Forty years of waterbird survey in the Archipelago Sea

Safeguarding and sharing an exceptional database

Safeguarding and sharing an exceptional database

This project aims at sharing an exceptional waterbird database with the scientific community. Dr. Lennart Saari has censused birds over 4 decades with strictly the same methodology. The bird surveys were carried out at Aasla (60º18´N, 21º57´E), Archipelago Sea, in Southern Finland.

Long term databases are crucial tools to monitor biodiversity changes through time. They prove to be essential when it comes to understanding the effect of climate change on our environment and to predict changes yet to come. Nevertheless to collect data on the long term is time consuming and expensive leading often to incomplete data or to databases with irregular methodology. In this context long term databases collected by a single person following a constant methodology over the years are extraordinary valuable. We present such a remarkable database to the scientific community.

The bird data cover the period 1975-2015. The waterfowl censuses consist of a combination of points and rounds counts (Koskimies  & Väisänen 1991). The same method has been used every year (see details in the method section). Briefly the census covers all inland water and most of the sea shore of Aasla. Waterfowl counts were performed nine times per year.

Requirement to use the database: co authorship for Dr. Lennart Saari, contact Lennart at: lennart.saari (at)

Header image: Dr. Lennart Saari (copyright Mia Rönkä)


Maju Ylönen, Master thesis, university of Turku, Finland

Héloise Bouloizeau, Master thesis, university of Angers, France

Martin Faucher, Camille Chateau, Cyriaque Carton-Moreau, L3, University of Angers, France