BEFORE THE EPA CHATHAM ROCK PHOSPHATE MARINE CONSENT APPLICATION

IN THE MATTER of the Exclusive Economic Zone and Continental Shelf (Environmental Effects) Act 2012

AND

IN THE MATTER of a decision-making committee appointed to consider a marine consent application made by Chatham Rock Phosphate Limited to undertake rock phosphate extraction on the Chatham Rise

______

STATEMENT OF EVIDENCE OF MARTIN WILLIAM CAWTHORN FOR CHATHAM ROCK PHOSPHATE LIMITED

Dated: 25 August 2014 ______

______

Barristers & Solicitors

J G A Winchester / H P Harwood Telephone: +64-4-499 4599 Facsimile: +64-4-472 6986 Email: [email protected] DX SX11174 P O Box 2402 Wellington

CONTENTS

EXECUTIVE SUMMARY ...... 4

INTRODUCTION ...... 5

Qualifications and experience ...... 5

Code of conduct ...... 7

Role in marine consent application ...... 7

Scope of Evidence...... 7

PREVALENCE AND DISTRIBUTION OF MARINE ANIMALS ON THE CHATHAM RISE ...... 7

Marine mammal habitat utilisation of the crest of the Chatham Rise ...... 9

CONSERVATION SIGNIFICANCE OF MARINE MAMMALS ON THE CHATHAM RISE ...... 10

LIKELY IMPACTS OF THE PROPOSED MINING ACTIVITY ON MARINE MAMMALS BASED ON THEIR ABUNDANCE AND HABITAT USAGE ...... 11

Ship strikes ...... 11

Entanglement ...... 12

Noise ...... 13

Behavioural response ...... 15

Human induced changes to marine environment ...... 15

Pollution ...... 16

Mitigation effectiveness ...... 16

RESPONSE TO SUBMISSIONS ...... 17

The Crown ...... 17

Ngai Tahu ...... 19

Greenpeace and Deep Sea Conservation Coalition Incorporated ...... 19

ECO ...... 20

KASM ...... 20

CONCLUSION ...... 21

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REFERENCES (CITED IN THIS EVIDENCE) ...... 22

APPENDICES ...... 24

Table 1. Threat Rankings for marine mammal species found across the Chatham Rise (after Baker 2010) ...... 24

Table 2. Vocalisation ranges of whales and dolphins within and near CRP's proposed marine consent area (based on Torres et al. 2013a) ...... 24

32. Species Accounts ...... 25

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EXECUTIVE SUMMARY

1. This evidence describes the distribution patterns of marine mammals over the Chatham Rise.

2. Two data sets of incidental sightings of cetacean species were used to describe their distribution:

(a) the Cawthorn dataset of incidental sightings from ships in transit to or from ports; and

(b) the Department of Conservation (DOC) cetacean sightings data.

3. The data sets provide 137 records of 12 different cetacean species and one species group, the beaked whales, sighted within the study area which consists of an approximately 100 km buffer area of the Chatham Rock Phosphate Ltd (CRP) mining permit area.

4. Most of the sightings of cetaceans within the study area are of sperm whales and pilot whales, which feed along the flanks of the Chatham Rise where they forage along the steep slopes for preferred food species. Various species of dolphins, beaked whales, killer whales, and baleen whales including southern right whales either use the Chatham Rise or transit it during their northward and southward migrations. The southern margin and south eastern end of the Chatham Rise are foraging grounds for southern right whales and beaked whales respectively.

5. The presence of CRP’s mining vessel, as well as fishing vessels, is unlikely to substantially increase the risk of ship strikes on whales or any form of entanglement.

6. Noise displacement, should it occur, should be of short duration, over a small area during the 4-5 day mining period.

7. As rorquals (blue, fin, sei and minke whales) and humpbacks will be in transit when in the vicinity of the Chatham Rise and dolphins feed in the upper part of the water column they are unlikely to be affected by any

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suspended sediment from the mining operation in the top centre of the Chatham Rise.

8. Mitigation methods should ensure that no mining begins when any whales are within a buffer area around the vessel, and thus the equipment on the seabed.

INTRODUCTION

Qualifications and experience

9. My full name is Martin William Cawthorn. I am the Managing Director of Cawthorn and Associates.

10. I hold a Bachelor of Science degree with Honours majoring in Zoology.

11. I have had 45 years of specialist marine mammal research experience (whales and seals). During that time I have held the following positions:

(a) 1962-66: Technical Officer (Marine Mammals), NZ Marine Department Research Division;

(b) 1966-71: Scientist, Section, Fisheries Research Board of Canada, Arctic Biological Station, Ste Anne de Bellevue, Quebec, Canada;

(c) 1976-87: Scientist (Marine Mammals/Deepwater Fisheries), MAF Fisheries Research Division;

(d) 1987-92: Senior Scientist (Marine Mammals), Department of Conservation; and

(e) 1992: established Cawthorn & Associates, consultants specialising in interactions between marine mammals, static and active fisheries, and marine industrial installations and activities.

(f) Adjunct Lecturer, Institute of Veterinary and Biological Studies, Massey University.

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12. My experience has included work in New Zealand, South West Pacific and Polynesia, Eastern Tropical Pacific, Central and South America, South Atlantic, Southern Indian Ocean, Southern Ocean/Antarctic, Western North Atlantic, Canadian Arctic, and the Norwegian Sea.

13. My specific experience within the New Zealand exclusive economic zone (EEZ) has included establishment and maintenance of a major incidental whale sightings system throughout the Tasman Sea and south west Pacific Ocean from the northern extremity of the New Zealand EEZ to the southern limit.

14. I was resident government biologist at Tory Channel Whaling Station from the latter days of humpback whaling through the entire period of sperm whaling until closure after the 1964-5 season. I organised and conducted aerial and shipboard surveys of sperm whales, including whale marking surveys, around the entire New Zealand coast. I conducted studies of seasonal distribution and movements of all whale species; studies of marine mammal ageing and reproduction; and feeding and dietary studies of sperm whales from the Cook Strait region. I also conducted shipboard and aerial surveys of all cetacean species off the East Coast, surveys across the Chatham Rise to Chatham Island and local waters.

15. I participated in a three year survey of Hector’s dolphins in Clifford and Cloudy Bay, and most recently organised and conducted a 12 month aerial survey of all marine mammals in nearshore waters of the south Taranaki Bight.

