The Effects of depth on microplastics distribution and ingestion by a biological indicator species: Mytilus galloprovincialis

Global plastic production rates are currently at the highest that they have ever been and are projected to continue to increase over the next 20 years. Models that have only accounted for surface plastics have severely underestimated actual plastic loads in the world’s oceans, largely due to the distribution of microplastics below the water’s surface. Despite being ingested by organisms at nearly every trophic level and observed in virtually every ocean environment, the complex nature of microplastics’ distribution patterns remains poorly understood. Recent studies have observed distinct depth profiles of microplastics, thereby implying differential bioavailability to biotic communities depending on their position in the water column. To date, depth profiles of microplastics have only been characterized in open ocean environments and gyres, and no study of depth profiles has directly, quantitatively linked vertical distribution of microplastics in the water column to ingestion by marine organisms. This study has aimed to further our understanding of microplastic depth profiles and the implications for biological communities by (1) determining the vertical distribution of microplastics in a stratified marine habitat in Puget Sound and (2) relating that distribution to ingested plastic loads in a biological indicator species at different depths. In both water samples and mussel samples taken from our study site in Totten Inlet, 99% of plastics found were filamentous. No distinct patterns of distribution were observed in either water samples or mussel samples from 0-4 m depths

Where have all the forage fish gone? Response of rhinoceros auklets to an anomalously poor breeding season

The effectiveness of using seabirds as indicators of marine conditions is predicated on the idea that focal species are sensitive to changes in environmental parameters. Species with more behavioral plasticity may be less sensitive to and presumably buffered from a wider range of environmental conditions, thereby compensating for potential perturbations in the system. Rhinoceros Auklet (Cerorhinca monocerata) breeding populations in Washington State typically show little interannual variability in reproductive parameters, suggesting that they are relatively insensitive to the range of conditions that they typically experience. However, in 2016, we documented a highly anomalous breeding season for Rhinoceros Auklets on Protection Island (PI), WA, in the Salish Sea but not on Destruction Island, on the outer Washington coast. We continued our long-term breeding season monitoring at both breeding colonies in 2017, providing us with the opportunity to evaluate the population-level response to the 2016 season. On Protection Island, burrow occupancy (the proportion of burrows that were reproductively active) was the lowest recorded in 12 years of monitoring (58% vs. long-term mean of 72%). In contrast, hatching and fledging success were both comparable to the 12-year mean values, 85% and 78%, respectively. As in 2016, none of the three reproductive parameters differed from long-term mean values for the Destruction Island breeding population in 2017. In stark contrast to 2016, nestling provisioning, as measured by fish per bill load and bill load weight, on PI was comparable to long-term values. The lower burrow occupancy on PI suggests a population-level effect from the 2016 breeding failure and a concurrent adult mortality event. This depressed breeding effort may have been driven by elevated adult mortality the previous summer and/or birds deciding not to breed during the 2017 season

Using Age to Assess Retention Time of Ingested Plastic in Seabirds

For the past 30 years, plastic pollution research has used plastic ingested and retain in seabirds’ gastrointestinal (GIT) tract as indicators of pollution on different spatial and temporal scales. Types and size of plastic found in birds’ stomachs were used to determine pollution types and severity at different times and places. However, the length of time that birds can retain plastic in their GIT is unknown, making ingested plastic’s use as a bioindicator questionable. We assessed retention times in two seabird species, the Northern Fulmar (Fulmarus glacialis) and the Cassin’s Auklet (Ptychoramphus aleuticus), and compared the size and density of pieces of plastic in juveniles and adults of each species. Juveniles have a known time of ingesting plastic (fledging to when they died) while adults have an unknown time. We predicted that if retention times were long, the adults would have smaller and greater density plastic than juveniles due to grinding in the GIT wearing down pieces. If retention times in juveniles and adults were similar, the size and density of plastic pieces would be similar. Plastic from fulmars were similar size in both age groups, suggesting that fulmars do not retain plastic for long. Adult auklets’ GIT contained smaller pieces than juveniles, indicating longer retention times. The method provides a protocol to assessing wear and thus retention times of plastic either retrospectively using archived samples or from new samples

Some like it hot: using citizen science to identify marine bird hotspots in Puget Sound

