Guidelines for seismic surveys. ACCOBAMS/ASCOBANS: Measures that apply to seismic surveys echo those for military and civil activities involving sonar use in addition to some specific measures presented here. Thus, the use of the lowest practicable source power is recommended as well as adopting suitable array configurations and pulse synchronization in order to limit horizontal propagation. The sequencing of seismic lines should be adapted to account for any predictable movements of animals across the survey area and avoid blocking escape routes. Moreover, multiple operating vessels should be regulated or prohibited. In the case of more than one seismic vessel operating in the same area, a minimum separation distance should be maintained. Model noise propagation verified in the field should be run to identify Exclusion/Safety Zones. Visual and passive acoustic monitoring (MMO and XXX) should be carried out continuously and with appropriate tools, such as the “big eyes” for visual surveying. Inadequate conditions for visual or acoustic monitoring (i.e. night, bad weather etc.) should cause a restriction of activities. Furthermore, increased precaution in deep waters and known areas of beaked whale presence is strongly recommended as well as application of ramp up/soft start protocols. In case of sightings in the Exclusion Zone, activities should be stopped, reduced or delayed or, if applicable, the vessel route changed. As a precautionary measure, a 30 minute interval (120 in increased concern situations or in the presence of deep divers) without animals in the EZ before the beginning of noise emissions is required. Finally, no EZ for particularly sensible/vulnerable species (i.e. beaked whales and sperm whales) should be adopted in order to enable the shut-down of noise sources whenever a sighting of such species occurs in the entire monitoring area.
