Seabirds: strategic ornithological compensatory measures: review

11 Glossary and common acronyms

11.1 Glossary: Definitions for key terms used in the report

Biosecurity: Measures to prevent new invasive species arrivals, or re-invasion by previously eliminated invasive species.

Breeding success/productivity: Number of chicks fledged per breeding pair.

Burrow-nesting birds: Birds, such as puffins, petrels, and some species of auklets, excavate burrows in the soil or use pre-existing burrows to nest.

Cliff-nesting birds: Birds. such as Guillemot, Razorbill, and Kittiwake, that lay their eggs on narrow ledges in steep cliffs or rocky ledges along coastal areas.

Compensatory measure: Any type of management intervention that could act to offset an assessed loss or damage to a protected site or population. Specifically, here in terms of compensation under the Habitats Directive for impacts on seabird populations, this includes management interventions that (fully or partially) offset assessed findings of an adverse effect on site integrity to a seabird species as a qualifying feature of an SPA. Compensatory measure is often used as a more general term referring to a potential suite or category of conservation actions. Compensatory measure is synonymous with compensatory measure.

Conservation action: A specific management intervention carried out to deliver a gain and/or recovery of a habitat or population. Specifically, here we refer to those management interventions that have potential to lead to population level gains and/or recovery for a seabird species. Conservation actions have potential to be used as compensatory measures subject to meeting various tests (both relating to efficacy and other factors such as additionality).

Control of invasive species: The ongoing management of an invasive species to minimise its impact on the environment. Control measures aim to maintain a low near zero density of an invasive species; to reduce the population, prevent its spread, or mitigate its effects on native species and ecosystems.

Crevice-nesting birds: Birds, such as shearwaters, petrels (also burrow nesting), and sometimes Razorbills (also cliff-nesting), that lay their eggs in narrow crevices or cavities, often found in rocky cliffs or boulder fields.

Deterrence: In this context, ‘deterrence’ refers to a management action to control avian predators (see Ecological feasibility: Avian predator management). It involves the use of physical objects and/or bioacoustics, along with other methods, to impede avian predators from predating on other species (e.g. seabirds).

Diversionary feeding: The use of food to divert the activity or behaviour of a target species (avian predators) from an action that causes a negative impact on other species (e.g. seabirds and waterbirds), without the intention of increasing the density of the target population.

Eradication of invasive species: The complete and permanent removal of wild populations of an invasive species from a defined area. Eradication efforts aim to eliminate all individuals of the target species, thereby preventing its spread and restoring the ecosystem to its previous state.

Extinction: Global loss of a species.

Extirpation: Loss of a species from part of its global range, e.g. a region or a country. Sometimes also called ‘local extinction’.

Focal seabird species: The seabird species that have been identified as those species that could benefit from the initial list of compensatory measures both due to ecologically and over general likelihood of them requiring compensation for offshore wind impacts. See Table 4.

Google Scholar: A freely accessible web search engine that indexes the full text or metadata of scholarly literature across an array of publishing formats and disciplines.

Ground-nesting birds: Birds such as gulls and some species of terns that lay their eggs on the ground in open areas or rocky outcrops.

Harvest: The act of collecting, capturing, or killing of eggs, chicks or mature individuals for food, sport, or other purposes.

Highly Pathogenic Avian Influenza (HPAI): A highly contagious and highly pathogenic (that is often leading to severe disease including fatal disease) viral agent causing disease. Also known as ‘bird flu’. An outbreak of HPAI caused by a H5NI strain of influenza is affecting wild bird populations globally including seabird populations in the UK, this has been underway since late 2021 and is ongoing at the time of writing (2023).

Invasive alien species: See invasive non-native species.

Invasive non-native species (INNS): Species that have been introduced, either accidentally or deliberately, to a region where they are not present and have serious negative ecological consequences where they establish.

Metapopulation: A group of spatially separated populations of the same species which interact at some level.

Scoping review: Used to broadly characterise the available evidence and to use that evidence to clarify definitions, understand what type of research have been conducted, and understand knowledge gaps around a topic. Specifically in the context of this project this approach is used where no specific conservation actions have been identified corresponding to a compensatory measure, or where many potential actions are identified (with no clearly defined preferred options). These reviews seek to identify potential conservation actions and where possible to evaluate the evidence to support these (though not in a more narrative way than for systematic reviews).

