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Marine mammal mitigation

Marine mammal mitigation is often used (and sometimes stipulated) to minimise effects of industrial operations on marine mammals (e.g. seals, porpoises, dolphins, and whales, Markus and Sánchez, 2018).

Marine mammal mitigation is often used (and sometimes stipulated) to minimise effects of industrial operations on marine mammals (e.g. seals, porpoises, dolphins, and whales, Markus and Sánchez, 2018). Such activities include, but are not limited to: seismic surveys, pile driving, drilling, dredging, seabed mapping and explosives (Hastie et al., 2019). Marine mammal mitigation is used to ensure that there are no marine mammals in the immediate vicinity before any loud sounds are emitted into the ocean (JNCC, 2017). The simplest methods used for marine mammal mitigation involve time and area planning of industrial activities to avoid marine mammals. Further mitigation includes detection of animals close to the noise source and real-time mitigation (delay and/or suspension of operations), and soft-start or ramp-up (where sound levels are increased gradually over time, Von Benda-Beckmann et al., 2014).

Marine mammal mitigation guidelines

Various guidelines (Markus and Sánchez, 2018) have been written to implement marine mammal mitigation. Regulatory agencies, such as the UK’s Joint Nature Conservation Committee (JNCC), Ireland’s National Parks & Wildlife Service (NPWS), New Zealand’s Department of Conservation (DOC), Australia’s Department of the Environment & Energy (DEE) and the USA’s Bureau of Ocean Energy Management (BOEM) and Bureau of Safety and Environmental Enforcement (BSEE), have specific guidelines that must be followed for marine mammal mitigation during offshore industrial activities. Each set of guidelines indicates the amount of time required to search for marine mammals before operations begin, the distance around operations that must be kept clear (exclusion zone), what to do if a marine mammal is observed, how the soft-start must be carried out, what to do if and when a shut-down procedure is required and the regulations of noise activities at night or during line changes for seismic surveys. During offshore industrial activities these marine mammal mitigation guidelines are enforced by certified Marine Mammal Observers (MMOs), Protected Species Observers (PSOs) and/or Passive Acoustic Monitoring (PAM) operators. All Ocean Science Consulting Limited (OSC) MMOs, PSOs and PAM operators are trained specifically to work closely with clients to make sure they understand operational requirements and enforcement of marine mammal mitigation guidelines. Please consult the main webpage www.osc.co.uk for more information on the services we offer.

Marine Mammal Observers and Passive Acoustic Monitoring operators

A marine mammal observer (MMO) performing visual observations during industrial operations. © OSC 2019. OSC employs highly qualified MMOs, PSOs and PAM operators, whenever possible these are full-time OSC staff, allowing us to provide consistent high-quality services. All of OSC’s MMOs and PAM operators have marine biology (or equivalent) undergraduate degrees as a minimum requirement and have also undergone extensive pre-employment long-term trainee programmes. The majority of our MMOs are also trained PAM operators, which allows a high degree of flexibility in the offshore working environment. All our observers and operators hold the full suite of up-to-date offshore training and medical certificates, are fully-insured and benefit from 24-hour land-based logistical and expert technical support throughout the entire survey duration. All OSC MMOs and PAM operators are contractually obliged to stay up-to-date on all marine mammal mitigation guidelines allowing us to know exactly what is required in your area.

Company experience

OSC specialises in marine mammal mitigation. Operating world-wide since 2004, with offices in Scotland, Greece, and New Zealand, OSC’s scientists have worked for a wide-range of clients including the military, Boskalis, BASF, CGGVeritas, Dragados, Fugro, Gardline, Horizon Geosciences, Maritech, Maersk, MEWO, Noble, Noble Denton, OTAQ, Petrogas, PGS, RSK, RWE Dea, Scottish Power Renewables, SFF, Shell, SLR, Subsea7, Tulip Oil, Wintershall, to name a but few. OSC’s services are regularly praised, with much custom from repeat clients. Client testimonials are also available upon request. OSC is contracted both directly or subcontracted and adhere strictly to confidentiality agreements.


Hastie, G., Merchant, N.D., Götz, T., Russell, D.J., Thompson, P., and Janik, V.M. (2019): Effects of impulsive noise on marine mammals: investigating range‐dependent risk. Ecological Applications, e01906. JNCC (2017): JNCC guidelines for minimising the risk of injury and disturbance to marine mammals from geophysical surveys Aberdeen. 28 pp. Markus, T., and Sánchez, P.P.S. (2018): Managing and regulating underwater noise pollution. In M. Salomon, and T. Markus (Eds): Handbook on Marine Environment Protection : Science, Impacts and Sustainable Management. Springer International Publishing, Cham, pp. 971-995. Von Benda-Beckmann, A.M., Wensveen, P.J., Kvadsheim, P.H., Lam, F.-P.A., Miller, P.J.O., Tyack, P.L., and Ainslie, M.A. (2014): Modeling effectiveness of gradual increases in source level to mitigate effects of sonar on marine mammals. Conservation Biology 28, 119-128.