This

plan shall be provided to and approved by the Marlborough District

Council prior to the establishment of the farm.

2. The objectives of the Marine Mammal Management Plan are to:

a) ensure the adverse effects on marine mammals from the operation

of the salmon farms are appropriately avoided, remedied or

mitigated;

b) determine how the operation of the salmon farm will be managed

adaptively to avoid, remedy and mitigate adverse effects on marine

mammals;

c) ensure that the best practicable option is adopted to avoid

entanglement or entrapment of marine mammals, having regard

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to best international practice, ongoing research and allowing for

technological improvements in net design and construction;

d) establish a monitoring programme to assess the effectiveness of

the Marine Mammal Management Plan; and

e) establish reporting and response procedures in the event of

marine mammal entrapment, entanglement, injury or death.

3. The Marine Mammal Management Plan shall include, but not be limited

to, the following details:

a) limiting the maximum mesh size of any predator netting to

200mm (the internal measurement when the net is stretched in the

direction of the long diagonal of the meshes). (A cross reference to

Schedule 3 of the Fisheries (Commercial Fishing) Regulations 2001 which

covers mesh measurement requirements might also be appropriate.);

b) ensuring predator nets are sufficiently tensioned and maintained at

that tension at all times so as to avoid the net folding or collapsing

inwards if pushed by an adult dolphin or adult fur seal;

c) ensuring the twine diameter of the predator net is of a sufficient

gauge to:

i. be detected acoustically by dolphins; and

ii. avoid the net folding or collapsing inwards if pushed by an

adult dolphin or adult fur seal;

d) ensuring predator nets extend above the waterline for a sufficient

distance to exclude entry by seals, but no higher;

e) predator net maintenance requirements, including:

i. standards and scheduling;

ii. repairing holes and tears immediately;

iii. avoiding predator nets being left open over night or for

extended periods of time;

iv. avoiding forming entrapment pockets in predator nets;

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f) procedures for auditing marine farm security following any marine

mammal gaining access beyond a predator net, and taking all

practical steps to correct any faults found;

g) procedures to ensure visual surface marine mammal surveys are

conducted prior to major net maintenance work and that nets are

not opened, removed or shifted if dolphins are observed within

2km of the farm;

h) procedures for capture and release of any entrapped or entangled

marine mammal;

i) procedures for the retrieval, storage and transport of dead marine

mammals for formal identification and autopsy purposes;

j) staff training requirements;

k) ensuring there is no feeding of marine mammals;

l) ensuring dead fish are removed promptly from the fish pens;

m) ensuring anchor warps are maintained under sufficient tension to

prevent possible entanglement of cetaceans;

n) ensuring all lines associated with the farm are secured at all times,

and that any loose lines are secured and/or retrieved promptly;

o) ensuring that all nets are removed from farm structures that are

left fallow, untended or are abandoned. (Note: this requirement

shall be supported by way of surety or bond in favour of the

Marlborough District Council of an amount adequate to enable

the Council to recover the reasonable costs of net removal should

the consent holder, upon request, fail to do so);

p) ensuring all net and cordage debris, plastic strapping and other

farm, domestic or other non-biodegradable waste is collected,

retained and disposed of at an approved solid waste facility on-

shore, and that if any loose debris does enter the water around the

farm, it is retrieved from the seabed, water column or foreshore

promptly;

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q) reporting requirements to the Marlborough District Council and

the Department of Conservation, and in particular:

i. a minimum of annual summary reports of all incidents

involving marine mammals becoming entangled or

entrapped at a salmon farm;

ii. immediate reporting (within 24 hours) of any incident

where a marine mammal may be injured or killed;

iii. reporting (within one week) of actions undertaken to

remedy any unforeseen events such as a marine mammal

becoming entrapped or entangled at a salmon farm.

85. Note the Marine Mammal Management Plan and any conditions of consent do

not abrogate the consent holder’s responsibilities to obtain a permit issued

under the Marine Mammals Protection Act 1978 for any actions which would

come under the definition of “take” under that Act. Pursuant to section 2(1)

of the Marine Mammals Protection Act 1978 “take” includes to catch, kill, injure,

herd, harass or disturb any marine mammal, or attempt to do any of these things.

