Beach litter sources around Nuuk, Greenland: An analysis by UArctic summer school graduate course students

Modeling studies illustrate the potential for long-range transport of plastics into the Arctic, although the degree to which this occurs remains relatively undocumented. We utilised a teaching exercise at a UArctic summer school graduate course in Nuuk, Greenland to conduct a preliminary in-depth analysis of beach litter sources in the Nuup Kangerlua fjord. Students and instructors collected and analysed 1800 litter items weighing 200 kg from one location in the fjord and another at its mouth. The results suggest a predominance of local sources to macrolitter, rather than long-range transport from Europe. Fisheries-related items and rope were common. Packaging which could be identified was largely suspected to be products distributed in Greenland, and soft plastics, which rarely disperse far from its source, were also common. The results suggest local measures to reduce mismanaged waste and emissions from fisheries are important for reducing marine litter in West Greenland.

Current levels of microplastic pollution impact wild seabird gut microbiomes

Microplastics contaminate environments worldwide and are ingested by numerous species, whose health is affected in multiple ways. A key dimension of health that may be affected is the gut microbiome, but these effects are relatively unexplored. Here, we investigated if microplastics are associated with changes in proventricular and cloacal microbiomes in two seabird species that chronically ingest microplastics: northern fulmars and Cory's shearwaters. The amount of microplastics in the gut was significantly correlated with gut microbial diversity and composition: microplastics were associated with decreases in commensal microbiota and increases in (zoonotic) pathogens and antibiotic-resistant and plastic-degrading microbes. These results illustrate that environmentally relevant microplastic concentrations and mixtures are associated with changes in gut microbiomes in wild seabirds.

Co-contaminants of microplastics in two seabird species from the Canadian Arctic

Through ingestion and subsequent egestion, Arctic seabirds can bioaccumulate microplastics at and around their colony breeding sites. While microplastics in Arctic seabirds have been well documented, it is not yet understood to what extent these particles can act as transport vehicles for plastic-associated contaminants, including legacy persistent organic pollutants (POPs), trace metals, and organic additives. We investigated the occurrence and pattern of organic and inorganic co-contaminants of microplastics in two seabird species from the Canadian Arctic - northern fulmar (Fulmarus glacialis) and black-legged kittiwake (Rissa tridactyla). We found that fulmars had higher levels of plastic contamination and emerging organic compounds (known to be plastic additives) than kittiwakes, whereas higher concentrations of legacy POPs were found in kittiwakes than the fulmars. Furthermore, fulmars, the species with the much larger foraging range (∼200 km), had higher plastic pollution and overall contaminant burdens, indicating that birds may be acting as long-range transport vectors for plastic-associated pollution. Our results suggest a potential connection between plastic additive contamination and plastic pollution burdens in the bird stomachs, highlighting the importance of treating plastic particles and plastic-associated organic additives as co-contaminants rather than separate pollution issues.

A rapid assessment technique for coastal plastic debris sampling: Applications for remote regions and community science

Marine debris is an environmental issue of increasing importance worldwide, with 80% of marine plastics estimated to originate from land-based sources. While much work has been conducted to quantify plastics in coastal environments, many of these approaches are site-specific and not amenable to rapid surveys. We surveyed beaches around Nova Scotia, Canada for plastic and other anthropogenic debris to: 1) quantify debris density on the high tide line; and 2) test a rapid survey technique using digital photos, with applications for community science and remote regions. Most (72%) beaches in Nova Scotia contained debris, but plastic densities along the daily high tide line were relatively low (mean 0.2 debris/m²) with little interannual variation. Despite small differences in plastic densities between observers, this rapid assessment technique appears viable for relative quantification and monitoring of plastic debris on beaches across large geographic scales to assess trends and sources.

First evidence of diverging migration and overwintering strategies in glaucous gulls (Larus hyperboreus) from the Canadian Arctic

Many seabird populations differ in their migration strategies, where individuals travel in different directions to separate wintering areas. These migratory strategies may expose individuals to different threats, thus understanding migratory connectivity is crucial to assess risks to populations. Glaucous gulls (Larus hyperboreus) are generalist predators with flexible migratory behaviour that may alter these behaviours in response to climate change and anthropogenic activities, such as access to landfills, yet little is known about their migration. We deployed GPS and GLS tracking devices on glaucous gulls from Coats Island, Nunavut, Canada to obtain the first insights into their migration and habitat use outside of the breeding season. Gulls used two migration strategies during the non-breeding season, where one migrated as far as the Sea of Okhotsk in the Pacific and the remainder (n = 7) wintered in the North Atlantic. Gulls primarily overwintered in pelagic (56%) and coastal (38%) habitats. While in coastal habitats, one gull visited one landfill once, but visits increased with a 1 km and 3 km buffer, suggesting that urban glaucous gulls primarily used non-landfill habitats. This research can be used as a baseline to explore changes in migratory behaviour and inform future conservation of Arctic-breeding gulls.

