Abundance of waterbirds in the wintering season

Abundance of waterbirds in the wintering season Authors Ainars Aunins (LV), Leif Nilsson (SWE), Martti Hario (FIN), Stefan Garthe (GER), Mindaugas Dagys (LIT), Ib Krag Pedersen (DEN), Henrik Skov (DHI), Aleksi Lehikoinen (FIN), Markku Mikkola-Roos (FIN), Susanne Ranft (GER), Antra Stipniece (LV), Leho Luigujoe (EST), Andres Kuresoo (EST), Włodzimierz Meissner (POL) and Samuli Korpinen (HELCOM Secretariat). Reference to this core indicator report: [Author s name(s)], [Year]. [Title]. HELCOM Core Indicator Report. Online. [Date Viewed], [Web link]. Page 1

Contents Key message... 3 What is the status of the wintering water birds?... 3 Have the species abundances exceeded the set thresholds?... 3 The waterbird index... 3 Current status of waterbird functional groups in the winter... 4 How have the abundance of waterbird species changed?... 6 The fluctuations of abundance of waterbird species... 6 Off-shore waterbirds... 6 Coastal water birds... 7 Description of the indicator... 12 Policy relevance... 13 How the indicator describes the Baltic marine environment... 13 Role in the food web... 13 Responses to anthropogenic pressures... 14 Relation to other indicators... 15 Metadata... 16 Data source... 16 Description of data... 16 Geographic coverage... 16 Temporal coverage... 16 Recommendation for monitoring... 16 Off-shore... 16 Coast... 16 Assessment units... 17 Methodology and frequency of data collection... 17 Methodology of data analyses... 17 Determination of GES... 18 For off-shore areas provisional GES boundaries are suggested... 18 Strengths and weaknesses of data... 18 Further work required... 18 References... 19 Annex 1... 20 Page 2

Common Eider Tufted Duck Mallard Mute Swan Goosander Steller s Eider Common Pochard Greater Scaup Eurasian Coot Red-breasted Merganser Goldeneye Great Cormorant Smew Whooper Swan HELCOM Core Indicator of Biodiversity Key message Abundances of the wintering waterbird species have fluctuated strongly since 1991. Four of the 14 assessed species increased and five decreased 30 % or more in 2010 compared to the baseline year. An analysis of functional groups shows that especially the fish-feeding species have increased, whereas benthic-feeding species have shown recent decline. 250 200 150 100 50 0-50 -100 Figure 1. The abundance change of wintering waterbird species between 1991 and 2010. The green lines (30% increase/decrease) represent a natural range of fluctuation. Eight of 14 species exceed the limits and, thus, the environmental state cannot be considered good. What is the status of the wintering water birds? Have the species abundances exceeded the set thresholds? The waterbird index Abundances of 14 waterbird species in the wintering season were assessed. Nine of the species showed abundance changes over 30 % (Figure 1), indicating that the marine environment has greatly changed during that time period. Comparing to older records, one can estimate that the change has not been to right direction and may indicate high eutrophication, shift in food web to small fish and loss of mussel beds in coastal areas. The total abundance of waterfowl in the wintering season has decreased by about 30% from the baseline since 1991 (Figure 2). The decline is considered as an alarming signal and its root causes should be studied, but may be caused by the decline of benthic-feeding ducks (Figure 3). It is good to note that the index did not include gulls but included the offshore benthic-feeding ducks which were not, however, assessed at species-level due to high deficiency of offshore data. Page 3

