Steven Degraer

and

Colleagues from the Belgian offshore wind farm monitoring program, ICES Working Group on Marine Benthos and Renewable Energy Developments, and

ICES Benthos Ecology Working Group

Lessons learned from the Belgian offshore wind farm monitoring programme,

with specific attention to answering the “so what” question

Priorities and Challenges of Monitoring Design – Ecological Impacts Atlantic Offshore Renewable Energy Development and Fisheries Workshop

Issues under consideration Underwater noise, Hydrodynamics and sedimentology, Electro-magnetic fields, Hard substrate epifouling organisms, Hard substrate-associated fish, Soft substrate macrobenthos, Soft substrate epibenthos and fish, Seabirds, Marine mammals

Mandatory monitoring programme to ensure... • possible mitigation or halting of activities • understanding of impact processes to support future policy and management

The Belgian ecological monitoring program

Governance • Financed by wind industry • Coordinated by federal research institute • Executed by several research institutes

We already know a lot from ecological monitoring… …yet focused on local and structural impacts.

If we are however asked • on how much offshore wind

farms alter the wider marine ecosystem, and

• whether these changes are acceptable,

we often cannot come up with an answer…

When assessing offshore wind farm impacts… spatial scale matters.

Single windmill Single wind farm Multiple wind farms

Current monitoring programs

Belgian part of the North Sea:

+ 0%

Hard substrate associated species Soft sediment associated species

Species richness - benthos

Spatial scale matters… Example: benthic species richness in Belgian wind farms

Wind farm scale: + 190%

pre-construction post-construction

Rumes et al. (2013)

91

264

Rumes et al. (2013)

Spatial scale matters… Example: macrofauna biomass in Belgian wind farms

Single windmill scale: x 4000

Wind farm scale: x 14

Belgian part of the North Sea:

X 1,03

Bio

mas

s (k

g A

DW

)

Single windmill biomass

pre-construction post-construction

Spatial scale matters... Then, how to best assess impacts?

Acceptable or unacceptable?

Uncertainty in valuing impacts “Offshore wind farms do change the local environment. Importantly, these changes are across all ecosystem components and some can be regarded as (potentially) negative, e.g. … and some (potentially) positive,…”

Lindeboom et al., 2015, Hydrobiologia

Good or bad? Positive or negative?

US fisheries industry

Good Bad Neutral Acceptable Not acceptable

Spatial scale matters Example: Offshore wind farms “biodiversity” hotspots

Positive Negative Neutral

Offshore industry

Policy makers

Marine managers

Scientists

Marine managers

US fisheries industry

Scientists Scientists

THE VIEWPOINT SEEMS DETERMINING THE SPATIAL SCALE AT WHICH ONE VALUES IMPACTS.

Spatial scale and, ecosystem processes and functioning... Touching upon goods and services provided by the sea,

Example: Atlantic cod productivity

Spatial scale and, ecosystem processes and functioning... Touching upon goods and services provided by the sea,

Example: Atlantic cod productivity Major concern: Do offshore wind farms impact cod fisheries? Overarching questions: How much overlap between cod fishing grounds and wind farms? … What is the magnitude of the change of cod productivity? Operational questions: How much change in… …juvenile mortality due to piling noise? …adult fitness due to reef effect? …migration routes due to the wind farm presence? …spawning and nursery ground distribution? … …adult spatial distribution patterns?

Those questions are justified only at an explicitly defined spatial and temporal

scales.

A possible way forward... Basic and targeted monitoring

Basic monitoring Targeted monitoring

The challenge • Selection of most

pertinent operational questions.

• Smart and well-considered data collection needed.

• In situ BACI and gradient design data collection, in situ experiments and lab experiments

Distance from foundation (m)

Num

ber o

f det

ectio

ns

Fish densities

– up to 29.000 individuals of pouting per wind turbine...

Stomach content analysis and fitness consequences – Hard substrate epifauna is an important food source for pouting...

Targeted monitoring... An example: small-scale gadoid distribution

Small-scale distribution of cod

Reubens et al.

Addressing meaningful environmental impacts… Lessons learned from the Belgian monitoring program and beyond

Step 1: Identify key issues for ecological impact monitoring 1. Fish are an integral part of the ecosystem. 2. Have the right operational questions in place (not solely focusing on structural

aspects). 3. Understanding of an impact rather than its mere observation is needed.

Step 2: Outline effective ecological impact monitoring programs 1. Spatial and temporal scales of monitoring programs to be adapted according to the

operational questions. 2. These scales seldom coincide with wind farms nor administrative boundaries! 3. Outline integrated monitoring programs with maximum integration of the different

ecosystem components under consideration. 4. Distinguish between ecosystem variability that is crucial to incorporate and noise.

Step 3: Increase monitoring program efficiency and effectiveness 1. Monitoring to be coordinated by one central scientific organisation and executed by

those have the most appropriate expertise. 2. Set adaptive monitoring programs as to accommodate for new insights.

THANK YOU