“Windanker” - Naturstyrelsen

IfAÖ Institut für Angewandte Ökosystemforschung GmbH

Carl-Hopp-Str. 4a, 18069 Rostock

Tel.: +49 381 252312-00

Fax: +49 381 252312-29

General Summary of Environmental Impact

Study for the 1st and 2nd Year of the Study on

the Basic Results for the Construction and

Operation

of the Offshore Wind Farm

“Windanker”

Version: 24 Mar 2016

General Summary of Environmental Impact Study for the 1st and 2nd Year of the Study on the Basic Re-sults for the Construction and Operation of the Off-

shore Wind Farm “Windanker”

Contents I

Table of contents

Page

1 Reason and brief description of the project 1

2 Description of environmental factors 2

2.1 Human, including human health 3

2.2 Sea bed 3

2.3 Water 3

2.4 Climate / air 4

2.5 Landscape / scenery 4

2.6 Cultural assets and other material goods 4

2.7 Macrophytes 4

2.8 Macrobenthos 5

2.9 Fish 5

2.10 Birds 6

2.10.1 Migratory birds 6


2.11 Bats 9

2.12 Marine mammals 10

3 Description of the environmental impact of the project 11

3.1 Human, including human health 11

3.2 Soil 12

3.3 Water 12

3.4 Climate / Air 12

3.5 Landscape / scenery 13

3.6 Cultural assets and other material goods 13

3.7 Macrobenthos 13

3.8 Fish 14

3.9 Birds 15

3.9.1 Resting birds 15


3.10 Bats 17

3.11 Marine mammals 17

4 There is a potential hazard to protected resources that are part of the marine

environment and risk assessment for bird migration. 19

General summary of the environmental impact study for the first and second year of the study of the basic

documenting of construction and operation of the Windanker offshore wind farm

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1 Reason and brief description of the project

Iberdrola Renovables Deutschland GmbH is planning to build and operate the “Windanker” off-

shore wind farm (OWF) with 42 offshore wind turbine generators (OWTGs) including secondary

equipment (internal cabling, a transformer substation) in the exclusive economic zone (EEZ) of the

Baltic Sea.

The planned area for the OWF “Windanker” project is in the Arkona Basin approx. 38 km to the

northeast of Rügen (see Fig. 1). The depth of the water in the assessment area is between approx.

41 and 45 m.

Fig. 1: Location of the “Windanker” wind farm in the German Baltic Sea

The project area of the “Windanker” offshore wind farm studied in this document has a size of 17.9

km2 and is defined by the coordinates in Tab. 1.

Tab. 1: The main coordinates of the project area for the “Windanker” offshore wind farm (not incl. the safety zone, WGS84, version: 13 Nov 2015)

East longitude North latitude Area

[Grd° min’ sec”] [Grd° min’ sec”]

14° 0' 00.606" 54° 54' 11.252"

17.9 km²

(not incl. safety zone)

14° 1' 48.842" 54° 51' 16.932"

14° 2' 20.391" 54° 51' 59.590"

14° 1' 12.486" 54° 50' 43.652"

14° 4' 32.344" 54° 52' 57.248"



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East longitude North latitude Area

[Grd° min’ sec”] [Grd° min’ sec”]

14° 2' 24.573" 54° 54' 43.609"

The key data (height, space, etc.) for the “Windanker” offshore wind farm can be seen in Tab. 2.

The planned design of the wind farm currently places the OWTGs in a maximum power class of 8.0

MW. By contrast, the park is laid out for a 6 MW plant.

Tab. 2: Key data for the “Windanker” offshore wind farm

Information about OWF

Number of OWTGs 42

Additional structures Transformer substation

1

Planned nominal power of the OWTGs 6.0 MW

Distance between OWTGs 675 m x 900 m

Rotor blade diameter max. 180 m

Hub elevation above LAT approx. 110 m

Total height approx. 200 m

Foundation Monopile

Description of foundation Steel pipe tower with max. 10 m diameter

Crater protection Rockfill in circle around the turbine, diameter of 50 m

It can currently be assumed that a transformer will be installed on each OWTG in order to trans-

form the power from the low voltage to medium voltage range. The installed total output is ex-

pected to be 252 MW. To bundle the electrical power produced in the wind farm, the plans currently

set forth internal cabling (voltage of 36 kV, for example), which is fed to a transformer substation

and then transformed to the transmission voltage sent to the mainland (e.g. 36/120 kV transform-

er). The produced output of the OWF is delivered to the mainland by export lines. The total length

of the internally laid cable is expected to be approx. 34 km. The electrical energy produced in the

OWF is transferred to the public electricity network by means of three-phase transmission technol-

ogy provided by 50Herz Transmission GmbH. The cable routes for the offshore wind farm in the

EEZ, the 12 sm zone and on land are the subject matter of another planning procedure by the

transmission network operator

2 Description of environmental factors

The environment was described and analysed in terms of protecting it in the forecast area that the

project will affect. The selection of the addressed protected resources takes into account both the

impact that the project will have (influential factors) and the sensitivity of each protected resource.

A scale of 1 to 3 (low, moderate, high) was used to rate the significance of the project area for each

protected resource considered. For example, the project’s impact on the population of a certain

animal species group in the protected resource “Plants and Animals” was rated on the basis of the

criteria of rarity / endangeredness, regional or national importance of the species, functioning na-

ture of the habitat and diversity / distinctiveness, although all the criteria were not always included.



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2.1 Human, including human health

The considered sea space is approx. 38 km from especially important and sensitive areas in terms

of recreational usage (main tourist destinations on the island of Rügen and Bornholm). There is

very little recreational usage in the area of the sea under consideration. The area is only rarely

used by boats operated for recreational purposes since it is beyond the popular areas close to the

coast and sailing areas.

On the 3-level scale, the project’s impact on the population of the protected resource “human” is

rated overall as low due to the distance between the OWF and the important areas of the coast

used for recreation and the short amounts of time people spend in the sea area under considera-

tion.

2.2 Sea bed

The sediments found in the project area are largely homogeneous and do not differ from the envi-

ronment. For this reason, the project’s impact on the sea bed is rated as low in terms of the criteria

regional or national importance, diversity and distinctiveness, rarity and endangerment.

