Marine Mammal Observers (MMOs)

Governments world-wide are imposing ever stricter environmental regulations on all forms of industrial operations. In marine industries, Marine Mammal Observers (MMOs) are suitably experienced and qualified personnel responsible for implementing guidelines set out to protect marine mammals (e.g. whales, dolphins, porpoises and seals etc.) from underwater noise created by industrial activities (

Marine Mammal Observers are required to operate close to the sound source, either on the vessel/platform producing the noise (the ‘source vessel’) or on a nearby guard or chase vessel, and to observe the surrounding area from the highest/best vantage point possible. An exclusion zone (usually 500 m) is set up around the noise source and, if a marine mammal is observed within this area, Marine Mammal Observers may be required to implement agreed mitigation measures. In some parts of the world, Marine Mammal Observers are also required to watch for other marine megafauna such as marine turtles and sharks, which may have their own mitigation procedures.

Activities that utilise Marine Mammal Observers include seismic surveys (, seabed mapping, construction (e.g. bridges, meteorological masts), Marine Renewable Energy Devices, MREDs (e.g. wind farms, tidal/wave turbines etc.), dredging (e.g. aggregate), oil and gas exploration, production and decommissioning (and other activities involving the use of explosives), and military sonar exercises.

At Ocean Science Consulting (, the majority of our Marine Mammal Observers are also trained Passive Acoustic Monitoring (PAM) operators ( Passive Acoustic Monitoring ( is used regularly in conjunction with Marine Mammal Observers to increase the probability of locating marine mammals, and is a very useful tool when visibility is poor (e.g. fog, rough sea states and darkness).

A Marine Mammal Observer on a seismic vessel in the North Sea scanning the ocean for marine mammals. © OSC 2013.

A Marine Mammal Observer on a seismic vessel in the North Sea scanning the ocean for marine mammals. © OSC 2013.

UK Guidelines

Mitigation guidelines for minimising the potential disturbance and injury to marine mammals from industrial noise on the United Kingdom Continental Shelf (UKCS) have been written by the Joint Nature Conservation Committee (JNCC). These guidelines either are adopted by, or form the backbone, of many other regulatory agencies worldwide.

Generally, there is an observation period (usually 30 or 60 mins) of the mitigation zone, where there cannot be any marine mammal sightings before the sound source is switched on. Following source activation, wherever possible it is achieved with a gradual increase in power, known as a ‘soft start’ or ‘ramp up’, permitting marine mammals adequate time and/or warning to vacate the area before full power is reached. In some cases, if a marine mammal is observed within the mitigation zone there must be a delay and/or shut down of the sound or disturbance source.

Guidelines throughout the world vary usually in the species included, mitigation zone size, pre-watch duration, soft start duration, and sound/disturbance source shut down procedures, and it is paramount that an experienced Marine Mammal Observer is familiar with these guidelines.

Humpback whale (Megaptera novaeangliae) in the Indian Ocean observed near Rottnest Island in Western Australia. © OSC 2013.

Humpback whale (Megaptera novaeangliae) in the Indian Ocean observed near Rottnest Island in Western Australia. © OSC 2013.

New Zealand Guidelines

New Zealand has recently produced its own set of guidelines entitled ‘2012 Code of Conduct for Minimising Acoustic Disturbance to Marine Mammals from Seismic Survey Operations’ ( This code of conduct is more stringent than the JNCC guidelines, and naturally relevant to marine mammals likely to be found within New Zealand’s territorial waters. Mitigation zone sizes vary from 1,500 m to 200 m depending on a combination of whether the animal is a ‘species of concern’ and if there are calves present.

New Zealand’s Government, the Department Of Conservation (DOC), is working hard to use data collected by Marine Mammal Observers for research purposes. It is a requirement that all sightings of marine mammals in New Zealand waters are submitted to DOC to enable them to assess population levels and behaviour more accurately, and to better define migration routes.

If working in the western waters of the North Island, there are also special considerations if a Hector’s dolphin (Cephalorhynchus hectori) is sighted, as it is possibly the highly endangered Maui’s dolphin (C. h. maui), a sub-species. These animals are identifiable only though DNA analysis, and are thus indistinguishable in the field. When Marine Mammal Observers positively identify a Hector’s dolphin, DOC must be notified immediately to enable them to dispatch a boat and/or plane in the hope of performing a biopsy to determine subspecific identity.

The efforts of Marine Mammal Observers contribute to ongoing scientific research on these endangered species. Moreover, DOC can track (using biopsy results), the movements of individual Maui’s dolphins by documenting sample replication and cross-referencing with previous records. At the population-level, this yields more accurate geographic range estimations.

Ocean Science Consulting

Ocean Science Consulting ( was an official advisor to the 2012 New Zealand Government, and helped form the guidelines ( Ocean Science Consulting staff comprise a number of full time employees and trusted long-term contractors. All staff are qualified with at least a degree in marine biology (or equivalent), are JNCC certified, and possess current offshore survival and medical certificates. These attributes enable Ocean Science Consulting to mobilise qualified staff to any location in the world at very short notice. Our Marine Mammal Observers are also able to call upon expert technical support 24 hours a day throughout the entire survey duration.

Ocean Science Consulting is a marine consultancy, not a recruitment agency, and is also able to provide a number of other in-house services namely: Protected Species Observers (PSO), Marine Mammal and Seabird Observers (MMSO), Passive Acoustic Monitoring (PAM) operators (, Passive Acoustic Monitoring equipment (, and underwater noise measurement ( At Ocean Science Consulting, our Marine Mammal Observers are often qualified in more than one, if not all, of these other disciplines, providing greater flexibility, which is advantageous to both our staff and the client.

Ocean Science Consulting has been operating world-wide since 2004, and has undertaken contracts all over the world for a variety of clients, including both UK and foreign militaries Shell, Fugro, Maersk, CGG Veritas, BHP Billiton, BASF, Petrobras, etc. A full list of clients is available on our main website ( with references and testimonials available upon request.

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