Figure 2. The multi-species index for the abundances of waterbirds during 1991 2012 in the coastal areas of the Baltic Sea. The index does not include gulls but includes offshore benthic-feeding ducks (Long-tailed Duck, scoters) and auks which were not assessed at the species level due to shortage of offshore data. A virtual average year between 1991 2012 has been set as the baseline (100). The species list is given in Table 1. See methods to see the Current status of waterbird functional groups in the winter The functional groups of Baltic waterbirds in the wintering season include: - subtidal herbivorous benthic feeders, - subtidal invertebrate benthic feeders, and - pelagic fish feeders. Figure 3 shows the abundance indices of the three functional groups and Table 2 shows the species included in the groups. The herbivorous waterbirds do not show significant and consistent trend over the past two decades (Figure 3 A). The benthic-feeding waterbirds had a peak abundance in mid-1990s, and since that there has been a decline, exceeding 30% from the year of 1991 (Figure 3 B). As most of benthic-feeding waterbirds are offshore-feeding species, like long-tailed duck and common scoter, it is assumed that the long-term decline of these species has become visible also in the coastal zone (see Figure 4). The fish-feeding waterbirds have shown the largest inter-annual fluctuations among waterbirds (Figure 3 C). The abundance doubled in the late-1990s and has only slightly declined from that during the 2000s. The temporal changes may reflect the great increase of small fish in the Baltic Sea during the 1990s and the exponential increase of Great Cormorant. Page 4

A B C Figure 3. The abundance index for waterbird functional groups (a: herbivorous birds, b: benthic-feeding birds, and c: fish-feeding birds) during 1991-2012 in the coastal areas of the Baltic Sea. The species list is given in Table 1. A virtual average year between 1991 2012 has been set as the baseline (100). See methods to see the index calculation Page 5

Lkm, number ( 100 000) 2 3 4 5 6 7 HELCOM Core Indicator of Biodiversity How have the abundance of waterbird species changed? The fluctuations of abundance of waterbird species The state of wintering waterbirds has been very dynamic during the past two decades as shown by the species-specific abundance curves. Off-shore waterbirds The monitoring of offshore waterbirds has not been coordinated among the Baltic Sea countries and therefore the spatial and temporal consistency of the monitoring has been inefficient. Because of this, this indicator has (at least temporarily) made use of other data sources, especially the migration statistics. The abundance of Long-tailed Duck (Clangula hyemalis) in the Baltic Sea has dropped significantly during the recent two decades (Figure 4). The result is based on migration statistics along the main migration route. The result in Figure 4 is based on observations from Söderskär island, but the same signal is seen from other sites like Hanko (Lehikoinen et al. 2008). The autumn statistics support the conclusion (Hario et al. 2009). The migration statistics are considered reliable because the whole migrating population winters in the Baltic Sea area. Even older estimates of the migration observations suggest that the population had declined already before 1960s (Hario et al. 2009). The species breeds in the northern tundra and visits the Baltic Sea only during the wintering season to feed in the offshore reefs on benthic fauna. Because most of the population is found from the offshore areas, the abundance based on the current monitoring methods is highly uncertain. Based on offshore surveys in the Baltic, there are similar signals from the declined abundance (Durinck et al. 1994, Skov et al. 2007, Skov et al. 2011). Alli, Long-tailed duck 1970 1980 1990 2000 2010 Figure 4. Abundance of Long-tailed Duck (Clangula hyemalis) between 1968 and 2008 as observed during spring migration from the Söderskär island in the Gulf of Finland. Söderskär has been mentioned as the best migration monitoring site in the Gulf of Finland where the majority of Long-tailed Ducks migrates (Hario et al. 2009). Source: Finnish Game and Fisheries Research Institute. Page 6

The Common Scoter (Melanitta nigra) abundance has shown a different trend: the spring migration statistics show an increasing trend at least until late 1990s (Lehikoinen et al. 2008), after which a slight decrease has been observed (Hario et al. 2009). Coastal water birds Of the 14 species included in the assessment, 4 show strong increase and 5 show strong decrease, while 5 populations have similar abundance level as in 1991 (Figure 5). Hence, 9 of the 14 species have exceeded the 30% threshold which was set to signal strong population fluctuations (Table 1). The strong increases and decreases of wintering populations of waterbird species may reflect the unstable state of the Baltic Sea where strong eutrophication development has caused fluctuations of prey species (plants, invertebrates and fish). Moreover, the human activities at sea have increased during the assessment period (1991-2012) which may have caused additional pressure on the populations (oiling, by-catch in fisheries). Table 1. The abundance change between 1991 and 2010. Note that no change refers only to the abundance comparison between the two years: 1991 and 2010. The years 2011-2012 were left out due to incomplete data set. Species Change in 2010 (%) Statistical significance Whooper Swan +200% (increase) p<0.01 Smew +30% (increase) p<0.01 Goldeneye +50% (increase) p<0.01 Great Cormorant +50% (increase) p<0.01 Red-breasted Merganser -30% (decrease) p<0.01 Greater Scaup -60% (decrease) p<0.01 Eurasian Coot -60% (decrease) p<0.01 Common Pochard -70% (decrease) p<0.01 Steller s Eider -80% (decrease) p<0.01 Common Eider Tufted Duck Mallard Mute Swan Goosander No change No change No change No change No change Page 7

