The breeding populations of most waterfowl have declined over the last few decades.
Of ducks hunted as game, the total population of the European wigeon has been in decline since the early 1990s. The same is true with the common pochard and the tufted duck, and with the common coot, a hunted species that belongs to the rail. The populations of the northern pintail and garganey have also long been in decline. The population of the northern shoveler has fluctuated heavily during the time it has been monitored. While common goldeneye populations have clearly declined since the early 1990s, they have recovered somewhat over the last few years. Of the ducks hunted as game, only mallard populations have increased over the course of the entire monitoring period.
Eutrophication poses a threat to waterfowl
Waterfowl populations in eutrophicated lakes and sea bays have, in general, almost halved in size over 20 years. On the other hand, waterfowl populations have remained more stable in oligotrophic waters.
In wetlands, the problems faced by most common waterfowl species, such as the European wigeon and the tufted duck, are attributable to nutrient discharges from agriculture, which leads to excessive eutrophication of waters. To improve the state of waterfowl populations, the runoff of nutrients into wetlands needs to be reduced and management measures – including the management of landscapes through grazing, the elimination of aquatic plants and the removal of fish in the Cyprinidae family –should be taken to improve the living conditions of waterfowl.
Hunters and birdwatchers collect data
Regarding Finnish inland waters, data on breeding populations is based on nationwide waterfowl counts which have been carried out since 1986. Data are collected by hunters and birdwatchers. Finland is an important breeding area for many European ducks. The country therefore plays a key role in the investigation of changes in populations and the reasons for such changes. As waterfowl are migratory birds, solutions regarding the status of duck populations cannot be implemented through decisions taken solely by a single country.
Working in collaboration with the Finnish Museum of Natural History, the Natural Resources Institute Finland (Luke) produces an annual report on the status of waterfowl populations. Luke also investigates environmental changes, such as habitat destruction, climate change, hunting and the impact of the predator–prey relationships on waterfowl populations. Long-term trends in the diversity of aquatic nature and the reasons for such trends can be ascertained by studying water fowl.
This information is needed for habitat management planning and hunting regulation, as well as for maintaining the diversity of aquatic nature. Such information is used by the wildlife and game administration and parties responsible for protecting water fowl and aquatic nature.
Photo on top of the page: Veli-Matti Väänänen