Fishing has interfered with the natural structure of the surface sediment, which is subject to regular

anthropogenic influence. Another contaminant is the elevated concentration of pollutants . Accord-

ingly, the project’s impact on the entire complex in the present study is rated as low.

2.3 Water

No special functions that affect the hydrographic conditions such as water exchange, salt content

or currents have any particular effect, since no specific morphological formations such as straits or

sills have developed in the studied area for the planned OWF.

In comparison to the diverse changes in coastal and bank structures in the neighbouring Bay of

Pomerania (ports, bank reinforcements, dikes, etc.), the water structure in the area of the planned

OWF is only slightly influenced in anthropogenic terms (influence of trawling).

In regard to the water properties, no extreme contamination due to pollutants in the water or in

floating matter is known. General contamination as a result of the coastal or sea water of the Baltic

Sea is relevant. The nutrient contamination in terms of nitrogen and phosphorous is above the ori-

entation values and there are mesotrophic conditions so that low to moderate eutrophication can

be derived. Furthermore, relatively high resuspension potential for nutrient contamination and pollu-

tants from the widespread silty, clayey sediments must be taken into account and can lead in par-

ticular to elevated contamination of the water close to the sea floor on account of the temporary

layering of the body of water.

If the criteria of the degree of naturalness and the water properties / trophy are applied, a high rat-

ing level is derived for the impact on the surface water in the area of the planned OWF.

The sensitivity of the water area with respect to anthropogenic influences that are connected with

swirled-up sediment is rated as moderate to high. There is high potential for resuspension. Due to

the temporary layering of the body of water, the distribution can be limited so elevated contamina-

tion cannot be ruled out in deep water.

The project’s impact on the protected resource of water in the entire project area is rated as high.

Since the protected resource of water in the project area is closely interconnected with other pro-



2016-03-24 4

tected resources through resuspension of sediment, nutrition and pollutants, for example, and with

the sea bed as a habitat with the protected resource of plants and animals, the rating of the water

also plays a role in the rating of the project’s impact on the population of fish, the macrobenthos

and the sea bed.

2.4 Climate / air

The climate conditions in the sea area exhibit a high degree of naturalness. Global climate change

has had some impact on the air and water temperature as well as the atmospheric circulation. The

protected resource is defined by a high level of naturalness, and the project’s impact is rated as

high in this study.

2.5 Landscape / scenery

The Baltic Sea should be classified as one of the largest undeveloped natural habitats in Europe.

Visibility on the open sea and from the islands (outside of settlements) is only limited by natural

climate conditions (clouds, wind, sun). The horizon merges with the sea. The conspicuousness of

the few vertical structures such as ships, buoys or offshore wind turbines is very high as a result.

As a result, the visual sensitivity and risk as a result of development is to be rated as high.

Anthropogenous imprints occur temporarily in the sea area due to the regular shipping traffic on the

main shipping routes. There are visibility axes between the project area and the islands of Rügen

and Bornholm.

The project area has subordinate significance for landscape-related recreation since it is far away

from the coastal areas that are important for recreational usage. People enjoying recreational activ-

ities on ships and boats in the vicinity of the OWF will see the turbines. The project’s influence on

the protected resource of landscape / scenery in the project area is rated overall as low.

2.6 Cultural assets and other material goods

The following criteria and parameters will be used to describe the cultural assets and other material

goods:

Cultural monuments (wrecks)

Cultural goods (fishing)

Natural resources

Other resources and material goods (submarine cables, powerline rights, pipelines, etc.)

In the environmental impact study, there is no rating of the significance/sensitivity of these factors

since cultural and other material goods must fundamentally be taken into account.

2.7 Macrophytes

In the examination period, no macrophyte species were proven on account of the water depth in

the various examination campaigns. As a result, there was no further consideration of this species

group.



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2.8 Macrobenthos

In the two-year study of benthos, a total of 28 species of epifauna and 5 supraspecific taxa were

proven in the assessment area. Overall, the mollusca, polychaeta and crustacea were the most

diverse large groups of species in the project area.

The infauna in the “Windanker” project area consist of 40 species and 13 supraspecific taxa. The

most diverse strains of infauna in the four campaigns were polychaeta followed by mollusca and

crustacea.

There were minor differences between the project and reference area with regard to the fauna

communities. From a benthological point of view, the “Windanker” project area and the reference

area for subsequent studies appear to be comparable.

In the project area, a total of 13 Red List species could be proven in the basic results from the au-

tumn of 2011 to the spring of 2013. Five species were found that are considered to be highly en-

dangered in the Baltic Sea: the amphipod Pontoporeia femorata, the giant isopod Saduria ento-

mon, the muscle Astarte elliptica, blunt gaper Mya truncata and the hydrozoan Halitholus yoldiaarc-

ticae (Endangered category 2).

In terms of the rating criteria of “rarity and endangeredness”, “diversity and distinctiveness, “natu-

ralness” and the regional and national significance of the macrobenthos community found in the

area, the impact of the project within the scope of a collective assessment of the environmental

protection was rated as moderate.

2.9 Fish

In total, 27 species could be proven, with 19-25 species found in each campaign and area. The

composition of the species in the studied “Windanker” area corresponded to the demersal fishing

community typical for the middle Baltic Sea on a sandy sea bed.

In the comparison of the fishing results collected in the studied area, there was a high degree of

similarity between the demersal fish communities that make their home in the project and reference

area. The fish communities in both assessment areas were dominated by cod, plaice, flounder and

whiting. Only minor differences were seen between the project and reference area when the overall

quantity of these species and the associated longitudinal frequency distributions for the four com-

pleted fishing campaigns were compared.

Three of the proven species are on the Red List for the Baltic Sea of 2013. They include European

eel classified as “critically endangered” (Endangered category 2) and two species, feint and Atlantic

salmon, classified as “endangered” (Endangered category 3)

The discovery of an individual feint means that a fish or round mouth species that requires special

protection in accordance with Appendix II of the FFH Directive) was found.

