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Abstract:
The data shows a modelled distribution of seabirds in open sea, based on a two-step model on transect counts of seabirds in Norwegian waters in 10x10 square kilometre resolution. The maps consist of 10x10 km2 grid and shows predicted abundance of the species based on two-step analysis (see Data Analysis) of data available over the distribution of seabirds in Norwegian and adjacent sea areas (see Dataset) in winter season. Along with the maps we also present uncertainty in predictions that 95% confidence intervals and standard error. The confidence intervals were not possible to define at very low densities. It is important to note that uncertainty does not allow for systematic errors caused by differences in detectability (see Methods). Conspicuous species that often follows after the vessel is systematically overestimated. This is especially true species fulmars, kittiwakes, herring gulls, black-backed gulls and gull. Small dark species diver is probably equivalent underestimated. This is especially auks: auk, puffin, razorbills, murres and guillemots. Abundance estimates should be regarded as indexes.