Impacts of offshore oil spill accidents on island bird communities: A test run study around Orkney and Svalbard archipelagos.

The sea area around the Orkney archipelago, Scotland is subjected to substantial maritime shipping activities. By contract, the Svalbard archipelago, Norway currently has a rather low marine traffic profile. Future projections, however, indicate that the Trans-Arctic route might change the whole transportation picture and Svalbard may be at the centre of maritime activities. Both archipelagos have sensitive environmental resources at sea and inland, including bird communities. There are, for instance, 13 Red Listed species present in Orkney and 2 in Svalbard. In this regard, it is important to address oil spill risks along existing and projected shipping routes. Hypothetical spills were simulated in twelve scenarios for both the Orkney and Svalbard archipelagos with the OpenDrift open-source software. The results indicate risks to seabird communities. For Orkney, the spills resulted in the most extensive contamination of the sea and land environments in autumn. For Svalbard, autumn spills on the contrary presented the lowest risk to seabirds. Based on the simulations, we recommend increased caution for shipping activities in the problematic seasons, improved local readiness for ship accidents and sufficient pre-incident planning.

Tracking the impacts of COVID-19 pandemic-related debris on wildlife using digital platforms.

Since the start of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; COVID-19) pandemic in December 2019, there have been global surges of single-use plastic use. Due to the importance of personal protective equipment (PPE) and sanitation items in protecting against virus transmission and from testing, facemasks, respirators, disposable gloves and disposable wet wipes have become global staples in households and institutions. Widespread use and insufficient infrastructure, combined with improper waste management have resulted in an emerging category of litter. With widespread presence in the environment, such items pose a direct threat to wildlife as animals can interact with them in a series of ways. We examined the scope of COVID-19 pandemic-related debris, including PPE and sanitation items, on wildlife from April 2020 to December 2021. We document the geographic occurrence of incidents, debris types, and consequences of incidents that were obtained from social media searches, unpublished reports from colleagues, and reports available from the citizen science database "Birds and Debris". There were 114 unique sightings of wildlife interactions with pandemic-related debris (38 from 2020 and 76 from 2021). Within the context of this dataset, most incidents involved birds (83.3 %), while fewer affected mammals (10.5 %), invertebrates (3.5 %), fish (1.8 %), and sea turtles (0.9 %). Sightings originated in 23 countries, and consisted mostly of entanglements (42.1 %) and nest incorporations (40.4 %). We verified sightings by contacting the original observers and were able to identify replicated sightings and increase the resolution of the data collected compared with previously published results. Due to the complexities associated with global use and accessibility of digital platforms, we likely underestimate the number of animals harmed by debris. Overall, the global scope of this study demonstrates that online and social media platforms are a valuable way to collect biologically relevant citizen science data and track rapidly emerging environmental challenges.

A standardised method for estimating the level of visible debris in bird nests.

Unlike records of plastic ingestion and entanglement in seabirds which date back to the 1960s, the literature regarding debris in bird nests is comparatively limited. It is important to identify standardised methods early so that data are collected in a consistent manner, ensuring that future studies can be comparable. Here, we outline a method that can be applied to photographs for estimating the proportion of visible debris at the surface of a nest. This method uses ImageJ software to superimpose a grid onto a photograph of a nest/s. The number of cells with and without debris are then counted. Our proposed method is repeatable, straightforward, and accessible. We optimised the method to estimate the level of visible debris in Northern Gannet (Morus bassanus) nests, however, with some modification (i.e., adjustment of grid cell size), it could be applied to other seabird species, and terrestrial birds, that incorporate debris within nests.

Measuring nest incorporation of anthropogenic debris by seabirds: An opportunistic approach increases geographic scope and reduces costs.

Data on the prevalence of anthropogenic debris in seabird nests can be collected alongside other research or through community science initiatives to increase the temporal and spatial scale of data collection. To assess the usefulness of this approach, we collated data on nest incorporation of debris for 14 seabird species from 84 colonies across five countries in northwest Europe. Of 10,274 nests monitored 12% contained debris, however, there was large variation in the proportion of nests containing debris among species and colonies. For several species, the prevalence of debris in nests was significantly related to the mean Human Footprint Index (HFI), a proxy for human impact on the environment, within 100 km of the colony. Collecting opportunistic data on nest incorporation of debris by seabirds provides a cost-effective method of detecting changes in the prevalence of debris in the marine environment across a large geographic scale.