16. I have provided consultancy services to Australian, Canadian, Japanese, New Zealand, Norwegian and Tongan government agencies, and most recently to the United Kingdom Government Department of Environment Fisheries and Rural Affairs (2002-3) and the Australian Fisheries Management Authority (2008). I have also provided consultancy services to private aquaculture enterprises and participated in resource consent hearings regarding the potential effects on marine mammals of marine farming, marine electricity generation, and iron sand extraction.

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Code of Conduct

17. I confirm that I have read the Code of Conduct for expert witnesses contained in the Environment Court of New Zealand Practice Note 2011 and that have complied with it when preparing my evidence. Other than when I state that I am relying on the advice of another person, this evidence is entirely within my area of expertise. I have not omitted to consider material facts known to me that might alter or detract from the opinions that I express.

Role in marine consent application

18. I have been asked to prepare and present evidence on marine mammal distribution in the Chatham Rise, particularly within the proposed marine consent area.

Scope of evidence

19. In this brief of evidence, I will discuss:

(a) the prevalence and distribution of marine mammals on the Chatham Rise;

(b) the conservation significance of marine mammals that are present on the Chatham Rise;

(c) the likely impacts of the proposed mining activity on marine mammals based on their abundance and habitat usage; and

(d) mitigation effectiveness.

20. I also respond to aspects of the submissions which concern marine mammals.

PREVALENCE AND DISTRIBUTION OF MARINE MAMMALS ON THE CHATHAM RISE

21. The Chatham Rise extends east for more than 1000km from to beyond the Chatham Islands. Physical features are

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Mernoo Bank at the western end of the Rise and the Chatham Islands about 700km east. The northern and southern flanks of the Rise are steep, rising from about 2000m to 350-400m in depth.

22. The Rise lies at the boundary between warm, saline, sub-tropical water to the north and cooler, less saline, sub-Antarctic water to the south. The boundary is known as the Subtropical Convergence or Subtropical Front (STF).

23. Significant numbers of marine mammals are supported along the Chatham Rise by the high primary productivity of its ecosystem.

24. Two data sets of incidental sightings of cetaceans recorded from vessels at sea were used by Torres (2013) to describe the seasonal distribution of cetaceans over the Chatham Rise and within the CRP mining area:

(a) the Cawthorn data set (Cawthorn 2009); and

(b) the DOC sighting data (DOC 2012).

25. These data sets provide 137 records of 12 different cetacean species and one species group (beaked whales) sighted between July 1981 and November 2007.

26. The majority of cetacean sightings recorded within the Chatham Rise study area are of sperm and pilot whales: two highly social, deep diving species that forage for squid along the shelf edge in areas of steep slope and water depths ≥ 500m. Two threatened species: the (Nationally Critical) and the (Nationally Endangered), have been sighted on the Chatham Rise but not within CRP’s proposed marine consent area (CRP Marine Consent Application and Environmental Impact Assessment May 2014). The Crown, in its submission, has included MPI Fisheries Observer Whale Sightings, and Chatham Islands Whale Strandings data collected since 1872 (see comments in Response to submissions). While these data bring the sightings up-to-date they do not, in my view, substantially alter the patterns of whale distribution presented in Torres (2013) and Berkenbusch (2014).

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27. New Zealand waters are host to eight species of baleen whales and 37 species of toothed whales including dolphins and a single porpoise (Baker, A N, 1983). Two species of eared seals, the New Zealand fur seal () and the (Phocarctos hookeri), breed within the New Zealand EEZ.

28. Of the whales and dolphins, 12 species including one species group (beaked whales), have been recorded in Chatham Rise waters between 1981 and 2007 (Torres et al. 2013). The large whales are in transit during north to south migrations in spring to early summer, or south to north migrations in autumn to early winter, across the Chatham Rise. There is no evidence the Chatham Rise is a cetacean breeding area.

29. Toothed whales, particularly sperm and pilot whales, which predominate in sightings, feed on squids in deep water along the northern and southern flanks of the Chatham Rise. Sperm whales exploit the winter spawning concentrations of orange roughy on the sea mounts at the eastern end of the Rise (MWC pers.obs).

30. New Zealand fur seals breed at the Chatham Islands and at Banks Peninsula and forage across the eastern and western Chatham Rise respectively.

31. New Zealand sea lions breed primarily at the subantarctic Auckland and Campbell Islands. There is one small breeding rookery of sea lions at Otago Peninsula. Sea lions are virtually unknown at the Chatham Islands although it is possible they occur there occasionally as vagrants as do elephant seals (Mirounga leonina) and leopard seals (Hydruga leptonyx).

Marine mammal habitat untilisation of the crest of the Chatham Rise

32. When discussing whale ‘habitat’, the term must be qualified for clarity of understanding. Krebs (1985) defines ‘habitat’ as “any part of the earth where that species can live, either temporarily or permanently. Each ‘habitat’ is assumed to have a suitability for that species.” Thus when discussing whales their entire oceanic range is ‘habitat’, as are specific parts of that range used for breeding and feeding.

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33. Most of the large baleen whales range from the equatorial tropics to the Antarctic and back in a calendar year. Their breeding habitat lies between the equator and about 23°S. Most of their feeding is done in cool temperate waters south of New Zealand. Blue whales are one of the exceptions and will feed opportunistically on krill during migration, but like fin whales and humpbacks begin feeding in earnest at about 65°S.

34. Sperm whales, the largest of the toothed whales, calve in the tropics in the latitudes between about 15°S and 21°S, their breeding habitat. Large breeding males, females and immatures then migrate south to about 40°- 42°S where they segregate. Females and immatures head back north, rarely venturing into water less than 1000m deep. The large breeding males and bachelors continue south, pausing en route at favoured spots like and the flanks of the Chatham Rise to feed on fish and squids respectively. At the Chatham Rise they are joined by pilot whales, also open-ocean, deep-water species which feed on squids. The Chatham Rise is a feeding habitat for these species.

35. Other species of cetacean recorded across the Chatham Rise include dusky dolphins, bottlenose, common dolphins and killer whales. None of these animals are known to be deep feeders. Dusky, common and bottlenose dolphins feed on lanternfish, small pelagic school fish and squids. Lantern fish and squids rise toward the surface at night while schoolfish can be taken in near surface water day or night. All these dolphins inhabit the upper 150m of the water column and are unlikely to be found deeper. Killer whales found over the Rise are most likely in transit and searching for dolphins, fur seals or schoolfish. None of these species are dependent on seafloor biota at 400m for food.

CONSERVATION SIGNIFICANCE OF MARINE MAMMALS ON THE CHATHAM RISE

36. All marine mammals are fully protected under the Marine Mammals Protection Act 1978 throughout the entire 200 nm EEZ.

