During the clearance operations, altogether 74 munitions were cleared. A wide range of mitigation measures were in place to reduce potential impacts on marine life: marine mammal observers ensured that marine mammals were not in the clearance area, seal scrammers were in place to scare away any seals that could have been in the area, porpoises were monitored with acoustic monitoring and fish scarers were used to drive the fish away from the area. In addition, in order to reduce underwater noise from the clearance operations, bubble curtains (i.e. barriers created by compressed air bubbles) were used for all munitions in the Eastern part of the Gulf Finland and for munitions with a total charge of over 22 kg.

The first quarterly results analysed underwater noise measurements for a subsection of the cleared munitions. Results of underwater noise monitoring during munitions clearance and analyses of water quality changes during preparatory activities will be presented in the next monitoring reports. Based on the monitoring:

  • The number of munitions to be cleared was smaller than planned (15 objects were identified as not being munitions during the pre-clearance surveys).
  • The size of the munitions was either smaller or in line with the information presented in the permit applications.
  • The total underwater noise caused by munition clearance was smaller than had been assessed in the permit applications.
  • Underwater noise monitoring showed that the risk of causing hearing loss to marine mammals was smaller than assessed.
  • Neither seals nor porpoises were detected in the area during the clearance operation.

Monitoring activities are performed in line with the Finnish Environmental Monitoring Programme, approved as part of the Water Permit decision granted by the Regional State Administrative Agency Southern Finland in April 2018. It covers monitoring of underwater noise, water quality, cultural heritage and fishery.

The monitoring report was prepared by the environmental consultancy Sitowise Oy. The environmental fieldwork contractor Luode Consulting Oy monitored the underwater noise during munitions clearance.

All findings presented in the quarterly monitoring reports for 2Q-4Q18 will be compiled into an annual monitoring report for 2018, to be published in 2Q19. The reports will be available on Nord Stream 2’s website.