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MMO and PSO for towed streamer, Gabon

Client: Major oil company
Topic: MMO, PSO and PAM for 3D towed streamer seismic survey



Provision of MMO (marine mammal observer), PSO (protected species observer) and PAM (passive acoustic monitoring) services for a 3D towed streamer seismic survey offshore Gabon


  • The depth of the water in the survey area ranged from shallow to deep, meaning that different sections of the JNCC (Joint Nature Conservancy Council) guidelines had to be employed
  • Close proximity to an oil terminal


  • MMOs ensured that all requirements of the JNCC guidelines and local amendments were met
  • Kept a watch for marine mammals for a minimum of 30 minutes prior to commencement of any use of the airguns (the pre-shooting search)
  • Delaying shooting if marine mammals were detected within 500m of the airguns when shooting is due to commence, until at least 20 minutes after the animals are last seen in the exclusion zone
  • Used a soft start, commencing shooting at low power levels and building up slowly in uniform stages (i.e. by increasing the number of airguns firing) to full power levels
  • Ensuring that no shooting took place, other than that necessary for the normal operations of a seismic survey or for a soft start
  • MMOs collected sighting data, which may be of use in furthering the understanding of cetacean distribution and the potential impacts of seismic activity
  • MMO, PSO and PAM daily, weekly, monthly and final reporting
  • Environmental disturbances recorded by four dedicated consultants on-board who complied with the JNCC guidelines
  • MMOs made visual assessments to determine if any marine mammals were within 500m of the centre of the airgun array
  • Communication with the observers before and during soft starts and during line abortions and re-starts
  • Constant watching while on the line, effectively the pre-watch in case of re-start of the line, saving the client and/or contractor considerable money


  • MMOs and PSOs issued advice on adherence to the JNCC guidelines  
  • Geographical location and movement of marine mammals and turtles logged
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