In regard to the diverse species, rarity and endangerment, distinctiveness and diversity, natural-

ness and regional and national significance, the sensitivity of the population was rated as moder-

ate in the environmental impact study.



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2.10 Birds

2.10.1 Migratory birds

In order to record the migratory birds, transect surveys were carried out using ships and aircraft in

the area under investigation comprising the assessment area and the reference area.

A total of 30 species of birds were recorded in the first year (March 2012 to March 2013) of the

basic study and 21 species of birds were recorded in the 2nd year (March 2013 to April 2014) 21 in

transect surveys carried out by ship.

Sea ducks were found almost exclusively in the larger assessment area of counts made by aircraft,

which also includes the lowlands of Adlergrund, the foothills of Rønnebank and the northwestern

Bay of Pomerania. The species was largely missing as a migratory bird in the project area with a 2

km buffer zone. Only 16 long-tailed ducks were extrapolated for the first year of the study, and 12

long-tailed ducks were identified on one occasion, and 60 long-tailed ducks on a second occasion

in the second year of the study for the project area with a 2 km buffer zone.

In the 2,835 km² assessment area, a maximum of 2,000 loons were extrapolated in the first year of

the study, and a maximum of 2,870 loons were extrapolated in the second year of the study; in the

project area with a 2 km buffer zone, there were 58 individual loons (1st year of the study) and,

respectively, 60 individual loons (2nd year of the study). The counts made by ship in the two years

of the study showed a significant dominance of the red-throated diver as compared to the black-

throated diver. The densities were relatively low over the entire study period, however.

Seagulls were present throughout out the study period with the highest populations in mid-winter.

Herring gulls gathered in the vicinity of fishing cutters. Lesser black-backed gulls were encountered

regularly, but in particular during migration.

Mew gulls were primarily present from December to April and reached a peak population of 50-100

birds, as well as a maximum number of 1,241 individual birds (counts taken by aircraft). There were

small numbers of black-headed gulls, and they were primarily detected during migration. The high-

est extrapolated population number was obtained in April 2014 with a total of 283 black-headed

gulls (count taken by aircraft).

Two species of razorbills were regularly verified in the assessment area. The common guillemot

was primarily encountered during the winter months. Their numbers fluctuated between 12 and

1,415 birds according to counts made by ship. The percentages in the project area regularly re-

mained below the percentage of area for the area. Razor-billed auks wintered with a maximum of

maximal 300 individuals in the assessment area. The population of razor-billed auks in the project

area including a 2 km buffer zone was low.

Population counts of international significance are reached for counts of the common guillemot

made by ship in the assessment area. The peak number of 1,415 individuals can be used to calcu-

late a percentage of 2.84% of the Baltic population (previous year: 1,088 individuals, 2.18%), which

was estimated as a comparative value. At no other time from March 2013 to April 2014 did the

common guillemot exceed the 1% criterion, while it reached this criterion a total of five times during

the first year of the study. Using the seasonal average values in accordance with StUK 4, with a

winter population of 243 individuals, the common guillemot did not exceed the 1% criterion. In

terms of the population in the German Baltic area, it reached a percentage of over 10% with its

average winter population.



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In addition to the common guillemot, the great black-backed gull and the lesser black-backed gull

also exceeded the limit of 10% of the population in the German Baltic area. It must be pointed out,

however, that the comparative population of lesser black-backed gull of 160 individuals is very low,

and with three observed birds, a value of 16 can already be reached by extrapolation. In addition, it

should be noted that the lesser black-backed gull specifically follows cutters and ships in search of

food. As a result, the extrapolations most likely did not provide an optimum reflection of the actual

populations in the assessment area. If one were to consider only those individuals that were actual-

ly observed, the limit of 16 lesser black-backed gulls would only have been exceeded on one date.

Due to the strong populations of individual guillmots, the assessment area is of high significance as

a migration stopover area. On the other hand, no concentration of sea birds was identified in the

project area. The values for the common guillemot including the 2 km buffer zone reached a maxi-

mum of 0.4% of the biogeographic population in the Baltic area. In the first year of the study the

figure was 0.27%. In terms of the population in the German Baltic area, there was a percentage of

6.86% for the project area and 14.1 % including the buffer zone, and so the project area was of

low to average population-biological significance.

It was not possible to directly detect the use of the assessment area by breeding birds. In May, only

small populations of seagulls and auks were identified, which can be attributed to adult birds being

bound to the breeding colonies. The significance of the assessment area to the breeding period is

therefore assessed as low.

The range of species identified during the survey of marine birds included all major groups of ma-

rine birds (loons, sea ducks, seagulls, auks). Some species were exclusively or overwhelmingly

observed while flying, however, and so the sea ducks, for example, cannot be considered regular

migratory birds within the context of the assessment area. As such, a distinction must be made as

compared to pelagic species (e.g. large seagulls), which frequently look for food while flying. Bear-

ing in mind this distinction, nine regular species of migratory birds (consistency of floating birds

>25%) occurred in the assessment area, which corresponds to the expected value for such deep

areas of the southern and western Baltic Sea. The same applies to the population levels identified

during the study period. The diversity and specificity of the bird community must therefore be as-

sessed as medium. The same applies to the project area, since comparable population densities

exist there.

Along with red-throated and black-throated divers, as well as little gulls, three species from Appen-

dix I of the Birds Directive were regularly found in the assessment area. In addition, it should be

taken into consideration that most of the identified species of sea birds fall under the AEWA, which

obligates the Federal Republic of Germany to undertake measures to protect these species. Over-

all, the assessment area therefore has a great deal of significance in terms of the criterion for rare

and endangered species. Since the three specified species were seen sporadically in the project

area, a medium significance is deduced.

There were disruptions in the assessment area due to ship traffic and fishing activities, which dis-

ruptions are limited in terms of their intensity or their temporal and spatial scope. The criterion of

naturalness has been assessed as having a medium significance for the assessment area.

Due to the regular occurrence of three species from Appendix I of the Birds Directive, the high de-

gree of importance as a migration stopover area for the common guillemot as well as the average

diversity and specificity of the migratory bird community, the assessment area has a medium to

high significance to the protected marine birds, even taking into account existing previous im-



2016-03-24 8

pacts. As a result lower density and consistency of the population of most species, the project area

has a medium significance for marine birds.