Goldeneye (Bucephala clangula) Common eider (Somateria mollissima) Tufted duck (Aythya fuligula) Page 8

Common pochard (Aythya ferina) Mallard (Anas platyrhynchos) Eurasian coot (Fulica atra) Page 9

Mute swan (Cygnus olor) Whooper swan (Cygnus cygnus) Smew (Mergellus albellus) Page 10

Red-breasted merganser (Mergus serrator) Goosander (Mergus merganser) Steller s eider (Polysticta stelleri) Page 11

Great cormorant (Phalacrocorax carbo) Figure 5. Temporal changes of waterbird species in the Baltic Sea during 1991-2012 in the coastal areas of the Baltic Sea. The years 2011-2012 have incomplete data and may bias the result. A virtual average year between 1991-2012 has been set as the baseline (100). See methods to see the calculation. Description of the indicator Seabirds are important predators in the marine ecosystem. In the wintertime, seabirds aggregate in certain feeding grounds where their abundances can be monitored. The indicator follows temporal change in the abundance of key seabird species, which have functional significance in the marine ecosystem (Tables 1 and 2). The indicator follows the OSPAR EcoQO 1 methodology for the status of seabirds in the North Sea (ICES 2008, 2011). The OSPAR EcoQO for abundance of seabirds was developed in the ICES WKSEQUIN workshop in 2008 (see the outcome here) and the most recent computation of the EcoQO was made by the ICES WGSE in 2011 (see outcome here). The abundance indicator consists of a TRIM analysis 2 of selected species, their abundance estimates over time and deviation of abundance from a baseline year. In the OSPAR EcoQO, a 30 % deviation from the baseline (or 20% for some species) was considered acceptable for a population. In the OSPAR Region II, the baseline year 2000 was chosen for the sake of simplicity as no true reference year can yet be set for bird species in that region. The Baltic indicator will be computed based on the same assumptions until better criteria can be developed. The EcoQO follows how many species meet the target range. Changes in wintering waterbird abundance should be within target levels for 75% of species monitored in any of the assessment areas. If the trends of the one quarter of these species exceed the respective target levels in any given year, action will be triggered. In the Baltic Sea, good environmental status is tentatively being set for the above-mentioned 75% threshold. The %-threshold is, obviously, very sensitive to the number of species included and therefore this will be discussed once the data has been compiled. 1 The OSPAR ecological quality objective is Changes in breeding seabird abundance should be within target levels for 75% of species monitored in any of the OSPAR regions or their subdivisions." 2 TRIM (TRends and Indices for Monitoring data) is a free software package used to determine species' population trends. See http://www.ebcc.info/trim.html Page 12

