Use constraints: Data can be used freely given that the source is cited (following creative commons license CC-BY). The source should be cited as: “HELCOM HOLAS 3 Dataset (2023)"

Lineage provided per country:

Estonia:

Observations/haulout units dataset consists of two monitoring schemes: a) horizontal (during 2000-2007) or aerial (sincce 2008) observations of grey seal at grey seal haulout sites and b) horizontal observations of ringed seals at ringed seal haulout sites. Census data on ringed seals have been collected mainly during boat or land censuses, as there was insufficient ice cover during the census period. In ice conditions, it was only possible to conduct a flight census in 2018. In 2017, there were no censuses of ringed seals.

Aerial counts of grey seal haulouts started at 2008. Before 2008 grey seal censuses were made by boat/land counting method. Usually, three counts per season.

Ringed seal counts were launched, using horizontal count method also at 2008.

The accuracy of the data is lower, the monitoring data do not cover all the main monitoring areas.

Monitoring method (grey seal):

https://keskkonnaagentuur.ee/media/2020/download

Monitoring method (ringed seal):

(will be available at https://keskkonnaagentuur.ee/seireankeedid)

National monitoring program description and annual reports (grey seal):

https://kese.envir.ee/kese/viewProgramNew.action?uid=473598

National monitoring program description and annual reports (ringed seal):

https://kese.envir.ee/kese/viewProgramNew.action?uid=1207300

Poland:

Since 2016 data collected on yearly basis by CIEP. Data collected based on HELCOM Guidelines. Grey Seal: 2x pups' counts + 3x population counts. Harbour Seal 1 count per year. Data set has been validated and quality is assured.

Finland:

Luke carries out annual aerial census during the peak of molting time in late May/early June in Finland during the international Baltic grey seal census period (see https://helcom.fi/media/publications/Guidelines-for-monitoring-Seal-abundance-and-distribution-in-the-HELCOM-area.pdf). Grey seals are photographed when they are visible and hauling out on rocks. Individual seal numbers are later counted from images. Gained result is the regional minimum estimate of grey seals, because part of the population is always submerged and not visible on land or surface.