management of marine systems, obtaining the evidence to …€¦ · · 2016-04-18and industry...
TRANSCRIPT
Dr Rafael Pérez-Domínguez
Principal Marine Ecologist
CIEEM Welsh Section Spring Seminar.
08 April 2016, Swansea University
http://www.apemltd.co.uk/
Management of marine systems,
obtaining the evidence to support
conservation and development
Introduction to APEM
Edinburgh
Stockport
Oxford
Cardiff
Chester
Cambridge
• Aquatic science and remote sensing
consultancy covering catchment to sea
• Experts in freshwater and marine ecology
• 130+ staff in seven UK sites, offices in
Germany and USA
• Established 1987, Manchester Uni. originally
• Committed to core scientific principles
• Staff from a range of academic, regulatory
and industry backgrounds
• Working with private companies and all UK
environmental regulators
Evidence to support conservation and development
Contents
• Evidence and Management
• Survey pre-planning
• Questions and Goals
• What to measure?
• Survey design considerations
• Data requirements
• Sample size & scale of integration
• Effect of Variance (noise); Replication
• Conclusions
• Case studies
Evidence and Management
Main questions for managers:
• What is the normal situation?
• How does it vary?
• Has there been a change?
• How big is the change?
• What caused it?
• Can we propose a mechanism?
• Can we predict further changes?
Evidence and Monitoring
Monitoring should aim to:
• specific TARGETS
• gather quality evidence
• integrate multiple evidence lines
• lead to a robust assessment
• be practically feasible
• remain within budget
… cost effective and statistically robust design
Survey pre-planning: Questions and Goals
Monitoring objectives I:
1. Estimation of temporal & spatial changes in abundance (e.g. species distribution; diversity)
2. Prediction at unsampled locations & times (species-habitat models)
set baseline conditions…
Bijleveld et al. 2012 Methods in Ecology and Evolution 3: 526-536
Survey pre-planning: Questions and Goals
Monitoring objective II:
1. be able to answer few questions: a. does change correlate with the onset of a disturbance?
b. is it specific to the impacted location?
c. do we have enough confidence to rule out effects when we do not see change? POWER!
How to do it? Measure something…
Survey pre-planning: What to measure?
Best quality metrics for monitoring should:
– be sensitive to human pressure
– provide a robust indication (signal to noise ratio high)
– be accurate and technically feasible
– have available reference
– have wide biogeographical relevance
– be bound by time and budget constraints
– be of easy interpretation by non-specialists
follow best practice and guidance
Survey design considerations:
• Data analysis and evidence requirements
• Distribution of sites and stations; inclusion of control areas
• Level of resolution needed – Sampling frequency
– Sample integration scale
– Replication & data quality
• Budget Effort (£)
Reso
luti
on
design 1
design 2
King et al. Nature Communications 1, Article number 53
Systematic Random Stratified Random
Station array
Mud
Reef
Sand
Systematic
Random
Stratified Random
Station array
• Simple grid-based point intercept, gradient and transect survey
• Easy to set up, effective for benthic species & estimate at unsampled locations
• Autocorrelation issues if samples are too close
• Best for homogeneous habitats
Mud
Reef
Sand
Systematic
Random
Stratified Random
• Random sample survey design, grid-based with random replacement,
• Works well in most situations
• Do not require former knowledge, useful for pilot studies
• Good to asses sample covariation (autocorrelation)
Station array
Mud
Reef
Sand
Systematic
Random
Stratified Random
• Effort allocation to strata, and systematic or random sampling is applied within each stratum
• Requires previous knowledge of the habitats across the sampling area
• Very suited for heterogeneous areas
• Can result in significant reductions in sampling needs
Station array
Survey design considerations: Diversity
• Minimum sampling effort
• Probability estimates
• Density of target species
– Doubling the area yields < 5-10% new species
– Estimated sample area needed to get a particular Taxa 90% of the times
ARBITRARY cut-off points
aim for a reasonable balance
Ranked Species
To
tal
ab
un
da
nce
habitat 1
habitat 2
K dominance curves
Area / Vol. / no samples or no ind.
Nu
mb
er
of
Sp
ec
ies
Spp. accumulation curves
Survey design considerations: Precision & Power
• Variability & random noise; – replication
• Power / precision
Goal-derived cut-off points
what is ‘biologically’ meaningful
Literature reviews?, former
examples?, Pilot study
µ=5.2 SD=2.1
1
2
3
4
5
6
7
8
2 3 5 10 25 75 300
Sample size 3 5 10 25…..
