Todd Exploration Management Services Ltd 18SBB3D Seismic
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18SBB3D Seismic Survey Marine Mammal Impact Assessment Report Number 740.10079 7 February 2018 Todd Exploration Management Services Ltd 32-38 Molesworth Street New Plymouth 4310 New Zealand Version: v1.0 Todd Exploration Management Services Ltd Report Number 740.10079 18SBB3D Seismic Survey 29 January 2018 Marine Mammal Impact Assessment v1.0 Page 2 18SBB3D Seismic Survey Marine Mammal Impact Assessment PREPARED BY: SLR Consulting NZ Limited Company Number 2443058 5 Duncan Street Port Nelson 7010, Nelson New Zealand (PO Box 5061, Port Nelson 7043 Nelson New Zealand) +64 274 898 628 [email protected] www.slrconsulting.com This report has been prepared by SLR Consulting NZ Limited with all reasonable skill, care and diligence, and taking account of the timescale and resources allocated to it by agreement with the Client. Information reported herein is based on the interpretation of data collected, which has been accepted in good faith as being accurate and valid. This report is for the exclusive use of Todd Exploration Management Services Ltd. No warranties or guarantees are expressed or should be inferred by any third parties. This report may not be relied upon by other parties without written consent from SLR. SLR disclaims any responsibility to the Client and others in respect of any matters outside the agreed scope of the work. DOCUMENT CONTROL Reference Date Prepared Checked Authorised 740.10079-R01-v1.0 29 January 2018 Helen McConnell, Nicole Dan Govier Dan Govier Pannell, Dan Govier 740.10079-R01-v0.3 25 January 2018 Helen McConnell, Nicole Dan Govier Dan Govier Pannell, Dan Govier 740.10079-R01-v0.2 12 January 2018 Helen McConnell, Nicole Dan Govier Dan Govier Pannell, Dan Govier 740.10079-R01-v0.1 27 December 2017 Helen McConnell, Nicole Dan Govier Dan Govier Pannell, Dan Govier SLR Consulting NZ Limited Todd Exploration Management Services Ltd Report Number 740.10079 18SBB3D Seismic Survey 29 January 2018 Marine Mammal Impact Assessment v1.0 Page 3 Executive Summary Todd Exploration Management Services Limited (TEMS) is proposing to operate a three dimensional (3D) marine seismic survey in the South Taranaki Bight. While the actual area to be surveyed will only be about 320 km2, the Operational Area required for the ‘18SBB3D Seismic Survey’ encompasses an area of approximately 1,856 km2 between Hawera and Whanganui. It straddles both the Exclusive Economic Zone (EEZ) ( from 12 M out to 200 M) and the Coastal Marine Area (CMA) (from mean high water springs out to 12 M) and includes a region known as the ‘Patea Shoals’ ( an area of the South Taranaki Bight offshore from Patea as depicted in LINZ Charts and Beaumont et al., 2013). The seismic survey is proposed to commence in February 2018 and last approximately 5 days. A marine seismic survey in the EEZ is classified as a permitted activity under the Exclusive Economic Zone & Continental Shelf (Environmental Effects) Act 2012 (EEZ Act) providing the operator complies with the Department of Conservation’s (DOC) ‘2013 Code of Conduct for Minimising Acoustic Disturbance to Marine Mammals from Seismic Survey Operations’ (Code of Conduct). For seismic operations in the CMA, Section 16 of the Resource Management Act 1991 states that proponents of activities “shall adopt the best practicable option to ensure that the emission of noise from that land or water does not exceed a reasonable level”. Despite technically being voluntary within the CMA, compliance with the Code of Conduct is sufficient to satisfy this RMA requirement. The preparation of a Marine Mammal Impact Assessment (MMIA) is a requirement of the Code of Conduct in order to describe the proposed seismic operations, provide a description of the baseline environment, identify potential effects of the operations on the environment, and to specify any proposed mitigation measures. An Environmental Risk Assessment (ERA) process is utilised throughout this MMIA to assess the significance of any predicted effects on the biological, socio- economic and cultural environments of relevance to the Operational Area. Engagement with stakeholders was also undertaken by TEMS as a key part of survey preparations. Potential marine mammal presence in the Operational Area was thoroughly assessed using marine mammal sighting and stranding data. This assessment indicated that dwarf minke whales, bottlenose dolphins, dusky dolphins, false killer whales, Gray’s beaked whales, Cuvier’s beaked whales, long- finned pilot whales, pygmy blue whales, sperm whales, pygmy sperm whales, common dolphins and New Zealand fur seals are the marine mammal species most likely to be present. A number of these species are classified as threatened under the New Zealand Threat Classification System and are considered to be ‘nationally critical’ (Bryde’s whale, killer whale, and Maui’s dolphin), ‘nationally endangered’ (bottlenose dolphin, and Hector’s dolphin), or ‘nationally vulnerable’ (southern right whale). Furthermore, the greater South Taranaki Bight has been identified as an important feeding and potential nursery