During the entire 2-year study period in the assessment area, a total of 146 species of migratory

birds were identified. As such, 100 species were identified exclusively during the day, 10 species

were identified exclusively during the night, and 36 species were identified both during the day and

during the night.

Of the species that were identified, 60 fall in the endangered or protected category (for example the

European Wild Birds Directive, SPEC, AEWA agreement, and the red list for migratory species of

birds in Germany).

In visual observations within 1,500 m around the anchoring point, the ten most frequently encoun-

tered species in the spring were (in descending order): Herring gulls, black scooters, cormorants,

mew gulls, great black-backed gull, little gulls, lesser black-backed gull, common siskins, house

swallows and common black-headed gulls.

In the fall, this included herring gulls, common chaffinches, cranes, common siskins, black scoot-

ers, common eiders, cormorants, titlarks, great black-backed gull and widgeons.

In surveys of nighttime migration, the ten most frequently encountered species in the spring were

(in ascending order): Robins, redwings, mew gulls, herring gulls, common song thrushes, western

curlews, common snipes, common redshanks, common blackbirds and common black-headed

gulls. In the fall, this included: Common song thrushes, robins, common blackbirds, goldcrests,

brants, redwings, barnacle geese, dunlins, white wagtails and sandpipers.

In visual observations, the ten most frequently encountered species in the spring of the second

year of the study (in descending order, the number in parentheses = the number of individuals ob-

served): Long-tailed ducks, herring gulls, black scooters, cormorants, mew gulls, common eiders,

common black-headed gulls, cranes, house swallows, common mergansers and widgeons. In addi-

tion, there were unidentified loons, unidentified large seagulls, unidentified geese and swans. In the

fall of the second year of the study, the ten most frequently encountered species were: Herring

gulls, barnacle goose, widgeons, cranes, titlarks, black scooters, common eiders, common siskins,

cormorants and house swallows. In addition, there were unidentified song birds and unidentified

ducks. The five most frequently encountered species/species groups at a distance of more than

1,500 m around the anchoring point in spring were: Unidentified ducks, unidentified swans, uniden-

tified large seagulls, unidentified geese and unidentified loons. In the fall this included: unidentified

geese cranes, unidentified ducks, widgeons and grey geese.

In surveys of nighttime migrations in the second year of the study, the ten most frequently encoun-

tered species in spring were: Common skylarks, common blackbirds, common song thrushes, red-

wings, robins, lapwings, European golden plovers, widgeons, western curlews and fieldfares. In the

fall, this included: Star, common blackbirds, redwings, robins, titlarks, common song thrushes,

common skylarks, lapwings, fieldfares and white wagtails.

The seasonal course of the daytime migration of marine and terrestrial birds was characterised in

both years of the study in general by a concentration in the months from March until May, as well

as from September until November, however as expected, species-specific migrational periods

could be identified.



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In the case of several marine birds, no clear migrational direction could initially be determined in

early spring, which indicates a change in location between the migration stopover areas of the Bal-

tic. Over the continued course of the spring, in most marine birds, a northerly and easterly direction

of flight was predominant, which indicated that the detected flight movements were “true” vernal

migration. In the spring, cranes migrated to the north and northeast and presumably reached the

assessment area after coming from Rügen in particular. In the fall, the flights of most marine birds

were predominantly oriented in a westerly direction. As expected, cranes, titlarks and other terres-

trial birds migrated primarily in a southerly, southeasterly and southwesterly direction.

In the areas covered by visual observations, the most pronounced migrational activity during the

day for most species took place in the lowest 200 meters. As such, a significant percentage of

loons, geese, widgeons, black scooters, cranes and seagulls migrated at high levels of up to 50 m,

while cranes and geese frequently migrated and the remaining species less often migrated at a

height of 100 meters and above. Long-tailed ducks migrated during the daytime, primarily in the

lowest 10 m, while auks migrated in the lowest 5 m.

In order to assess the significance of the project area for migratory birds, the criteria of endanger-

ment and rarity, uniqueness and diversity, regional or, respectively, pan-regional significance, as

well as the type of migration, the concentration range, guidelines and mass migration events were

taken into consideration.

The assessment category, “Guideline and concentration areas” has been assessed the highest

significance, since large numbers of individual terrestrial birds in the region of the southern Baltic,

in particular Swedish breeding populations, fly over the Baltic and migrational concentrations are

expected in the sea regions between Rügen and Sweden due to the peninsula-like character of

Rügen as well as the landmass of Sweden. This is also indicated by the results of radar observa-

tions. The appearance of increased numbers in the project area must be expected, in particular

when westerly winds are prevailing.

The “migration activity and its intensity” is assessed as low to high. Sea ducks, loons and terrestrial

birds that migrate during the daytime exhibited moderate migrational intensity in the region.

The assessment category, “number of species has been assessed as having medium significance.

Observations during the study period described here revealed a total of 146 species. From among

the total of 27 species that are to be protected in accordance with Appendix I of the Birds Directive,

loons and cranes migrate in larger numbers over Adlergrund.

The population assessment of migratory birds in the region of the “Windanker” project area is the

result of the aggregation of the criteria, guideline and concentration area, migration activity and

number of species, wherein overall, the criterion of migration activity has been given the greatest

priority. In summary, the population of marine birds, terrestrial birds that migrate at night and

cranes are of high significance. Terrestrial birds that migrate during the daytime and birds of prey

can be assessed as having medium significance.

2.11 Bats

The studies revealed eight instances of contact with bats in the fall of 2013, three in the spring of

2014 and three in the fall of 2014. These instances of contact were categorised as the Nathusius

pipistrelle and soprano pipistrelle species (most frequent) as well as a myotis species and a nyctal-

oid species. The results of the studies from the fall of 2013, spring of 2014 and fall of 2014 largely



2016-03-24 10

confirm the picture presented in the literature. It is not possible to discern any specific significance

of the project area “Windanker” for bat migration over the Baltic from the data collected.