37. The conservation status of the whale species found throughout New Zealand waters was revised in 2009. All marine mammal taxa recorded from the NZ EEZ since 1880 were considered. This included

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migrant and vagrant marine mammals that also occur naturally outside the EEZ, where they may or may not be considered threatened.

38. For non-endemic taxa, the listing provided is based on the status of the New Zealand population only (Baker CS et al., 2010).

39. The conservation status and current Threat Rankings of marine mammals found across the Chatham Rise are presented in Table 1 attached to my evidence.

LIKELY IMPACTS OF THE PROPOSED MINING ACTIVITY ON MARINE MAMMALS BASED ON THEIR ABUNDANCE AND HABITAT USAGE

Ship strikes

40. Ship strikes are difficult to quantify and describe. Although whales may be struck in the water by large or small vessels, the most serious injuries or lethal strikes on whales are caused by vessels ≥ 80 m overall length (oal) (such as container ships, bulk carriers, and large passenger vessels) travelling at speeds in excess of 11.8 knots (Torres 2013). On vessels this size, travelling at this speed, any whale strike would be unlikely to be felt at the moment of impact and thus may not be reported.

41. In the New Zealand region, vessels described above normally make passage, port to port, within 30 NM from shore, and rarely travel across the central Chatham Rise.

42. The only vessels working along the Chatham Rise on a regular basis are New Zealand based fishing vessels and the RS Tangaroa. Most of the deep water fishing on the Chatham Rise uses bottom trawls and the operational speeds of these vessels would be unlikely to exceed 5 knots when not in transit to port. Under these conditions the chance of any ship strike on whales during fishing is infinitesimally small.

43. Similarly, given the mining vessel’s speed during operation (about 1 knot) the probability of a whale strike by the mining vessel is less than that by a trawler under way.

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44. To put this into context, in the 2008 calendar year, 123 fishing vessels performed 18,568 fishing events in the Chatham Rise fisheries management area (FMA3 approximately 42.1° to 46°S, 176°E to the EEZ boundary). There has been no history of whale strikes by any fishing vessel in that, or any other region around New Zealand. The presence of one additional vessel on the Chatham Rise from mining activities by CRP is unlikely to substantially increase the risk of ship strike to cetaceans in the area (Torres et al 2012).

45. Overall, I consider that the risk of injury to marine mammals through ship strike while the mining vessel is operating is very unlikely. The risk of marine mammal strike while the mining vessel is transiting to or from port is no different to the risk posed by fishing vessels operating on the Chatham Rise.

Entanglement

46. Whale entanglements in New Zealand waters are infrequent events. Only 22 whales of all species have been recorded by the Department of Conservation (DOC) entangled in fishing gear since 1977 (about 1.6 per year). 9% (2) of these were southern right whales and 77% (17) were humpbacks. 86% of all entanglements were in rock lobster pot buoylines, predominantly along the east coast of the South Island. It is possible these figures are conservative as it is likely that a few animals which picked up buoylines were never observed.

47. Some species of whales such as humpbacks and right whales are prone to entanglement in fishing gear, particularly where loose lines are involved. Before 1955-66, 16 instances of (sperm) whale entanglement with submarine telegraphic cables were reported in the scientific literature. There has been an absence of reported entanglements since 1959 (Wood and Carter 2008), which the authors attribute to improvements in cable construction and cable laying techniques, such as eliminating slack and the absence of coils of cable on the seafloor in which sperm whales were caught by their lower jaws. The deepest recorded entanglement of this type was of one at 1145 m (Heezen 1957).

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48. In the case of CRP's proposed rock phosphate mining operation, all four cables from the vessel to the drag head and pump frame on the sea floor 350-400 m below will be under tension. The suction pipe through which the phosphate nodules will be brought to the surface will have a diameter of about 750 mm, and similarly the fall-pipe for the unwanted sediment returned to the seabed.

49. As the extraction operation along the top of the Chatham Rise will be some distance removed from the deeper water on the flanks of the Chatham Rise where sperm whales feed, the potential for contact between whales and gear while never zero, is in my view, insignificant. Cetaceans will be able to perceive the lines and pipe rising to the surface visually and acoustically.

50. Any sperm whales encountered near the extraction zone will be in transit across the Chatham Rise and will not be making deep dives. The chances of these animals becoming involved in any way with the drag head on the bottom, its supporting cables and suction pipe, or the vessel at the surface are, I believe, exceptionally low.

51. Overall, I consider entanglement with the operational cables and pipes is a very low risk for small marine mammals on the Chatham Rise and larger mammals transiting the Rise. The risk to larger mammals deep diving on the flanks of the Chatham Rise is also considered to be low as the start points for dives will be located away from the mining area.

Noise

52. All whales are acoustic animals, relying on sound for communication, navigation, echolocation of prey and perception of their surroundings. Wherever they are there is always noise generated by biological sources such as fish, invertebrates, other whales, weather and sea conditions, geological sources such as volcanoes and earthquakes, and anthropogenic sources such as shipping and fishing. Together these background noises constitute the ambient noise in the marine environment.

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53. Whales are therefore very sensitive to any sounds different from or above the ambient level. If these sounds are from anthropogenic sources, such as seismic profiling, mining, or military echo sounding, they can compromise the whales’ ability to communicate, find food, find mates, navigate, avoid predators and, in extreme circumstances, can cause changes in behaviour, excessive stress and physiological damage leading to death.

54. Baleen whales are low frequency specialists that use sound predominantly for communication and vision for prey location, whereas all toothed whales use sound for communication, perception, navigation and foraging. Torres et al (2013a) provides information on the vocalisation ranges of different marine mammal species, which can be used to understand whether masking impacts of mammal communications by anthropogenic noise may occur. A summary of the vocalisation ranges of key marine species sighted in and near the proposed marine consent area is in Table 2 (CRP Marine Consent Application and Environmental Impact Assessment 2014, p 348).

55. There is some overlap in the dredger noise spectrum and the functional auditory range of dolphins, but GHD (2012) indicated that interference with dolphins’ bio-sonar and communication is only possible at distances less than 500 m from a dredger vessel.

56. WODA (2013) suggests that permanent threshold shifts in hearing (TS) (deafness or physical injury) were extremely unlikely to occur due to the low noise emissions from a dredging vessel as measured by various studies globally.