The indicator will follow the changes in abundance over the entire sea area and include a set of selected waterbird species. There will be 4 5 assessment units in the Baltic. Policy relevance The waterbirds are an integral part of the Baltic marine ecosystem. They are predators of fish, macroinvertebrates and other bird species, scavengers of carcasses and fishery discards and herbivores of littoral vegetation. The indicator addresses the HELCOM ecological objective Viable populations of species which is part of the biodiversity goal Favorable conservation status of Baltic biodiversity (HELCOM 2007). The indicator addresses the population abundance and distribution as required for assessments of the MSFD qualitative descriptor 1 (biodiversity) (Anon. 2008) and stated in the EC Decision 477/2010/EU for the MSFD (Anon. 2010). The indicator can also be used for the assessment of the MSFD qualitative descriptor 4 (food webs) as recommended by the MSFD Task Group 4 (Rogers et al. 2010). How the indicator describes the Baltic marine environment Role in the food web Seabirds are important predators in the marine ecosystem. However the wintertime abundance cannot be directly compared with the breeding bird indicator as the birds move more dynamically during the wintering within the Baltic Sea and between other areas. In the wintertime, seabirds aggregate in certain feeding grounds where their abundances can be monitored. Their abundance is supported by the ecosystem productivity, but they also have top-down impacts on their prey species. In the Baltic Sea, majority of waterbird species overwinter in the marine area, aggregating in suitable feeding habitats. Hence, the abundance wintering and breeding populations respond to different pressures and they should be assessed separately. Table 2. Species selected for the indicator and categorized by their functional groups. Species (winter populations) Black-throated Diver Gavia arctica Red-throated Diver Gavia stellata Great Crested Grebe Podiceps cristatus Goosander Mergus merganser Red-breasted Merganser Mergus serrator Great Cormorant Phalacrocorax carbo Smew Mergus albellus Razorbill Alca torda Common Guillemot Uria aalge Black Guillemot Cepphus grille Velvet Scoter Melanitta fusca Common Scoter Melanitta nigra Long-tailed Duck Clangula hyemalis Common Eider Somateria mollissima Tufted Duck Aythya fuligula Greater Scaup Aythya marila Common Pochard Aythya ferina Goldeneye Bucephala clangula Mute Swan Cygnus olor Mallard Anas platyrhynchos Functional group Coastal pelagic fish feeder Coastal pelagic fish feeder Coastal pelagic fish feeder Coastal pelagic fish feeder Coastal pelagic fish feeder Coastal pelagic fish feeder Offshore pelagic fish feeder Offshore pelagic fish feeder Offshore pelagic fish feeder Subtidal offshore benthic feeder Subtidal offshore benthic feeder Subtidal offshore benthic feeder Subtidal offshore benthic feeder Subtidal coastal benthic feeder Subtidal coastal benthic feeder Subtidal coastal benthic feeder Subtidal herbivorous benthic feeder Subtidal herbivorous benthic feeder Page 13

Coot Fulica atra Little Gull Larus minutus Common Gull Larus canus Herring Gull Larus argentatus Great Black-backed Gull Larus marinus Subtidal herbivorous benthic feeder The wintering waterbirds use all ice-free areas of the Baltic Sea as the wintering area and therefore the distribution may change depending on environmental conditions. Division of Baltic Sea to sub-regions may give additional information of the suitability of the sub-basins as wintering grounds for species. Figure 6 shows temporal changes of Common Eider in seven sub-regions of the Baltic Sea and shows, inter alia, that the species has declined more in the central and northern areas than in Danish Straits and Kattegat. Figure 6. Temporal changes of Common Eider in seven sub-regions of the Baltic Sea during 1991 2012. Responses to anthropogenic pressures Several anthropogenic pressures affect the abundance of wintering waterbirds. (Table 3). All the selected waterbird populations are affected by the eutrophication state. In the oligotrophic end of the eutrophication state, the bird populations are limited by the availability of food sources, whereas towards eutrophic conditions plant and zoobenthos biomass increases which first benefit seabird populations, but in the extreme end cause decrease in food availability. Page 14