However at this time, the available data material for the Baltic region is not sufficient to allow valid

and quantifiable conclusions to be drawn about the migrational movements of bats at this time. In

particular, it is not possible to obtain substantial insights into the possible concentration regions of

bats migrating over the Baltic on the basis of the available information.

2.12 Marine mammals

Porpoises

Porpoises were detected in very small numbers in the assessment area during the entire study

period of marine mammal migration (June 2012 to August 2013) and the combined bird / marine

mammal migrations (May 2012 to April 2014). In the first year of the study, only one porpoise was

sighted during a marine mammal flight in July 2012. In the second year of the study, no porpoises

could be detected within the context of the marine mammal and digital flights. In two of a total of

eight bird flights in the second year of the study, a total of four porpoises were sighted. There were

no juveniles among the animals spotted.

Accordingly, the presence of porpoises in the assessment area is low year round. Evidence of por-

poises is limited to the spring and summer months.

Seasonal differences in the use of habitat by porpoises was determined on the basis of acoustic

studies at two POD stations. As such, in both years of the study, an increased occurrence was only

recorded during the period between July and August, and currently, until September, especially in

the summer. The animals appear to have completely left the region during the period between No-

vember and May, thus in the winter and spring, since there were only sporadic detections during

this period. Over the entire study period, the activity density at the POD-WA POD station was

12.2% PPD (1st year: 7.8%, 2nd year: 17.0%), which indicates an overall low use of the region.

The population assessment for porpoises in the region of the “Windanker” project area is the result

of the aggregation of the criteria of rarity / endangerment, diversity and specificity, and the function

of the habitat, wherein the criterion of the function of the habitat has been given the greatest priori-

ty. Overall, the criterion of rarity / endangerment is assessed as “high” for porpoises.

The results lead to the conclusion that the planning area for the “Windanker” offshore wind park is

located in an area, in which the presence of porpoises is very low to a maximum of low. Low signif-

icance is therefore derived for porpoises in terms of the criterion of diversity and specificity.

The function of the habitat is assessed as “medium”, since the waters around the project area are

demonstrably used by porpoises and such potential natural habitats are located indirect proximity

(<15 km). There is no intensive use, however.

It should be observed that the planned “Windanker” OWP is located in the postulated distribution

area of the eastern subpopulation, which is threatened with extinction. It is therefore likely that

those porpoises that are found in the waters around the planned “Windanker” OWP also belong to

this subpopulation. Animals from the western subpopulation may also be found, since the waters

around Rügen are part of the distribution area for both populations, and a sharp boundary between

these two wandering species cannot be assumed. However there is insufficient temporal or spatial

data concerning the possible migrational behaviour of both populations to make a reliable state-

ment concerning the presence in the assessment area.



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Seals and grey seals

During the aircraft and ship-based surveys for the “Windanker” project, a total of six grey seals and

three seals were observed. In addition, seven unidentified seals were spotted, whereby it is must

be assumed that the animals could likewise be assigned to one of the two species. Overall, the

frequency / density is rated as “low”.

In addition, the criterion of rarity / endangerment is assessed as “high” for seals and grey seals.

Use by seals and grey seals as a feeding ground and migrational area may be assumed as a func-

tion of the habitat. The immediate proximity of productive sandbank and reef habitats (FFH areas

“Adlergrund” and “Westliche Rönnebank”) to the project area as well as the increased percentage

of seal sightings in the vicinity of these partial areas reinforce the character thereof as a feeding

ground.

Overall, the criterion of the function of the habitat has been assigned a “medium” significance.

Summary assessment of marine mammal populations

In summary, the population of porpoises in the region of the “Windanker” project area may be as-

sessed as being of medium significance. The corresponding population assessment of seals and

grey seals in the region of the “Windanker” project area lead to the aggregated assessment that the

seal and grey seal populations are of “medium” significance.

The population of the protected marine mammals is assessed as having a medium assessment

level.

3 Description of the environmental impact of the project

Based on the importance and the sensitivity of the affected protected resources, and the determi-

nation of the known or, respectively, forecast impact of the project / impacting factors, the environ-

mental impact in the region of the project area can be estimated. In so doing, a distinction has been

made between construction and demolition-related impact, turbine impact as well as operational

impact. The following criteria and parameters have been used to evaluate the impact on the pro-

tected resources:

scope, duration and intensity, and derived therefrom: structural and functional impact.

3.1 Human, including human health

The project-related impacts due to the construction of the “Windanker” offshore wind park with ref-

erence to protected human resources can be verified as both large scale (in the event of a ship

collision) or medium scale, and local. In the immediate vicinity, the construction-related impacts of

noise and pollutant emissions, visual disturbance and the use of land will result in minor structural

and functional impacts.

The recreational function on-site will be primarily affected by the project-related impacts, i.e. locally,

wherein the structural and functional impacts decrease as the distance from the offshore wind park

increases, and are no longer relevant for the nearest land sites. Noise related to construction and

operation will not be audible from the islands of Rügen and Bornholm and in terms of timing, the

OWTG will only be limitedly visible over the course of the year when visibility is good.

Structural and functional impacts that can be classified as of a very high level may only occur for

the fishing profession as a result of pollutant emissions in the event of an accident. The risk of a



2016-03-24 12

ship collision with the turbines of the offshore wind park is determined in the technical risk analysis.

A navigation ban will result in medium structural and functional impacts.

All other construction, turbine and operational impacts, as well as demolition-related impacts, will

result in low structural and functional impacts.

Overall, low structural and functional impacts can be assumed with reference to the protected hu-

man resource.

3.2 Soil

The project-related impacts on protected soil resources due to the construction of the Windanker

offshore wind park will occur only a local to large-scale level. All impacts with the exception of acci-

dent-related pollutant emissions (ship collision) (high), can only result in low to medium structural

and functional impacts. This also applies to overbuilding the soil as a turbine-related impact. Taking

the technical wind park parameters as a basis, with approximately 17.9 km² representing approxi-

mately 0.47% of the total wind park area, the percentage of over-build area relative to the total

project area is low. Impacts that are of medium structural and functional significance include the

changes in geothermal reactions as a result of heat emissions and pollutant emissions in the event

of malfunctions. The occurrence of a ship collision with the turbines of the offshore wind park is

assessed in the technical risk analysis. Overall, a low structural and functional impact is assumed.

