Marine mammals and potential impacts from the TTR mining operation -

Second Expert Supplementary Statement

22 May 2017 1TTR Marine Consent Application

Dr Simon ChilderhouseBlue Planet Marine New Zealand Ltd

Nelson, New Zealand

www.blueplanetmarine.com

Second Supplementary Statement

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Item How covered

Sensitivity of hearing of marine mammals Oral

Updated summary of marine mammal data in Taranaki Oral – Slide 3

Rerun of habitat modelling Second Supplementary Evidence

Predicted noise level contours for mining Mr Humpheson

Additional relevant cetacean evidence Oral

Define all noise sources and incorporate into modelling Mr Humpheson

Modelling of noise propagation Mr Humpheson

Modelling of background and project noise Mr Humpheson

Graphical representation of noise within 100km Oral – Slide 4

Integration of USA NOAA and other noise guidelines Oral – Slide 5-10

Present draft results to expert caucus Second Supplementary Evidence

Review other noise related evidence provided by other parties Oral – Slide 11

Noise contour maps Mr Humpheson

Marine mammal spatial data Second Supplementary Evidence

Second Supplementary Evidence of van Helden Oral – Slide 12

Duncan et al. Review of Humpheson acoustic report Oral – Slide 13

Updated marine mammal data

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Blue whale records

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Noise guidelines

When reviewing potential impacts, is it important to be able to reference credible threshold levels to be able to usefully comment on impact.

I updated my original impact assessment in the following ways:

Applied new results from Mr Humpheson’s sound propagation model

Applied updated USA Government thresholds for the assessment of acoustic impact on marine mammals:

NOAA Interim Interim Sound Threshold Guidance for behavioural impacts

NOAA Marine Mammal Acoustic Technical Guidance for Permanent Threshold Shift (PTS)

No update for Temporary Threshold Shift (TTS)

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Threshold for behavioural impact

NOAA is developing comprehensive guidance on sound characteristics likely to cause injury and behavioural disruption in the context of the Marine Mammal Protection Act (MMPA), Endangered Species Act (ESA) and other statutes.

Until formal guidance is available, NOAA Fisheries uses conservative thresholds of received sound pressure levels from broad band sounds that may cause behavioural disturbance.

NOAA have now developed formal advice on PTS in the Marine Mammal Acoustic Technical Guidance but updated advice on behavioural disturbance is not available and therefore the Interim Threshold still applies.

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Threshold for behavioural impact

The key issue with this Interim Sound Threshold Guidance is that the thresholds are set consistent with requirements of the USA legislation and regulations. Also given their interim nature, these thresholds have been set conservatively.

While the USA legislation and regulations differ from New Zealand ones, they have broadly similar aims and objectives. Furthermore, these thresholds are based on the best available science for assessing impacts on marine mammals and, therefore to a degree are independent of policy documents.

Overall, it is appropriate to apply the USA Interim Threshold for behavioural impact to assess the potential impacts of noise on New Zealand marine mammals.

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Threshold for behavioural impact According to the USA MMPA under which the Interim thresholds have

been developed, the definition of “harassment” includes any activity which “… has the potential to disturb a marine mammal or marine mammal stock in the wild by causing disruption of behavioural patterns, including, but not limited to, migration, breathing, nursing, breeding, feeding, or sheltering”.

NOAA themselves note that this is a conservative application in that an activity only has to have the potential to disrupt behaviour although given the highly variable response of marine mammals to acoustic stimuli, it is appropriate to take a conservative approach.

The exact behavioural disturbance resulting from exposure to the source has also been set conservatively and the disturbance may be simply:

a marine mammal changing swimming direction and moving away from the noise source;

a brief or minor separation of mothers and calves; or

an extended cessation of vocal behaviour. 8

NOAA interim sound thresholds Behavioural threshold from NOAA Interim Sound Threshold Guidance

120 (dB re 1 μPa)

Permanent Threshold Shift (PTS) from NOAA Marine Mammal Acoustic Technical Guidance for Permanent Threshold Shift (PTS)

Temporary Threshold Shift (TTS) from Finneran & Jenkins (2012)

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Marine Mammal group Interim criteria for PTS New criteria for PTSLow frequency cetaceans 190 dBrms LE,LF,24h: 199 dB

