The New Zealand Government’s Department of Conservation (DOC) has developed the ‘2013 code of conduct for minimising acoustic disturbance to marine mammals from seismic survey operations’ (DOC 2013), known as the Code. The Code is available for any organisation carrying out seismic operations in New Zealand continental waters. The Code can be downloaded from the following link: www.doc.govt.nz
BASICS OF THE NEW ZEALAND SEISMIC ‘CODE’
Before the acoustic source (i.e. seismic air guns) is activated, a pre-start observation or ‘watch’ is required. This involves Marine Mammal Observers (MMOs; www.marinemammalobserver.co.uk) conducting visual observations and/or a Passive Acoustic Monitoring (PAM) Operator (www.pamoperator.co.uk) listening for marine mammals within relevant mitigation zones. Mitigation zones must be clear of marine mammals (other than New Zealand fur seals (Arctocephalus forsteri)) for 30 minutes and of fur seals for 10 minutes. If a marine mammal is seen within the relevant mitigation zone, there is a delay in starting the source. Once the source has been activated, the Code calls for the source to be shut down if a species of concern is seen in its relevant mitigation zone. The source is delayed or reactivated if the animal is seen to move outside its relevant mitigation zone, or 30 minutes has elapsed since the last detection, 10 minutes for New Zealand fur seals.
A soft start procedure is also required. This means that each time the source is activated, its power must be increased gradually (i.e. start with the lowest capacity air gun and gradually add successively higher capacity air guns). The soft start procedure must be carried out over a period of 20–40 minutes. The exception to this is when there is a break in full power firing for less than 10 minutes, and no marine mammals have been seen in the mitigation zones. In this case, the source can be reactivated at full power.
A flowchart below shows the steps of the entire mitigation process.
For further information on observer deployment, crew observations, acoustic source tests, multiple acoustic sources, and line turns, please refer to section 3.8 Operational requirements, of the Code.
For details on specific PAM requirements (e.g. 24 hour monitoring), please see www.pamoperators.com
NEW ZEALAND SEISMIC GUIDELINES
While the basics of the code are similar to many other guidelines worldwide (e.g. Gulf of México – www.protectedspeciesobservation.co.uk), there are also some slight and major differences.
Before conducting seismic surveys, operators should be aware of the notification, pre-survey planning, and Marine Mammal Impact Assessment (MMIA) process required. More information on this, and recording and reporting, can be found at: www.doc.govt.nz
The Code has slightly different mitigation procedures based on the level of acoustic source output. The levels are:
- Level 1: an operational acoustic source capacity of >427 cubic inches. These tend to be large-scale geophysical investigations (often oil & gas);
- Level 2: 151–426 cubic inches. Lower scale investigations (often scientific); and,
- Level 3: <150 cubic inches. Small scale survey technologies. Not subject to provisions of the Code.
The Code includes traditional streamer seismic surveys, as well as borehole seismic surveying (check-shot and all types of Vertical Seismic Profile (VSP) surveying), which are classified into the same operational capacity levels.
Unlike any other guidelines worldwide, the Code also has varying mitigation procedures for different classifications of marine mammals. The categories are: species of concern with calf/calves, species of concern, other marine mammals, and New Zealand fur seals. A full list of the species of concern can be found in Schedule 2 of the Code. For each survey level the size of the mitigation zone varies for the different categories of marine mammal. There is also no shutdown procedure required for ‘other marine mammals’, and the mitigation zone only needs to be clear of New Zealand fur seals for 10 minutes, instead of the 30 minutes for other species.
Under the Code there are additional requirements for starting the acoustic source of level 1 surveys in a new location in poor sighting conditions. Poor sighting conditions are defined as hours of darkness, visibility ≤1.5 km, and sea state >Beaufort 3. If sighting conditions are poor the following conditions must be met:
- MMOs did not see any marine mammals within 20 nautical miles of planned start-up position for the last 2 hours of good sighting conditions preceding proposed operations; or,
- If there has been less than 2 hours of good sighting conditions, the following conditions must be met:
- Two MMOs and a PAM Operator have been monitoring for 2 hours immediately preceding proposed operations;
- No species of concern have been detected (visually or acoustically) in relevant mitigation zones in the 2 hours immediately preceding proposed operations;
- No fur seals have been seen in the relevant mitigation zone in the 10 minutes immediately preceding the proposed operations; and,
- No other marine mammals have been detected for 30 minutes immediately preceding proposed operations.
Within the Code, MMOs and PAM Operators are classed as being trained or qualified.
DEFINITION: TRAINED MMOs & PAM OPERATORS
A trained MMO or PAM Operator must have completed the respective MMO or PAM DOC-approved course or assessment process. MMO and PAM Operators new to the field have to complete a full course, whereas experienced MMOs and PAM Operators can complete an assessment.
DEFINITION: QUALIFIED MMOs & PAM OPERATORS
A qualified MMO or PAM Operator must have completed a DOC-approved course/assessment process, and must have a minimum of 12 weeks of marine seismic experience in New Zealand continental waters as an MMO or PAM Operator. The qualifications are not interchangeable, i.e. if an MMO completes the MMO course they cannot work as a PAM Operator until they have completed a PAM course.
Ocean Science Consulting (OSC) is currently the only trainer offering an approved PAM Operator assessment course. The OSC course is led by veteran scientists and authors of the ‘Marine Mammal Observer and Passive Acoustic Monitoring Handbook’ (Todd et al. 2014), who undertake independent research and supply MMO and PAM services for industries worldwide. A list of training and assessment courses can be found at: www.doc.govt.nz.
With PAM being a relatively new field, qualified PAM Operators may have 3 years of professional experience and a minimum of 12 weeks of international marine seismic experience, if no PAM Operators with the required New Zealand experience are available. Further exception may be given in extreme circumstances.
MMO & PAM REQUIREMENT FOR LEVEL 1 SURVEYS
Level 1 surveys require two MMOs and two PAM Operators, and seismic crew cannot act as MMOs or PAM Operators. When the acoustic source is in the water in the operational area during level 1 surveys, at least one MMO (during daylight hours) and one PAM Operator must be on watch at all times. Ideally, both MMOs are on watch during pre-start observations.
MMO REQUIREMENT FOR LEVEL 2 SURVEYS
For level 2 surveys, there must be two MMOs on-board, with at least one on watch during daylight hours. Crew may be trained as MMOs and PAM Operators. For level 2 surveys, PAM is optional.
A full list of MMO and PAM Operator duties are available in the Code and its accompanying reference document (DOC 2012).
This site gives only summary of marine mammal mitigation techniques used in the New Zealand seismic survey guidelines; please see the DOC website for official documents: www.doc.govt.nz.
|DOC (2012) 2012 Code of conduct for minimising acoustic disturbance to marine mammals from seismic|
|survey operations: reference document. p. 28. Publishing Team, Department of Conservation, Wellington, New Zealand.|
Todd V.L.G., Todd I.B., Gardiner J.C. & Morrin E.C.N. (2014) Marine Mammal Observation and
|Passive Acoustic Monitoring Handbook. Pelagic Publishing Ltd, UK. In press. www.amazon.co.uk|
The Marine Mammal and Passive Acoustic Monitoring Handbook can also be purchased on the publisher’s website, www.nhbs.com, or at any good book retailer.