Dr Rafael Pérez-Domínguez

Principal Marine Ecologist

CIEEM Welsh Section Spring Seminar.

08 April 2016, Swansea University

r.perez@apemltd.co.uk

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

Laboratories Field science

Aerial surveys Consultancy

Introduction to APEM

Filed and consultancy services include freshwater and marine

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

Output: Detailed Habitat Maps for the area C

ASE

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 r.perez@apemltd.co.uk

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?