An ecologically sound and participatory monitoring network for pan-Arctic seabirds.

In a warming Arctic, circumpolar long-term monitoring programs are key to advancing ecological knowledge and informing environmental policies. Calls for better involvement of Arctic peoples in all stages of the monitoring process are widespread, although such transformation of Arctic science is still in its infancy. Seabirds stand out as ecological sentinels of environmental changes, and priority has been given to implement the Circumpolar Seabird Monitoring Plan (CSMP). We assessed the representativeness of a pan-Arctic seabird monitoring network focused on the black-legged kittiwake (Rissa tridactyla) by comparing the distribution of environmental variables for all known versus monitored colonies. We found that with respect to its spatiotemporal coverage, this monitoring network does not fully embrace current and future environmental gradients. To improve the current scheme, we designed a method to identify colonies whose inclusion in the monitoring network will improve its ecological representativeness, limit logistical constraints, and improve involvement of Arctic peoples. We thereby highlight that inclusion of study sites in the Bering Sea, Siberia, western Russia, northern Norway, and southeastern Greenland could improve the current monitoring network and that their proximity to local populations might allow increased involvement of local communities. Our framework can be applied to improve existing monitoring networks in other ecoregions and sociological contexts.

Una red de monitoreo participativa y ecológica para las aves marinas del Ártico Resumen En un Ártico cada vez más cálido, los programas circumpolares de monitoreo a largo plazo son importantes para potenciar el conocimiento ecológico e informar las políticas ambientales. Existe un llamado generalizado para involucrar de mejor manera a los pueblos árticos en el proceso de monitoreo, aunque dicha transformación de la ciencia ártica todavía está en desarrollo. Las aves marinas resaltan como centinelas del cambio ambiental y se ha priorizado implementar el Plan Circumpolar de Monitoreo de Aves Marinas (CSMP). Comparamos la distribución de las variables ambientales de todas las colonias conocidas de la gaviota tridáctila (Rissa tridactyla) contra las colonias monitoreadas para evaluar la representación de una red pan­ártica de monitoreo enfocada en esta especie. Encontramos que esta red de monitoreo no considera del todo los gradientes ambientales actuales y futuros con respecto a la cobertura espaciotemporal. Para mejorar el esquema actual, diseñamos un método para identificar las colonias cuya inclusión en la red de monitoreo mejorará su representación ecológica, limitará las restricciones logísticas e incrementará la participación de los pueblos árticos. Por lo tanto, resaltamos que la inclusión de los sitios de estudio en el Mar de Bering, Siberia, Rusia occidental, el norte de Noruega y el sureste de Groenlandia mejorarían la red actual de monitoreo. También destacamos que la proximidad de los sitios de estudio con las poblaciones locales podría permitir una mayor participación de estas. Nuestro marco puede aplicarse para mejorar las redes de monitoreo existentes en otros contextos socioecológicos y ecoregiones.

Spatial distribution of selenium-mercury in Arctic seabirds.

Mercury (Hg) is a metallic trace element toxic for humans and wildlife that can originate from natural and anthropic sources. Hg spatial gradients have been found in seabirds from the Arctic and other oceans, suggesting contrasting toxicity risks across regions. Selenium (Se) plays a protective role against Hg toxicity, but its spatial distribution has been much less investigated than that of Hg. From 2015 to 2017, we measured spatial co-exposure of Hg and Se in blood samples of two seabird species, the Brünnich's guillemot (Uria lomvia) and the black-legged kittiwake (Rissa tridactyla) from 17 colonies in the Arctic and subarctic regions, and we calculated their molar ratios (Se:Hg), as a measure of Hg sequestration by Se and, therefore, of Hg exposure risk. We also evaluated concentration differences between species and ocean basins (Pacific-Arctic and Atlantic-Arctic), and examined the influence of trophic ecology on Hg and Se concentrations using nitrogen and carbon stable isotopes. In the Atlantic-Arctic ocean, we found a negative west-to-east gradient of Hg and Se for guillemots, and a positive west-to-east gradient of Se for kittiwakes, suggesting that these species are better protected from Hg toxicity in the European Arctic. Differences in Se gradients between species suggest that they do not follow environmental Se spatial variations. This, together with the absence of a general pattern for isotopes influence on trace element concentrations, could be due to foraging ecology differences between species. In both oceans, the two species showed similar Hg concentrations, but guillemots showed lower Se concentrations and Se:Hg than kittiwakes, suggesting a higher Hg toxicity risk in guillemots. Within species, neither Hg, nor Se or Se:Hg differed between both oceans. Our study highlights the importance of considering Se together with Hg, along with different species and regions, when evaluating Hg toxic effects on marine predators in international monitoring programs.