Oil pollution affects most of the seabirds, oiling feathers and causing hypothermia. Although the number of oil slicks has significantly decreased in the Baltic Sea, oily surface waters still are a significant anthropogenic pressure for seabirds. Estimates of the number of birds oiled are uncertain. By-catch of seabirds in fishing activities is a problem for all fish feeders and benthic divers. Estimates of the number of birds drowned in fishing gear are uncertain. Hunting of seabirds is a significant pressure for some of the selected key species. Particularly, bags of eider and goldeneyes are heavy. Because the pressures affecting the selected key seabirds in the winter populations are similar, it is possible to use an index indicator where assessment can be first made on the species level and then functional groups are assessed separately (see methodology). Table 3. Pressures affecting the waterbird populations. Species (wintering population) Black-throated diver Red-throated diver Great crested grebe Goosander Red-breasted merganser Razorbill Common guillemot Black guillemot Velvet scoter Common scoter Long-tailed duck Eider Tufted duck Greater scaup Goldeneye Mute swan Mallard Coot Anthropogenic pressure eutrophication, oil, by-catch eutrophication, oil, by-catch eutrophication, oil, by-catch eutrophication, oil, by-catch eutrophication, oil, by-catch eutrophication, oil, by-catch eutrophication, oil, by-catch eutrophication, oil, by-catch eutrophication, oil, by-catch eutrophication, oil, by-catch eutrophication, oil, by-catch eutrophication, oil, by-catch eutrophication, by-catch eutrophication, by-catch eutrophication, by-catch eutrophication eutrophication eutrophication Relation to other indicators When assessing GES of the Baltic Sea, there should not be any mismatch between GES of different indicators. For example, the nutrient concentration targets in the Baltic Sea have been agreed in the HELCOM BSAP. Therefore, the seabird GES boundaries should not be set on levels which cannot be reached when nutrient targets have been reached. In addition, competitive interactions between fish feeding birds and large fish affect the target setting. With the current long-term management plan of cod, the cod stocks will increase, which likely affects (negatively) the food availability for birds. The GES boundaries for birds should not be set too high in such conditions. The policy decisions under different frameworks have possibly conflicting objectives. The Favourable Conservation Status under the Birds Directive may be difficult to reach, if the environment changes to more oligotrophic direction. However, decrease of by-catch, oil pollution and hunting would allow higher bird populations and may mitigate this conflict. Page 15

Metadata Data source National monitoring data from coastal mid-winter censuses from all the HELCOM Contracting Parties. Description of data Data format: - Data is in a format to fit to the TRIM software (columns: site, year, species, abundance). If no data, abundance should be -1. Only one abundance value per species per year. - Site information: (1) geographical position of the central point + polygon shapefile; (2) the area could be included in order to estimate densities (can be included at a later stage); (3) specify the method of counting. - Raw or pre-processed count data data/indices from 1991 to 2012 (or the latest year available). - Weather conditions (e.g. ice cover) are used to interpret the results. It can be included in the database as a separate column. Geographic coverage The data covers mainly coastal areas where the national monitoring is done. Coastal data covers the entire Baltic Sea (see Annex 1.) Offshore censuses are made on a project-basis. Two larger censuses have been made in the Baltic Sea (Skov et al. 2007, 2011), whereas partial censuses in smaller areas are presented in Annex 1. Temporal coverage Indicator uses time series between 1991-2012 (or the latest year in time series). The last two years are partly incomplete (German data missing) and therefore the current assessment concentrates on 1991 2010. The software requires either annual data or data at regular intervals. The time series datasets of wintering seabirds are not uniform enough to make a state assessment. Available sources of information are Durinck et al. (1994) and Skov et al. (2000, 2007 and 2011). Recommendation for monitoring Off-shore It is recommended to survey the whole Baltic Sea at least every 3 years in a coordinated way. All ice-free areas should be surveyed and attention should be turned also to new ice-free areas in the Gulf of Bothnia and Gulf of Finland. It is recommended to develop digital methods for aerial surveys and follow the standards in the ship-based and aerial surveys.seals Monitoring is highly relevant in main reproduction areas (see separate core indicator report Population growth rate, abundance and distribution of marine mammals. Coast Continue as it is but ensure monitoring in the new ice-free areas (Gulf of Bothnia, eastern Gulf of Finland). Page 16

