Russell DJF, Grecian WJ, Masden EA, Hammond PS, Owen E, Daunt F, Wanless S

Structures and marine top predators:

overlap and interactions

dr60@st-andrews.ac.uk

Why marine predators?

• Indicator species

• Influencers

• Can monitor on a– Large spatial scale

– Fine spatial scale

DisturbanceHearing damageHabitat changesCollision risk

De facto MPAsRest stopsNavigation aidsArtificial Reefs

CommissioningOperationDecommissioning

Positive?Negative?

Structure Life-stage

Photo: Ron Morris

What is influence of structures on top predators?

• Establish the magnitude of the effects of man-made structures compared to the spatial and temporal variability of the North Sea ecosystem

– With regard marine apex predators at a

1. Large spatial scale

2. Fine spatial scale

• MAPS

– Man-made structures and Apex Predators: Spatial overlap and interactions

• To what extent could existing data be used to address this?

M. Arso S.Russell S.Russell

1. Large scale

• Assess the influence of, and overlap between, man-made structures and the distribution of apex predators in the North Sea

– compared to the spatial and temporal variability of the ecosystem

• Habitat preference analyses

– Relate data pertaining to distribution to environmental drivers• Predict overall distribution

• By including presence of structures as covariates

– Determine association between distributions and structures

1. Large scale - cetaceans• Small Cetacean Abundance in the North Sea and adjacent

waters Survey (SCANS II)❖ Hammond et al. 2013

• White-beaked dolphin

– Winter sea surface temperature

• Minke Whale

• Harbour porpoise– Winter sea surface temperature

– Depth– Distance to coast– Structure presence

1.Large scale - seabirds

• European Seabirds At Sea (ESAS) survey data (1979-2011)

• Black-legged kittiwake

• Common guillemot

• European shag

• Razorbill

• Northern fulmar

– Structure presence

1. Large scale - seals

• Animal-borne GPS tracking data– SMRU & University of Aberdeen

• Grey seals (n=30)– Depth– Distance to haul-out site– Lagged winter sea surface temperature– Sediment type– Structure presence

• Harbour seals (n=55)– Depth– Distance to haul-out site– Lagged winter sea surface temperature– Sediment type

F.Landes

2. Fine scale

• Whether detectable influence on distribution dependent on...

– Data suitability

– Prevalence of the species

– Proportion of range that overlaps with structures• Harbour seals

– Levels of individual variation• Distribution analyses based on mean population-level response

• Generalist predators often composed of individual specialists

• Influence of structures most likely driven at a local scale

– Given structures within range…• What is the probability they are used

– Rest stops

– Navigation signposts

– Artificial Reefs

No detected influence of structure presence on distribution

≠ No influence of structures on a population

2. Fine scale - seabirds

• RSPB/CEH animal-borne GPS data

• Median encounter rate with structures low for all species

– <5% of locations within 500 m of a structure

• Some tracks with relatively high encounter rate showed a potential association with structures– E.g. 2 of the 267 tagged kittiwakes

– Underlying mechanism unclear

black-legged kittiwakes (n= 267)razorbill (n=125)northern fulmar (n=32)common guillemot (n=64)European shag (n=73)

FAME & STAR

2. Fine scale - seabirds

1. Identify encounters– Within 500m of structure

2. Identify behavioural states– Hidden Markov Models

• Foraging

• Travelling

• Resting

3. Does encountering a structure affect probability of foraging?

• At a population level the presence of structures did not increase the likelihood of foraging

2. Fine scale - seals

Individuals use structures for foraging- Limited sample size of high-resolution GPS tags-Analytical limitations

M.Page

Summary - Cetaceans

• Known– Present around oil & gas installations

❖ Todd et al. 2016; Delefosse et al. 2018

– Harbour porpoise • Foraging at structures

❖ Todd et al. 2009; Scheidat et al. 2011

• Evidence of association between structures and harbour porpoise distribution

– White beaked dolphin and minke whale• No evidence of association between distribution and structures

– Data suitability issues

• Next questions to address– How robust is the association between structures and harbour porpoise

distribution?• Is it causal?

➢Repeat analyses with data from 1994 and 2016 (SCANS I & III)

M. Arso

Summary - Seabirds• Oil & gas infrastructure only considered

• Known

– Large scale

• No evidence that distribution is influenced by structures

– Data suitability issues

– Fine scale

• Structures may influence the behaviour of a few individuals

• At a population level, no impact of structures on foraging behaviour

• Next questions to address

– What is the mechanism underlying the associations between individuals and structures?

• Are they following fishing boat following pipelines?➢ Vessel Monitoring data

• Are they resting on structures?

• Are these structures visible?

S.Russell

Summary - seals

• Known

– Large scale

• No evidence that distribution is influenced by structures

– May change with increasing near-shore abundance of structures

• Overlap with structures can be quantified

– Fine scale• Evidence that some individuals forage at platforms,

pipelines, windfarm foundations❖ Russell et al. 2014

• Since MAPS project

– Increased sample size of grey seal GPS tags 3-fold• From 30 to >100

• Potential use of structures for navigation

– Appropriate analytical framework available

• Next questions to address

– Quantify how do structures influence behaviour?• Structure type

• Structure age

• Importance of structures for – Navigation

– Foraging

– Rest stops

– Combine with distribution maps• Population level prevalence

Summary - seals

• INSITE– Industry sponsors– ISAB– Richard Heard

• Department for Business, Energy & Industrial Strategy – John Hartley (Hartley Anderson Ltd.)

• Colleagues at SMRU, CREEM, UHI, RSPB and CEH – Particularly Matt Carter

• SMRU Instrumentation• Professor Paul Thompson, University of Aberdeen• Joint Nature Conservation Committee (JNCC) for provision of ESAS data• Data funders

Argyll Bird Club, Department for Business, Energy & Industrial Strategy, Environment Wales, European Union, Fair Isle Bird Observatory Trust, JNCC, Marine Scotland, Natural England, Natural Environment Research Council, Natural Resources Wales, SMRU, Scottish Natural Heritage, RSPB, Vodafone UK.

Thank you

@_SMRU_