Quantifying marine traffic intensity in Northwest Greenland and the potential disturbance of two seabird colonies.

Marine traffic poses a growing threat to wildlife in the marine environment, including Arctic seabirds, which are exposed to high vessel densities when breeding in coastal areas. However, little is known about the magnitude of the problem. Here, we utilized underwater acoustic monitoring to quantify marine traffic and above-water disturbances at two thick-billed murre colonies in Greenland in 2016. We detected a total of 307 vessels, and only 4 % was known from automatic monitoring systems. Based on proximity, noise emission, and boating behavior, we classified 11 vessels as disturbing and an additional 12 as potentially disturbing for the seabirds. One colony facing population decline was located closest to the main boating route and experienced 2-5 times more disturbances than the other (increasing) colony, suggesting a negative impact of marine traffic. Our study shows that underwater acoustics can be a useful method to quantify above-water disturbances of seabird colonies.

Bycatch mitigation in the West Greenland lumpfish (Cyclopterus lumpus) fishery using modified gillnets.

Bycatch in gillnets is a global issue and mitigation measures that balance target species catch rates, bycatch reduction and fisher support are scarce. In the North Atlantic lumpfish fisheries, bycatch includes marine mammals and seabirds, and there are no permanent technical initiatives to reduce the bycatch. In the West Greenland fishery, common eider bycatch is several thousand individuals annually. We explored if bycatch in this fishery could be reduced by modifying standard lumpfish gillnets by adding a 45 cm high small-meshed net panel to the bottom part of the net. We tested the nets in combination with standard nets and estimated catch rates in a controlled setting in 2021 and in the commercial fishery in 2022. The modified nets had a 71% reduced bycatch rate for common eider and a 25% reduced catch rate for female lumpfish. A combination of the panel and increased seaweed entanglement was the most likely explanation for the effect. In addition to the effect of the net modification, the common eider bycatch decreased significantly during the season, and we recommend studying the net effect further and exploring the option of postponing the fishing season as a simpler way of reducing bycatch.

Foraging range scales with colony size in high-latitude seabirds.

Density-dependent prey depletion around breeding colonies has long been considered an important factor controlling the population dynamics of colonial animals.1-4 Ashmole proposed that as seabird colony size increases, intraspecific competition leads to declines in reproductive success, as breeding adults must spend more time and energy to find prey farther from the colony.1 Seabird colony size often varies over several orders of magnitude within the same species and can include millions of individuals per colony.5,6 As such, colony size likely plays an important role in determining the individual behavior of its members and how the colony interacts with the surrounding environment.6 Using tracking data from murres (Uria spp.), the world's most densely breeding seabirds, we show that the distribution of foraging-trip distances scales to colony size0.33 during the chick-rearing stage, consistent with Ashmole's halo theory.1,2 This pattern occurred across colonies varying in size over three orders of magnitude and distributed throughout the North Atlantic region. The strong relationship between colony size and foraging range means that the foraging areas of some colonial species can be estimated from colony sizes, which is more practical to measure over a large geographic scale. Two-thirds of the North Atlantic murre population breed at the 16 largest colonies; by extrapolating the predicted foraging ranges to sites without tracking data, we show that only two of these large colonies have significant coverage as marine protected areas. Our results are an important example of how theoretical models, in this case, Ashmole's version of central-place-foraging theory, can be applied to inform conservation and management in colonial breeding species.

Mercury contamination and potential health risks to Arctic seabirds and shorebirds.