3.3 Water

The project-related impacts on protected water resources due to the construction of the Windanker

offshore wind park will occur only a local to large-scale level. All turbine and almost all operational-

ly-related impacts with the exception of malfunctions and accident-related impacts (here, ship colli-

sions with OWTG, very high structural and functional impacts) would result in low structural and

functional impacts. The construction-related impacts due to turbidity plumes, the re-suspension of

sediments and of nutrients and pollutants, as well as turbine-related disruption of the flow condi-

tions will likewise only result in low structural and functional impacts. In terms of operation, the im-

pact as a result of pollutant emissions in the event of malfunctions (e.g. a crack or the like in the il

collection system of the nacelle) may result in structural or functional impacts that can be assessed

as low to medium. Overall, a low structural and functional impact is assumed.

3.4 Climate / Air

The project-related impacts on protected air environmental/air resources due to the construction of

the Windanker offshore wind farm will occur only a local to moderate-level. All of the factors, with

the exception of accidents (a collision between ship and offshore wind turbine: moderate impact),

will have minor structural and functional impacts. No impacts on the protected resources are ex-

pected as a result of the pollutants released during (trouble-free) operations. Locally significant

turbulence and vortices (changes in the wind field) will only have moderate structural and functional

impacts in the direct vicinity of the offshore wind turbine, but quickly diminish in intensity and effec-

tiveness outside of the offshore wind farm. This will result in a minor structural and functional im-

pact in terms of this criterion. Overall, there are minor structural and functional impacts on valuable

environmental/air resources.



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3.5 Landscape / scenery

The planned building of the Windanker offshore wind farm will for the most part have a demonstra-

bly large- to medium-scale impact on the overall appearance of the landscape. This does not in-

clude construction-related space requirements, operations-related noise emissions and shadows,

which have a local impact. The construction-related impacts are of minor structural and functional

significance, as they occur only in the short-term in a landscape that is used minimally for recrea-

tional purposes. Most of the impacts are of minimal structural and functional significance. This also

applies to potential noise emissions from the site and from operations, the loss of space, rotational

motion and shadows. These are limited mainly to a local or moderate scale and are not detrimental

to the overall appearance of the landscape. The site- and operation-related visual disturbance, the

dominant technological character taken on by the landscape as well as beaconing of the turbines

have a moderate structural and functional impact overall. Here it should be mentioned that, to a

limited extent, the structural and functional impacts of a “very high” magnitude occur only within a

radius of approximately 10 km of the Windanker offshore wind farm (“high” defined as up to 20 km,

“moderate” up to 30 km). Thus, only the open Baltic Sea and its shipping routes, the commercial

vessels and fishing-related traffic in those areas are affected.

Substantial visual impacts from the wind farm can be ruled out due to the long distances away from

the tested points of view on the coast. Noise from construction and operation is not audible from

the nearest locations on land.

Overall, minor structural and functional impacts can be expected.

3.6 Cultural assets and other material goods

The Windanker offshore wind farm project will for the most part have a minimal structural and func-

tional impact on cultural assets and other properties. These impacts include fishing, underwater

cables, pipelines, rights of use for lines as well as shipwrecks. Traditional fishing operations may

experience moderate structural and functional impacts caused by the site and operations. It is not

possible to quantify catch losses for traditional fishing operations as a cultural asset, as no statisti-

cal distinction is made between industrial and traditional fishing. Major structural and functional

impacts caused by the release of pollutants may result in the event of an accident (discharge of

large quantities of oil with impact on fish or fishing). The likelihood of such an event is addressed

under Technical Risk Analysis. For details, please refer to this document.

Overall, moderate structural and functional impacts can be expected for protected cultural re-

sources and other material goods.

3.7 Macrobenthos

During the construction phase, the habitat of the benthic communities will be destroyed on a local

scale. Further impacts during the construction phase will be limited primarily to medium-scale ef-

fects associated with the hydrotrenching of cabling on the sea floor within the wind farm. Due to the

presence of long-living species of bivalvia, it can be expected that it will take several years for the

current population to recover. The various work undertaken during the construction phase will

therefore only have a minor, small-scale impact on the macrobenthos. Foundations and crater pro-

tection will cause small-scale, significant and long-term transformations in the makeup of the ben-

thic communities (artificial reef). The formation of turbidity plumes, sediment suspension and

changes in the soil morphology, particularly when laying cabling within the park, will result in mod-



2016-03-24 14

erate structural and functional impacts. The usage ban within the offshore wind farm that is ex-

pected in this case is likely to result in a natural succession of macrobenthos in the long term. The

estimable effects related to the project site thus far will have minor structural and functional im-

pacts. Based on the statements concerning the construction phase, local habitats will also be de-

stroyed as a result of the site. Unlike the construction phase, the destruction by the wind turbines,

however, is to be classified as long-term (depending on duration of operations). The introduction of

a hard substrate will promote the settlement of species (hard soil fauna) that are foreign to or un-

common in the area, or, in other words, result in a change in the natural biocoenosis caused by

anthropogenic factors. However, a major transfer of biomass due to the settlement of the hard-

bottom community on top of the soft-bottom communities outside of the offshore wind farm is not

expected. The expected cessation of trawling here will be accompanied by a biocoenosis transfor-

mation, but this is difficult to predict. The other impacts caused by the transport of sediment or ca-

ble effects (heat) are generally considered to affect a rather small area. In a worst-case scenario,

the operation of the turbines will also result in minor structural and functional impacts (when using

three-phase power cables and foregoing the use of anti-fouling coatings). At the planned cabling

installation depth, the heating of sediment associated with the operation of the offshore wind farm

will comply with the currently applicable thresholds put forth by the Federal Agency for Nature Con-

servation (BfN) and Federal Environment Agency (Umweltbundesamt, UBA). Substantial, long-term

impacts in the event of ship accidents are possible if these result in larger quantities of pollutants

being released into the environment (refer to Technical Risk Analysis). However, due to the many

potential variables involved in this scenario, it is impossible to perform a detailed analysis as part of

this investigation (worst-case scenario: serious structural and functional impacts).