Assessing the effects of tidal stream marine renewable energy on seabirds: A conceptual framework.

We are at a crossroads where many nation states, including the United Kingdom of Great Britain and Northern Ireland (UK), are committing to increased electricity production from "green energy", of which tidal stream marine renewable energy is one such resource. However, many questions remain regarding the effects of tidal energy devices on marine wildlife, including seabirds, of which the UK has internationally important numbers. Guidelines are lacking on how best to use both well-established and novel survey methods to assess seabird use of tidal flow areas, leading to a data-rich but information poor (DRIP) situation. This review provides a conceptual framework for assessing the effects of tidal stream energy devices on seabirds, summarises current knowledge and highlights knowledge gaps. Finally, recommendations are given for how best to pursue knowledge on this topic.

Monitoring nest incorporation of anthropogenic debris by Northern Gannets across their range.

Anthropogenic marine debris is a recognised global issue, which can impact a wide range of organisms. This has led to a rise in research focused on plastic ingestion, but quantitative data on entanglement are still limited, especially regarding seabirds, due to challenges associated with monitoring entanglement in the marine environment. However, for seabird species that build substantial surface nests there is the opportunity to monitor nest incorporation of debris that individuals collect as nesting material. Here, we monitored nest incorporation of anthropogenic marine debris by Northern Gannets (Morus bassanus) from 29 colonies across the species' range to determine a) the frequency of occurrence of incorporated debris and b) whether the Northern Gannet is a suitable indicator species for monitoring anthropogenic debris in the marine environment within their range. Using data obtained from visual observations, digital photography and published literature, we recorded incorporated debris in 46% of 7280 Northern Gannet nests, from all but one of 29 colonies monitored. Significant spatial variation was observed in the frequency of occurrence of debris incorporated into nests among colonies, partly attributed to when the colony was established and local fishing intensity. Threadlike plastics, most likely from fishing activities, was most frequently recorded in nests, being present in 45% of 5842 nests, in colonies where debris type was identified. Comparisons with local beach debris indicate a preference for threadlike plastics by Northern Gannets. Recording debris in gannet nests provides an efficient and non-invasive method for monitoring the effectiveness of actions introduced to reduce debris pollution from fishing activities in the marine environment.

Quantifying avian avoidance of offshore wind turbines: Current evidence and key knowledge gaps.

The risk of collision between birds and turbines is seen as one of the key issues in the planning process for offshore wind farms. In some cases, predictions of collision risk have led to projects either being withdrawn from the planning process, or refused planning consent. Despite this, the evidence base on which collision risk is assessed is extremely limited and assessments rely on models which can be highly sensitive to assumptions, notably about bird collision avoidance behaviour. We present a synthesis of the current state of knowledge about collision risk and avoidance behaviour in seabirds. Evidence suggests species-specific responses to turbines and that in order to avoid collision, most birds adjust their flight paths at some distance from the turbines, rather than making last-second adjustments. We highlight the key gaps in knowledge and make recommendations for future data collection.

Black guillemot ecology in relation to tidal stream energy generation: An evaluation of current knowledge and information gaps.

The black guillemot Cepphus grylle has been identified as a species likely to interact with marine renewable energy devices, specifically tidal turbines, with the potential to experience negative impacts. This likelihood is primarily based on the species being a diving seabird, and an inshore, benthic forager often associating with tidal streams. These behavioural properties may bring them into contact with turbine blades, or make them susceptible to alterations to tidal current speed, and/or changes in benthic habitat structure. We examine the knowledge currently available to assess the potential impacts of tidal stream turbines on black guillemot ecology, highlight knowledge gaps and make recommendations for future research. The key ecological aspects investigated include: foraging movements, diving behaviour, seasonal distribution, other sources of disturbance and colony recovery. Relating to foraging behaviour, between studies there is heterogeneity in black guillemot habitat use in relation to season, tide, diurnal cycles, and bathymetry. Currently, there is also little knowledge regarding the benthic habitats associated with foraging. With respect to diving behaviour, there is currently no available research regarding how black guillemots orientate and manoeuvre within the water column. Black guillemots are considered to be a non-migratory species, however little is known about their winter foraging range and habitat. The effect of human disturbance on breeding habitat and the metapopulation responses to potential mortalities are unknown. It is clear further understanding of black guillemot foraging habitat and behaviour is needed to provide renewable energy developers with the knowledge to sustainably locate tidal turbines and mitigate their impacts.

