Presentation #4 of 9: Allen Risby of DONG Energy explaining work on monitoring effects on red throated diver distribution in Liverpool Bay

1. Monitoring red-throated
diver distribution in
Liverpool Bay
Allen Risby
DONG Energy

2. • Burbo Bank Extension Offshore Wind Farm
• Requirement for red throated diver monitoring
• Power analysis & objectives
• Survey method
• Modelling & reporting
• Conclusions
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Agenda

3. Burbo Bank Extension Offshore Wind Farm
The site was awarded in May 2010 by The
Crown Estate
• Total Area: 40 km²
• Capacity: max 259 MW
• DCO September 2014
• Proposed 32 turbines with 8 MW capacity
• Construction due to commence 2016, with
commissioning Q1 2017.
Other offshore wind farm projects in or near
Liverpool Bay (with operational year)
• North Hoyle (2003)
• Barrow (2006)
• Burbo Bank (2007)
• Rhyl Flats (2009)
• Walney I+II (2011 / 2012)
• Ormonde (2012)
• West of Duddon Sands (2014)
• Gwynt y Mor (under construction)
• Walney Extension (planned)
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4. Liverpool Bay Special Protection Area
• Burbo Bank Extension lies mostly within
Liverpool Bay SPA;
• Liverpool Bay SPA designated in 2010, for
red-throated diver Gavia stellata and
common scoter Melanitta nigra; and
• North Hoyle, Rhyl Flats, Burbo Bank and
Gwynt-y-Môr also contained within Liverpool
Bay SPA.
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5. Burbo Bank Extension OWF - Examination
• Planning Inspectorate (PINS) Examination
September 2013 – March 2014
• Nationally significant infrastructure project
• Key ornithological issue is extent of
displacement of red-throated diver,
consequences of displacement and
implications for Liverpool Bay SPA
• Cumulative assessment with Burbo Bank,
Gwynt-y-Môr and Rhyl Flats wind farms
• Outline ornithological survey document agreed
during Examination with Natural England &
Natural Resources Wales
• PINS recommendation and DECC AA
• DCO granted, deemed Marine Licence with
monitoring condition

6. Agreed approach to RTD Monitoring
Two objectives:
1) Measure displacement effect of Burbo Bank Extension on RTD
• Digital video aerial surveys focussed on the Burbo Bank Extension site and a 4
km buffer at a suitable resolution to assess the displacement effect
2) Measure change in RTD density across the SPA following Burbo Bank
Extension construction
• Digital video aerial surveys covering Liverpool Bay SPA (full extent but not 100%
coverage) at a suitable resolution to assess the change in density across the
SPA
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7. Scope for RTD Monitoring
• A series of high resolution digital video aerial surveys to compare pre-construction
and post-construction distribution of RTD, the post-construction monitoring to extend
to up to 3 years (which may be non-sequential upon agreement)
• Survey designed to allow comparison with existing Liverpool Bay SPA surveys (such
as Bradbury et al, 2011) and be of sufficient "power" to provide statistical confidence
in the results
• HiDef approach based on the survey intensity and frequency identified in the digital
video aerial surveys carried out in 2011 for JNCC
• Survey methodology for Burbo Extension agreed with MMO, NE and NRW
• Surveys are taking place between November and March, as this is the key time of
year for RTD in Liverpool Bay
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8. Power analysis
• HiDef undertook a suite of digital aerial surveys in winter 2011 for JNCC to calculate
power to detect change in SPA
• This programme provides good basis for understanding how much survey is required to
detect change at Burbo Bank Extension
• This demonstrates that 2 surveys per winter with 17.5% coverage of the SPA will detect
33% decrease and 50% increase with sufficient power
Scenario
Coverage of
site
Number of
surveys
Decline to be
detected
Increase to be
detected
Power to detect
change
1 5.83% 2 33% 50% 58.4%
2 17.5% 2 33% 50% 81.0%
3 5.83% 2 50% 100% 96.4%
4 17.5% 2 50% 100% 99.8%
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9. Objective 1
• To measure the displacement effect from
Burbo Bank and Burbo Bank Extension and
measure the displacement distance in 500 m
bands from boundary
• Eight transects at 2.75 km apart – this is
approximately 20.2% coverage
• Area surveyed five times per winter (monthly
in Nov, Dec, Jan, Feb & Mar)
• One survey season during pre-construction
(now completed) and up to three during post-
construction (2017/18 onwards)
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10. Objective 2
• To determine displacement effects of Burbo
Bank Extension and other wind farms on
RTD populations in Liverpool Bay SPA
• 44 transects at 2.75km apart – this is
approximately 18.6% coverage
• Area surveyed twice per winter (monthly in
Jan & Feb)
• One survey season pre-construction (now
completed) and up to three years post-
construction
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11. The survey method
• HiDef bespoke system designed for bird
and marine mammal surveys
• Uses a rig with four ultra high resolution
video cameras (~ 500MPx)
• Cameras always angled away from sun
glare to stop data loss
• Surveys flown at 550m (1800ft) to avoid
flushing RTD and common scoter
• Uses a resolution of 2cm GSD
• Total strip width of 500m along continuous
transects – avoids pseudo-replication of
plot based approach
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12. Red-throated diver images from Liverpool Bay
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Flock of 6 red-throated divers Red-throated diver flying south-west
Red-throated diver with fish

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14. January 2015 SPA-wide survey
summary of observations (circa 20% coverage)
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15. Data modelling
• Analysis based on constructing density surface models (DSM) for RTD
• Strip transects broken into 100s of ‘segments’
• Calculates abundance with upper and lower confidence intervals (CI) and coefficient of
variance (CV) in fine matrix of grid cells
• Modern modelling approach uses ‘Complex Regional Spatial Smoother’ (CReSS)
• CReSS well-adapted for birds with patchy distribution, such as seabirds
• This modelling approach has been used at one other UK offshore wind farm, as well as
for a recent series of bird and marine mammal surveys for Marine Scotland

16. Pre-construction survey report
• The DSM will use bathymetry as a co-
variate for diver distribution
• Combines recent digital and historical
visual aerial survey data going back to
2001
• Report on the ability of model to detect
changes in RTD abundance around
Burbo Bank and Burbo Bank Extension,
as well as within the SPA
• Report on the ability to detect
displacement in 500m or 1km bands from
Burbo Bank Extension
• This is an example output from another
wind farm site where this technique has
been recently used
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17. Conclusions
• Post consent monitoring that moves
monitoring away from old FEPA-style
Before and After Control Impact (BACI)
licence conditions
• Monitoring at the scale of the Liverpool
Bay SPA is more meaningful for
displacement than wind farm + buffer
monitoring alone
• Ability to incorporate previous (visual)
aerial survey data into the baseline
model
• Digital aerial surveys allow the data to
be subsequently re-analysed for other
target species.
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18. Thank-You.
Any Questions?
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