Medium frequency cetaceans 190 dBrms LE,MF,24h: 198 dB

High frequency cetaceans 190 dBrms LE,HF,24h: 173 dB

Pinnipeds 180 dBrms LE,PW,24h: 173 dB

Marine Mammal group (Type II) Weighted TTS SEL (dB re 1 μPa2·s)

Low-frequency cetaceans 178

Mid-frequency cetaceans 178

High-frequency cetaceans 152

Estimated noise impacts from TTR operation

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Sound Pressure Levels (SPL) and Sound Exposure Levels (SEL) as estimated using the dBSeaModes model algorithm and the following thresholds for low and medium frequency cetaceans:

Behavioural impact (orange) from NOAA Interim Sound Thresholds.

Permanent Threshold Shift (PTS - red) from NOAA Acoustic Technical Guidance

Temporary Threshold Shift (TTS - yellow) from Finneran & Jenkins (2012)

SPL

(dB re 1μPa)SEL (dB re 1μPa2.s)

Distance from

source (m)

Humpheson’s dBSeaModes

model algorithm 10 sec 10 min 1 h 3 h 24 h

0 171 181 199 207 211 220

500 135 145 163 171 175 184

1000 130 140 158 166 170 179

2000 128 138 156 164 168 177

4000 126 136 154 162 166 175

8000 122 132 150 158 162 171

10000 120 130 148 156 160 169

16000 117 127 145 153 157 166

Typical sources of anthropogenic noise

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Sound sourceSource level

(dB re 1 µPa @ 1m)Power (W)

10,000 lb explosive 304 21,000,000,000,000Seismic air gun array 260 660,000,000,000Pile driving 1000 kJ hammer 237 460,000Multibeam sonar deep water 245 77,000Cargo vessel (173 m length @ 16 knots) 192 66SIMARD Sonar 190 42TTR mining operation (ESTIMATED) 171 10Small boat outboard 160 0.042Acoustic deterrent device (PINGER) 150 0.004Estimated noise from drilling rig 150 0.004

TTR Condition 12 Maximum noise threshold 135 @ 500m

Source: Hildebrand (2009) Anthropogenic and natural sources of ambient noise in the ocean

Evidence of other experts Most examples cited of acoustic impacts are from operations that bear no

relationship to the TTR operation

TTR noise profile has been characterised as representing a significant impact for marine mammals. The reality is that it will be significantly quieter than most large container vessels operating in NZ but will be long term

Condition 12 was pro-actively proposed by TTRL to protect marine mammals

Developed by group of experts including those representing DOC

Most conservative underwater noise restriction that has ever been proposed for any underwater anthropogenic activity in New Zealand

Wording was agreed with DOC

No other mitigation approach or alternate threshold has been proposed

Measurable, enforceable and conservative control on underwater noise that will minimise potential impacts on marine mammals

STB/Cook Strait region is an area of high diversity but there nothing to suggest that mining site is important for marine mammals

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van Helden Supplementary Evidence

Reported hearing ranges and completeness of species list

Appropriateness of presentation of marine mammal sighting and stranding data

Clarity around NIWA acoustic project

NOAA Interim Acoustic Guidelines and new NOAA Marine Mammal Acoustic Technical Guidance

Appropriateness of Condition 12 given recent developments in assessing acoustic disturbance

Adequacy of proposed acoustic monitoring for Condition 12

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Duncan et al. Review of Humpheson report

Operation highly unlikely to meet target level of 135 dB at 500m

Proposed risk assessment methodology

Source level

Marine mammal density information

Estimation of probability and consequence

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Conclusions Huge body of complex information provided about a wide range of issues

around assessing the impact of noise on marine mammals including

Source levels, propagation models, marine mammal hearing sensitivity, thresholds at which marine mammal show disturbance to acoustics

While all of this information has been useful in understanding the potential interaction, I believe that information around establishing the threshold of disturbance is the single most important piece of information as it underpins Condition 12

If Condition 12 is accurately set at a level so as to minimise impacts on marine mammals, then all of this other information is essentially irrelevant as TTR must meet this level to operate. If Condition 12 is set conservatively, then acoustic impacts on marine mammals will minimised.

I believe that Condition 12 as written is measurable, enforceable and represents a conservative control on underwater noise that will minimise potential impacts on marine mammals

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