ScotWind: The leasing round ran by Crown Estate Scotland for rights to develop offshore wind projects under the Scottish Government’s Sectoral Marine Plan for Offshore Wind.

Seabird Monitoring Programme (SMP): A coordinated programme of annual seabird monitoring across the UK, the Republic of Ireland, the Channel Islands and the Isle of Man established in 1986.

Search strings: A combination of keywords, truncation symbols, and Boolean operators that are entered into the search box of a library database or search engine.

Special Protection Areas (SPAs): Protected areas for birds in the UK classified under: the Conservation of Habitats and Species Regulations 2017 (as amended) in England and Wales (including the adjacent territorial sea) and to a limited extent in Scotland (reserved matters) and Northern Ireland (excepted matters); The Conservation (Natural Habitats &c.) Regulations 1994 (as amended) in Scotland; the Conservation (Natural Habitats &c.) (Northern Ireland) Regulations 1995 (as amended) in Northern Ireland; the Conservation of Offshore Marine Habitats and Species Regulations 2017 (as amended) in the UK offshore area.

Strategic compensation*: This follows the same general principles as compensatory measures (see ‘compensatory measures’) but is where such measures are to be delivered at scale and/or over extended timeframes, which cannot generally be delivered by individual offshore wind project developers alone. Such measure(s) would usually be led and delivered by a range of organisations, including Government, industry and relevant stakeholders. Strategic compensatory measures would normally be identified at a plan level and applied across multiple offshore wind projects to provide ecologically meaningful compensation to designated site habitats and species adversely impacted, to compensate for identified adverse effects on site integrity, thus to support maintaining the coherence of the site network (SPA or SAC sites). *This definition is adapted from the working definition for strategic compensation developed by the Collaboration of Offshore Wind Strategic Compensation (COWSC).

Sula Sgeir: A small, uninhabited rocky Scottish island in the North Atlantic, 18 kilometres west of Rona. It is one of the most remote islands of the British Isles.

Supplementary feeding: The use of feeding as a conservation method to improve the population viability or density of a particular species or population.

Systematic review: A literature review approach that seeks to provide an objective and valid summary of primary research findings by following a fully documented and pre-planned procedure that is repeatable. In this report this approach is used for compensatory measures where one (or a few) specific conservation actions had been identified initially.

Records: Here we use records to refer to the documents (e.g. research articles, review papers, reports, theses, databases) that arose from the literature searches from Web of Science and Google Scholar, as well as additional references.

Removal: In this context, ‘removal’ refers to a management action to control avian predators (see Ecological feasibility: Avian predator management). It involves the removal of an avian predator’s nest, offspring, and/or mature individuals, employing either lethal or non-lethal means, with the objective of avoiding them from causing further negative effects on other species (e.g. seabirds).

Targeted review: Similar to a Scoping Review, but for where a recent detailed review already exists. In this report this type of review is to put an existing synthesis in context of strategic compensation and supplement with findings from other relevant literature. It seeks to identify which conservation actions are ecologically effective in strategic compensation terms.

Web of Science: A bibliographic database (or search engine) of scholarly articles from >20,000 peer-reviewed journals worldwide. The platform provides tools for advanced search, citation analysis and bibliometrics.

11.2 Common acronyms used in the report

AEOSI: Adverse Effect on Site Integrity

ANOVA: Analysis of Variance

BACI: Before-After-Controlled-Impact

DET: Deterrence techniques used for avian predator management

DF: Diversionary feeding

GAM: Generalised Additive Models

GLM: Generalised Linear Models

HPAI: Highly Pathogenic Avian Influenza

HRA: Habitats Regulation Appraisal

ICES: International Council for the Exploration of the Sea

INTOG: The Scottish Government’s Sectoral Marine Plan for Innovation and Targeted Oil and Gas Decarbonisation.

IUCN: International Union for Conservation of Nature

LMM: Linear Mixed Models

MSY: Maximum Sustainable Yield (fisheries management target)

NAEOSI: No Adverse Effect on Site Integrity

REM: Removal techniques used for avian predator management

OWF: Offshore wind farm

SMP: Seabird Monitoring Programme

SST: Sea Surface Temperature

TAC: Total Allowable Catch

WP: Work package