Scottish seabird conservation action plan: vulnerability report

Annex 2: Assessing Exposure

Table A2. 1: The sources for exposure information on each impact/ threat .

Threat/ impact: Climate change

Activity: Multiple activities

Exposure information sources: Marine Climate Change Impacts Partnership (MCCIP)

Threat/ impact: Collision mortality, displacement and barrier to species movement.

Activity: Energy generation - Offshore wind: Operation and maintenance

(Marine energy – Offshore wind)

Exposure information sources: Location of existing and planned offshore wind farms together with future planned areas for offshore wind developments identified through the Sectoral Plan for Offshore Wind Energy.

Threat/ impact: Underwater collision mortality

Activity: Energy generation - Tidal stream: Operation and maintenance

Wave energy generation

(Marine energy – wave and tidal)

Exposure information sources: Location of existing tidal developments known. (Tidal lease sites and tidal draft plan options, Marine Scotland - National Marine Plan Interactive (atkinsgeospatial.com))

Threat/ impact: Marine litter

Activity: Multiple activities

Exposure information sources: Some existing marine litter indicators are available (e.g. SCRAPBook^[6], OSPAR Marine indicators^[7], Great British beach clean^[8]). Spatial extent currently unclear, especially at scale relevant to seabirds.

Threat/ impact: Habitat loss & mortality from invasive predatory mammals

Activity: Multiple activities

Exposure information sources: Exposure assessments use the UK Marine Strategy assessment of invasive predatory Mammals on seabird islands (Mitchell et al. 2018) along with distribution data and maps from Stanbury et al. (2017).

Threat/ impact: Reduction in prey by fishing

Activity: Fisheries

Exposure information sources: ICES Advice on fishing opportunities, catch, and effort for sandeels in the North Sea. The latest advice for each sandeel area adjacent to the Scottish Coast contains information on annual fishing pressure and landings up to 2018 and estimates of stock size up to 2019. For northern North Sea & Shetland see ICES (2019a) and for northern and central North Sea see ICES (2019b).

No stock assessment data available that would enable a straightforward exposure assessment for fishing pressure on other prey species – sprat, juvenile herring, juvenile cod, whiting etc.

Threat/ impact: Disturbance

Activity: Recreation, tourism and transport activities

Exposure information sources: Data on vessel traffic (available from Marine Scotland via NMPi). The distribution of a wide range of recreational activities is recorded by the Scottish Marine Recreation & Tourism Survey^[9] with associated maps by activity available from Marine Scotland via NMPi.

Threat/ impact: Intentional taking of adults/eggs

Activity: Licenced culling, control & harvesting

Exposure information sources: NatureScot licensing data.

Threat/ impact: Mortality from oil contamination

Activity: Multiple activities

Exposure information sources: Seabird Oil Sensitivity Index^[10] (based upon seabird survey data collected from 1995-2015) aids planning and emergency decision making with regards to oil pollution, identifying areas at sea where seabirds are likely to be most sensitive to oil pollution. The UK Beached Bird Survey and SOTEAG^[11], also undertake monitoring of oiled seabirds.

a. Northern fulmar non-breeding distribution and b. Northern fulmar breeding distribution. Offshore distribution data taken from Waggitt et al. (2019). Dots indicate colonies which contain >0.01% of the Scottish breeding population based on Seabird Monitoring Program^[12] data.

Table A2. 2: Species distribution categorisations and the data confidence scores used in the exposure analysis.

Br=Breeding season, Nbr=Non-breeding season

Common name: Northern fulmar (Br)

Distribution description: Breeds throughout Scotland, but largest aggregations in North and West, and vast foraging forages throughout Scottish waters.

Distribution score: Widespread

Data description: Conspicuous at sea, extensive breeding survey effort and some GPS tracking data.

Data confidence score: High

Common name: Northern fulmar (Nbr)

Distribution description: Forages throughout Scottish waters, but in lower densities than breeding.

Distribution score: Widespread

Data description: Conspicuous at sea, extensive survey effort and some GLS tracking data.

Data confidence score: High

Common name: Manx shearwater (Br)

Distribution description: Breeds in a small number of sites in the West of Scotland, with extensive foraging ranges and occurs on passage elsewhere.

