Dan WilhelmssonDept. of Zoology, Stockholm University

Environmental effects of offshore wind power

Offshore windpower: - less ”not in my back yard”problems- beneficial wind conditions

Modified from Fiskeriverket, 2003

- Denmark aims for offshore windpower to supply 40% of energy needs by 2030.

- Netherlands: 1360 MW by 2020

- Finland has assessed offshore windpower potential in Gulf of Bothnia, 2000 km2, 17 000 MW

- Sweden: 10 % generated from wind power by 2010. Today around 1%. Plans for around 1000 offshore plants. 500-600 in the Baltic Sea.

- Germany: Will double the amount of wind power in 25 years. Offshore wind power primarily in the North Sea, but around 1000 plants in the Baltic Sea (e.g. Kriegers flak)

- UK and Ireland...

7000-10 000 off-shore windpower plants in

Northern Europe.

2000-3000 in the Baltic Sea

Today plants generate about 600 kw. New ones offshore= 3-5 MW

Height: 100 m from sea level to tip of the blade

Piles are 3 - 4.5 m in diameter

Parks containing tens to houndreds of power plants

VINDKRAFTSREV

Principal issues to consider for establishment (modified from EcoServe, 2000) Nature of wind resourceSeabed structure/geologyWater depthDistance to shoreDistance to service portDistance to grid connectionTide and currentsShipping/navigation routesRecreational boatingLocation of existing subsea cables and pipelinesFisheriesDredgingCoastal landscapeLocal military activity (e.g. firing ranges,, offshore training)

Potential environmental impacts during construction (modified from Tougard et al. )

-Destruction of bottom area

-Sediment spill and increased turbidity

-Noise amd other disturbance due to construction activities

Potential impacts during operation

- Noise and vibrations from the turbines

- Electromagnetic fields

- The physical presence of the turbines

- Shade effects

- Maintenance operations

- Introduction of hard substrate (artificial reefs)

Major environmental concerns:

- Birds

- Marine mammals

- Fish

- Sea bed/areas of high conservation significance

Birds:

- Disturbance during construction (sounds, feeding ability; season may be important)

- Collision risks

Loss/gains of resting and foraging areas

Marine mammals

(seals, porpoises)

- Primarily noise disturbance

- May leave the area during construction (decline in abundance of porpoises in Nysteds in Denmark)

Invertebrates and algae:

- Excavating activities during contruction cause destruction and disturbance of the bottom flora and fauna (construction phase)

- Sedimentation and incresed turbidity disturb filter feeder and shade benthic vegetation (construction phase)

- Altered hydrodynamic conditions erosion and deposition of sediment changes in substrate (local effects)

- Introduction of new substrate different community? Invasive species?

Fish

- Noise, vibrations (avoidance? behavior disturbances? habituation?)

- Electromagnetic fields (salmon, eel)

- ”Reef effects” (artificial reefs)

”INFLUENCE OF OFF-SHORE WIND POWER ON DEMERSAL FISH”

Wilhelmsson, D., Malm, T., and Öhman M. 2006. ICES Journal of Marine Science 63.

ARTIFICIAL REEFS”Man made structures intentionally or uintentionally

placed on the sea floor”

JAPANJAPAN

SOUTH-EAST ASIA

USA

SWEDEN….?

VINDKRAFTSREV

Aabel et al. 1997, Beets, J. 1998, Nakamura et al. 1985

Hair et al. 1994, Rilov et al. 2002, Relini et al. 1994, White et al. 1990

FIELD SURVEY, 2003

KALMARSUND

8 windmill sites + 6 control sites

LINJETAXERING

ABVV

SJUSTRÅLIG SMÖRBULT Gobiusculus flavescens

Storlek: 6 cmFöda: plankton Nytta: föda för andra fiskar

Two-spotted goby, G. flavescens

Sand Goby (Common goby?), Pomatoschistus sp.

Black goby, G. niger

Viviparous eelpout, Z. viviparus

Sea scorpion, T. bubalis

Bull-rout, M. Scorpius

Fifteen-spined stickleback, S. spinachia

Lump sucker, C. lumpus

Greater sand-eel, H. lanceolatus

Nine-spined stickleback, G. aculeatus

Flounder, P. Flesus

Deep-snouted pipefish, S. typhle

1038 adult fish, ~ 300 000 juveniles, 12 species

0

5000

10000

15000

20000

25000

30000

1

Fish

abu

ndan

ce

Monopiles

Distance: 1-5 m

Distance: 20-25 m

Control: 1-5 m

Control: 20-25 m

P<0,05

(Wilcoxon´s)

0

5

10

15

20

25

30

1

Fish

abu

ndan

ce

Monopiles

Distance: 1-5 m

Distance: 20-25 m

Controls: 1-5 m

Controls: 20-25 m

*p<0,05Wilcoxon´s

*

010

2030

405060

7080

90100

On windmills 1-5 m fromwindmills

20-25 m fromwindmills

% c

over

age

Filamentous red algae

Mytilus edulis

p=0,012Wilcoxon´s

DISCUSSION:

•Monopiles + bottom = artificial reef system

•Two-spotted goby uses the monopiles to resume in the shallow water column for enhanced flux of plankton (Wheeler 1980, Roundtree 1989, Wilkins and Myers 1992)

* Enhanced benthic productivity attracts and support higher abundances of benthic fish? (Bray et al. 1981, Kellison and Sedberry 1998)

•Increased prey abundance (Two-spotted goby

and Mytilus) and enhanced spawning habitats (shells from Blue mussels and gravel areas) (McGrath 1974, Fjosne and Gjosaeter 1996, Svensson et al. 2000, Jansson et al. 1985, Zander 1988)

• Increased recruitment to the area? (Beets 1989, Rilov 2002)

-Reef effects of only marginal significance??

- Perhaps not:

1. long range of influence

2. good feeding grounds for commercial fish

3. Windpower parks = MPAs Increased fish biomass Refuges

(disturbance effects on more mobile fish are however not clearly established)

THANKS TO:

Statens Energimyndighet, Vindforsk - FOI, Airicole AB, Torleif Malm, Maria

Bodin, Saleh Yahaya, Sara Hallén, Sara Svensson, Måns Rutström, Kalmar

University, Daladyk, Fire brigades in Torsås och Kalmar, Björkenäs Camping,

Bergkvara

-Aquaculture? Fish, mussels?

Monitoring programs:

e.g.:

- Nysteds Offshore Wind Farm/Horns rev

- Utgrunden II:

Vindval (Swedish Environmental Protection Agency)

- Enhance the knowledge on the impacts on the marine environment

- Facilitate EIAs and the expansion of offshore wind

power

- Capacity building at universities and institutes

Effects on fish, fisheries, benthos, birds, mammals

THANK YOU!

Management implications:

Increased habitat heterogeneity

Baltic Sea: Increased fish abundance

North Sea: Increased fish abundance and diversity?

OFF-SHORE WINDPOWER PLANTS – ARTIFICIAL REEFS?

IMPORTANT FACTORS:

LOCATIONCOMPLEXITY

SIZEMATERIAL

VERTICAL RELIEF

WHY THESE ARTIFICIAL REEF EFFECTS?:

SHELTER: main structure, epibiota

FOOD: epibiota, water velocity

BEHAVIORAL CUES

Reasons for deploying ARs:

Enhance fisheries (aggregation or production)

Restore marine habitats

Protection of habitats

Create dive sites

”Secondary ARs”