57. Behavioural responses and temporary threshold shift (TTS) are the most serious effects that may arise from dredging noise on marine mammals in the CRP proposed mining area. TTS will only occur if the marine mammals stay within a certain range of the vessel for an extended period of time. The noise emissions from the proposed mining operations are likely to be loudest below and around 1 kHz, outside the range of greatest sensitivity of the dolphin and toothed whale species found on the Chatham Rise.

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58. GHD’s (2012) predictions based on likely noise impacts from a trailing suction hopper dredger (including the vessel and all components of the dredging system) indicate that it is unlikely that dolphins will be impacted by dredging operations such that the predicted noise exposure level is more than 183dB re 1µPa²-s at 1m, half that specified by the Seismic Code at 200m (186dB re 1µPa²-s).

Behavioural response

59. It is possible that drag head and vessel noise could result in some marine mammal species moving away from the sound source. In the case of the trailing suction hopper dredger system assessed by GHD (2012), notable impacts were predicted to occur only if a marine mammal was to remain within 50 m of the dredge for 12 hours per day. This is considered highly unlikely for CRP’s mining operation.

60. The duration of the disturbance would also be limited to the mining area for about 4-5 days during mining operations. Displacement of marine mammals, should it occur, is therefore expected to be of short duration over a small area limited to the location of the vessel during each 4-5 day mining period.

Human induced changes to marine environment

61. CRP’s proposed mining operation will undoubtedly disrupt the benthic environment for some time. However any detrimental effects from this disruption on marine mammals are expected to be short term, small scale, and unlikely.

62. The disruption of the benthic environment is unlikely to affect marine mammals. Most of the feeding is done by toothed whales (sperm, pilot and beaked whales) in deep water along the flanks of the Chatham Rise. Dolphins feed predominantly in the upper part of the water column. Sightings of rorquals (blue, fin, sei, and minke whales) and humpbacks suggest that they cross the Chatham Rise during their migration, when they rarely feed.

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63. Southern right whales remain offshore from April to October when they pursue large aggregations of copepods on which to feed. On the south eastern Chatham Rise, one individual has been observed feeding among vessels of the NZ fishing fleet (MWC pers obs). They are skim feeders that utilise the surface layers of the water column and are frequently seen swimming at the surface with their mouths open. They are unlikely to be affected by any suspended sediment from the mining operation on the centre of the Chatham Rise.

Pollution

64. The main environmental toxins that are currently a concern for populations of marine mammals are persistent organic pollutants (POPs) and include PCBs, PBDEs, dioxins and furans. Pollutants can also include oil pollution derived substances, marine debris, metals, sewage-related pathogens, excessive amounts of nutrients causing environmental changes, and radionuclides. Mr Kennedy discusses this further in his evidence.

65. If an oil spill or other chemical release were to occur due to mining operations, these toxins could bio-accumulate in marine mammals and have long-term effects on individuals and populations. However, given the range of marine mammal species and the nature of the proposed mining project, the impact of pollution on these animals is likely to be negligible (Torres et al 2013).

MITIGATION EFFECTIVENESS

66. The potential for prolonged overlap of marine mammals with the proposed mining operation is in my opinion low, the percentage of marine mammal populations that might be affected is small to negligible, and the impacts are recoverable and unlikely to affect marine mammal species at the population level.

67. The likelihood of overlap is mitigated by the inclusion of pre-start observations to avoid interactions with marine mammals, and regular observations for their presence in the vicinity of the mining vessel.

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68. Mining operations are expected to occur for 4-5 days, followed by about 6 days when the vessel is in transit or in port, limiting the time when marine mammals could be affected by the mining operations.

69. The observations of marine mammals along the Chatham Rise indicate that a significant proportion of a species’ population is unlikely to pass close to the mining operations. Avoiding areas with high noise levels is likely to provide effective mitigation to mobile marine mammals and cumulative injury is unlikely to occur.

70. Although this assessment indicates there is a low environmental risk of any adverse impact on marine mammals, a mitigation zone around the mining vessel will be employed as a matter of good practice. A mitigation zone will be scanned around the vessel for at least 10 minutes before the start of mining. If marine mammals are observed in the mitigation zone, mining will not commence until they have left the area (having not been observed for at least 30 minutes). This mitigation will ensure that the area in and around the mining vessel, and thus the mining activity on the seabed, is clear of marine mammals before commencement of mining operations. The potential impact, following the utilisation of this proposed avoidance measure, remains a low environmental risk (CRP MCA and EIA vol.1 May 2014).

RESPONSE TO SUBMISSIONS

71. I reviewed submissions from Crown Law, Ngai Tahu, ECO, Deepsea Conservation Coalition and Greenpeace (these two are identical hence a single response) and KASM which raised matters concerning marine mammals.

The Crown

72. In paragraph 3 on page 21 of the Crown's submission the Crown states: "The application does not provide detailed information about abundance, distribution and use of the proposed mining area by marine mammals … the application does not provide specific or robust data either from systematic observational surveys or Passive Acoustic Monitoring."

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73. No dedicated systematic marine mammal surveys across the Chatham Rise, an area slightly larger than the South Island, have ever been undertaken. The reasons include availability of suitable vessels, lack of funding, changing government and departmental policies and priorities, initial lack of qualified observers, and the constraints imposed by very vigorous wind and sea conditions, etc. The use of Passive Acoustic Monitoring (PAM), while highly desirable, is also constrained by the level of ambient noise, the continuity of whale vocalisations, and anthropogenic noise from an active fishing fleet and vessels in passage. It might be possible to conduct aerial surveys along the Rise, however the availability of suitably experienced aircraft crews and observers coupled with the weather in the area would make this method extremely expensive, time consuming and difficult to achieve.

74. The alternative to the above is to use incidental sightings collected by the crews, observers and others aboard vessels working across the Chatham Rise. It is important to ensure the data collected are done so systematically. The data from the Cawthorn dataset were collected by trained, experienced observers using standardised data forms. All sightings were audited on receipt. Those improperly completed were rejected and not entered into the data base. The forms used by DoC are similar to the previous forms and completed with similar rigour. The MPI Observers who man all fishing vessels are trained in their use. It is accepted that some species of whales which are difficult to observe at sea, such as beaked whales, will be under-represented in the record. Nevertheless, these data sets represent the most comprehensive data base of marine mammal species observations at sea collected throughout the New Zealand region. Strandings undoubtedly provide useful information on species in the area of stranding, but as these are random events generated by natural mortality, disease, storms, starvation, or any number of events they cannot be considered systematic information (see paragraph 78 above).