Overall, moderate structural and functional impacts can be assumed.

3.8 Fish

Noise emissions during the construction of the offshore wind farm may result in flight reactions as

well as temporary shifts in the hearing thresholds or physiological damage in fish, which amounts

to major structural and functional impacts. With regard to prevention and reduction precautions, the

structural and functional impacts can be limited to a moderate scale, however. A consequence of

desealing of the surface when the offshore wind turbine is demolished, fishing will return to the

area. This will also have moderate structural and functional impacts. Overall, the expected struc-

tural and functional impacts during the construction and demolition phases with respect to the spe-

ciation of fish can be classified as “moderate”.

Demolition will for the most part have minor structural and functional impacts. The return of fishing

due to the desealing of the surface, on the other hand, may also have moderate impacts.

Overall, the site-related impacts will be of minimal structural and functional significance. The usage

and transit ban and the attendant cessation of fishing related to site (wind farm and safety zone)

may have a positive effect on fish fauna due to a reduction in fishing-related morbidity in species

which are fished as well as well as those which are not. The site-related impacts, which are mainly

due to use of space and surface sealing, will overall have minor structural and functional impacts.

The operation of the turbines will, for example, only result in minor structural and functional impacts

on fish speciation due to heat from the electrical cables, vibrations, and infrasonic noise (when

using three-phase current system and foregoing the use of antifouling coatings). Major structural

and functional impacts are possible in the event of ship accidents if these lead to a release of larger

quantities of pollutants into the environment (refer to Technical Risk Analysis). However, due to the



2016-03-24 15

many potential variables involved in this scenario, it is impossible to perform a detailed analysis as

part of this investigation.

Overall, there will be moderate structural and functional impacts on fish speciation.

3.9 Birds

3.9.1 Resting birds

The operation- and site-related impacts of the planned wind farm involve the risk of collisions as

well as displacement and barrier effects. The project area, including buffer zone, regularly sees

loons, auks, seagulls, and sea ducks that adeptly navigate a large marine region. Avoidance of a

wind farm has been documented in the case of loons, sea ducks, and auks. In some cases, sea-

gulls even spent more time in the area of the turbine site than before construction. A habituation to

the constant disturbances is also to be expected. The disruptive and displacement effects of the

offshore wind farm will occur within a 2 km buffer zone around the site during the entire operating

life with specific minor to moderate intensity depending on the specific species.

The risk of collisions with inactive turbines is minor for the species found in the project area. These

were the findings from studies on anatidae conducted at the Utgrunden and Nysted offshore wind

farms. Based on the data, models were then created for auks. Spinning rotors, on the other hand,

potentially pose a greater threat. However, many low-flying resting birds (e.g. diving ducks, loons)

usually travel below the level of the rotors. Anatidae also avoid wind farms during dark nights.

The impacts of construction and demolition of the site (noise, light emissions, visual disturbances)

are limited in terms of time and space and are of minimal to moderate intensity. Only the transport

of sediment might reduce the amount of food available to fish-eating birds on a moderate scale.

These factors are therefore expected to have minor structural and functional impacts. System- and

operational related effects, on the other hand, are long-lasting. The risk of collisions is local and of

minor to moderate intensity; displacement and barrier effects occur on a moderate scale with minor

to moderate intensity.

Overall assessment

Throughout the construction and operational phases, moderate structural and functional changes

are expected overall for resting birds and other species that come to feed.


Construction-related impacts

The construction-related impacts from noise emissions and visual disturbances are to some extent

large in scale but are considered to be of low intensity and in the short term. Overall, minor struc-

tural and functional impacts on the area in question can be expected in terms of the suitability for

migratory birds.

Demolition-related impacts

In general, demolition will result in a progression of site- and operations-related disturbance factors

(collision hazard, barriers). These will be entirely absent once all work is complete. The negative

impacts of demolition activities at the site are to be considered the same as the construction-

related impacts. The impacts on bird migration are to some degree large in scale, but of short dura-



2016-03-24 16

tion and low intensity. With respect to migratory birds, there will be overall minor structural and

functional impacts during the period under consideration.

Site-related impacts

The site-related impacts are limited to barrier effects and collision hazards or bird strikes. Barrier

effects are considered to be small to large in scale, long-term and of low intensity. The impacts of

potential collisions with migratory birds at a height of 20 - 200 m are considered to be local, long-

term and of minor to moderate intensity. Overall, minor to moderate structural and functional im-

pacts in the area in question can be expected in terms of its suitability for migratory birds.

Operation-related impacts

The effects involved in operating the turbines are mainly limited to collision hazards and barrier

effects. Barrier effects are considered to be moderate to large in scale, long-term and of low inten-

sity. They are found in particular to cause local changes in direction or height accompanied by a

minor increase in energy consumption. Birds flying at heights up to 500 m are most likely to be

affected by potential barrier effects. In addition to a small portion of the individual birds crossing

through the offshore wind farm, minimal vertical adjustments would for the most part be necessary,

and even birds required to make horizontal flight path adjustments would only be minimally affect-

ed.

The impacts that potential collisions or bird strikes would have on bird migration are considered to

be local and long-term to a moderate or, in exceptional cases, high intensity. The hazard is antici-

pated to be greatest during the night, with northeasterly or southwesterly winds and under poor

weather and visibility conditions for all birds flying at a maximal height of approximately 20 - 200 m

(in the range of the rotors), as rotor motion is difficult to predict under these conditions. Vertical

radar tests confirm that fewer signals indicating an increased risk of bird strike at these heights are

detected during the night (up to 200 m) than during the day. This means that only a relatively small

portion of the birds that cross the Baltic Sea in a broad-front migration formation are threatened by

bird strike around the rotors of the offshore turbine. The hazard of collision is also reduced greatly

with northwesterly or southeasterly winds when the rotors are rotating more or less parallel to the

main direction of migration.

Both impacts in combination produce result in structural and functional interference with bird migra-

tion over the period under consideration.

