Marine Seismic Surveys

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’, known as the Code.

Requirements depend upon the total combined operational capacity of the acoustic source.

Level 1: >7 litres or 427 cubic inches

Level 2: 2.50–6.99 litres or 151–426 cubic inches

Level 3: <2.49 litres or 150 cubic inches

More information on Level 1 surveys is available here, and further details on Level 2 surveys are available here. Level 3 surveys are exempt from the Code.

Prior to conducting Level 1 or Level 2 surveys, a Marine Mammal Impact Assessment (MMIA) must be submitted to the Director-General of Conservation. For details on what an MMIA must include, please see here. If conducting surveys in Areas of Ecological Importance (AEI), including Marine Mammal Sanctuaries (MMS), Sound Transmission Loss Modelling (STLM; which can be undertaken by OSC-NZ) needs to be included in the MMIA. Additional requirements may also be necessary, and could include:

  • Additional observation platforms;
  • Increased pre-observation periods;
  • Aerial observations;
  • Acoustic source power restrictions; and/or,
  • Avoid trapping marine mammals in confined areas (e.g. narrow, constricted seaways), sometimes termed ‘embayment’.

Two Marine Mammal Observers (MMOs) are required for Level 1 and Level 2 surveys, but use of PAM is only a requirement for Level 1 surveys currently. Two PAM Operators must be on the seismic vessel for the duration of the survey, with one on watch at all times.