Total coastal count 2015

According to the national plans for the Swedish midwinter counts, total counts of the inshore coastal areas (incl. the archipelagos) are made at longer intervals. Originally the plan was to cover the Swedish coast from the Norwegian border to the northern parts of the Stockholm archipelago as the areas further north in the Baltic were normally ice-covered when the International Waterfowl Counts (IWC) started 1967. These censuses were made as a combination of aerial surveys (mostly in the aechipelagos) and extended coastal ground counts.

Similar country-wide surveys were also undertaken in 1971 and 2004. Surveys with a larger regional coverage have been made on a number of other occassions too. There was an intention to make country-wide surveys in 1987-1989. This was possible in 1987 but almost all areas except the west coast was more or less totally covered with ice. In the milder winters there was a lack of suitable aircrafts.

In January 2015 the open coasts of south Sweden from Falkenberg on the west coast to the mainland part of Kalmarsund and the coast of Gotland was covered by ground counts, whereas the rest of the area was covered by aerial surveys (see map below!).

In January 2016 the offshore areas of the Swedish part of the Baltic were surveyed as a part of an international project so for the first time the entire Swedish waters were covered. 

On the West coast total counts of the counting units was made, i.e. all areas were cover from the air in a way that all parts were covered. In the east coast archipoelagos this kind of coverage was not possible due to the large areas to cover so line transects had to be made. In 2004 as well as in the 1970s large areas in the archipelagos on the east coast were ice-covered and accordingly total counts wre possible. In 2015 all areas could be covered except the archipelagos of Södermanland. In the national estimates we had to use estimated totals for this part based on partial surveys in the area.

Normally the surveys were done by two observers, one in the front seat beside the pilote and one in the back seat. We concentrated the surveys on a main belt covering 200 m on each side of the aircraft. Outside this zone observations were recorded in two bands (B = 200 - 500 m, and C = 500 - 1000 m). We did not use distance sampling in the archipelagos as this method does not work in that environment.  In practice a zone of about 40 m on each side below the aircraft could not be covered. The observations were recorded on a continuously running tape-recorded, whereas the track of the flight was automatically recorded on a GPS. The observations were later connected with a geographical position in the data-base.

The main results are presented in tables and maps (follow the links below!). Further information is found for the common species in the species accounts.

Regional totals for 2015 (In Swedish, tables)

Distribution maps for 2015

Comparisons of the surveys in 1971, 2004 and 2015