Boertmann, D., Tougaard, J., Johansen, K. & Mosbech, A. 2010. Guidelines to environmental impact assessment of seismic activities in Greenland waters. 2nd edition. National Environmental Research Institute, Aarhus University, Denmark. 42 pp. – NERI Technical Report no. 785.
Summary
This report is meant as a guideline for companies preparing environmental impact assessments of seismic activities in ice free Greenland waters.
Protection zones
A number of protection zones for sensitive marine mammals (walrus, narwhal and bowhead whale) are designated and maps indicating the most important offshore fishing grounds are provided.
Best practice
The current knowledge on impacts on marine mammals, fish and invertebrates of seismic surveys is reviewed and a set of ‘best practice’ actions for conducting these surveys in relation to marine mammals is given.
The ‘best practice’ actions required in Greenland (by the Bureau of Minerals and Petroleum) are in line with the UK regulation (JNCC (2009) recommendations), which is also adopted for the regulation in many other areas.
- The airgun array should not be larger than needed for the specific survey.
- A safety zone of 500 m from the airgun array shall be applied.
- A pre-shooting search shall be conducted before commencement of any use of the airguns. If waters are less than 200 m deep, this search shall last 30 min. If waters are more that 200 m deep, it shall be extended to 60 min. If marine mammals are spotted within the safety zone, the ramp-up procedure shall be delayed 20 minutes, from the time when the animal has left the safety zone (or the ship has moved so far that the animal is outside). The pre-shooting search can be initiated before the end of a survey line, while the airguns are still firing
- The array shall not be started at full power, but individual airguns should be added one by one or if not possible, output of each airgun slowly increased by manipulation of pressure (ramp-up or soft start procedure).
- The ramp-up procedure shall occur over a period of about 20 min and can occur while the survey ship is en route to the starting point of the transect line.
- Ramp-up should not be initiated if marine mammals are inside the array or within the safety zone (500 m) of the array. If marine mammals are discovered within this safety zone during the ramp-up procedure, the airguns shall be turned off, and a new ramp-up procedure initiated when the mammal has left the safety zone - i.e. at least 20 min. after the last sighting.
- If proper ramp-up cannot be performed for technical or other reasons, other measures should be taken to assure that no animals are within the safety zone at start up.
- If the array is shut down for any reason while on the transect line it can be re-initiated at full power given that the silent break is not longer than 5 min. Otherwise a full ramp-up procedure should be followed.
- The array should be shut down completely between lines, if the transit time is longer than the time it takes to conduct a ramp-up and a full ramp-up should be initiated prior to arrival at the next line. If transit time is less than 20 min the array can be operated during transit, preferably at reduced power output.
- A Marine Mammal and Seabird Observer (MMSO) shall be posted on the source vessel (where the airguns are deployed from) and be continuously on the look-out particularly for whales during the pre-shooting search and when airguns are operated.
- Observation of marine mammals during shooting and inside the safety may not lead to shutdown.
- A log of marine mammal observations should be kept on the ship and reported as part of the cruise report.
- Passive Acoustic Monitoring (PAM) of vocalizing whales can be deployed for monitoring purposes especially in areas with bowhead whales. But it is not a demand.
- Airguns should not be used outside the transect lines, except in the cases mentioned above (ramp-up prior to arrival and on short transit lines) and for strictly necessary testing purposes. Testing the array at full power should be initiated with a ramp-up procedure as above.
Marine mammal and seabird observers (MMSOs)
At least two Marine Mammal and Seabird Observers (MMSOs) shall be on board the seismic vessels operating in Greenland waters in order to observe continuously when operating the airguns. They shall be especially trained in observation methodology and seismic mitigation.
The MMSOs have two tasks. Firstly, they have to watch systematically for marine mammals before start-up and during seismic survey in order to mitigate and observe safety distances to whales and seals.
Secondly, the MMSOs shall collect data on abundance and distribution of seabirds and marine mammals through systematic surveys. This task shall be carried out both during times when seismic survey is conducted, and when sailing in transit.
The latter task is not secondary to the former, and considerable effort should be spent on the systematic surveys.
The purpose of the second task is to improve the knowledge on temporal and spatial distribution of marine mammals and seabirds in the West Greenland waters, which generally is low. The collected data will be included in the NERI-databases of background information. The information in these databases will constitute the basis for future EIA-work by NERI and is moreover available to the companies which shall operate in Greenland waters and prepare EIAs of their activities. Data have to be collected according to NERI standards to fit into the databases, and guidelines to observation methodology will be provided when a seismic survey is approved by BMP.
Full report in pdf (4,07 MB)
