The ‘2013 code of conduct for minimising acoustic disturbance to marine mammals from seismic survey operations’ (the Code) has different requirements for seismic surveys depending on the total combied operational capacity of the acoustic source (DOC 2013). Level 1 surveys are marine seismic surveys whose acoustic source has a total combined operational capacity >7 litres or 427 cubic inches. For details on level 2 surveys, see www.nzlevel2seismicsurveys.co.nz. Level 3 surveys (acoustic sources <2.49 litres or 150 cubic inches) are exempt from the Code.
Level 1 surveys are most often large-scale geophysical investigations used for the exploration of oil and gas, including borehole seismic surveys.
For a general overview of the Code, please see www.codeofconductseismicnewzealand.co.nz
PRE-SURVEY PLANNING & MARINE MAMMAL IMPACT ASSESSMENTS
Before conducting any level 1 surveys, a Marine Mammal Impact Assessment (MMIA) must be submitted to the Director-General of Conservation. For details on what an MMMIA must include, please see www.marinemammalimpactassessment.co.nz
Additional requirements are necessary when planning and conducting surveys in Areas of Ecological Importance (AEI; www.areasofecologicalimportance.co.nz), which includes Marine Mammal Sanctuaries (MMS; www.marinemammalsanctuaries.co.nz).
MMO & PAM REQUIREMENTS
Level 1 surveys require two Marine Mammal Observers (MMOs) and two Passive Acoustic Monitoring (PAM) Operators. Seismic crew cannot act as MMOs or PAM Operators, as the observers must remain independent. 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 and other critical times.
PAM equipment used during level 1 surveys must be able to estimate bearing and distance of vocalising cetaceans up to a minimum of 1.5 km.
SEISMIC OPERATIONS WITHOUT A PAM SYSTEM
If a PAM system malfunctions or breaks during a level 1 survey, specific provisions must be followed. After the PAM system malfunctions or breaks, seismic operations are allowed to continue for 20 minutes while the PAM Operator diagnoses the problem. If more time is required to repair or change the PAM system, seismic operations may continue for an addition two hours without PAM is the following five conditions are met:
- It is daylight hours and the sea state is ≤ Beaufort 4;
- In the previous two hours no marine mammals have been detected solely by PAM in the relevant mitigation zones
- Two MMOs are looking for marine mammals during the entire time PAM is not operational;
- The Department Of Conservation (DOC) is notified via email as soon as possible with the time and location where the PAM system malfunctioned/broke; and,
- Seismic operations without a PAM system do no exceed a cumulative four hours in any 24 hour period.
STARTING THE ACOUSTIC SOURCE IN A NEW LOCATION IN POOR SIGHTING CONDITIONS
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 two hours of good sighting conditions preceding proposed operations; or,
- If there has been less than two hours of good sighting conditions, the following conditions must be met:
- Two MMOs and a PAM Operator have been monitoring for two hours immediately preceding proposed operations;
- No species of concern (www.speciesofconcern.co.nz) have been detected (visually or acoustically) in relevant mitigation zones in the two hours immediately preceding proposed operations;
- No fur seals (Arctocephalus forsteri) 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.
General pre-start observation requirements for level 1 surveys are explained in: www.codeofconductseismicnewzealand.co.nz
DELAYED STARTS & SHUTDOWNS
Detections (visual or acoustic) of marine mammals in the relevant mitigation zones during level 1 surveys call for a delay in the activation of the acoustic source. The acoustic source is shutdown when a species of concern is detected in the relevant mitigation zone.
|DOC (2013) 2013 Code of conduct for minimising acoustic disturbance to marine mammals from seismic survey operations.|
|p. 36. Publishing Team, Department of Conservation, Wellington, New Zealand.|