Assessment units The assessment is relevant for the entire Baltic Sea area, but the relevance of Bothnian Bay and eastern Gulf of Finland may increase only after a few years. Expert judgment is needed to judge how many assessment units are used, but preliminary the indicator is computed for the whole area and then to 4-5 assessment units. Sub-basin assessment units in the Baltic Sea (blue lines). Methodology and frequency of data collection Offshore censuses: See Skov et al. 2007 and 2011 National censuses: See Annex 1. Methodology of data analyses TRIM: see the web page of the European Bird Census Council (EBCC): Indicator: see ICES 2008 and 2011. Calculation of multi-species index: The multi-species index uses the geometric mean of species abundance indices, where every species is treated equally and standard errors are used to present variability of data. Page 17

Method by Gregory et al. (2005) Ī multi-species index value T number of indices (species) I t species abundance index value Determination of GES Good Environmental Status (GES) is determined by a proportion of bird populations exceeding the limits of population fluctuations (see methodology above). Tentatively the indicator follows the OSPAR ecoqo, which allows 30 % fluctuations on both sides of the baseline (20 % for alcids), whereas the index baseline was set to the year 1991 (set as 1.0). In OSPAR ecoqo they have 16 populations of which 75 % should stay within the limits. If that is exceeded, an action is triggered. Good environmental status is tentatively being set for the above-mentioned 75% threshold. The %- threshold is, obviously, very sensitive to the number of species included and therefore this will be discussed once the data has been compiled. More information can be read from the ICES Workshop on Seabird Ecological Quality Indicator (ICES 2008). For off-shore areas provisional GES boundaries are suggested Until further (modeling) studies have confirmed possible GES boundaries for the selected bird species, it is proposed that the GES is tentatively defined as a 50% deviation from mean of the reference period of 1992-1993 (based on available temporal trends in Skov et al. 2011). Strengths and weaknesses of data Strengths: - The wintering birds are monitored in all Contracting Parties. - The index methodology is based on temporal change in fixed areas and therefore the assessment does not require a full coverage of the Baltic Sea area. Weaknesses: The indicator currently has a couple of weaknesses which must be addressed in near future: - not all wintering grounds are covered, as a consequence of milder winters northern sub-basins, e.g. Bothnian Sea, have opened for wintering birds. - monitoring methods differ between the offshore monitoring and national monitoring practices, - GES boundary is tentative, because of the uncertainty of interlinkages with other GES boundaries. Further work required - Baseline year should be set species-specifically based on pressures affecting the species. - Deviation from the baseline should be confirmed for every species. - The 75 % trigger level should be further discussed and the use of other integration could be discussed. - Because the species and functional groups may have different significances in the ecosystem, weighting factors could be considered. They could be based on the conservation value of the Baltic population in the European context or the proportion of the species in the wintering seabird abundance. Page 18

