A cumulative perspective on marine environmental
impacts – example Offshore Wind Farms & Seabirds
Malte Busch1, Dr. Andreas Kannen2, Dr. Stefan Garthe3 and Dr. Mark Jessop4
1
Natural England, before at HZG; 2 Helmholtz-Zentrum Geesthacht (HZG); 3 Research and Technology Centre (FTZ), University of Kiel; 4 Coastal & Marine Research Centre (CMRC), University College Cork
Aim: While current statutory cumulative impact assessment is restricted to Offshore Wind Farms (OWF) in the direct vicinity, the overall consequences of
large scale OWF development at the North Sea scale are neglected. Using the example of interactions between Offshore Wind Farming (OWF) and seabird
habitats in the North Sea this study [1] developed an approach to estimate impacts at a trans-national scale. It therefore aimed to offer a pre-operational
solution to a practical problem clearly formulated by planning practitioners and scientists, and thereby to support implementation of the Ecosystem Approach.
Problem:
• Spatial competition
between OWF, other sea
uses and nature
conservation areas
• Cumulative impacts are
much more relevant than
single impacts from one
individual wind farm.
Scenario analysed: Present
and planned OWFs were
combined with estimations for
search area utilisation in the
UK and the Netherlands based
on the technical state of art:
5 MW per km2 and arrays not
exceeding 500 MW.
This scenario is based on
existing plans for OWF in the
investigation area until 2030.
Investigation Area:
• North Sea EEZs of
Germany, Netherlands,
Belgium and UK
• based on ICES areas and
data availability
Bird species selected :
• Red-throated and blackthroated divers;
• Lesser black-backed gull;
• Northern gannet;
Approach: (1) Vulnerable marine areas for selected seabird species were
identified. Seasonal abundance (maps 1-4) was calculated and
accumulated in a single map (map 5) displaying the respective highest
value for each raster cell across all seasons.
1.)
(2) Overlay of sea bird abundance with existing & intended OWFs.
2.)
5.)
spring
summer
3.)
4.)
(3) Analysing mitigation potential within search areas by comparing a best
case & worst case siting scenario.
autumn
winter
Results
 “Proof of concept” for a technically feasible approach using existing data
sources to rate potential cumulative impacts of the analysed OWF scenario
on selected bird species at trans-national scale;
 First estimate of cumulative habitat loss/change at North Sea scale differentiated along abundance categories applied as a proxy for habitat quality;
 Holistic picture of how nationally enforced activities accumulate and threaten the habitat of seabirds across the North Sea;
Planning implications
 Urgent need for increased trans-national communication and cooperation about sea use development and their trans-national effects;
 Need for standardised trans-national survey- and monitoring protocols and for adjustment or expansion of monitoring initiatives to deliver relevant
information for planning;
Reference
[1] Busch, M., Kannen, A., Garthe, S. & Jessop, M. (2012): Consequences of a cumulative perspective on marine environmental impacts: offshore wind farming
and seabirds at North Sea scale in context of the EU Marine Strategy Framework Directive. Ocean and Coastal Management, doi: 10.1016/ocecoaman.2012.10.016.
Dr. Andreas Kannen (andreas.kannen@hzg.de)
Helmholtz-Zentrum Geesthacht | Max-Planck-Strasse 1 | 21502 Geesthacht
Phone: +49-(0)4152-87-1874 | Fax: +49-(0)4152-87-2818 | www.hzg.de