Since the last Arctic Monitoring and Assessment Programme (AMAP) effort to review biological effects of mercury (Hg) on Arctic biota in 2011 and 2018, there has been a considerable number of new Arctic bird studies. This review article provides contemporary Hg exposure and potential health risk for 36 Arctic seabird and shorebird species, representing a larger portion of the Arctic than during previous AMAP assessments now also including parts of the Russian Arctic. To assess risk to birds, we used Hg toxicity benchmarks established for blood and converted to egg, liver, and feather tissues. Several Arctic seabird populations showed Hg concentrations that exceeded toxicity benchmarks, with 50 % of individual birds exceeding the "no adverse health effect" level. In particular, 5 % of all studied birds were considered to be at moderate or higher risk to Hg toxicity. However, most seabirds (95 %) were generally at lower risk to Hg toxicity. The highest Hg contamination was observed in seabirds breeding in the western Atlantic and Pacific Oceans. Most Arctic shorebirds exhibited low Hg concentrations, with approximately 45 % of individuals categorized at no risk, 2.5 % at high risk category, and no individual at severe risk. Although the majority Arctic-breeding seabirds and shorebirds appeared at lower risk to Hg toxicity, recent studies have reported deleterious effects of Hg on some pituitary hormones, genotoxicity, and reproductive performance. Adult survival appeared unaffected by Hg exposure, although long-term banding studies incorporating Hg are still limited. Although Hg contamination across the Arctic is considered low for most bird species, Hg in combination with other stressors, including other contaminants, diseases, parasites, and climate change, may still cause adverse effects. Future investigations on the global impact of Hg on Arctic birds should be conducted within a multi-stressor framework. This information helps to address Article 22 (Effectiveness Evaluation) of the Minamata Convention on Mercury as a global pollutant.

North Atlantic winter cyclones starve seabirds.

Each winter, the North Atlantic Ocean is the stage for numerous cyclones, the most severe ones leading to seabird mass-mortality events called "winter wrecks."1-3 During these, thousands of emaciated seabird carcasses are washed ashore along European and North American coasts. Winter cyclones can therefore shape seabird population dynamics4,5 by affecting survival rates as well as the body condition of surviving individuals and thus their future reproduction. However, most often the geographic origins of impacted seabirds and the causes of their deaths remain unclear.6 We performed the first ocean-basin scale assessment of cyclone exposure in a seabird community by coupling winter tracking data for ∼1,500 individuals of five key North Atlantic seabird species (Alle alle, Fratercula arctica, Uria aalge, Uria lomvia, and Rissa tridactyla) and cyclone locations. We then explored the energetic consequences of different cyclonic conditions using a mechanistic bioenergetics model7 and tested the hypothesis that cyclones dramatically increase seabird energy requirements. We demonstrated that cyclones of high intensity impacted birds from all studied species and breeding colonies during winter but especially those aggregating in the Labrador Sea, the Davis Strait, the surroundings of Iceland, and the Barents Sea. Our broad-scale analyses suggested that cyclonic conditions do not increase seabird energy requirements, implying that they die because of the unavailability of their prey and/or their inability to feed during cyclones. Our study provides essential information on seabird cyclone exposure in a context of marked cyclone regime changes due to global warming.8.

Meeting Paris agreement objectives will temper seabird winter distribution shifts in the North Atlantic Ocean.

We explored the implications of reaching the Paris Agreement Objective of limiting global warming to <2°C for the future winter distribution of the North Atlantic seabird community. We predicted and quantified current and future winter habitats of five North Atlantic Ocean seabird species (Alle alle, Fratercula arctica, Uria aalge, Uria lomvia and Rissa tridactyla) using tracking data for ~1500 individuals through resource selection functions based on mechanistic modeling of seabird energy requirements, and a dynamic bioclimate envelope model of seabird prey. Future winter distributions were predicted to shift with climate change, especially when global warming exceed 2°C under a "no mitigation" scenario, modifying seabird wintering hotspots in the North Atlantic Ocean. Our findings suggest that meeting Paris agreement objectives will limit changes in seabird selected habitat location and size in the North Atlantic Ocean during the 21st century. We thereby provide key information for the design of adaptive marine-protected areas in a changing ocean.

Seasonal variation of mercury contamination in Arctic seabirds: A pan-Arctic assessment.

Mercury (Hg) is a natural trace element found in high concentrations in top predators, including Arctic seabirds. Most current knowledge about Hg concentrations in Arctic seabirds relates to exposure during the summer breeding period when researchers can easily access seabirds at colonies. However, the few studies focused on winter have shown higher Hg concentrations during the non-breeding period than breeding period in several tissues. Hence, improving knowledge about Hg exposure during the non-breeding period is crucial to understanding the threats and risks encountered by these species year-round. We used feathers of nine migratory alcid species occurring at high latitudes to study bird Hg exposure during both the breeding and non-breeding periods. Overall, Hg concentrations during the non-breeding period were ~3 times higher than during the breeding period. In addition, spatial differences were apparent within and between the Atlantic and Pacific regions. While Hg concentrations during the non-breeding period were ~9 times and ~3 times higher than during the breeding period for the West and East Atlantic respectively, Hg concentrations in the Pacific during the non-breeding period were only ~1.7 times higher than during the breeding period. In addition, individual Hg concentrations during the non-breeding period for most of the seabird colonies were above 5 µg g-1 dry weight (dw), which is considered to be the threshold at which deleterious effects are observed, suggesting that some breeding populations might be vulnerable to non-breeding Hg exposure. Since wintering area locations, and migration routes may influence seasonal Hg concentrations, it is crucial to improve our knowledge about spatial ecotoxicology to fully understand the risks associated with Hg contamination in Arctic seabirds.