Inter-individual variation in the migratory behaviour of a generalist seabird, the herring gull (Larus smithsoniansus), from the Canadian Arctic

The Arctic is warming three times faster than the rest of the globe, causing rapid transformational changes in Arctic ecosystems. As these changes increase, understanding seabird movements will be important for predicting how they respond to climate change, and thus how we plan for conservation. Moreover, as most Arctic-breeding seabirds only spend the breeding season in the Arctic, climate change may also affect them through habitat changes in their non-breeding range. We used Global Location Sensors (GLS) to provide new insights on the movement of Arctic-breeding herring gulls (Larus smithsoniansus) in North America. We tracked gulls that wintered in the Gulf of Mexico (n = 7) or the Great Lakes (n = 1), and found that migratory routes and stopover sites varied between individuals, and between southbound and northbound migration. This inter-individual variation suggests that herring gulls, as a generalist species, can make use of an array of regions during migration, but may be more susceptible to climate change impacts in their overwintering locations than during migration. However, due to our limited sample size, future, multi-year studies are recommended to better understand the impacts of climate change on this Arctic-breeding seabird.

Annual plastic ingestion and isotopic niche patterns of two sympatric gull species at Newfoundland, Canada

Ingestion of plastic pollution by pelagic seabirds is well-documented globally, but increasingly, researchers are investigating plastic ingestion in generalist predators and scavengers like gulls. We studied the gut contents of two sympatric gull species, American herring gulls (Larus smithsoniansus) and great black-backed gulls (L. marinus), collected year-round as part of "kill-to-scare" measures at the regional sanitary landfill in St. John's, Newfoundland and Labrador, Canada, to compare ingested anthropogenic debris, trophic position and diet breadth through the year. Although great black-backed gulls fed at a higher trophic level, frequency of occurrence of plastic ingestion was similar to American herring gulls, and varied little through the year. Diet breadth (isotopic niche size) was similar between species, but American herring gulls fed at a lower trophic level during winter, perhaps indicating a change in their reliance on anthropogenic food subsidies throughout their annual cycle.

Breeding seabirds as vectors of microplastics from sea to land: Evidence from colonies in Arctic Canada

The presence and persistence of microplastics in the environment is increasingly recognized, however, how they are distributed throughout environmental systems requires further understanding. Seabirds have been identified as vectors of chemical contaminants from marine to terrestrial environments, and studies have recently identified seabirds as possible vectors of plastic pollution in the marine environment. However, their role in the distribution of microplastic pollution in the Arctic has yet to be explored. We examined two species of seabirds known to ingest plastics: northern fulmars (Fulmarus glacialis; n = 27) and thick-billed murres (Uria lomvia; n = 30) as potential vectors for the transport of microplastics in and around breeding colonies. Our results indicated anthropogenic particles in the faecal precursors of both species. Twenty-four anthropogenic particles were found in the fulmar faecal precursor samples (M = 0.89, SD = 1.09; 23 fibres and one fragment), and 10 anthropogenic particles were found in the murre faecal precursor samples (M = 0.33, SD = 0.92; 5 fibres, 4 fragments, and one foam). Through the use of bird population surveys and the quantification of anthropogenic particles found in the faecal precursors of sampled seabirds from the same colony, we estimate that fulmars and murres may deposit between 3.3 (CI_boot 1.9 × 10⁶-4.9 × 10⁶) and 45.5 (CI_boot 9.1 × 10⁶-91.9 × 10⁶) million anthropogenic particles, respectively, per year into the environment during their breeding period at these colonies. These estimates indicate that migratory seabirds could be contributing to the distribution and local hotspots of microplastics in Arctic environments, however, they are still likely a relatively small source of plastic pollution in terms of mass in the environment and may not contribute as much as other reported sources such as atmospheric deposition in the Arctic.

Review of plastic pollution policies of Arctic countries in relation to seabirds

Marine plastic is a ubiquitous environmental problem that can have an impact on a variety of marine biota, such as seabirds, making it an important concern for scientists and policy makers. Although research on plastic ingestion by seabirds is increasing, few studies have examined policies and long-term monitoring programs to reduce marine plastic in the Arctic. This paper provides a review of international, national, and regional policies and long-term monitoring programs that address marine plastic in relation to seabirds in the Arctic countries: Canada, the Kingdom of Denmark (Greenland and the Faroe Islands), Finland, Iceland, Norway, the Russian Federation, Sweden, and the United States of America. Results show that a broad range of international, national, regional and local policies address marine debris, specifically through waste management and the prevention of pollution from ships. However, few policies directly address seabirds and other marine biota. Further, policies are implemented inconsistently across regions, making it difficult to enforce and monitor the efficacy of these policies given the long-range transport of plastic pollution globally. To reduce marine plastic pollution in the Arctic environment, pan-Arctic and international collaboration is needed to implement standardized policies and long-term monitoring programs for marine plastic in the Arctic and worldwide.

Plastic ingestion by four seabird species in the Canadian Arctic: Comparisons across species and time

Plastic pollution ingestion by seabirds is an increasing environmental problem even in remote areas such as the Arctic, yet knowledge on plastic pollution ingestion by several Arctic seabirds is limited, making it difficult to assess trends. We examined plastic pollution ingestion by northern fulmars (Fulmarus glacialis), black-legged kittiwakes (Rissa tridactyla), thick-billed murres (Uria lomvia) and black guillemots (Cepphus grylle) in the Canadian Arctic to assess species-specific and temporal differences in plastic ingestion over ten years. Seventy-two percent of fulmars and 15% of kittiwakes ingested plastic, while guillemots and murres did not. The number and mass of plastic ingested by fulmars decreased between the two periods (2008 and 2018), but the frequency of occurrence of plastic ingestion did not change, although sample sizes were less than ideal. Future research with larger samples is recommended to reinforce these trends in plastic ingestion by Arctic seabirds.