Evidence for Taranaki mining hearing

Professor Liz Slooten

Zoology Department

Qualifications

• Professor, Zoology Department, Otago University

• Marine mammal research since 1984

• More than 100 scientific publications

• Member of Cetacean Specialist Group (IUCN)

• Member of Scientific Committee, International Whaling Commission

• Vice President, NZ Marine Sciences Society

• Sir Charles Fleming Award for Environmental Science (Royal Society)

• Professor John Morton Award (NZ Marine Sciences Society)

• Organiser of large marine mammal conference in NZ in 2013

Key points of evidence

• Poor information on marine mammals present in the area

– Incomplete species list

– No data on numbers of individuals for each species

– No estimates of number of marine mammals affected by noise• Physical injury

• Behavioural disturbance

• Lack of data on noise

– Noise generated by mining operation

– Background, natural sound environment

– Propagation of mining noise off Taranaki

• Potential impacts include

– Direct impacts such as ship strike, injury and disturbance caused by noise

– Indirect impacts such as ecological changes with flow on effects to higher level

predators

• Cumulative impacts

Wide range of marine mammals in the area

• Including the Critically Endangered Maui dolphin

• Blue whales

• Sperm whales, beaked whales, common dolphins, fur seals

Fishing threat to Maui dolphins partially solved

• 3-4 Maui dolphins killed per year

• Sustainable level 1 dolphin every 10-23 years

Davies NM, Bian R, Starr P, Lallemand P, Gilbert D, McKenzie J 2008. Risk analysis for Hector’s dolphin and

Maui’s dolphin. Report for Ministry of Fisheries, by NIWA and industry researchers.

Martien KK, Taylor BL, Slooten E, Dawson S 1999. A sensitivity analysis to guide research and management for Hector’s dolphin.

Biological Conservation 90: 183-191.

Slooten E., Fletcher D, Taylor BL 2000. Accounting for uncertainty in risk assessment. Conservation Biology 14: 1264-1270.

Davies NM, Bian R, Starr P, Lallemand P, Gilbert D, McKenzie J 2008. Risk analysis for Hector’s dolphin and Maui’s dolphin. Wellington,

Ministry of Fisheries. www.fish.govt.nz

Burkhart, S.M. and Slooten, E. 2003. Population viability analysis for Hector's dolphin (Cephalorhynchus hectori): A stochastic population

model for local populations. New Zealand Journal of Marine and Freshwater Research 37: 553-566.

Slooten, E. 2007. Conservation management in the face of uncertainty: Effectiveness of four options for managing Hector’s dolphin

bycatch. Endangered Species Research 3: 169-179.

Slooten E, Dawson SM 2010. Effectiveness of new protection measures for Hector’s dolphin. Aquatic Conservation: Marine and

Freshwater Ecosystems, 20: 334-347.

Slooten E, Davies NM 2012. Hector’s dolphin risk assessments: Old and new analyses show consistent results. Journal of the Royal

Society of New Zealand 42: 49-60.

Slooten E. 2013 Effectiveness of area-based management in reducing bycatch of the New Zealand dolphin. Endangered Species

Research 20: 121-130.

Slooten E. 2015. Effectiveness of partial protection for Maui's dolphin. Paper SC/66a/SM12, presented to the Scientific Committee of the

International Whaling Commission, San Diego, USA, June 2015.

Risk analyses:

• Consistent results, despite range of different methods

- e.g. PVA, Bayesian fisheries models, etc.

• Substantial population declines

• Current population size 25-30% of original size

• Without fisheries mortality, could recover to 50% within 50 yrs

• Current protection not yet effective

• Implementing the recommendations of the International Whaling Commission and IUCN would result in population recovery

Current protection

Different levels of protection to different

distances offshore.

Continued population declines.

IWC recommendation

Consistent protection from

gillnets and trawling for Maui

dolphin (recovery), ongoing

decline for Hector’s dolphin.

IUCN recommendation

Consistent protection from

gillnets and trawling for the

species as a whole. Recovery

for Hector’s and Maui dolphin.

Protection options:

no gillnets

no gillnets + no trawling

dolphin distribution

Top 3 threatened small cetaceans

• Baiji

– Yangtze river dolphin

– < 50 individuals in 1998

– Now thought to be extinct

• Vaquita

– Gulf of California harbour porpoise

– 30 individuals

– Mexico implemented full protection in 2015

– Extending the protected area by 7x

– Population continued to decline

– Mexico now considering taking vaquita into captivity

• Maui dolphin

– 63 individuals

– International Whaling Commission has recommended full protection

– Extending the protected area by 4x

• Still considerable overlap

• dolphins and gillnets

• especially dolphins and trawling

• Analysed using individual-based model

dolphin

gillnet

trawler

Current level of risk

no gillnets

no gillnets + no trawling

> 100 m deep

50-100 m deep

< 50 m deep

Input data include:

• Dolphin distribution and movements

– Distribution data from line-transect surveys

– Surveys with equal effort with respect to distance from shore

– Public sightings and strandings for very low-density areas

– Movement data from photo-ID research by Otago University

– Tagging data from Greg Stone and co-workers

– Field data showing dolphins are attracted to each other and to trawlers

• Dolphin reproduction and survival data

– Optimistic survival rate curves for marine mammal populations with no human impact

– Reproduction depends on presence of other dolphins within homerange

• Fishing effort

– Penny et al. 2007, report commissioned by Ministry of Fisheries– Assessment of socio-economic costs associated with dolphin protection

– Distribution and intensity of fishing effort from MPI

– Average daily movement of trawlers from NIWA

Current protection IWC recommendation

4 x current area

Comparison of effectiveness of current protection & IWC recommendation

Protection from Current IWC

Gillnets 19% 86%

Trawling 5% 86%

Total 19% 86%

no gillnets

no gillnets + no trawling

dolphin distribution

Population size in 20 years’ time

Pro

babili

tyMuch higher probability of population increase for IWC option

= IWC recommendation

= Current management

Mining site

in context of IWC protection

Gillnetting

Trawling

In Press

Scientific Journal “Endangered Species Research”

Maui dolphin is one of the case study species

Concern that noise may cause Maui dolphins to abandon habitat

Which could bring them into closer contact with other impacts

Including fishing

Seismic survey proposal

Rejected to protect harbour

porpoise population

Harbour porpoise now known to react

to shipping noise, which has most of

its energy in the low frequency range

and has until recently been thought to

be of relatively little importance for

harbour porpoise, Maui dolphins and

other species that produce high

frequency sounds

Dyndo et al. 5015

Harbour porpoise numbers reduced within 10 km of pile driving

Increased numbers at 25 and 50 km from the pile driving

Hatch L, Clark CW, van Parijs SM, Frankel AS and Ponirakis DW 2012. Quantifying loss of

acoustic communication space for right whales in and around a U.S. National Marine Sanctuary.

Conservation Biology 26: 983-994.

Masking of right whale

communication by

shipping noise

When ship noise

overlaps whale

Whales modify their

calls in response to

shipping noise