µ=5.2 SD=2.1
14
20% effect
10% effect
65
95% confidence limits
Sample autocorrelation Habitat heterogeneity
Behaviour & Seasonality
Patchiness
Dissimilar abundance Sampling bias
Uncertainty on sample
integration Operational conditions
problems
Sample array Stratified random designs; modelling Target times-areas of max activity / abundance Replication & sample integration Intercalibration & standards; multi gear assessments Sp. accumulation curves and / or proxy habitat quantification Modify methods & gear to increase operational range
adjustments
Conclusions: Improving sampling design
Severn Estuary and Bristol Channel Ecological Studies
• Scoping, gap analysis and survey design to assess potential effects of
a Tidal Lagoon for electricity generation
• Pre-assessment of Far- and Near-field pressures on fish (marine
assemblage and migratory features), plankton (phyto and
zooplankton/Ichthyoplankton), microphytobenthos and benthos
(epifauna and infauna)
• Scoping data needs for the assessment (goal driven), implementation
of statistically robust designs by optimisation of sampling size (power
analysis) & assessment metrics/ methods
• Scoring and spatial visualisation of environmental (or ecological)
status/ potential as deviation from reference condition
• Includes the assessment of population consequences from individual
behaviour, i.e. life cycle models to predict impacts on migratory fish
features
• Purpose is to inform the impact assessment as part of the
management of impacts
CA
SE 1
Design of the data collection programmes
1. Focused on data needs, able to produce the evidence necessary to
address gaps identified in the initial scoping and to ensure a robust
evaluation of project pressures on sensitive receptors
2. stratified sampling design using: physical attributes (e.g. salinity,
substrata type, shore elevation/bathymetry, etc.); biotope
information (where these are known); and
3. potential pressure gradients – Survey across the Project area (near
field sites) and expected ZoI of coastal processes (far field sites);
4. multiple gear sets (WFD type) specific to the expected environment
(habitat), the receptor and survey conditions;
5. survey effort with spatial (habitat) & seasonal replication and
commensurate to expected effect size/biological significance and
variability (power analysis effort to detect 50% change in mean
taxon richness)
6. Metrics: Structural- Species diversity, Abundance (extent) and
distribution; Size and biomass; Functional- Habitat dependencies;
guild assessment (trophic and ecology)
CA
SE 1
FISH CHARACTERISATION
• 10 inshore trawl
boxes – WFD-
compliant 1.5 m-
wide beam trawl
• 20 offshore trawl
lines – WFD-
compliant Otter
trawl
A2 littoral biotopes (soft sediments) A3 infralittoral biotopes (rock) A4 circalittoral biotopes (rock) A5 sublittoral biotopes (soft sediments) A5.6 Biogenic Reef; B3.1 splash zone
Total effort 560 sampling events (2 years plan & 4 seasonal
surveys), 45-65 species expected (lower estimate from
species accumulation curves & pilot survey results) by the
end of the programme
CA
SE 1
PLANKTON CHARACTERISATION
• 53 & 200 micron
plankton samplers;
Zooplankton
• Niskin water
sampler;
Phytoplankton
(species & cell
counts); and
• chl-a (proxy for
biomass)
Total effort/year 96 sampling events (seasonal); expected to
achieve enough power to detect 50% change with
confidence
CA
SE 1
BENTHOS CHARACTERISATION
Subtidal habitats
• Single Day grab (0.1m2) sample
for fauna; PSA subsample from
sediment texture
• 2 seasonal surveys (Feb and
June)
Intertidal habitats
• Aerial survey & Phase I survey
(data for biotope/habitat
distribution)
• Phase II survey (Quantitative
data -species richness,
diversity, abundance/density)
• One survey/year (August to
September)
CA
SE 1
Swansea Bay Topographic and Habitat Mapping project
• Survey design & habitat mapping project
• Full area coverage and transect-based Phase I intertidal verification
survey
• Purpose was to inform the impact assessment as part of the
management of impacts
• High-resolution aerial surveys of the coastal area from The Mumbles to
Kenfig using one of APEM’s survey aeroplanes
• Geo-referencing of images
• Digital Elevation Model (DEM) extraction for topography
• Review and analysis of imagery in GIS to determine broadscale
habitat types
• Targeted Phase I biotope survey to ground truth imagery & provide
greater detail on habitat types
• Outputs were sent to the Regulator as part of the consenting process
for the Swansea Bay Tidal Lagoon project
CA
SE 2
Hilbre Swash Baseline & Operational Stage Licence Monitoring:
Benthic survey
• Baseline benthic characterisation survey of aggregate extraction licence
area to meet NRW licence conditions and manage impacts
CA
SE 3
License area
Control areas
• Subtidal grab survey for
faunal and sediment
Particle Size Distribution
analysis
• Outputs: Field report and
data report that were sent
to NRW to meet licence
conditions and allow
Lafarge Tarmac Marine
Ltd to commence the
aggregate (sand)
extraction
Bathing Water Investigations: Microbial tracer and coastal
hydrographic surveys
• Compliance assessment and microbial pollution source apportionment
• data provision for modelling impacts, compliance assessment
• Survey specialists: APEM, CREH Ltd. & Fugro
• 49 coastal sites; 5 areas – River gauging & sampling (flow &
source concentration)
– Phage tracer (connectivity)
– ADCPs (currents)
– Drogues and tracers (dispersion)
– 49 coastal sites
• Applications – Evidence to quantify improvements
– Improved prediction of pollution events and improved public health
– Improve accuracy of prediction and greater compliance
CA
SE 4
Dr Rafael Perez-Dominguez Principal Marine Ecologist [email protected]
Conclusions: Improving evidence for management
• Objectives must be defined early in the planning phase
• Add as much replicated sites as practically feasible. If possible impact areas
should also be replicated to improve ability to detect changes
• Interanual variability, temporal and spatial covariation must be considered to
scope the number of sites and times in monitoring programmes. How many
years are required for a characterisation?
• Robust designs require robust assessment metrics, low natural variability and
good signal-to-noise ratio. Standard sampling protocols should be used.
• Pilot studies are a very useful design tool for scoping sampling needs and
sampling designs (e.g. stratified designs)
• Increasing sampling effort (sample size & number of replicates) generally
improves resolution, but effort cannot be increased indefinitely… cost
• Increasing size effect reduces the number of samples required (power
increases)… alternatively delaying the assessment reduce sampling needs as the
deviation from baseline would be larger. Acceptable?