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Basic Environmental Policy

Guidelines for Minimizing the Impact to Marine Mammals from Seismic Surveys

Recognizing the importance of the conservation of marine ecosystem and its biodiversity, the Japan Agency for Marine-Earth Science and Technology (hereinafter referred to as "JAMSTEC"), when a seismic survey (multichannel seismic (MCS) and single-channel seismic (SCS) reflection survey, and refraction survey using ocean bottom seismograph (OBS) etc.) is being conducted in areas where marine mammals including cetaceans are likely to be present, should follow the following guidelines with a view to minimize its impact on marine mammals.

  1. Prior to the cruise, the desk research should be taken as much as possible in order to understand what marine mammal are likely to be present in the survey area. In particular, seasonal important activities such as during periods of migration, breeding or calving should be recognized and are taken into account as appropriate.
  2. Prior to the cruise, any relevant regulatory guidelines with respect to marine mammals of the coastal State should be investigated, and in the event of a provision resulting in a conflict with the guidelines of JAMSTEC, measures described in paragraph 3 below be reviewed as appropriate. All crews, scientists and marine technicians engaged in marine seismic surveys should, as far as possible, be lectured on marine mammals.
  3. Where seismic surveys conducted by the vessel of JAMSTEC does not conflict with the relevant regulatory guidelines with respect to marine mammals of the coastal State, the following measures for minimizing impact to marine mammals should be taken:
    1. The Marine Mammal Observer (person who will engage in visual observations for the presence of marine mammals from the bridge) should be deployed, and conduct visual observations whether the Predefined Ranges from the acoustic source (hereinafter referred to as the "precaution zones") are free from marine mammals at least 30 minutes before commencement of shooting.
      *Predefined Ranges: range of the passive sound pressure levels is determined for each acoustic source.
    2. In the case of using multiple acoustic sources, whenever the commencement of the survey line or shooting has stopped for more than 60 minutes, the soft-start procedures (means of turning on the acoustic source at the lowest power level and gradually increasing the output until full power is achieved) should be carried out. A method of implementation and parameters (e.g. location, time and interval, etc.) of the soft-start should be recorded. In the case of using a single acoustic source, as is not appropriate for the soft-start procedures, a normal shooting procedure should be carried out, provided that parameters referred above should be recorded.
    3. If any marine mammals are visually detected during the seismic survey within the precaution zones, then shooting should be stopped and not restarted for at least 60 minutes. After the interval, the procedure set out in sub-paragraph b) above should be applied.
  4. During seismic surveys, where possible, any sightings of marine mammals made by the marine mammal observer should be recorded. When the survey is completed, records of its findings and any mitigation measures taken during seismic surveys should be maintained.

As of 26th November 2013
Japan Agency for Marine-Earth Science and Technology (JAMSTEC)