Impacts in the event of malfunctions

Repair work during the operating phase requires the rotors of the affected turbines to be stopped

due to the malfunction. In the short term, the shutdown reduces the species-specific collision haz-

ard or bird strike risk on a local scale. Similarly, the species-specific barrier effect is diminished.

The impacts of repair work can be attributed to increased ship activity, construction equipment and

construction activities during the construction phase (barrier effect caused by noise and visual dis-

turbances). The effects are, at most, moderate in scale and temporary, since they involve only indi-

vidual turbines; the intensity of the impacts is considered to be low. Overall, minor structural and

functional impacts on the area in question can be expected in terms of the suitability for migratory

birds.

Overall assessment

Throughout the construction and operational phases, moderate structural and functional impacts

are expected overall for migratory birds.



2016-03-24 17

3.10 Bats

At present, it is impossible to rule out the possibility of bats crossing the Baltic Sea and, therefore,

the project site as well. However, it is assumed that this does not occur in corridors of migratory

clustering as observed in the case of migratory birds. The turbines attract animals (light and/or

food), creating a risk of collisions with the offshore wind turbine. The hazard is greatest at low wind

speeds or when there is no wind.

For all relevant construction-, demolition-, site- and operation-related impacts, only minor structural

and functional impacts are expected.

3.11 Marine mammals

Construction-related impacts

It can be assumed that porpoises and seals will leave the site during construction of the offshore

wind farm. Nor can fatal injuries be ruled out during piling operations. Due to the excellent acoustic

properties of water, a large-scale effect can be expected, and due to the high noise levels, this will

not be mitigated by habituation either. Taking into account reasonable state-of-the-art measures for

preventing and minimising the impacts of piling-related noise, moderate structural and functional

impacts are generally to be expected.

Demolition-related impacts

The demolition-related negative impacts are essentially to be regarded as equivalent to the con-

struction-related impacts. The absence of piling, however, would overall result in moderate struc-

tural and functional impacts for marine mammals in the area under investigation.

Site-related impacts

The impacts of the turbines are limited primarily to behavioural changes from the barrier effect,

beaconing, changes in the flow regime and the soil morphology. These are estimated to be of small

to moderate scale, long-term and of low intensity. Overall, minor structural and functional impacts

in the area under consideration can be expected in terms of suitability for marine mammals.

Operation-related impacts

The operation-related effects of the offshore wind turbine with respect to marine mammals are re-

stricted mainly to behavioural changes caused by noise during operations and by maintenance

ships. In addition, electromagnetic fields from the park-internal cabling could result in changes to

patterns of movement.

The audibility zone of a supply ship is about 20 km for porpoises and seals; porpoises have a more

heightened sense of sound in the frequency range >500 Hz, whereas seals hear more in the low-

frequency range. The audibility zone for porpoises was measured at approximately 125 m for oper-

ational noise from the offshore wind turbine. Seals can hear this noise at a distance of about 2 km.

Overall, the worst-case scenario overall with respect to marine mammals involves moderate struc-

tural and functional impacts during the period under consideration.

Impacts in the event of malfunctions or accidents during the construction and operational phase



2016-03-24 18

The impacts of malfunctions are associated mainly with injuries or poisoning from the release of

hazardous substances, changes in behaviour caused by repair ships as well as poisoning and inju-

ries from a release of hazardous substances following a collision between a ship and the turbines

in the offshore wind farm. While most of the impacts from malfunctions are of minor to moderate

structural and functional scope, these might be moderate in the event of a more serious accident

over the period under consideration.

Summary

Overall, moderate structural and functional impacts on marine mammals can be expected.



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4 There is a potential hazard to protected resources that are

part of the marine environment and risk assessment for

bird migration.

Table 3 below provides a protected resources overview assessment; the structural and functional

impact as well as their probable hazards for each protected resource as part of the marine envi-

ronment.

Table 3: Overview of potential hazards for the marine environment, broken down by pro-tected resource

Protected resource Abundance Structural and functional impact

Hazard to protected resource or bird migra-

tion

humans low low none

soil low low none

water high low none

Climate / Air high low none

Landscape / scenery low low none

Cultural assets and other material goods

- moderate none

Macrobenthos* moderate moderate none

Fish moderate moderate** none**

Resting birds moderate moderate none

Migratory birds

marine birds nocturnal terrestrial birds diurnal terrestrial birds birds of prey cranes

high high moderate moderate high

moderate none**

Bats low low none

Marine mammals

porpoises grey seals common seals

moderate moderate moderate

moderate** none**

*including macrophytes for which no structural and functional impacts or hazard to the protected resource can be determined, **factoring in prevention and reduction precautions

In the worst-case scenario, the piling that is required may pose a hazard to marine mammals and

fish. The hazard of auditory damage to marine animals and fish due to piling operations during

construction operations exists throughout the large effect zones. Considerable risk mitigation is

possible through use of state-of-the-art, reasonable preventative and mitigating measures during

construction. What is critical is compliance with the binding thresholds of 160 dB SEL 750 m away

from the emission source as defined as the required threshold by the Federal Maritime and Hydro-

graphic Agency (BSH). If this requirement is met, no hazard to any protected resource in the ma-

rine environment is expected.

The findings on the environmental effects examined in the environmental impact study with respect

to the individual and interacting protected resources of the marine environment showed that no

hazard to these resources is expected if potential preventative and mitigating measures are taken.

Major to extreme structural and functional impacts on certain protected resources are only ex-



2016-03-24 20

pected in the event of an accident. A technical risk analysis provides an assessment of the risk of

collision (between a ship and the turbines of the offshore wind farm).

Taking into consideration other offshore wind farms near the Windanker offshore wind farm site,

potential cumulative impacts with respect to the individual protected resources. The cabling of the

Windanker offshore wind farm as well as the cable routes of the other wind farms that are cumula-

tively factored in here are not taken into consideration, as they are assessed using a separate

method. Overall, the cumulative impacts assessed in the environmental impact study with respect

to the Windanker offshore wind farm do not result in a higher classification with respect to the

structural and functional impacts or a hazard to a particular protected resource.

“Windanker” - Naturstyrelsen

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