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: Winter waterfowl censuses have taken place in Estonia since 1960. Today, the midwinter waterbird census is part of the international waterbird census (IWC), which has been in operation since 1967. The midwinter waterbird census has become a collaborative project with volunteers, the Estonian Ornithological Society, the Estonian University of Life Sciences, the University of Tartu and the Environmental Agency. Within the framework of the national environmental monitoring program, annual counts are organized in 119 coastal sectors.

Method: https://kese.envir.ee/kese/viewProgramNew.action?uid=473581

Program description and annual reports:

https://keskkonnaagentuur.ee/media/2041/download

Germany: Number of breeding birds in the nature reserves at the Baltic coast of Schleswig-Holstein.

Volunteers of different NGOs surveyed breeding waterbirds in the nature reserves at the Baltic coast of Schleswig-Holstein. The data quality differs among the species. Especially for geese, ducks, sawbills and shelducks there are methodological problems in counting “breeding pairs”, and the dataset is therefore inhomogeneous (breeding-pairs or only families were counted).

Link to metadata of dataset used for indicator calculation:

https://metadata.helcom.fi/geonetwork/srv/eng/catalog.search#/metadata/333f73d8-d7d6-4410-8ed3-46c5d9c2f06a