75. I am unclear what is intended by paragraph 6 on page 22. However, I note that descriptions of the use of marine mammals of crest of the Chatham Rise is set out in paragraphs 32 to 35 above and in the species accounts below. I reiterate that significant data about marine mammal use of the Chatham Rise is readily available and that dedicated marine

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mammal surveys of the Chatham Rise would be a difficult and disproportionately large and expensive exercise.

Ngai Tahu

76. The parts of Ngai Tahu's submission, its CIA and the report prepared by Anton van Helden (see footnote 10 of the CIA) that focus on the distribution of marine mammals, the reliance on sighting data and the potential effects on marine mammals have been addressed by my earlier evidence or response to the Crown's submission.

77. Mr van Helden's observation that sightings data are inevitably skewed to readily visible animals is accepted. However, as the volume of sightings increase over time the less frequently encountered species begin to appear in the record.

78. While strandings data are helpful it should be remembered that strandings on the Chatham Islands are random events which occur some distance from the marine consent area and usually give no indication where the animals involved came from. The numerical dominance of stranding events in the record does not substantially alter the seasonal pattern derived from the sightings data. Similarly, the roughly bimodal stranding record of sperm whales confirms the migratory pattern of this species. The dominance of Gray’s beaked whales in the stranding record is also expected (see species accounts).

Greenpeace and Deep Sea Conservation Coalition Incorporated

79. Greenpeace and the Deep Sea Conservation Coalition Incorporated state at page 16"CRP does not appear to have completed any surveys of the Marine Consent Application Area for marine mammals during any of their six research expeditions, using either visual or acoustic survey methods."

80. As mentioned above, to complete dedicated marine mammal surveys of the marine consent area would be prohibitively costly and would take years to complete. Hence, the initial reliance on the considerable amount of incidental sightings data already collected (1970-2014) covering all

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seasons is entirely reasonable and satisfactory. Acoustic surveying methods such as PAM are subject to considerable limitations discussed above.

ECO

81. It is suggested the proposal will impact on sperm and pilot whales, and at least the southern flank of the Chatham Rise is probably an important foraging habitat for southern right whales in winter.

82. In relation to this submission, please see my evidence above and species accounts. ECO's statement that the proposal will impact on sperm and pilot whales is, in my view, incorrect.

KASM

83. On paragraph 4 of page 31 KASM state: "There are only approximately 900 southern right whales with fewer than ‘a dozen’ reproductive females remaining in New Zealand and cows with calves inhabit coastal waters."

84. In 1998 the New Zealand population of right whales was estimated to number 900 individuals, based on mark recapture models of individuals identified from DNA profiles and photographs of natural markings (Carroll et al 2011b). More recent work integrating DNA profile data from 1995- 2009 suggests the population has approximately doubled since 1998 (Carroll et al 2011c).

85. At paragraph 1 on page 32 KASM state: "The effectiveness of Marine Mammal Observers and PAM is questioned."

86. There are always limitations to the effectiveness of any observers on vessels or in aircraft in sighting whales at sea. Nevertheless, in the absence of any other alternative, the Fisheries Observers who have to collect whale observations in a structured manner, at regular hours during daylight, is the best option we currently have for the collection of whale sightings across such a large area as the Chatham Rise. The limitations of PAM are well known and understood.

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CONCLUSION

87. Recorded sightings of cetaceans in the Chatham Rise area are dominated by sperm and pilot whales which forage along the steep, productive, northern and southern flanks of the Chatham Rise. Humpback whales and rorquals (blue whales, fin and sei whales, and minke whales) transit the Chatham Rise during their northward and southward migrations. Killer whales can be expected in the area of the Chatham Islands in autumn when New Zealand fur seal pups are weaned and take to the sea alone. Southern right whales forage along the south side of the Chatham Rise and beaked whales are found over the south eastern end of the Chatham Rise.

88. Potential impacts from CRP's proposed mining operation will probably be limited to displacement by noise and disturbance of the substrate. Both of these effects are likely to be short term and localised. Vessel strikes on whales are most unlikely to occur because of the very slow operational speed of the mining vessel. However, best watchkeeping practice must apply at all times while in transit to avoid any whale strikes.

Martin Cawthorn 25 August 2014

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REFERENCES (cited in this evidence)

Baird, SJ 2011. New Zealand fur seals – summary of current knowledge. New Zealand Aquatic Environment and Biodiversity Report No.72. Ministry of Fisheries, Wellington 2011.

Baker, AN 1983. Whales and dolphins of New Zealand and Australia: an identification guide. Victoria University Press.

Baker, CS, Chilvers BL, Constantine R, DuFresne S, Mattlin RH, van Helden A, & Hitchmough R 2010. Conservation status of New Zealand Marine mammals (suborders Cetacea and Pinnipedia) 2009, NZ Journal Marine and Freshwater Research, 44:2, 101-115.

Bannister J L 2008. Great Whales, CSIRO Publishing 142pp.

Berkenbusch K, Abraham ER, Torres LG, 2013. New Zealand marine mammals and commercial fisheries. New Zealand Aquatic and Environment Group Report No. 119. 104pp.

Carroll,EL, Patenaude NJ, Childerhouse SJ, Kraus SD, Fewster RM, Baker CS, (2011b). Abundance of the New Zealand subantarctic southern right whale population estimated from photo-identification and genotype mark-recapture. Marine Biology 158(11):2565-2575

Cawthorn MW, 2009. Incidental cetacean sighting records by transiting ships between New Zealand and overseas ports. Cawthorn & Associates, Plimmerton, New Zealand.

Childerhouse,S.J., Dawson,S, Slooten,E. 1995. Abundance and seasonal residence of sperm whales at Kaikoura, New Zealand. Canadian Journal of Zoology, 1995, 73(4): 723-731, 10.1139/z95-084

CRP Marine Consent Application and Environmental Impact Assessment, May 2014. Vol.1, 452pp

Evans,P.G.H. 1987. The Natural History of Whales and Dolphins. Christopher Helm. 343pp.

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GHD 2012. Underwater Construction and Operational Noise Impact Assessment. Rept. for Port expansion Project Appendix K3 of Port Expansion Project EIS for the Port of Townsville Ltd p 54 and appendices.

Heezen BC, 1957. Whales entangled in deep sea cables. Deep-Sea Research Vol.4: 105-115.

Krebs, C.J. 1985. Ecology: The experimental Analysis of Distribution and Abundance. 3rd edn. Harper & Row, New York. 800pp.

Olsen PA, Ensor P, Olavarria C, Schmitt N, Childerhouse S, Constantine R., Miller BS, Double MC, 2013. New Zealand blue whales: initial photo-identification of a little known population. IWC SC/65a/SH12.