Distribution score: Localised

Data description: Relatively conspicuous at sea. One well monitored colony (Rum) but limited regular breeding survey effort elsewhere. Tracking data from a single colony in Scotland.

Data confidence score: Medium

Common name: European Storm-petrel (Br)

Distribution description: Breeds in the West and North of Scotland, with extensive foraging ranges and occurs on passage elsewhere.

Distribution score: Localised

Data description: Small size makes detection at sea challenging. Limited breeding survey effort in much of range, and limited tracking data from 2 colonies.

Data confidence score: Low

Common name: Leach's storm petrel (Br)

Distribution description: Breeds in a small number of sites in the North and West of Scotland, foraging predominantly in offshore waters in West of Scotland, although on passage elsewhere.

Distribution score: Localised

Data description: Relatively challenging to observe at sea with limited breeding survey effort in much of range and tracking data from 1 colony.

Data confidence score: Low

Common name: Arctic skua (Br)

Distribution description: Breeds predominantly in the North and also West of Scotland, with foraging and passage throughout Scottish waters.

Distribution score: Localised

Data description: Conspicuous at sea. Due to remote/expansive breeding, limited survey effort in much of range, and limited tracking data.

Data confidence score: Low

Common name: Great skua (Br)

Distribution description: Breeds predominantly in the North and also West of Scotland, with foraging and passage throughout Scottish waters.

Distribution score: Localised

Data description: Conspicuous at sea. Due to remote/expansive breeding, limited survey effort in much of range, and no tracking data due to tagging effects.

Data confidence score: Low

Common name: Great skua (Nbr)

Distribution description: Occurs throughout Scottish waters on passage but largely absent from majority of Scotland during winter period.

Distribution score: Restricted

Data description: Conspicuous at sea but low densities and no tracking data.

Data confidence score: Low

Common name: Great black-backed gull (Br)

Distribution description: Breeds throughout Scotland but greatest breeding aggregations in North and West, foraging and passage throughout Scottish waters.

Distribution score: Widespread

Data description: Conspicuous at sea, extensive breeding survey effort but limited GPS tracking data due to tagging effects.

Data confidence score: Medium

Common name: Great black-backed gull (Nbr)

Distribution description: Occurs throughout Scottish waters

Distribution score: Widespread

Data description: Conspicuous at sea, but no tracking data.

Data confidence score: Medium

Common name: Herring gull (Br)

Distribution description: Breeds on throughout Scotland and forages throughout Scottish waters.

Distribution score: Widespread

Data description: Conspicuous at sea, extensive breeding survey effort but limited tracking data in Scotland.

Data confidence score: Medium

Common name: Herring gull (Nbr)

Distribution description: Occurs throughout Scottish waters

Distribution score: Widespread

Data description: Extensive survey effort but no tracking data.

Data confidence score: Medium

Common name: Lesser black-backed gull (Br)

Distribution description: Breeds on throughout Scotland (including many terrestrial sites in the central belt) and forages throughout Scottish waters.

Distribution score: Widespread

Data description: Conspicuous at sea, extensive survey effort and some tracking data in Scotland.

Data confidence score: Medium

Common name: Lesser black-backed gull (Nbr)

Distribution description: Occurs throughout Scottish waters on passage but largely absent from majority of Scotland during winter period, although some individuals remain in the South.

Distribution score: Restricted

Data description: Conspicuous at sea and some tracking data.

Data confidence score: Medium

Common name: Black-headed gull (Br)

Distribution description: Breeds on throughout Scotland (including many terrestrial sites) and forages throughout Scottish waters.

Distribution score: Widespread

Data description: Conspicuous at sea, extensive survey effort, no tracking data

Data confidence score: Medium

Common name: Black-headed gull (Nbr)

Distribution description: Occurs throughout Scotland and generally inshore waters

Distribution score: Widespread

Data description: Conspicuous at sea, extensive survey effort, no tracking data

Data confidence score: Medium

Common name: Common gull (Br)

Distribution description: Breeds on throughout Scotland (including many terrestrial sites) and forages throughout Scottish waters.