210Po and 210Pb activity concentrations in Greenlandic seabirds and dose assessment.

Naturally occurring radionuclides, in particular, polonium-210 (210Po), have a greater contribution than anthropogenic radionuclides to the annual effective dose received by the general public due to consumption of seafood. Knowledge of potential trophic sources and transfer of 210Po to seabird species and subsequently to the Greenlandic people is, however, still poor. Here, we assess the transfer of 210Po and 210Pb to seabirds sampled during autumn and winter 2017 and 2018 in Greenland and provide a dose assessment. The activity concentrations of 210Po in muscle and liver, respectively, ranged from 0.2 ± 0.1 Bq kg-1 w.w. in glaucous gull (Larus hyperboreus) to 21.2 ± 22.6 Bq kg-1 w.w. in thick-billed murre (Uria lomvia) and from 32.0 ± 9.4 Bq kg-1 w.w. in common eider (Somateria mollissima) to 40.5 ± 49.0 Bq kg-1 w.w. in thick-billed murre. 210Po was non-uniformly distributed in the body of thick-billed murre. Kidneys and feathers showed higher 210Po activity concentrations than heart and bone. The 210Po/210Pb activity concentration ratios are higher than unity, indicating that 210Po is preferentially taken up by seabirds compared to its progenitor 210Pb. The derived annual absorbed dose from 210Po to the whole body of thick-billed murre was 6.4 × 102 ± 3.0 × 102 µGy. The annual effective dose to the average adult and representative person in Greenland due to ingestion of 210Po in seabirds was estimated to 13.0 µSv and 57.0 µSv, respectively. This derived dose is low and poses a slight risk, and risk communication is therefore deemed unnecessary.

Melatonin and corticosterone profiles under polar day in a seabird with sexually opposite activity-rhythms.

The 24 h geophysical light-dark cycle is the main organizer of daily rhythms, scheduling physiology and behavior. This cycle attenuates greatly during the continuous light of summer at polar latitudes, resulting in species-specific and even individual-specific patterns of behavioral rhythmicity, but the physiological mechanisms underlying this variation are poorly understood. To address this knowledge gap and to better understand the roles of the hormones melatonin and corticosterone in rhythmic behavior during this 'polar day', we exploited the behavior of thick-billed murres (Uria lomvia), a charadriiform seabird with sexually opposite ('antiphase') activity-rhythms that have a duration of 24 h. Melatonin concentration in the plasma of inactive males was unexpectedly high around midday and subsequently fell during a sudden decrease in light intensity as the colony became shaded. Corticosterone concentration in plasma did not vary with time of day or activity in either sex. While the reasons for these unusual patterns remain unclear, we propose that a flexible melatonin response and little diel variation of corticosterone may be adaptive in thick-billed murres, and perhaps other polar birds and mammals, by stabilizing glucocorticoids' role of modulating energy storage and mobilization across the diel cycle and facilitating the appropriate reaction to unexpected stimuli experienced across the diel cycle while attending the colony.

Helminths in common eiders (Somateria mollissima): Sex, age, and migration have differential effects on parasite loads.

In birds, parasites cause detrimental effects to the individual host, including reduced survival and reproductive output. The level of parasitic infection can vary with a range of factors, including migratory status, body size, sex, and age of hosts, or season. Understanding this baseline variation is important in order to identify the effects of external changes such as climate change on the parasitic load and potential impacts to individuals and populations. In this study, we compared the infection level (prevalence, intensity, and abundance) of gastrointestinal parasites in a total of 457 common eiders (Somateria mollissima) from four different sampling locations (Belcher Islands, Cape Dorset, West Greenland and Newfoundland), and explored the effects of migration, sex and age on levels of parasitism. Across all samples, eiders were infected with one nematode genus, two acanthocephalan genera, three genera of cestodes, and three trematode genera. Migratory phase and status alone did not explain the observed variation in infection levels; the expectation that post-migratory eiders would be more parasitized than pre-migratory eiders, due to the energetic cost of migration, did not fit our results. No effect of age was detected, whereas effects of sex and body size were only detected for certain parasitic taxa and was inconsistent with location. Since gastrointestinal helminths are trophically-transmitted, future studies of the regional and temporal variation in the diet of eiders and the associated variation and infestation level of intermediate hosts might further explain the observed variation of the parasitic load in eiders in different regions.

