Modelling of Sea Duck Spatial Distribution in Relation to Food Resources in Lithuanian Offshore Waters Under the Gradient of Winter Climatic Conditions

The current study is the first attempt to apply geostatistical analysis in studying ecological relationship between populations of wintering sea ducks and communities of molluscs in Lithuanian offshore waters. Biological diversity of mollusc communities was found to have primary importance in determining spatial distribution of sea ducks under the most complicated winter climatic conditions, especially in the areas where sea duck populations were mainly feeding on molluscs. This finding strongly supports the earlier hypothetical assumption stating that under unfavourable winter climatic conditions large and dynamic sea duck populations are likely to over-exploit their benthic food stocks and the whole regional population of sea ducks is forced to gradually move towards the southwestern part of the Baltic Sea. The current study also proves that it is not the total biomass of certain mollusc species, but the average weight of mollusc specimens which is of a primary importance in determining spatial distribu...