Distribution score: Widespread

Data description: Conspicuous at sea, extensive survey effort, no tracking data

Data confidence score: Medium

Common name: Common gull (Br)

Distribution description: Occurs throughout Scotland and generally inshore waters

Distribution score: Widespread

Data description: Conspicuous at sea, extensive survey effort, no tracking data

Data confidence score: Medium

Common name: Little gull (Nbr)

Distribution description: Small numbers, predominantly in waters in South-east of Scotland.

Distribution score: Restricted

Data description: Limited survey effort in Scotland and no tracking data.

Data confidence score: Low

Common name: Black-legged kittiwake (Br)

Distribution description: Breeds on throughout Scotland and forages throughout Scottish waters.

Distribution score: Widespread

Data description: Extensive survey effort and GPS tracking data from numerous colonies in Scotland.

Data confidence score: High

Common name: Black-legged kittiwake (Nbr)

Distribution description: Occurs throughout Scottish waters, but lower densities than during breeding.

Distribution score: Widespread

Data description: Extensive survey effort and GLS tracking data from colonies in Scotland.

Data confidence score: High

Common name: Little tern (Br)

Distribution description: Localised coastal distribution close to small number of breeding locations. Absent during non-breeding season.

Distribution score: Restricted

Data description: Small and challenging to detect during at sea surveys due to low densities, remote/limited breeding survey effort in Scotland and no tracking data.

Data confidence score: Low

Common name: Common tern (Br)

Distribution description: Largely coastal distribution throughout Scotland. Absent during non-breeding season.

Distribution score: Localised

Data description: Conspicuous during at sea surveys, some breeding survey effort and limited tracking data in Scotland.

Data confidence score: Medium

Common name: Arctic tern (Br)

Distribution description: Largely coastal distribution throughout Scotland. Absent during non-breeding season.

Distribution score: Localised

Data description: Conspicuous during at sea surveys, some breeding survey effort and limited tracking data in Scotland.

Data confidence score: Medium

Common name: Sandwich tern (Br)

Distribution description: Largely coastal distribution throughout Scotland. Absent during non-breeding season.

Distribution score: Localised

Data description: Conspicuous during at sea surveys, some breeding survey effort and no tracking data in Scotland.

Data confidence score: Medium

Common name: Northern gannet (Br)

Distribution description: Several large breeding colonies (gannetries) distributed across Scotland and forages throughout Scottish waters.

Distribution score: Widespread

Data description: Large and conspicuous during at sea surveys, extensive breeding survey effort and tracking data from selected colonies in Scotland.

Data confidence score: High

Common name: Northern gannet (Nbr)

Distribution description: Occurs throughout Scottish waters, but in lower densities compared to summer and a relatively short winter period.

Distribution score: Widespread foraging and

Data description: Large and conspicuous during at sea surveys, and some year-round tracking data from colonies in Scotland.

Data confidence score: High

Common name: Great cormorant (Br)

Distribution description: Largely coastal breeding distribution in the south and east of Scotland.

Distribution score: Localised

Data description: Conspicuous and inshore during at sea surveys, good survey effort within more coastal areas but no tracking data in Scotland.

Data confidence score: Medium

Common name: Great cormorant (Nbr)

Distribution description: Largely coastal foraging distribution throughout Scotland.

Distribution score: Localised

Data description: Conspicuous and inshore during at sea surveys, and no tracking data in Scotland.

Data confidence score: Medium

Common name: European shag (Br)

Distribution description: Coastal breeding and foraging distribution throughout Scotland.

Distribution score: Localised

Data description: Conspicuous and inshore during at sea surveys, good survey effort within more coastal areas, GPS tracking data from selected colonies in Scotland.

Data confidence score: Medium

Common name: European shag (Nbr)

Distribution description: Coastal distribution throughout Scotland, with partial non-breeding migration in some populations.

Distribution score: Localised

Data description: Conspicuous and inshore during at sea surveys, and GLS tracking data from limited number of colonies in Scotland.

Data confidence score: Medium

Common name: Razorbill (Br)

Distribution description: Occurs and breeds throughout Scottish waters

Distribution score: Widespread

Data description: Conspicuous and during at sea surveys, extensive breeding survey effort and GPS tracking data from selected colonies in Scotland.

