At HELCOM level: there is currently a regionally organized registry of impulsive events in the Baltic Sea region. The registry is hosted by ICES and the development of the registry follows the same approach as for the OSPAR region. Such registry makes an account of the number of days with selected activities that create impulsive sounds that can be harmful for marine animals and make it possible to evaluate cumulative impacts of noise. The registry of impulsive events requires information on e.g. position data of the activity, licensing block/area, date of operation, source operation, sound mitigation system. The registry is implemented as a GIS-based tool where sound levels of events (or proxies for sound level, such as air gun array size and hydraulic hammer energy) are stored and a map visualisation is enabled. At national level: anthropogenic activities at sea (e.g. construction) during the implementation of which sound impulses may arise are shall be approved by the responsible supervisory authorities, including providing of adequate monitoring by the operator. The results of the monitoring shall be submitted to the State Environmental Service of the Republic of Latvia (SES) and the results shall be available for the assessment of the environmental state of affected areas.

At HELCOM level: there is currently a regionally organized registry of impulsive events in the Baltic Sea region. The registry is hosted by ICES and the development of the registry follows the same approach as for the OSPAR region. Such registry makes an account of the number of days with selected activities that create impulsive sounds that can be harmful for marine animals and make it possible to evaluate cumulative impacts of noise. The registry of impulsive events requires information on e.g. position data of the activity, licensing block/area, date of operation, source operation, sound mitigation system. The registry is implemented as a GIS-based tool where sound levels of events (or proxies for sound level, such as air gun array size and hydraulic hammer energy) are stored and a map visualisation is enabled. At national level: anthropogenic activities at sea (e.g. construction) during the implementation of which sound impulses may arise are shall be approved by the responsible supervisory authorities, including providing of adequate monitoring by the operator. The results of the monitoring shall be submitted to the State Environmental Service of the Republic of Latvia (SES) and the results shall be available for the assessment of the environmental state of affected areas.

In one to two places (the Gulf of Riga and the Baltic Sea), hydrophones are placed, recording the intensity of continuous low-frequency sound. The information obtained is used for common (in Baltic Sea scale) sound distribution modelling.

In one to two places (the Gulf of Riga and the Baltic Sea), hydrophones are placed, recording the intensity of continuous low-frequency sound. The information obtained is used for common (in Baltic Sea scale) sound distribution modelling.