emma sheehan 2015 storms and the seabed mpas
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Storm impacts on the seabed in protected and fished areasE.V., Sheehan, Bridger, D., Nancollas, S., Cousens, S., Holmes, L. & Attrill, M.J. Marine Institute, Marine Biology and Ecology Research Centre, Plymouth University, Plymouth, PL4 8AA, UKThe recovery of the Lyme Bay reefs (south west UK) have been annually monitored since they were protected from towed demersal fishing in 2008. Marine Protected Areas (MPA) are thought to be more resilient against natural disturbance. NERC, Pig Shed Trust, SWIFA and SWFPO funded a survey to compare protected and non-protected reefs following the storms with data from the previous summer.The benthic community in the MPA was significantly affected by the storms. The number of species and individuals decreased. The population of many indicator taxa decreased such as branching sponges, sea squirts Phallusia mammillata, scallops Pecten maximus. Taxa that were not affected were those best adapted for disturbance such as common starfish Asterias rubens, gobies and hermit crabs Pagurus spp. Clearly some species were more resilient than others. While pink sea fans Eunicella verrucosa were still present, many were fouled and had black bases, but of most concern was that only two of the habitat building Ross corals Pentapora foliacea were observed in approximately 12,000 m of video transects.The opportunity now exists to assess whether recovery from storm disturbance is quicker than from human disturbance to assist with future climate change management and mitigation.TRANSCRIPT
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Storm impacts on the seabed in protected
and fished areasDr Emma Sheehan, Dani Bridger, Sophie Cousens, Sarah Nancollas, Luke
Holmes, Prof Martin Attrill
Richard Austin
Pig Shed Trust
SWIFA & SWFPO
@Dr_Emma_Sheehan
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Impacts to the seabed
- Port Wrinkle and Wembury banks of kelp
- Reports from fishermen that pots had been moved
- Keith Hiscock (2014) after the storms: Collation of
observations
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2008-2013 Before baseline
- Assess the impact of the storm
- Test the hypothesis that protected reefs are more
resilient to disturbance events than areas that are
open to fishing (see Tett et al 2013)
2008 2009 2010 2011 2012 2013
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Last minute funding
Natural Environment Research
Council
Pig Shed Trust
SWIFA
SWFPO
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Talk content
- Importance of biogenic reef services
- Storm impact results
- Relevance for conservation and management
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Importance of temperate
biogenic reefs
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Nursery/Protection
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Feeding habitat/egg case
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Spat settlement
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Stabilise sediments
Sheehan et al 2013 Mar. Poll. Bull
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Lyme Bay Statutory Instrument
Lyme RegisPlymouth
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Lyme Bay SI 11th July 2008Statutory Instruments 2008 No. 1584
Sea Fisheries, England. Conservation
The Lyme Bay Designated Area (Fishing Restrictions)
Order 2008
206 km2
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2008 -2014
Sheehan, et al Mar Poll Bull (2013)
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Methods
Flying Towed Array HD
(1)
- Relatively non-destructive
- Cost and time effective (8x 200 m transects per
day)
- Able to fly over variable seabed relief Sheehan, Stevens, Attrill (2010) PLOS ONE
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Natural Seaton Festival
2013
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Natural Seaton Festival
2013
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Natural Seaton Festival
2013
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Storms 2013 -2014
Richard Austin
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Storms 2013 -2014
Richard Austin
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Storms 2013 -2014
Richard Austin
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West Bay Wave Buoy
Channel Coastal Observatory
Year
Wa
ve
he
igh
t (m
)
0
1
2
3
4
5
6
7
8
Maximum wave height
Average wave height
2007 2008 2009 2010 2011 2012 2013 2014
Wave h
eig
ht
(m)
----- Maximum wave height
----- Average wave height
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Three components:
1. Comparison between MPA and
Open areas
2. Resilience of benthos in different
aged MPAs
3. Storm impacts on sediment veneers
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Three components:
1. Comparison between MPA and
Open areas predictive model
Waiting for wave model data to
complete the paper. Sorry..!
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Three components:
1. Comparison between MPA and
Open areas
Waiting for wave model data to
complete the paper. Sorry..!
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Results
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First observations
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First observations
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Diversity (non seasonal)
Time
2008 2009 2010 2011 2012 2013 Storm
Taxon r
ichness (
mean m
S
ED
)
5
10
15
20
25
30
35
MPA
Control
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Abundance (non seasonal)
Time
2008 2009 2010 2011 2012 2013 Storm
Abund
ance (
mean m
S
ED
)
0
20
40
60
80
100
120
140
MPA
Control
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Branching sponges
Time
2008 2009 2010 2011 2012 2013 Storm
Abundance (
mean m
S
ED
)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
MPA
Control
-
Pentapora foliacea
Time
2008 2009 2010 2011 2012 2013 Storm
Abundance (
mean m
S
ED
)
0.0
0.1
0.2
0.3
0.4
0.5
MPA
Control
-
Pecten maximus
Time
2008 2009 2010 2011 2012 2013 Storm
Abundance (
mean m
S
ED
)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
MPA
Control
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Eunicella verrucosa
Time
2008 2009 2010 2011 2012 2013 Storm
Abundance (
mean m
S
ED
)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
MPA
Control
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% E. verrucosa necrosis
Time
Before After
% n
ecr o
sis
0
20
40
60
80
100
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% E. verrucosa epiphytes
Time
Before After
% e
pip
hyte
s
0
20
40
60
80
100
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Asterias rubens
Time
2008 2009 2010 2011 2012 2013 Storm
Abundance (
mean m
S
ED
)
0.0
0.5
1.0
1.5
2.0
2.5
MPA
Control
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Gobies
Time
2008 2009 2010 2011 2012 2013 Storm
Abundance (
mean m
S
ED
)
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
MPA
Control
-
Pagurus spp.
Time
2008 2009 2010 2011 2012 2013 Storm
Abundance (
mean m
S
ED
)
0
2
4
6
8
10
12
14
16
MPA
Control
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Relevance for conservation,
management and fisheries
Resilience hypothesis
Significantly greater changes inside the MPA as the
species in open controls were better adapted to
disturbance but they are maintaining an unfavourable
system for delivering a range of ecosystem services.
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Thoughts
- Why did the storms cause
so much damage to the
seabed?
- Why did the MPA not
stand up better to the
storms
- Resistance Recovery?
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Conclusions- The box had not been
protected long enough to
be resilient against storms
- Open areas were resilient
against storms but were
only maintaining an
undesirable state
- Important to compare
recovery from storms with
recovery from bottom
towed fishing
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Acknowledgements
- Funders: NERC, Pig Shed Trust,
SWIFA, SWFPO, Defra, Natural
England
- Thank you to the people who
helped to protect LB reefs
- Robert King (Blue Turtle skipper),
John Walker and Kieran Perree
(Miss Pattie skippers past and
present
-Richard Austin for providing images
- Statistical support from Marti
Anderson and Bob Clarke