Data confidence score: High

Common name: Razorbill (Nbr)

Distribution description: Occurs throughout Scottish waters, but in reduced numbers and more offshore than during breeding.

Distribution score: Widespread

Data description: Conspicuous during at sea surveys, and GLS tracking data from colonies in Scotland.

Data confidence score: High

Common name: Common guillemot (Br)

Distribution description: Occurs and breeds throughout Scottish waters

Distribution score: Widespread

Data description: Conspicuous during at sea surveys, extensive breeding survey effort and GPS tracking data from selected colonies in Scotland.

Data confidence score: High

Common name: Common guillemot (Nbr)

Distribution description: Occurs throughout Scottish waters, but in reduced numbers and more offshore than during breeding.

Distribution score: Widespread

Data description: Conspicuous during at sea surveys, and GLS tracking data from colonies in Scotland.

Data confidence score: High

Common name: Black guillemot (Br)

Distribution description: Coastal foraging and breeding distribution to the North and West of Scotland.

Distribution score: Localised

Data description: Conspicuous and inshore during at sea surveys, good breeding survey effort and GPS tracking data from colonies in Scotland.

Data confidence score: Medium

Common name: Atlantic puffin (Br)

Distribution description: Occurs throughout Scottish waters.

Distribution score: Widespread

Data description: Conspicuous during at sea surveys, extensive breeding survey effort, but limited GPS tracking data from selected colonies in Scotland due to tagging effects.

Data confidence score: High

Common name: Atlantic puffin (Nbr)

Distribution description: Occurs throughout Scottish waters, but in reduced numbers and more offshore than during breeding.

Distribution score: Widespread

Data description: Conspicuous during at sea surveys, and GLS tracking data from colonies in Scotland.

Data confidence score: Medium

Table A2. 3: Pressure distribution scores used in exposure analysis

Pressure Name: Climate Change

Distribution Description: There is increasing evidence of climate change impacting seabirds throughout Scotland, both through direct impacts of extreme weather events and indirect impacts on prey populations. While the impacts vary by location, they are widespread with high exposure for all species.

Distribution Score: Widespread

Data Description: While there is high confidence that climate change is and will affect seabirds, there is low confidence as to how and where this will occur.

Data Confidence Score: Low

Pressure Name: Wind turbine collision mortality; displacement by wind turbines; wind turbines as barrier to species movement

Distribution Description: Currently, several discrete wind farms are located in the seas off Eastern Scotland and within 100km of shore. However, the Sectoral Marine Plan identifies several candidate areas for future development in both the West and North.

Distribution Score: Localised

Data Description: Locations of current sites known and plans identify candidate areas for future development.

Data Confidence Score: High

Pressure Name: Mortality by collision with underwater turbines etc

Distribution Description: Limited number of locations in NW of Scotland and Northern Isles.

Distribution Score: Restricted

Data Description: Locations of current sites known and plans identify candidate areas for future development.

Data Confidence Score: High

Pressure Name: Marine litter

Distribution Description: Widespread, but low level exposure throughout range.

Distribution Score: Localised

Data Description: Limited information available and data collected over limited spatial/ temporal scale which may not be relevant to seabirds.

Data Confidence Score: Low

Pressure Name: Habitat loss & mortality from invasive predatory mammals

Distribution Description: Majority of mainland Scotland and numerous offshore islands. Predominantly an issue during breeding and restricted to land.

Distribution Score: Localised

Data Description: Historical data for large parts of Scotland and specific surveys of other locations. Regular monitoring at some seabird colonies.

Data Confidence Score: High

Pressure Name: Reduction in prey by fishing

Distribution Description: The pressure occurs throughout Scottish waters, but the spatial extent of fisheries is limited and target fish species vary regionally

Distribution Score: Localised

Data Description: Stock assessment data routinely collected. Spatial scale of assessments may not be appropriate for some seabird species/ colonies, non- commercial prey species poorly covered.

