Review of European studies:

impacts of offshore wind

development on fish(es)

Andrew B Gill PhD FRSB

Dan Wilhelmsson PhD

PANGALIA

Environmental

The OWF context

Offshore Wind Development Phases

1. Construction (& survey)

2. Operation

©GE wind energy

3. Decommission

Temporal variability

in

stressors/effectors

Types of interaction and impact framework (modified from Boehlert & Gill 2010)

IMPACT PREDICTION

SOURCE PATHWAY RECEPTOR

Table 1. An example of identifying and representing the S-P-R linkages regarding the generation of underwater noise during construction of renewable energy devices.

Hazard Source Pathway Receptor

Pile Driving Noise

Construction of renewable energy device

Underwater acoustic transmission (pressure and particle motion)

Sedentary marine species Mobile marine species

0.00 0.05 0.10 0.15 0.20

Zeit in Sekunden

-4

-3

-2

-1

0

1

2

3

4

Schla

lldru

ck in k

Pa

Spitzenschalldruck ca. 3400 Pa

Zones of noise influence

Herring and

cod: ~ 80 km

Dab and

salmon: many

kilometres

Close to

source (up ~

200 m)

Possible consequences of disturbance

• Predicted effect -

• Displacement from spawning

and / or fishing grounds

• Reduced reproduction and survival

• Reduced catches

• Changes to fish distribution (sandeels)

causing associated changes in predator

• Fish eating seabird (little Tern)

• Egg abandonment and low chick

hatching locally

(Herring map from Coull et al. 1998 currently updated by Cefas)

Eddies

Eddies

Current

Tides

Surface zone

Bentho-Demersal zone

Pelagic Zone

Refuge

Up to 50m

Colonised hard substrate

Scour protection zone – hard substrate with crevices/holes

Current

Operation- Potential habitats and physical factors linked to fish distribution

Pre-OWF Post-OWF

Tides

Tide

Seabed – hard or soft substrate

Colonised hard lattice substrate

Photo by: Clover

© ABGill http://www.mywindpowersystem.com/

http://www.mywindpowersystem.com/

Eddies

Eddies

Current

Tides

Surface zone

Bentho-Demersal zone

Pelagic Zone

Refuge

Up to 50m

Colonised hard substrate

Scour protection zone – hard substrate with crevices/holes

Current

Operation- Potential habitats and physical factors linked to fish distribution

Pre-OWF Post-OWF

Tides

Tide

Seabed – hard or soft substrate

Colonised hard lattice substrate

© ABGill

Operation – Hard substratum / artificial reef?

• Epifauna

Mytilus edulis

Balanus crenatus

Balanus balanus

Jassa marmorata

Cancer pagurus

Pagurus bernhardus

Strongylocetrotus droebachiensis

Asterias rubens

Caprella linearis

Metridium senile

Sargartia troglodytes

Sargartiogeton undatus

Crepidula fornicata

Jassa marmorata

Tubularia indivisa

Telmatogeton japonicus

Copied from Offshore Windfarm & Environment Conference 2004, Denmark

Individual cod acoustic detection

Fish Biomass – local increase

Claisse et al. (2014)

OWF changes to Fish community • Variability in recruitment • Cumulative effects – multiple

turbines and OWF sites

plankton

Aerial predators

Decomposers

Pelagic fish

Demersal fish

Surface zone

Bentho-Demersal zone

Up to 50m

plankton

Ecosystem change - Interactions and energy flow within the fish assemblage pre and post OWF

Pre-OWF Post-OWF

Predators

Benthos

Organic input

Aerial predators

Decomposers

Pelagic fish

Demersal fish

Predators

Benthos Organic input

littoral*

Organic export

Organic import

Photography by Michael AW

http://www.mareano.no/

Photo: DTU Aqua/FIS

© ABGill

from Offshore Windfarm & Environment Conference 2004, Denmark

plankton

Aerial predators

Decomposers

Pelagic fish

Demersal fish

Surface zone

Bentho-Demersal zone

Up to 50m

plankton

Ecosystem change - Interactions and energy flow within the fish assemblage pre and post OWF

Pre-OWF Post-OWF

Predators

Benthos

Organic input

Aerial predators

Decomposers

Pelagic fish

Demersal fish

Predators

Benthos Organic input

littoral*

Organic export

Organic import

Photo: DTU Aqua/FIS

© ABGill

Decommissioning - Renewables to reefs?

Qs relating to Fish community - • Should turbine foundations

be removed at the end of the assets life?

• What percentage of decommissioned turbines would expect to turn in to reefs?

• Trade offs – biodiversity, de facto MPA, fisheries ?

Source: Fowler et al 2018

Summary

• Offshore wind turbine developments WILL affect fish – consider possible outcomes (+, -, 0) to determine impact

• Fish associate with OWF - community structure may alter leading to changes in trophic interactions within local ecosystem

• Temporal and spatial use may differ with life history stage

• Targeted collaborative research/monitoring essential - to address unknowns and reduce uncertainty particularly

understanding the significance of consequences

Thanks & Very happy to talk further :

Andrew B Gill PhD FRSB PANGALIA Environmental email: pangalia@mail.com www.pangalia.com