Effectiveness of the European Natura 2000 network to sustain a specialist wintering waterbird population in the face of climate change

Abstract

Analysis of coordinated Greater Scaup (Aythya marila) count data from the last 30 years showed a 38.1% decrease in wintering numbers in North-West Europe, from 309,000 during 1988–1991 to c.192,300 individuals during 2015–2018. Annual trends in wintering numbers differed throughout the range. Numbers decreased in the UK, Ireland, and in the Netherlands, while numbers were stable in Denmark. Germany, Poland, Sweden, and Estonia showed increasing numbers, suggesting a shift in the distribution of the species within its wintering grounds towards the east and north. Higher temperatures in northern and eastern areas were correlated with the range shift of the wintering distribution. Deaths from bycatch drowning of Scaup in fishing gear have significantly decreased in recent decades in the Netherlands, where currently the greatest threat is considered the deterioration of food resources. The increasing concentration of wintering Scaup in coastal Poland and Germany (where lack of effective implementation of conservation measures fail to protect the species from the impacts of bycatch and declining food quality) pose major threats to the entire population.

Changes in numbers and distribution of wintering waterbirds around Gotland 1969–2020

“…short-stopping. This has been shown at an international scale for some of the common species such as Tufted Duck, Common Goldeneye, and Goosander (Lehikoinen et al 2013), Smew (Pavon-Jordan et al 2015, and Greater Scaup (Marchowski et al 2020). In all these species the International Waterbird Census has rendered decreases in the southern parts of their winter ranges in Northwest Europe, whereas the numbers have increased in the northerly parts of their winter ranges.…”

“…In all these species the International Waterbird Census has rendered decreases in the southern parts of their winter ranges in Northwest Europe, whereas the numbers have increased in the northerly parts of their winter ranges. These changes in the winter distribution of several species may conceal trends in the real population size, whereas the total wintering population of the Greater Scaup (Marchowski et al 2020) in Europe has decreased during the same period. For a species like the Greater Scaup, the northerly wintering areas and especially Gotland have become more important over the years.…”

“…Of the species using the inshore waters around Gotland in this comparison the Greater Scaup stands out with 88 % of the national total in January 2015 found on Gotland (Table 2). According to Marchowski et al (2020), the European winter population of the species was estimated to 192,300 individuals in 2015-2019. The peak count from Gotland of 23,800 is hence 12 % of the flyway population.…”

“…-Medeltal för antalet sjöfåglar av olika arter från markinventeringar på Gotland (inklusive Fårö) i januari under två tidsperioder med heltäckande räkningar 1969-1978 and 2013-2020. (next page). Total January counts of the most common waterbird species counted from vantage points along the shores, covering the entire coast of mainland Gotland (including Fårö) in 1969-1978, 1987-1989, 1994, 2009, and 2013-2020. Totalsummor för de vanligaste sjöfågelarterna vid landbaserade midvinterinventeringar som täckte hela Gotlands kust (inklusive Fårö) under 1969(inklusive Fårö) under -1978(inklusive Fårö) under , 1987(inklusive Fårö) under -1989(inklusive Fårö) under , 1994(inklusive Fårö) under , 2009(inklusive Fårö) under och 2013(inklusive Fårö) under -2020.…”

Management of Marine Natura 2000 Sites as Exemplified by Seabirds Wintering in the Baltic Sea: The Case of Poland

“…In regions such as the Baltic Sea, where concentrations of wintering seaducks coincide with gillnet fishery, there is a conflict between this and nature conservation objectives [25]. In such hot spots, it is important to apply an appropriate management approach with the aim of reconciling conflicting interests [27].…”