Data Confidence Score: Medium

Pressure Name: Disturbance from recreation, tourism and leisure and transport

Distribution Description: Predominantly within 10km of shore. Recreational disturbance generally more limited during winter

Distribution Score: Localised

Data Description: The survey data has wide coverage but the information is not necessarily directly relevant to the threat of these activities on seabirds. Intermediate for vessel traffic (vessels <12m length not tracked).

Data Confidence Score: Low

Pressure Name: Intentional taking of adults/ chicks/ eggs (licenced control & harvesting)

Distribution Description: Occurs in small numbers throughout Scotland but affects limited species. Predominantly breeding season.

Distribution Score: Localised

Data Description: Locations of legal activities known.

Data Confidence Score: High

Pressure Name: Mortality from oil contamination

Distribution Description: Widespread, but low level exposure throughout range.

Distribution Score: Medium

Data Description: Long term data from beached bird surveys and surveillance by Oil and Gas sector, but more limited data on discharges from shipping traffic.

Data Confidence Score: Medium

Table A2. 4: Species for which matrix derived exposure scores were modified following expert review.

Br = Breeding season only, Nbr = Non-breeding season only.

Pressure Name: Wind turbine collision mortality

Exemptions/Justification

• Northern fulmar: Low flight heights
• Great skua (Nbr): Passage
• Lesser black-backed gull (Nbr): Passage
• Little gull (Nbr): Passage
• Little tern: Extreme coastal distribution
• Great cormorant: Extreme coastal distribution
• European shag: Extreme coastal distribution
• Razorbill: Low flight heights
• Common guillemot: Low flight heights
• Black guillemot: Low flight heights
• Atlantic puffin: Low flight heights

Pressure Name: Displacement by wind turbines

Exemptions/Justification

• Northern fulmar: Low flight heights & extensive foraging
• Manx shearwater: Low flight heights & extensive foraging
• European storm-petrel: Low flight heights & extensive foraging
• Leach’s storm-petrel: Low flight heights & extensive foraging
• Little tern: Extreme coastal distribution
• Great cormorant: Extreme coastal distribution
• European shag: Extreme coastal distribution
• Black guillemot: Extreme coastal distribution

Pressure Name: Wind turbines as a barrier to species movement

Exemptions/Justification

• Northern fulmar: Extensive foraging distributions
• Manx shearwater: Extensive foraging distributions
• European storm-petrel: Extensive foraging distributions
• Leach’s storm-petrel: Extensive foraging distributions
• Arctic skua: Extensive foraging distributions
• Great skua: Extensive foraging distributions
• Little tern: Extensive foraging distributions

Pressure Name: Mortality by collision with underwater turbines etc

Exemptions/Justification

• Great cormorant: Extreme coastal distribution
• European shag: Extreme coastal distribution
• Black guillemot: Extreme coastal distribution

Pressure Name: Habitat loss & mortality from invasive predatory mammals

Exemptions/Justification

• Northern fulmar (Nbr): Largely at sea
• Great skua (Nbr): Largely at sea
• Great black-backed gull (Nbr): Largely at sea
• Herring gull (Nbr): Largely at sea
• Lesser black-backed gull (Nbr): Largely at sea
• Black-headed gull (Nbr): Limited risk
• Common Gull (Nbr): Limited risk
• Little gull (Nbr): Largely at sea
• Black-legged kittiwake (Nbr): Largely at sea
• Northern gannet (Nbr): Largely at sea
• Great cormorant (Nbr): Roosts on land throughout non-br
• European shag (Nbr): Roosts on land throughout non-br
• Razorbill (Nbr): Largely at sea
• Common guillemot (Nbr): Largely at sea
• Atlantic puffin (Nbr): Largely at sea

Pressure Name: Intentional taking of adults/chicks/ eggs (licenced control & harvesting)

Exemptions/Justification

• Great black-backed gull: Some licenced/unlicenced cull
• Herring gull : Some licenced/unlicenced cull
• Lesser black-backed gull : Some licenced/unlicenced cull
• Black-headed gull: Some licenced/unlicenced cull
• Common gull : Some licenced/unlicenced cull
• Northern gannet (Br): Licenced harvest on Sula Sgeir
• Great cormorant: Some licenced/unlicenced cull