Seabirds and marine plastic debris in the northeastern Atlantic: A synthesis and recommendations for monitoring and research.

Marine plastic pollution is an increasing, and global, environmental issue. Numerous marine species are affected by plastic debris through entanglement, nest incorporation, and ingestion, which can lead to lethal and sub-lethal impacts. However, in the northeastern Atlantic Ocean, an area of international importance for seabirds, there has been little effort to date to assess information from studies of wildlife and plastic to better understand the spatiotemporal variation of how marine plastic affects different seabird species. To improve our understanding of seabirds and marine plastic in this region, we completed a synthesis of the published and grey literature to obtain information on all known documented cases of plastic ingestion and nest incorporation by this group. We found that of 69 seabird species that commonly occur in the northeastern Atlantic, 25 had evidence of ingesting plastic. However, data on plastic ingestion was available for only 49% of all species, with 74% of investigated species recorded ingesting plastic. We found only three published studies on nest incorporation, for the Northern Gannet (Morus bassanus) and Black-legged Kittiwake (Rissa tridactyla). For many species, sample sizes were small or not reported, and only 39% of studies were from the 21st century, whilst information from multiple countries and years was only available for 11 species. This indicates that we actually know very little about the current prevalence of plastic ingestion and nest incorporation for many species, several of them globally threatened. Furthermore, in the majority of studies, the metrics reported were inadequate to carry out robust comparisons among locations and species or perform meta-analyses. We recommend multi-jurisdictional collaboration to obtain a more comprehensive and current understanding of how marine plastic is affecting seabirds in the northeastern Atlantic Ocean.

Assessing vulnerability of marine bird populations to offshore wind farms.

Offshore wind farms may affect bird populations through collision mortality and displacement. Given the pressures to develop offshore wind farms, there is an urgent need to assess population-level impacts on protected marine birds. Here we refine an approach to assess aspects of their ecology that influence population vulnerability to wind farm impacts, also taking into account the conservation importance of each species. Flight height appears to be a key factor influencing collision mortality risk but improved data on flight heights of marine birds are needed. Collision index calculations identify populations of gulls, white-tailed eagles, northern gannets and skuas as of particularly high concern in Scottish waters. Displacement index calculations identify populations of divers and common scoters as most vulnerable to population-level impacts of displacement, but these are likely to be less evident than impacts of collision mortality. The collision and displacement indices developed here for Scottish marine bird populations could be applied to populations elsewhere, and this approach will help in identifying likely impacts of future offshore wind farms on marine birds and prioritising monitoring programmes, at least until data on macro-avoidance rates become available.

Assessing the impact of marine wind farms on birds through movement modelling.

Advances in technology and engineering, along with European Union renewable energy targets, have stimulated a rapid growth of the wind power sector. Wind farms contribute to carbon emission reductions, but there is a need to ensure that these structures do not adversely impact the populations that interact with them, particularly birds. We developed movement models based on observed avoidance responses of common eider Somateria mollissima to wind farms to predict, and identify potential measures to reduce, impacts. Flight trajectory data that were collected post-construction of the Danish Nysted offshore wind farm were used to parameterize competing models of bird movements around turbines. The model most closely fitting the observed data incorporated individual variation in the minimum distance at which birds responded to the turbines. We show how such models can contribute to the spatial planning of wind farms by assessing their extent, turbine spacing and configurations on the probability of birds passing between the turbines. Avian movement models can make new contributions to environmental assessments of wind farm developments, and provide insights into how to reduce impacts that can be identified at the planning stage.

Barriers to movement: Modelling energetic costs of avoiding marine wind farms amongst breeding seabirds.

Proposals for wind farms in areas of known importance for breeding seabirds highlight the need to understand the impacts of these structures. Using an energetic modelling approach, we examine the effects of wind farms as barriers to movement on seabirds of differing morphology. Additional costs, expressed in relation to typical daily energetic expenditures, were highest per unit flight for seabirds with high wing loadings, such as cormorants. Taking species-specific differences into account, costs were relatively higher in terns, due to the high daily frequency of foraging flights. For all species, costs of extra flight to avoid a wind farm appear much less than those imposed by low food abundance or adverse weather, although such costs will be additive to these. We conclude that adopting a species-specific approach is essential when assessing the impacts of wind farms on breeding seabird populations, to fully anticipate the effects of avoidance flights.