References Anon. (2008a): Directive 2008/56/EC of the European Parliament and the Council of 17 June 2008 establishing a framework for community action in the field of marine environmental policy (Marine Strategy Framework Directive). Official Journal of the European Union, L 164/19, 25.06.2008. Anon. (2010): Commission decision of 1 September 2010 on criteria and methodological standards on good environmental status of marine waters (2010/477/EU). OJ L 232/14, 2.9.2010. Durinck, J., Skov, H., Jensen, F.P. & Pihl, S. (1994) Important marine areas for wintering birds in the Baltic Sea. Report to the European Commission. Ornis Consult Ltd., Copenhagen. Gregory R.D., van Strien A.J., Vorisek P., Gmelig Meyling A.W., Noble D.G., Foppen R.P.B. et Gibbons D.W. (2005): Developing indicators for European birds. Philosophical Transactions of the Royal Society B 360: 269-288HELCOM (2007): Baltic Sea Action Plan. Available at: http:///bsap/en_gb/intro/ Hario M, Rintala J & Nordenswan G (2009) Allin aallonpohjat Itämerellä taustalla öljyvahingot, sopulisyklit vai metsästys? Suomen Riista 55: 83-96. HELCOM (2009) Biodiversity in the Baltic Sea An integrated thematic assessment on biodiversity and nature conservation in the Baltic Sea. Balt. Sea Environ. Proc. No. 116B. Available at: /publications HELCOM (2012) Development of a set of core indicators: Interim report of the HELCOM CORESET project, PART A. Description of the selection process. Baltic Sea Environment Proceedings No. 129 A. Available at: /publications. ICES (2008) Report of the Workshop on Seabird Ecological Quality Indicator (WKSEQUIN), 8-9 March 2008, Lisbon, Portugal. Available at: http://www.ices.dk/reports/lrc/2008/wksequin/wksequin2008.pdf ICES (2011) Report of the Working Group on Seabird Ecology (WGSE), 1-4 November 2011, Madeira, Portugal. Available at: http://www.ices.dk/reports/ssgef/2011/wgse11.pdf Lehikoinen, A., Ekroos, J., Jaatinen, K., Lehikoinen, P., Lindén, A., Piha, M., Vattulainen, A. & Vähätalo, A. (2008) Bird population trends based on the data of Hanko Bird Observatory (Finland) during 1979 2007. Tringa 4/2008. [Summary in English] Rogers, S., Casini, M., Cury, P., Heath, M., Irigoien, X., Kuosa, H. et al. (2010) MSFD, Task Group 4 Report, Food webs. European Commission Joint Research Center and ICES. Available at: http://www.ices.dk/projects/projects.asp. Skov et al. (2000) Inventory of inshore and marine Important Bird Areas in the Baltic Sea. BirdLife International, Cambridge. Skov, H., Durinck, J., Leopold, M.F. & Tasker, M.L. (2007) A quantitative method for evaluating the importance of marine areas for conservation of birds. Biological conservation 136: 362-371. Skov, H., Heinänen, S., Zydelis, R., Bellebaum, J., Bzoma, S., Dagys, M., Durinck, J. et al. (2011) Waterbird Populations and Pressures in the Baltic Sea. TemaNord 2011:550. Available at: http://www.norden.org/en/publications/publikationer/2011-550. Page 19

Annex 1 Data table 1. Monitoring of waterbirds in mid-winter counts on the coast. Country Coastal area State financed national monitoring? Number of sites/routes Temporal intervals Denmark Yes aerial line every 3 rd year transect and total counts, ground counts Yes counts from land with net-work of observers Estonia Most of the open Partly yes, 128 (coastal coastline volunteers sites) Finland Åland islands Yes 3 ship-based strip transect count Entire coast Volunteers ground survey100 sites Germany Mecklenburg- Western Pomerania (Little Belt, Kiel Bay, Bay of counts along shoreline Start of time series 2000 with present method, but 1968 with other method Data holder Remarks Key species coastal birds (divers, cormorants, geese, swans, ducks, waders, gulls, terns, auks) Annual 2000 Whoopers Swan, Bewicks Swan, geese Annual (only in January) 1967 Estonian Orn. Society Digitalized data since 1993 Annual 1968 SYKE 5 permanent coastal routes, totalling 265 km Annual varies but generally <1990s Finnish Museum of Natural History wintering seaducks, alcids, gulls Annual 1965 waterfowl (ducks, geese, swans, cormorants, divers etc.) All Page 20

Latvia Lithuania Poland Russia Sweden Mecklenburg, Southern Baltic Proper) Schleswig-Holstein Lithuanian coastline, Nemunas river delta, Curonian's spit national park area Western part of the Gulf of Gdańsk Neva estuary within St. Petersburg Swedish Baltic Sea Coast up to Kattegatt Volunteers ground survey; nearly the whole coastline in January Ground survey; nearly the whole coastline (about 120 km) from September to April Ground survey Annual 1966/67 the whole coastline has been divided into 60 counting sites, each site app. 10 km long 2-4 times a year 2007 8 monthly counts 1984 Waterbird Research Group KULING Annually Annual 1967 (1964 in South) counts along shoreline all waterbirds (swans, geese, ducks, mergansers, grebes, divers, cormorant, grey heron, rails, waders, gulls) waterfowl (ducks, geese, swans, cormorants, divers etc.) Swedish Baltic Sea Coast up to counts along shoreline+ae 1971-1973 (coastline, Surveys made with the abition to cover waterfowl (ducks, geese, swans, Page 21