Richards R 1994a. The ‘upland’ seal of the Antipodes and Macquarie Islands: an historian’s perspective. Journal of the Royal Society of New Zealand 24:289-295.

Taylor R, 1992. New Zealand fur seals at the Antipodes Islands. Journal of the Royal Society of New Zealand, 22: 107-122.

Taylor R, 2006. Straight through from London: The Antipodes and Bounty Islands, New Zealand. Heritage Expeditions 415pp.

Torres LG, Halliday J, Sturman J. November 2012 (Updated April 2013) Distribution Patterns of cetaceans on the Chatham Rise. NIWA Client Report No: 12302

World Organisation of Dredging Associations (WODA) 2013. Technical Guidance on: Underwater Sound in Relation to Dredging. June 2013. 8pp.

Wood,M.P.and Carter L. 2008. Whale entanglements with submarine telecommunication cables. IEE Journal of Ocean Engineering Vol 33(4): 445-450

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APPENDICES

Table 1. Threat Rankings for marine mammal species found across the Chatham Rise (after Baker 2010). Common name NZ Threat Status IUCN Classification Antarctic Migrant Endangered Fin whale Migrant Endangered Sei whale Migrant Endangered Antarctic minke Not threatened Data deficient Migrant Endangered Southern right whale Nationally endangered Least concern Sperm whale Not threatened Vulnerable Pilot whale Not threatened Data deficient Killer whale Vagrant Data deficient False killer whale Not threatened Data deficient Beaked whales Data deficient Data deficient Nationally endangered Data deficient Not threatened Least concern Not threatened Data deficient New Zealand fur seal Not threatened Least concern New Zealand sea lion Nationally critical Vulnerable Nationally critical Least concern Vagrant Least concern

Table 2. Vocalisation ranges of whales and dolphins within and near CRP’s proposed marine consent area (based on Torres et al. 2013a).

Cetacean species Vocalisation frequency range (kHz) Sperm whale (Physeter macrocephalus) 0.1 to 30 Common dolphin (Delphinus delphis) 0.2 to 150 Killer whale (Orcinus orca) 0.1 to 35 Dusky dolphin (Lagenorynchus obscurus) 1.0 to 27 Bottlenose dolphin (Tursiops spp.) 0.2 to 150 (Balaenoptera bonaerensis) 0.06 to 6.0

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32. Species Accounts

Sperm whale (Physeter macrocephalus)

Sperm whales occur in New Zealand waters in offshore and nearshore regions and are widely distributed from areas around the Kermadec Islands to the subantarctic and Chatham Islands

Sperm whales are the largest of all toothed whale species. They are cosmopolitan occurring in all oceans from equatorial to polar latitudes. Their wide geographical distribution, long migrations and lack of clear genetic differences prevent identification of population boundaries on a global scale.

Sperm whales are particularly distinctive and difficult to confuse with any other species. They are the most sexually dimorphic of all cetacean species. Adult males grow to 18.5m length while females reach only 12m. This sexual difference is reflected in the sperm whales’ seasonable distribution. Normally solitary adult males compete with one another for access to nursery groups of social adult females for mating. At this time, the sexually mature but non- breeding males which have left their maternal groups, form bachelor herds.

Births occur in summer but reproductive rates are very low. Cows with calves and attendant males migrate south and at 40°S - 42°S the cows and their ‘families’ turn around and head north once more where surface water temperatures remain above 15°C. The bachelor herds, including large males, head south toward the colder high latitudes, pausing en route to feed at areas where significant upwellings are generated by currents and steep seafloor topography, such as the Ritchie Bank, Palliser Bay, Kaikoura, the Chatham Rise and associated sea mounts and Solander Trough.

Sperm whales are predominantly found in waters deeper than 1000m in the open ocean and over the continental slope where they dive to several hundred metres to prey on deep-water squids and fishes. Their foraging dives to 600m and deeper, last about 45 minutes with brief surface intervals of several minutes between dives. Adult sperm whales spend more than 70% of their time foraging. Sperm whale distribution has been related to biologically productive areas supporting high squid biomass. Sperm whales are found around the margins of the Chatham Rise in all seasons of the year where they can feed on squid and preferred fish species particularly orange roughy taken off the seamounts in autumn and winter months.

Only recently have sperm whales been studied at sea in any detail. Off Sri Lanka one school of identified individuals was tracked over c. 140km during a 10 day period as it moved first north and then south along a 50km section of the continental shelf edge. The same whales were found in exactly the same location when resighted one year later, suggesting a surprising degree of long- term site fidelity for such an oceanic animal (Evans,P.G.H. 1987). Similar observations were made at Kaikoura in 1963 and 1964 when two very large battle-scarred male sperm whales were tagged in the South Bay area (Cawthorn pers. obs). The presence of sperm whales along the flanks of the Chatham Rise is another demonstration of site fidelity to a feeding habitat by this species.

Recent research in New Zealand has focussed on the Kaikoura area where, between 1988 and 1993, Childerhouse et al (1995) individually photo-identified

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86 sperm whales by distinguishing marks on their tail flukes. Re-sightings over the research period showed that some whales spend several weeks or months in the area. Half were seen in more than one field season, one individual was seen every year from winter 1989 to winter 1992, and like several others appears to return to the area regularly. Others (35%) were photographed on one day only and were probably transients. Almost all (88%) of the sightings were of single whales. Data analysis suggested an average population of between 60 and 108 sperm whales present in any one season. The Kaikoura sperm whale population occupies an area of about 10 by 15 nm and is the focus of the local whale watching industry. It should be noted that the Kaikoura sperm whales are but a component of the migrating males which pass north and south each year.

Pilot whale (Globicephala spp.)

Two species of pilot whales are found globally, the long-finned and short–finned pilot whales, both of which occur in New Zealand waters. Pilot whales are highly gregarious and will form aggregations of several hundred to more than a thousand. They are distinguished by the length of flippers. They can easily be confused when seen at sea, however short-finned pilot whales prefer warm temperate to tropical waters while long-finned pilot whales are mostly found in cold-temperate and sub-antarctic waters. In the New Zealand region, sightings occur throughout all seasons. They are frequently observed along the margins of the Chatham Rise in all seasons. Long-finned pilot whales are probably the most frequently stranded species in New Zealand. They come ashore as mass strandings at Farewell Spit and around the coast of Chatham Island where 1,000 animals were recorded ashore in 1918. Long-finned pilot whales are primarily squid feeders and will also take schoolfish such as mackerel, hake, and dogfish. Most feeding appears to take place at depths of 200-500 metres.