86. I am available to discuss the draft consent conditions further during expert

caucusing.

9 August 2012

________________________________________ Andrew Stephen Baxter

23


APPENDICES

Appendix 1: References

Au, W. 1993. The sonar of dolphins. Springer-Verlag, New York. 277pp.

Baker, CS , Chilvers, BL , Constantine, R. , DuFresne, S. , Mattlin, RH , van Helden, A. and Hitchmough, R. 2010. Conservation status of New Zealand marine mammals (suborders Cetacea and Pinnipedia) 2009. New Zealand Journal of Marine and Freshwater Research, iFirst 2010, 1-15

Childerhouse, S. and Baxter, A. 2010. Human interactions with dusky dolphins: a management perspective. In: The dusky dolphin - master acrobat off different shores. Ed: B Würsig and M Würsig. Elsevier/Academic Press, London, Burlington, San Diego; pp 245 – 275.

David, J. 2006. Likely sensitivity of bottlenose dolphins to pile-driving noise. Water and Environment Journal 20: 48-54.

Defence Scientific Establishment 1992. Unpublished report to Malcome Hunt Associates, Wellington.

Frankel, A. 2002. Sound Production. In Encyclopedia of Marine Mammals. Eds: W F Perrin, B Würsig and J G M Thewissen. Academic Press, San Diago, USA.

Hitchmough, R., Bull, L. and Cromerty, P. 2007. New Zealand Threat Classification lists – 2005. Wellington. Department of Conservation.

Marrett, R. 1992. Underater noise from tourist operations. Conservation Advisory Science Notes No. 1. Department of Conservation, Wellington. 6p.

Merriman, M G; Markowitz, T M; Harlin-Cognato, A D; and Stockin, K A 2009: Bottlenose dolphin (Tursiops truncatus) abundance, site fidelity, and group dynamics in the Marlborough Sounds, New Zealand. Aquatic Mammals 35(4) 511-522

Morton, A. and Symonds, H. 2002. Displacement of Orcinus orca (L.) by high amplitude sound in British Columbia, Canada. Journal of Marine Science 59: 71-80.

Nelson-Marlborough Conservancy 2008. Conservancy Report dated 18 February 2008. The New Zealand King Salmon Company Ltd, Application to “Take” Marine Mammals.

Reeves, R. 1992. Whale responses to anthropogenic sounds: a literature review. Science & Research Series No. 47. Department of Conservation, Wellington, New Zealand. 50pp.

Stone, G., Cavagnaro, L., Hutt, A., Kraus, S., Baldwin, K. and Brown, J. 2000. Reactions of Hector's dolphins to acoustic gillnet pingers. In: Compendium of published CSL reports, 1995/96 to 2000/2001. Department of Conservation, Wellington, New Zealand. 29pp

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Szymanski, M. Bain, D., Kiehl, K., Pennington, S., Wong, S. and Henry, K. 1999. Killer whale (Orcinus orca) hearing: auditory brainstem response and behavioural audiograms. Journal of the Acoustical Society of America 106:1134-1141.

The Ocean Ecology Institute 2007. Web page. Ocean Issues: Transmission loss: the factors that determine how much the sound’s received level is reduced from its source level.

Trial Analysis Unit, 1992. Noise ranging report for Department of Conservation. Vol. 1: Boats. Unpublished report, Trial Analysis Unit, Office of the Commodore, Auckland, New Zealand.

Wells, R.S. & Scott, M.D. 2002. Bottlenose dolphins. Pages 122-123 in W.F. Perrin, B. Würsig & J.G.M. Thewissen (eds). The Encyclopedia of Marine Mammals (1st Ed). Academic Press.

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Appendix 2: Marine Mammals Protection Act 1978 permit issued to NZ King Salmon

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Appendix 3: Areas open and closed to set netting in the Marlborough Sounds

Provided by Mr Alex Thompson, Ministry for Primary Industries, Nelson, 20 July 2012.

under the resource management act 1991 (the act) in the ... · docdm-1038877 - andrew baxter nzks...

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