Kattegatt rial surveys in archipelagos +boat surveys in some parts plane, ship, all ice-free parts, offshore areas not included), 1987-1989. 1992-1993 (plane + ship), 2004 all of the ice-free parts of the Swedish coast, offshor areas not inlcuded. cormorants, divers etc.) Page 22

Data table 2. Monitoring of waterbirds in mid-winter counts on offshore areas (defined as counts from plane or boat). Country Areas covered State financed national monitoring? Temporal intervals Counting method Denmark Entire area Yes 3 years Line transect from aircraft (250 ft) Wind farms Yes annual Estonia Gulf of Riga (entire Gulf) Finland Germany Entire area: 3 strips (2200 km) German EEZ: all areas German EEZ: Pomerania project project Line transect from aircraft (250 ft), 3 / 6 km transect spacing No 3 years number of strips: 3, transect width: 397 m, flight height: 250ft, transect spacing: 8 km, transect orientation: perpendicular to coast (SSW-NNE), coverage: 2200 km every 3 rd year Partenavia P-68 with bubble windows, number of strips: 4, transect width: 397 m, transect spacing: 8 km, flight height: 78 m (250ft), cruising speed: 185 km/h (100 knots) every 2 nd year ship-based strip transect count; number of strips: 4, transect width: 300 m, observation Start of time series 2010-2012 Remarks + Data holder Estonian University of Life Sciences Species 2009 Gavia arctica, Gavia stellata, Melanitta nigra, 2008 all German coastal and offshore waters of the Baltic Sea are counted within 3 flight days 2009 SCI Pomeranian Bight in the German EEZ and adjacent SCIs in the German coastal waters are counted within 7 ship days; earlier counts within the framework of Gavia arctica, Gavia stellata, Podiceps grisegena, Podiceps auritus, Mergus Page 23

Schleswig- Holstein (coastline and offshore shallow-waterareas (< 10 meter water deep)) Schleswig- Holstein (offshore) annual, regularly January and March, additionally other months (October- April) height above sea surface: 5-7 m, cruising speed: 7 18 knots, snapshot method for flying individuals plane: flight height: 250ft, speed: 180 km/h the Seabirds-at-Sea-programme since app. 2000. 1980 also monitoring of ships and fishing nets; flights along the coastline and over the offshore shallow-water-areas; regularly January and March, additionally other months (October-April) annual plane: strip transect count. 2004 January-March; number of stripes 15, 331 km, flight height: 250ft, speed: 180 km/h, SSW-NNE; also monitoring of ships and fishing nets; serrator, Somateria molllissima, Clangula hyemalis, Melanitta nigra, Melanitta fusca Somateria mollissima, Melanitta nigra, Clangula hyemalis Somateria mollissima, Melanitta nigra, Clangula hyemalis Latvia Latvian coast project Boat Gulf of Riga project Line transect from aircraft (250 ft), 3/6 km transect spacing Lithuania three areas project Boat Poland Whole Polish 12 miles zone. Two off-shore area: Słupsk Bank and Pomeranian Bay Yes Annual ship transect count with snap-shot technique; transect width: 2 x 300 = 600 m; 40 transect lines within 12-miles zone, 8 transect lines in Slupsk Bank and 6 transect lines in Pomeranian Bay. 1992-1993. 2007-2009 One year - 2005, and continuo usly from 2010 See Table 1. Sweden Skåne to project Strip transect from aircraft 2007 - Note there are old aerial surveys from Page 24

Stockholm (250 ft) 2011 1971-1978 for some areas and boat transects 1965-1978 The surveys in 2009 2011 were performed in order to develop a national monitoring program Kattegat project Strip transect from aircraft (250 ft) 2009 Old data from the seventies from boat and aircraft SW Scania, Blekinge and Hanö bukten Gävlebukten, Stockholm archipelago project Wind farms, strip transect from aircraft (250 ft) MARMONI, Utsjöbanksprojektet (Naturvårdsverket) Page 25