Common dolphin (Delphinus spp)

There are two recognised species of common dolphins, short beaked (Delphinus delphis) and long beaked (Delphinus capensis). Short beaked common dolphins are widely distributed and abundant throughout tropical and temperate zones in the Atlantic and Pacific oceans, including New Zealand waters. Abundance data for common dolphins are generally lacking, but the global population size has been estimated to exceed 4,000,000. The size of the New Zealand population is unknown but they are probably the most numerous of all species of dolphin in New Zealand waters and are distributed along the coasts of both main islands, across the Chatham Rise and into subantarctic waters. Common dolphins feed on small school fish and squids, including epipelagic species. They will feed at night around fishing vessels drawn to the ships by small schoolfish and squids attracted by deck lights and as a consequence have been taken accidentally by jack mackerel trawlers as accidental bycatch. Common dolphins are numerous around Cook Strait and have been observed forming ‘super schools’ travelling through the Strait from west to east continuously over a 7 hour period (MWC pers.obs). Common dolphins will form feeding associations with Bottlenose and Dusky dolphins.

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Killer whale (Orcinus orca)

Killer whales are among the most distinctive and easily recognised of all cetaceans. They are distinctively black and white, males have a tall erect triangular dorsal fin which can reach 1.8m height and in some males may be canted slightly forward. The dorsal fins of females and immature males are falcate. The flippers are large and broad with oval blunt tips. Killer whales have blunt snouts and poorly defined beaks. New born calves are 2m-2.5m long and 160-180kg. Adult females reach 8.5m long and adult males 9.8m and nearly 10,000kg weight

Killer whales are a cosmopolitan species occurring in tropical to polar waters. In the southern hemisphere different morphological forms of these whales have led to a review of their taxonomy. Currently however they are divided into “types” A to D based on characters such as the relative size of the eye patch, the extent of dorsal colouring and overall length. In New Zealand waters types A (resident), Type A (offshore, transient) and Type B may be seen. Type C killer whales are restricted to the Antarctic.

Killer whales are known to prey on marine mammals of all sizes from blue whales to dolphins and seals. They will take and in New Zealand they are known to forage close inshore in pursuit of rays and other fish. They feed cooperatively and an entire pod will work together to ensure prey such as seals are taken from rocks or ice. They are known to return to specific feeding areas at the optimum time of year to exploit the species they feed on (e.g. the Wellington coast in September – October for rays, fur seal rookeries in Cook Strait and Foveaux Strait in autumn for fur seal weaners).

Killer whale families are among the most stable units in the animal kingdom. Like elephants, they are matrilineal and members will remain in the family group for most of their life.

Dusky dolphin (Lagenorhynchus obscurus)

Dusky dolphins are coastal dolphins occurring in waters above the continental slope and shelf, usually less than 2000m depth. In New Zealand, this species exhibits some inshore-offshore shifts in abundance, moving into deeper waters in some areas. Between 1970 and 2013, there were comparatively few sightings in North Island areas revealing a prevalence of dusky dolphin in southern areas, including Stewart Island and south to the subantarctic islands. This is a gregarious, energetic species with groups of 1- to 20 animals being common. They will form aggregate ‘super schools’ of 100s to 1000s of individuals in the open ocean. In New Zealand waters sexual maturity of males and females is about 7 to 8 years of age, with most calving occurring in winter and spring after a gestation of about 11.4 months. Dusky dolphins feed on a variety of prey ranging from southern anchovy in shallow water to squid, hake and lantern fishes in deeper water.

Bottlenose dolphin (Tursiops spp)

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Bottlenose dolphins are found throughout the New Zealand 200nm EEZ with three separate coastal regional subpopulations in Bay of Islands, Marlborough Sounds and Fiordland (Baker et al 2010a). These three groups are genetically distinct, with little or no maternal gene flow or exchange among them. Bottlenose dolphins feed on a wide variety of squid species and both benthic and pelagic fish. Age at sexual maturity varies between regions. Females are sexually mature between 5 and 13 years and males between 9 and 14 years. Gestation lasts about 12 months with a calving interval of 3 to 6 years. Bottlenose dolphin females have a reproductive lifespan of about 48 years. Female longevity is over 57 years compared with 48 for males (Berkenbusch 2013).

False Killer whale (Pseudorca crassidens)

False killer whales are generally found in tropical to warm temperate waters in the south west Pacific Ocean with only a few observations of this species in cool temperate water. They are usually found in deep, offshore oceanic waters but on occasions move across the New Zealand continental shelf. They are typically found in groups of 20 to 100 individuals. Like many other social, oceanic toothed whale species, false killer whales will occasionally mass strand when they get too close to shore. In March 1978, 231 false killer whales came ashore at Manakau Harbour. A similar stranding of 172 at Black River Beach, Tasmania in June 1974 involved pregnant females with foetuses 1.2m to 1.6m long suggesting a winter calving season between 36°S and 42°S. This species feeds on squids and fish and will also take other cetaceans. They appear to have few threats but were observed in 2010 in the Bay of Islands being taken by killer whales. They were also observed twice in 2011 in feeding associations with bottlenose dolphins in Hauraki Gulf.

Beaked whales (Family Ziphiidae)

The Beaked whales are a cetacean group which has been poorly researched because the group are deep water, deep diving, squid eating toothed whales which live in the open ocean, usually far from land. Beaked whales are difficult to see in the open ocean as they are generally cryptically coloured and with only a few exceptions form groups of more than 3 to 5 animals. The majority of information on these whales has been derived from very infrequent strandings. New Zealand has long been identified as a ‘hotspot’ of diversity with one species, Gray’s beaked whale(Mesoplodon grayi), predominating with over 250 strandings recorded since 1970. The largest member of the Southern Hemisphere beaked whales, Arnoux’s beaked whale reaches a maximum length of about 9.5m. Beaked whales will approach land where the continental shelf in steep and narrow or congregate where seamounts and upwellings are prominent e.g. the eastern end of the Chatham Rise..

Baleen whales

Blue whale (Balaenoptera spp)

Two of the three Southern Hemisphere subspecies of blue whales occur in New Zealand waters, the Antarctic blue whale Balaenoptera musculus intermedia and the pygmy blue whale B.m.brevicauda. During the austral summer Antarctic blue whales are rarely found north of 55°S, whereas pygmy blues are rarely found south of this latitude. Both species feed almost exclusively on euphausid krill throughout

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their ranges hence they are most frequently found in areas of cold water upwelling where krill are often concentrated.

