Seabird Monitoring in the German North Sea and Baltic Sea 2016
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Seabird Monitoring in the German North Sea and Baltic Sea 2016 Kai Borkenhagen1, Nils Guse1, Mirko Hauswirth2, Hanna Markones1, Nele Markones1, Bettina Mendel1, Henriette Schwemmer1, Stefan Garthe1 1) Research and Technology Centre West Coast (FTZ), Kiel University, Hafentörn 1, D-25761 Büsum 2) Federal Agency for Nature Conservation, Vilm, D-18581 Putbus Seabird Monitoring 2016 Introduction Seabirds, as top predators, are an important component of marine ecosystems. They are under increasing pressure from anthropogenic activities such as fishing, the development of offshore wind energy, shipping traffic, marine pollution, etc. Recording species occurrence and improving knowledge of the distribution patterns, population trends and habitat requirements is vital to effectively manage protected areas and associated seabirds. The Birds Directive (BD) and the Marine Strategy Framework Directive (MSFD) of the European Union require their member states to regularly submit reports based on data presented in this report. In addition, the data are used to develop indicators to assess the state of the environment within the framework of the regional sea conventions OSPAR and HELCOM. The marine biodiversity monitoring programme for vertebrates is funded by the German Federal Agency for Nature Conservation (Bundesamt für Naturschutz - BfN) and carried out by the FTZ (Research and Technology Centre, Kiel University) in collaboration with the German Oceanographic Museum Stralsund (Deutsches Meeresmuseum - DMM) and the Institute for Terrestrial and Aquatic Wildlife Research of the Hanover University of Veterinary Medicine Foundation (Institut für Terrestrische und Aquatische Wildtierforschung der Stiftung Tierärztliche Hochschule Hannover - ITAW). The results presented in this report are based on regular large-scale surveys of seabird occurrence in the German North and Baltic Seas. These observations are based on standardised methods and provide data on spatio-temporal patterns and habitat use of seabirds in the ecosystems of the North Sea and Baltic Sea. Assessments within the framework of Birds Directive and MSFD and the development of indicators for OSPAR and HELCOM are based on these data. The data and findings furthermore contribute to marine spatial planning and the assessment of anthropogenic activities. Survey Overview North Sea A five-day aerial survey of the entire German Bight was planned for winter. For logistical reasons, (weather, plane availability) only three days were implemented. The five-day aerial spring survey of the German Bight which focused on the SPA Eastern German Bight was shortened by one day due to logistics. The five-day aerial survey of the German Bight during breeding season was implemented in full. The three cancelled aerial survey days were reallocated to a four-day joint survey of the Baltic Sea. The fifteen proposed ship-based survey days in the North Sea were implemented successfully (Table 1). Baltic Sea A four-day aerial survey of the whole German Bight including the SPA Pommeranian Bight was conducted in winter as part of the international joint survey. As this survey had not been in the planning stage at the time of applying for funds, resources allotted to the North Sea were reallocated to this survey. A one-day aerial survey of the SPA Pomeranian Bay was conducted as planned in both 1 Seabird Monitoring 2016 summer and autumn. The number of ship-based surveys implemented in the eastern German Bight surpassed the number originally aimed for (Table 1). Table 1: Survey plan and implemenentaton in 2016. P= plane; Sh= dhip; EGB = Eastern German Bight; PoBay = Pomeranian Bay; w= winter; sp= spring, su = summer; au = autumn. Survey planned implemented w sp su au w sp su Au entire German North Sea (January) p 5 3 entire survey (spring) p 5 4 SPA EGB & environs (spring) p th Sea entire North Sea (breeding season) p 5 3 Nor PhoViComp-Amrum Bank p 1 1 ship-based survey North Sea: ship of opportunity sh 15 15 entire German Baltic Sea (January) p 4 SPA Pomeranian Bay sh 7 7 7 7 partial survey SPA PoBay summer p 2 2 Baltic Sea ship-based survey Baltic Sea: ship of opportunity sh 8 15 Survey Results The course of the transect, the most important findings, and special observations of each individual survey are described below. Given that the spatial distribution of survey efforts may differ considerably, any numbers and density values are comparable to a limited extent only. North Sea Aerial seabird survey in the German Bight in February Seabirds of the German Bight were recorded during three monitoring flights between 26th and 29th February. We also present data from a survey flight monitoring the west coast of Schleswig-Holstein, funded by the Schleswig-Holstein Agency for Coastal Defence, National Park and Marine Conservation (LKN - Landesbetrieb für Küstenschutz, Nationalpark und Meeresschutz Schleswig- Holstein) (Figure 1). These data are included in the joint survey and are therefore presented together. Common scoters were the most abundant species with almost 35,000 individuals recorded and an average density of 18.85 individuals per km² (Table 2). The main distribution range of common scoters was southwest of Eiderstedt, west of the North Frisian Islands and north of the East Frisian Islands (Figure 2). Common eiders were abundant and predominantly observed near the coast. In addition, great numbers of seagulls as well as northern fulmars and auks were recorded. Three little auks, seven Atlantic puffins, a basking shark in the northwestern part of the EEZ and an unidentified shark west of Sylt are worthy of note (Table 2). 