area for blue whales. It is recognised that acoustic disturbance from seismic surveys has the potential to impact marine mammals. The Code of Conduct was developed by DOC in order to minimise both behavioural and physiological effects associated with acoustic disturbance. Operating in compliance with the Code of Conduct is the primary mitigation measure that will be employed during the 18SBB3D Seismic Survey, in particular: Marine Mammal Observers (MMO) will be present on the seismic survey vessel to detect marine mammals using both visual and acoustic techniques; seismic operations will be delayed if marine mammals are detected in close proximity to the acoustic source before start up; the power of the acoustic source will be gradually increased during a ‘soft start’ prior to any operations to ensure that any undetected marine mammals have an opportunity to leave the vicinity before full power is reached; and the acoustic source will be shut down if marine mammals enter the defined mitigation zones. SLR Consulting NZ Limited Todd Exploration Management Services Ltd Report Number 740.10079 18SBB3D Seismic Survey 29 January 2018 Marine Mammal Impact Assessment v1.0 Page 4 Executive Summary The survey is defined as a ‘Level 1’ survey under the Code of Conduct given it will use a 5085 cu.in source and TEMS will comply with the mitigation measures stipulated within the Code of Conduct. Further to the paragraph above, the implementation of defined mitigation zones around the acoustic source, which MMOs will continuously scan to detect any marine mammals that may enter these zones, and if required, will implement an immediate shutdown of the acoustic source. In order to predict how far sound emitted from the seismic survey will travel underwater, Sound Transmission Loss Modelling was conducted during the development of this MMIA. The primary purpose of this modelling is to assess the validity of the standard mitigation zones specified in the Code of Conduct. The modelling results did not comply with the Sound Exposure Level thresholds for the standard mitigation zones at 1 km for parts of the 18SBB3D seismic survey; hence, a larger mitigation zone has been proposed for this particular survey to ensure compliance levels are met. In particular, a mitigation zone of 1.5 km will be adopted as a conservative measure for all ‘Species of Concern’ (with or without calves) throughout the Operational Area. In addition to compliance with the Code of Conduct, TEMS have committed to the following management actions to avoid, remedy or mitigate potential adverse effects on ecological, socio- economic and cultural components of the environment during the proposed operations: The survey is intended to be time-limited to minimise sound emissions within the marine environment; Source modelling has been undertaken to ensure that the survey is using the lowest practical acoustic source volume while still ensuring the geological objectives of the survey can be fulfilled; A 1.5 km mitigation radius will be implemented for all species of concern (whether with or without calves present) to optimise the efficacy of mitigation measures; Seismic operations will continue around the clock (as possible) to reduce the overall duration of the survey; Marine mammal sightings will be collected whilst off-survey (e.g. during transit to and from the Operational Area to the local port etc.); MMOs will be vigilant for entanglement incidents and will report any dead marine mammals observed at sea; MMOs will notify DOC immediately of any Hector’s/Maui’s dolphin sightings; A Weekly MMO report will be provided to the relevant agencies (i.e. DOC and the Environmental Protection Authority (EPA); TEMS will consider covering the cost of necropsies on a case-by-case basis in the event of marine mammal strandings in the vicinity of the Operational Area; Seismic operations will be undertaken in accordance with industry best practice, including compliance with international conventions relating to waste disposal, atmospheric emissions, oil pollution and biosecurity; Iwi Marine Mammal Operators (MMOs) and Passive Acoustic Monitoring (PAM) operators will be provided with employment opportunities during the survey; and Post-survey engagements will be conducted to inform iwi and stakeholders of key survey outcomes. TEMS revised their initial Operational Area on account of the potential for encountering Maui’s dolphins towards the more shallow coastal waters near Hawera. Although the initial likelihood of encountering this species was unlikely, the revision of that initial Operational Area provides a further mitigation measure against any potential behavioural impacts on Maui’s dolphins. SLR Consulting NZ Limited Todd Exploration Management Services Ltd Report Number 740.10079 18SBB3D Seismic Survey 29 January 2018 Marine Mammal Impact Assessment v1.0 Page 5 Executive Summary Based on the ERA results, the predicted effects of the 18SBB3D seismic survey are generally considered to be negligible to moderate, with moderate effects representing a short-term impact that is sufficiently managed by the proposed mitigation measures and the short duration of the survey.