The present and future of microplastic pollution in the marine environment.

Plastic waste in the marine environment: A review of sources, occurrence and effects.

Due to the widespread use and durability of synthetic polymers, plastic debris occurs in the environment worldwide. In the present work, information on sources and fate of microplastic particles in the aquatic and terrestrial environment, and on their uptake and effects, mainly in aquatic organisms, is reviewed. Microplastics in the environment originate from a variety of sources. Quantitative information on the relevance of these sources is generally lacking, but first estimates indicate that abrasion and fragmentation of larger plastic items and materials containing synthetic polymers are likely to be most relevant. Microplastics are ingested and, mostly, excreted rapidly by numerous aquatic organisms. So far, there is no clear evidence of bioaccumulation or biomagnification. In laboratory studies, the ingestion of large amounts of microplastics mainly led to a lower food uptake and, consequently, reduced energy reserves and effects on other physiological functions. Based on the evaluated data, the lowest microplastic concentrations affecting marine organisms exposed via water are much higher than levels measured in marine water. In lugworms exposed via sediment, effects were observed at microplastic levels that were higher than those in subtidal sediments but in the same range as maximum levels in beach sediments. Hydrophobic contaminants are enriched on microplastics, but the available experimental results and modelling approaches indicate that the transfer of sorbed pollutants by microplastics is not likely to contribute significantly to bioaccumulation of these pollutants. Prior to being able to comprehensively assess possible environmental risks caused by microplastics a number of knowledge gaps need to be filled. However, in view of the persistence of microplastics in the environment, the high concentrations measured at some environmental sites and the prospective of strongly increasing concentrations, the release of plastics into the environment should be reduced in a broad and global effort regardless of a proof of an environmental risk.

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Microplastics in the aquatic and terrestrial environment: sources (with a specific focus on personal care products), fate and effects.

Trophic transfer of microplastics and mixed contaminants in the marine food web and implications for human health.

In this review we report new findings concerning interaction between marine debris and wildlife. Deleterious effects and consequences of entanglement, consumption and smothering are highlighted and discussed. The number of species known to have been affected by either entanglement or ingestion of plastic debris has doubled since 1997, from 267 to 557 species among all groups of wildlife. For marine turtles the number of affected species increased from 86 to 100 % (now 7 of 7 species), for marine mammals from 43 to 66 % (now 81 of 123 species) and for seabirds from 44 to 50 % of species (now 203 of 406 species). Strong increases in records were also listed for fish and invertebrates, groups that were previously not considered in detail. In future records of interactions between marine debris and wildlife we recommend to focus on standardized data on frequency of occurrence and quantities of debris ingested. In combination with dedicated impact studies in the wild or experiments, this will allow more detailed assessments of the deleterious effects of marine debris on individuals and populations.

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Deleterious Effects of Litter on Marine Life

https://www.bsc-eoc.org/library/BCBeachbirdAvery-Gomm2012.pdf

Northern fulmars as biological monitors of trends of plastic pollution in the eastern North Pacific

Identifying drivers of ecosystem change in large marine ecosystems is central for their effective management and conservation. This is a sizable challenge, particularly in ecosystems transcending international borders, where monitoring and conservation of long-range migratory species and their habitats are logistically and financially problematic. Here, using tools borrowed from epidemiology, we elucidated common drivers underlying species declines within a marine ecosystem, much in the way epidemiological analyses evaluate risk factors for negative health outcomes to better inform decisions. Thus, we identified ecological traits and dietary specializations associated with species declines in a community of marine predators that could be reflective of ecosystem change. To do so, we integrated count data from winter surveys collected in long-term marine bird monitoring programs conducted throughout the Salish Sea--a transboundary large marine ecosystem in North America's Pacific Northwest. We found that decadal declines in winter counts were most prevalent among pursuit divers such as alcids (Alcidae) and grebes (Podicipedidae) that have specialized diets based on forage fish, and that wide-ranging species without local breeding colonies were more prone to these declines. Although a combination of factors is most likely driving declines of diving forage fish specialists, we propose that changes in the availability of low-trophic prey may be forcing wintering range shifts of diving birds in the Salish Sea. Such a synthesis of long-term trends in a marine predator community not only provides unique insights into the types of species that are at risk of extirpation and why, but may also inform proactive conservation measures to counteract threats--information that is paramount for species-specific and ecosystem-wide conservation.

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Assessing ecological correlates of marine bird declines to inform marine conservation

3 Corresponding author Abstract: The British Columbia Coastal Waterbird Survey is a citizen science long-term monitoring program implemented by Bird Studies Canada to assess population trends and ecological needs of waterbirds using the province's coastal and inshore marine habitats. S tandard monthly counts from more than 200 defined sites within the Strait of Georgia were analysed using route-regression techniques to estimate population indices and assess trends in 57 waterbird species over a 12-year period spanning the non-breeding periods from 1999-2000 to 2010-11. A power analysis was also conducted to validate the rigor of the survey design. Results indicate that the survey is detecting annual changes of 3% or less for populations of 29 waterbirds of a wide variety of guilds. Thirty-three species showed stable populations or no trend, 22 species showed significantly declining trends, and just three species showed significant increasing trends. We evaluate these results in the context of other long-term monitoring initiatives in the Salish Sea, highlighting specific birds to watch from a conservation perspective. Among those that showed a declining trend were a guild of piscivores, including Western and Horned Grebes, Common, Red-throated and Pacific Loons, and Rhinoceros Auklet; several sea ducks (Black and White-winged Scoters, Long-tailed Duck, Barrow's Goldeneye, Harlequin Duck); two shorebirds (Dunlin, Surfbird); and Great Blue Heron. In the stable/no trend group were 20 species for which the Salish Sea is of recognised global or continental conservation importance, including one grebe, two cormorants, eight waterfowl (including five diving ducks), three shorebirds and two gulls. Next steps in the application of the B.C. Coastal Waterbird Survey and related datasets to conservation and research management questions are discussed, underscoring the importance of continued monitoring using this cost-effective approach and expanding the use of these data to hypothesis-testing to investigate factors potentially driving population changes.