Recent records including photo-identification and sound recordings, confirm the presence of blue whales throughout New Zealand waters. Preliminary observations of feeding off the west coast of the South Island in January 2013 and strong evidence of feeding off the east coast of the South island in March 2013 suggest these whales are more similar in appearance to the blue whales off Australia than to Antarctic blue whales(Olsen et al 2013)

Sei whale (Balaenoptera borealis) Fin whale (Balaenoptera physalus)

Both sei and fin whales are cosmopolitan species generally found in deep offshore water beyond the continental slope. They are mostly solitary during migration but will form large feeding aggregations of 20-100 individuals. During summer months they occupy waters between 45°S and 65°S. Sei whales live largely between the Antarctic and subtropical convergences while fin whales move somewhat further south than sei whales. Identification of fin whales at sea can be difficult as they are known to hybridise with blue whales. Age at sexual maturity for male Southern Hemisphere fin whales is 6-7 years; females7-8 years. For sei whales age at sexual maturity is about 10 years for both sexes. Both species are migrants within the New Zealand region (Berkenbusch 2013).

Minke whale (Balaenoptera bonaerensis)

Minke whales occur widely in coastal and offshore areas of the Southern Hemisphere from at least 7°S to the Antarctic pack ice. In general they are more oceanic than dwarf minkes. Known breeding grounds occur off Brazil, South Africa and Australia. They migrate to the Antarctic to feed through the austral summer. Annual and biennial breeding may be the norm and peak calving occurs in July and August after a gestation of about 10 months. Killer whales are important predators on this species. Most of their food is made up of krill although they will take small schoolfishes. The IWC has calculated the Southern Hemisphere population of this species (south of 60°S) to be about 750,000.

Humpback whale (Megaptera novaeangliae)

Compared with most other baleen whales humpbacks are rather stocky whales reaching about 16m. Their defining feature is their long wing-like flippers which are about 1/3 of their total length. Their colour is black above, white beneath continued through to the tail flukes. The colour pattern of the ventral surface of the flukes is distinctive and used to individually identify animals.

Humpbacks which migrate past New Zealand breed in the waters around New Caledonia, Fiji and Tonga. Mating and calving occur in winter after a 10-11 month gestation. Following calving the humpbacks return south and on reaching New Zealand split into 2 groups. One moves south along the east coast and on reaching East Cape they head due south toward the Bounty Islands. The other group travels down the west coast 20-50 nm offshore roughly along the 200m isobath through the Tasman Sea. They pass Stewart Island in October – November heading for the Antarctic feeding grounds. The northern migration of humpbacks takes place in winter (May-August) with the majority of the whales travelling in a straight line between Otago Peninsula and Banks Peninsula. From there they move a little closer inshore toward Kaikoura and parallel the shore to Cook Strait where the majority of the migrants swing northwest toward Cape Egmont and stay offshore as the move past North Cape.

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Feeding takes place mainly in Antarctic waters almost exclusively on krill. However, along the New Zealand coast on migration they will take ‘lobster krill’ the larval stage of Munida gregaria, opportunistically.

Commercial whaling throughout the whales’ range reduced the humpback numbers so much the stock ‘crashed’ around 1960 and commercial whaling on humpbacks ceased. Since that time, recovery of the east Australian stock has been slow but positive reaching about 10.6% per year. (Bannister 2008).

The most recent abundance estimate for Oceania humpbacks (Constantine et al 2012) totalled 4,329 (95%c.i.:3,345 to 5,313) humpbacks in 2005 representing the least abundant breeding population of humpbacks in the Southern Hemisphere

Southern right whale (Eubalaena australis)

Southern right whales are a large robust species characterised by the clusters of callosities over the eyes, the blowhole, running forward to the snout, along the lower lips and lower jaw. These are individually unique and can be used to identify individual animals. The other singular feature is right whale are the only large whales lacking a dorsal fin. The blow is characteristically “V” shaped. They are found in inshore waters in winter and spring, occasionally within the surfline in company with their calves. Mating occurs in winter with a 12 month gestation and birth in July-August. There is a well defined 3 year calving interval which may extend to 5 years depending on food availability. Right whales from the New Zealand stock have been shown to cross the Tasman Sea to mingle with those of southern Australia. Right whales are ‘skim feeders’ taking their copepod prey at the water close to the surface. The pre-whaling southern hemisphere population was probably around 65,000. It reached a low point of about 300 in the 1920s and with the benefit of full protection had risen to 7,500 in 1977, but with a doubling time of10 years the population must now be about 1, 500 animals (Bannister, 2008). Carroll et al (2011b) estimated the New Zealand population to be about 908 right whales.

New Zealand Fur Seal (Arctocephalus forsteri)

New Zealand fur seals are distributed around all of New Zealand and its offshore islands, the subantarctic islands (including Macquarie I.), and the south coast of Australia. Fur seals from the New Zealand region have been found to be genetically isolated from those in Australia.

New Zealand’s pristine fur seal population was substantially reduced by Polynesian subsistence hunting in the 400 or so years before European arrival. Fur seals were a major source of meat for Maori through the early centuries of human settlement and matched the importance of at many sites. The unrestricted depletion of mainland seals by Maori was in direct contrast to the selective take on the Chatham Islands where fur seals were the most important food source for Moriori who maintained a viable fur seal population through until European arrival.

European sealing began in 1792 and continued until 1875 when sealing was no longer commercially viable and the government first began to apply controls to the fishery. The last officially permitted take of seals was a government sanctioned cull in 1946. Since that time the seal population has recovered and breeding has slowly expanded northward. The most northerly breeding rookery is located at Gannet Island near Kawhia Harbour on the west coast of the North Island.

Fur seals are annual breeders producing one pup after a 10 month gestation. Pups are born in late November – December, and females mate soon after. Males

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disperse to haulouts often in more northern areas and females return after foraging trips to suckle their pups for the next 8 -12 months after which they are weaned.

Fur seals are vulnerable to bacterial diseases, parasites and environmental contaminants. A major stressor which can precipitate the onset of disease is low food volume or quality resulting from La Niňa summers. They are also taken in commercial trawl fisheries as incidental by-catch and predated upon by sharks, leopard seals, killer whales and New Zealand sea lions.

No formal population estimates of the fur seal population at the Chatham Islands has been made. DOC personnel at Waitangi could only suggest that “ it appeared to be increasing”.

The present size of the New Zealand fur seal population is unknown but has been “guesstimated” to be between 100,000 and 200,000 (Taylor 2006).

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