Modelling demographic impacts of a growing Arctic fishery on a seabird population in Canada and Greenland.

In Baffin Bay and Davis Strait, reports indicate that Northern Fulmars (Fulmarus glacialis) are vulnerable to bycatch in the fisheries for Greenland Halibut (Reinhardtius hippoglossoides). We modeled the potential current and future impacts the expanding halibut fishery may have on fulmar populations in the region using population viability analysis. By varying age-specific bycatch vulnerability, detectability, and the size of the at-risk population, we tested how different scenarios may influence population trajectories. From 2011 to 2015, the bycatch rate of fulmars was approximately 212 (SD ±â€¯111) individuals per year. This could cause declines (-12%) over three generations (66 years) at the three colonies closest to the fishing grounds. However, declines could be as high as -33% over this same period if unobservable bycatch is considered, and as low as -0.4% if bycatch is distributed among a larger population. Several uncertainties we modeled could be reduced by improving how bycatch data are recorded by at-sea observer programs.

Stable isotopes can be used to infer the overwintering locations of prebreeding marine birds in the Canadian Arctic.

Although assessments of winter carryover effects on fitness-related breeding parameters are vital for determining the links between environmental variation and fitness, direct methods of determining overwintering distributions (e.g., electronic tracking) can be expensive, limiting the number of individuals studied. Alternatively, stable isotope analysis in specific tissues can be used as an indirect means of determining individual overwintering areas of residency. Although increasingly used to infer the overwintering distributions of terrestrial birds, stable isotopes have been used less often to infer overwintering areas of marine birds. Using Arctic-breeding common eiders, we test the effectiveness of an integrated stable isotope approach (13-carbon, 15-nitrogen, and 2-hydrogen) to infer overwintering locations. Knowing the overwinter destinations of eiders from tracking studies at our study colony at East Bay Island, Nunavut, we sampled claw and blood tissues at two known overwintering locations, Nuuk, Greenland, and Newfoundland, Canada. These two locations yielded distinct tissue-specific isotopic profiles. We then compared the isotope profiles of tissues collected from eiders upon their arrival at our breeding colony, and used a k-means cluster analysis approach to match arriving eiders to an overwintering group. Samples from the claws of eiders were most effective for determining overwinter origin, due to this tissue's slow growth rate relative to the 40-day turnover rate of blood. Despite taking an integrative approach using multiple isotopes, k-means cluster analysis was most effective when using 13-carbon alone to assign eiders to an overwintering group. Our research demonstrates that it is possible to use stable isotope analysis to assign an overwintering location to a marine bird. There are few examples of the effective use of this technique on a marine bird at this scale; we provide a framework for applying this technique to detect changes in the migration phenology of birds' responses to rapid changes in the Arctic.

Circumpolar dynamics of a marine top-predator track ocean warming rates.

Global warming is a nonlinear process, and temperature may increase in a stepwise manner. Periods of abrupt warming can trigger persistent changes in the state of ecosystems, also called regime shifts. The responses of organisms to abrupt warming and associated regime shifts can be unlike responses to periods of slow or moderate change. Understanding of nonlinearity in the biological responses to climate warming is needed to assess the consequences of ongoing climate change. Here, we demonstrate that the population dynamics of a long-lived, wide-ranging marine predator are associated with changes in the rate of ocean warming. Data from 556 colonies of black-legged kittiwakes Rissa tridactyla distributed throughout its breeding range revealed that an abrupt warming of sea-surface temperature in the 1990s coincided with steep kittiwake population decline. Periods of moderate warming in sea temperatures did not seem to affect kittiwake dynamics. The rapid warming observed in the 1990s may have driven large-scale, circumpolar marine ecosystem shifts that strongly affected kittiwakes through bottom-up effects. Our study sheds light on the nonlinear response of a circumpolar seabird to large-scale changes in oceanographic conditions and indicates that marine top predators may be more sensitive to the rate of ocean warming rather than to warming itself.

Variation in Growth Drives the Duration of Parental Care: A Test of Ydenberg's Model.