Coastal waterbird population tr ends in the Strait of Georgia 1999-2011: Results from the first 12 years of the British Columbia Coastal Waterbird Survey

Waterbirds are often used as indicators of ecosystem function across broad spatial and temporal scales. Resolving which species are declining and the ecological characteristics they have in common can offer insights into ecosystem changes and their underlying mechanisms. Using 20 years of citizen science data collected by the British Columbia Coastal Waterbird Survey, we examine species-specific trends in abundance of 50 species in the Salish Sea and 37 species along the outer Pacific Ocean coast that we considered to form the core wintering coastal bird community of British Columbia, Canada. Further, we explore whether ecological commonalities increase the likelihood of a species undergoing declines by testing the hypotheses that waterbird abundance trends are influenced by dietary specialization and migration distance to breeding grounds. Results suggest that most populations are stable (i.e., temporal trends are not significant) in both the Salish Sea (36 of 50 spp.) and Pacific coast (32 of 37 spp.) regions. Twelve species displayed significant decline trends in the Salish Sea, whereas two had significant increases. Along the Pacific coast, only three species displayed significant decline trends, and two significant increases. This result is corroborated by guild-specific trends indicating that waterbirds occupying the Salish Sea are faring significantly worse than those residing along the outer coastal regions, almost irrespective of dietary specialization or migration distance. Our results provide evidence that differential environmental pressures between the inner and outer coastal regions may be causing overall loss of wintering waterbirds within, or abundance shifts away from, the Salish Sea. Potential mechanisms responsible for these observed patterns are discussed, including environmental (e.g., climate) and human-induced (e.g., nutrient and chemical pollution) pressures. Collaborative, inter-disciplinary research priorities to help understand these mechanisms are suggested. Vingt ans de suivi d'oiseaux aquatiques côtiers montrent des tendances régionales de pressions environnementales en Colombie-Britannique, Canada RÉSUMÉ. Les oiseaux aquatiques sont souvent utilisés comme indicateurs du fonctionnement des écosystèmes à de larges échelles spatiales et temporelles. La détermination des espèces en diminution et des caractéristiques écologiques qu'elles ont en commun permet de se faire une idée des changements dans les écosystèmes et des mécanismes sous-jacents. Au moyen de 20 ans de données de science citoyenne collectées lors du Coastal Waterbird Survey de la Colombie-Britannique, nous avons examiné les tendances dans l'abondance de 50 espèces dans la mer des Salish et de 37 espèces plus au large de la côte de l'océan Pacifique que nous avons considérées comme formant le noyau de la communauté d'oiseaux côtiers hivernant de la Colombie-Britannique, au Canada. En outre, nous avons étudié si les traits communs écologiques augmentaient la probabilité qu'une espèce subisse une baisse en testant les hypothèses selon lesquelles les tendances de l'abondance des oiseaux aquatiques étaient influencées par la spécialisation alimentaire et la distance de migration vers les sites de reproduction. Selon nos résultats, la plupart des populations étaient stables (c.-à-d. que les tendances temporelles n'étaient pas significatives) dans la mer des Salish (36 sur 50 sp.) et le long de la côte du Pacifique (32 sur 37 sp.). Douze espèces ont montré une tendance significative de diminution dans la mer des Salish, tandis que deux ont connu des augmentations significatives. Le long de la côte du Pacifique, seules trois espèces ont affiché une tendance à la baisse significative, et deux des augmentations significatives. Ce résultat est corroboré par les tendances propres à chaque guilde indiquant que les oiseaux aquatiques qui occupent la mer des Salish se portent nettement moins bien que ceux qui se tiennent plus au large des côtes, presque indépendamment de leur spécialisation alimentaire ou de leur distance de migration. Nos résultats montrent que les pressions environnementales variables entre les parties intérieures et extérieures des régions côtières peuvent être à l'origine de la perte globale des oiseaux aquatiques hivernant dans la mer des Salish ou d'un déplacement de ces oiseaux vers d'autres régions. Nous avons examiné les possibles mécanismes responsables des tendances observées, y compris les pressions environnementales (p. ex. le climat) et humaines (p. ex. la pollution par les nutriments et les produits chimiques). Enfin, nous proposons des priorités de recherche collaborative et interdisciplinaire pour faciliter la compréhension de ces mécanismes.

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Karen L. Barry

Papers

Northern fulmars as biological monitors of trends of plastic pollution in the eastern North Pacific

Assessing ecological correlates of marine bird declines to inform marine conservation

Coastal waterbird population tr ends in the Strait of Georgia 1999-2011: Results from the first 12 years of the British Columbia Coastal Waterbird Survey

Twenty years of coastal waterbird trends suggest regional patterns of environmental pressure in British Columbia, Canada