2 Seabird Monitoring 2016 Figure 1: Transect course of the aerial seabird survey in the German Bight in February 2016. 3 Seabird Monitoring 2016 Figure 2: Distribution of common scoters in the German Bight in February 2016. 4 Seabird Monitoring 2016 Table 2: Abundance and average density of species recorded in the transect during the aerial surveys of the German Bight in February 2016. species scientific name count density [ind. /km²] red-throated diver Gavia stellata 102 0.055 black-throated diver Gavia arctica 4 0.002 unidentified diver Gavia spec. 80 0.043 great crested grebe Podiceps cristatus 1 0.001 northern fulmar Fulmarus glacialis 198 0.106 northern gannet Morus bassanus 38 0.020 great cormorant Phalacrocorax carbo 1 0.001 greylag goose Anser anser 6 0.003 common shelduck Tadorna tadorna 2 0.001 common eider Somateria mollissima 4,414 2.367 common scoter Melanitta nigra 34,440 18.465 velvet scoter Melanitta fusca 6 0.003 unidentified duck 4 0.002 oystercatcher Haematopus ostralegus 111 0.060 unidentified sandpiper Calidris spec. 5 0.003 undetermined wader Limicolae 96 0.051 little gull Hydrocoloeus minutus 65 0.035 black-headed gull Chroicocephalus ridibundus 63 0.034 common gull Larus canus 402 0.216 unidentified small gull 12 0.006 lesser black-backed gull Larus fuscus 58 0.031 herring gull Larus argentatus 480 0.257 great black-backed gull Larus marinus 16 0.009 common / herring gull Larus canus / Larus argentatus 114 0.061 unidentified large gull 235 0.126 great / lesser black-backed gull Larus marinus / Larus fuscus 3 0.002 black-legged kittiwake Rissa tridactyla 163 0.087 unidentified gull 1,187 0.636 common guillemot Uria aalge 280 0.150 razorbill Alca torda 76 0.041 common guillemot / razorbill Uria aalge / Alca torda 213 0.114 little auk Alle alle 3 0.002 Atlantic puffin Fratercula arctica 7 0.004 unidentified bird 4 0.002 unidentified marine mammal 3 0.002 harbour porpoise Phocoena phocoena 54 0.029 grey / harbour seal 5 0.003 harbour seal Phoca vitulina 150 0.080 unidentified shark 1 0.001 basking shark Cetorhinus maximus 1 0.001 5 Seabird Monitoring 2016 Aerial seabird survey in the SPA Eastern German Bight in March An aerial survey of the SPA Eastern German Bight was implemented on 31st March (Figure 3). In terms of numbers, the scene was dominated by a variety of gull species (particularly common gulls, herring gulls, and lesser black-backed gulls). In addition, a number of divers and auks were observed (Table 3).The main distribution of divers was west of the SPA Eastern German Bight. However, numerous divers were observed in the SPA as well (Figure 4). Figure 3: Transect course of the aerial seabird survey in the SPA Eastern German Bight in March 2016. 6 Seabird Monitoring 2016 Figure 4: Distribution of divers in the SPA Eastern German Bight in March 2016. 7 Seabird Monitoring 2016 Table 3: Abundance and average density of species recorded in the transect during the aerial surveys of the SPA Eastern German Bight in March 2016. species scientific name count density [ind. /km²] red-throated diver Gavia stellata 97 0.190 black-throated diver Gavia arctica 3 0.006 unidentified diver Gavia spec. 86 0.168 nortern fulmar Fulmarus glacialis 7 0.014 northern gannet Morus bassanus 27 0.053 common eider Somateria mollissima 27 0.053 common scoter Melanitta nigra 9 0.018 little gull Hydrocoloeus minutus 21 0.041 black-headed gull Chroicocephalus ridibundus 17 0.033 common gull Larus canus 952 1.865 unidentified small gull 247 0.484 lesser black-backed gull Larus fuscus 151 0.296 herring gull Larus argentatus 268 0.525 great black-backed gull Larus marinus 1 0.002 common gull / herring gull Larus canus / Larus argentatus 3 0.006 unidentified large gull 92 0.180 black-legged kittiwake Rissa tridactyla 19 0.037 unidentified gull 68 0.133 sandwich tern Sterna sandvicensis 5 0.010 common / Arctic tern Sterna hirundo / Sterna paradisaea 1 0.002 common guillemot Uria aalge 38 0.074 common guillemot / razorbill Uria aalge / Alca torda 24 0.047 undetermined songbird 4 0.008 harbour porpoise Phocoena phocoena 12 0.024 grey / harbour seal 4 0.008 grey seal Halichoerus grypus 1 0.002 harbour seal Phoca vitulina 3 0.006 Aerial seabird survey of the inner German Bight in May The inner German Bight was covered by two aerial sureys on 1st and 4th May (Figure 5).