The duration of parental care in animals varies widely, from none to lifelong. Such variation is typically thought to represent a trade-off between growth and safety. Seabirds show wide variation in the age at which offspring leave the nest, making them ideal to test the idea that a trade-off between high energy gain at sea and high safety at the nest drives variation in departure age (Ydenberg's model). To directly test the model assumptions, we attached time-depth recorders to murre parents (fathers [which do all parental care at sea] and mothers; [Formula: see text] of each). Except for the initial mortality experienced by chicks departing from the colony, the mortality rate at sea was similar to the mortality rate at the colony. However, energy gained by the chick per day was ∼2.1 times as high at sea compared with at the colony because the father spent more time foraging, since he no longer needed to spend time commuting to and from the colony. Compared with the mother, the father spent ∼2.6 times as much time diving per day and dived in lower-quality foraging patches. We provide a simple model for optimal departure date based on only (1) the difference in growth rate at sea relative to the colony and (2) the assumption that transition mortality from one life-history stage to the other is size dependent. Apparently, large variation in the duration of parental care can arise simply as a result of variation in energy gain without any trade-off with safety.

Sex-specific, inverted rhythms of breeding-site attendance in an Arctic seabird.

In contrast to daily rhythms that are common in the presence of the geophysical light-dark cycle, organisms at polar latitudes exhibit many diel activity patterns during natural periods of continuous solar light or darkness (polar day and night, respectively), from 24 h rhythms to arrhythmicity. In Arctic Greenland (73.7° N, 56.6° W) during polar day, we observed breeding-site attendance rhythms of thick-billed murres (Uria lomvia; n = 21 pairs), a charadriiform seabird, which provide biparental care at the colony. We found that U. lomvia egg-incubation and chick-brooding attendance is rhythmic and synchronized to the geophysical day (mean period length [rhythm duration] ± 95% confidence interval = 24.13 ± 0.52 h). Individual pair members had temporally segregated, sex-specific colony-attendance rhythms that were opposite (inverted) to each other, and these sex-specific rhythms were prominent at the population level. Our results provide a basis for investigating circadian systems at polar latitudes and sex-specific parental-care strategies.

First Characterization of Avian Influenza Viruses from Greenland 2014.

In late February 2014, unusually high numbers of wild thick-billed murres (Uria lomvia) were found dead on the coast of South Greenland. To investigate the cause of death, 45 birds were submitted for laboratory examination in Denmark. Avian influenza viruses (AIVs) with subtypes H11N2 and low pathogenic H5N1 were detected in some of the birds. Characterization of the viruses by full genome sequencing revealed that all the gene segments belonged to the North American lineage of AIVs. The seemingly sparse and mixed subtype occurrence of low pathogenic AIVs in these birds, in addition to the emaciated appearance of the birds, suggests that the murre die-off was due to malnutrition as a result of sparse food availability or inclement weather. Here we present the first characterization of AIVs isolated in Greenland, and our results support the idea that wild birds in Greenland may be involved in the movement of AIV between North America and Europe.

Prevalence of marine debris in marine birds from the North Atlantic.

Marine birds have been found to ingest plastic debris in many of the world's oceans. Plastic accumulation data from necropsies findings and regurgitation studies are presented on 13 species of marine birds in the North Atlantic, from Georgia, USA to Nunavut, Canada and east to southwest Greenland and the Norwegian Sea. Of the species examined, the two surface plungers (great shearwaters Puffinus gravis; northern fulmars Fulmarus glacialis) had the highest prevalence of ingested plastic (71% and 51%, respectively). Great shearwaters also had the most pieces of plastics in their stomachs, with some individuals containing as many of 36 items. Seven species contained no evidence of plastic debris. Reporting of baseline data as done here is needed to ensure that data are available for marine birds over time and space scales in which we see changes in historical debris patterns in marine environments (i.e. decades) and among oceanographic regions.

Light-induced bird strikes on vessels in Southwest Greenland.

Light-induced bird strikes are known to occur when vessels navigate during darkness in icy waters using powerful searchlight. In Southwest Greenland, which is important internationally for wintering seabirds, we collected reports of incidents of bird strikes over 2-3 winters (2006-2009) from navy vessels, cargo vessels and trawlers (total n=19). Forty-one incidents were reported: mainly close to land (<4 km, 78%), but one as far offshore as 205 km. Up to 88 birds were reported killed in a single incident. All occurred between 5p.m. and 6a.m. and significantly more birds were involved when visibility was poor (snow) rather than moderate or good. Among five seabird species reported, the common eider (Somateria mollissima) accounted for 95% of the bird casualties. Based on spatial analyses of data on vessel traffic intensity and common eider density we are able to predict areas with high risk of bird strikes in Southwest Greenland.