Puget Sound, situated in the southern portion of the Salish Sea, supports approximately 172 marine bird species that face a multitude of threats, ranging from chronic oiling to entanglement in derelict fishing gear. As local population numbers shift due to both intrinsic and extrinsic forcing (e.g., on the breeding grounds), understanding the pattern of species\u27 use of habitats and locations across the Sound can inform conservation planning. Using data collected by the Puget Sound Seabird Survey (PSSS) - a citizen science program that collects information on the abundance and distribution of marine birds in the nearshore environment throughout Puget Sound - we developed and applied hotspot detection methods to 15 marine bird species that utilize the nearshore waters of the Sound. We found that species distributions ranged from ubiquitous/uniform (e.g., Glaucous-winged Gulls Larus glaucescens, Double-crested Cormorants Phalacrocorax auritus and Horned Grebes Podiceps auritus), to highly location specific (e.g., Pigeon Guillemots Cepphus columba, Harlequin Ducks Histrionicus histrionicus and White-winged Scoters Melanitta fusca). We identified three different types of hotspot behavior: “seasonal contraction” in density or occupancy location(s), “hotspots in abundance” but not occupancy, and “hotspots in both occupancy and abundance.” Hotspot locations were species-group specific, probably resulting from differences in nearshore depth profile among locations. These depth associations likely correspond to feeding behavior and availability of foraging habitat. Hotspot detection can be a useful tool for delineating priority areas for conservation and management. The tools developed in this study can be used to identify both hot and cold spots and, if seasonality is included, to determine if the hotspots are stable or seasonally intermittent

Mortalidad de aves marinas producida por luces artificiales terrestres

Artificial lights at night cause high mortality of seabirds, one of the most endangered groups of birds globally. Fledglings of burrow-nesting seabirds, and to a lesser extent adults, are attracted to and then grounded (i.e., forced to land) by lights when they fly at night. We reviewed the current state of knowledge of seabird attraction to light to identify information gaps and propose measures to address the problem. Although species in families such as Alcidae and Anatidae can be grounded by artificial light, the most affected seabirds are petrels and shearwaters (Procellariiformes). At least 56 species of Procellariiformes, more than one-third of them (24) threatened, are subject to grounding by lights. Seabirds grounded by lights have been found worldwide, mainly on oceanic islands but also at some continental locations. Petrel breeding grounds confined to formerly uninhabited islands are particularly at risk from light pollution due to tourism and urban sprawl. Where it is impractical to ban external lights, rescue programs of grounded birds offer the most immediate and employed mitigation to reduce the rate of light-induced mortality and save thousands of birds every year. These programs also provide useful information for seabird management. However, these data are typically fragmentary, biased, and uncertain and can lead to inaccurate impact estimates and poor understanding of the phenomenon of seabird attraction to lights. We believe the most urgently needed actions to mitigate and understand light-induced mortality of seabirds are estimation of mortality and effects on populations; determination of threshold light levels and safe distances from light sources; documentation of the fate of rescued birds; improvement of rescue campaigns, particularly in terms of increasing recovery rates and level of care; and research on seabird-friendly lights to reduce attraction.RESUMEN: Las luces artificiales nocturnas causan una mortalidad alta de aves marinas, uno de los grupos de aves en mayor peligro de extinción a nivel mundial. Los polluelos de aves marinas que anidan en madrigueras, y en menor medida los adultos, son atraídos y forzados a aterrizar por las luces cuando vuelan de noche. Revisamos el estado actual del conocimiento sobre la atracción de las aves marinas por la luz para identificar vacíos de información y proponer medidas para resolver el problema. Aunque las especies de familias como Alcidae y Anatidae pueden ser forzadas a aterrizar por la luz artificial, las aves marinas más afectadas son los petreles y las pardelas (Procellariiformes). Por lo menos 56 especies de Procellariiformes, más de un tercio (24) de ellas amenazadas, son propensas al aterrizaje atraídas por las luces. Las aves marinas forzadas a aterrizar han sido halladas en todo el mundo, principalmente en islas oceánicas, pero también en algunas localidades continentales. Los sitios de anidación de los petreles confinados anteriormente a islas deshabitadas están particularmente en riesgo de sufrir contaminación lumínica debido al turismo y al crecimiento urbano. En donde no es práctico prohibir las luces externas, los programas de rescate de las aves accidentadas ofrecen la mitigación más inmediata y empleada para reducir la tasa de mortalidad inducida por la luz y salvar a miles de aves cada año. Estos programas también proporcionan información útil para el manejo de aves marinas. Sin embargo, estos datos están típicamente fragmentados, sesgados y son inciertos, y pueden llevar a estimaciones inexactas del impacto y a un entendimiento pobre del fenómeno de la atracción de las aves marinas por la luz. Creemos que las acciones necesarias de mayor urgencia para mitigar y entender la mortalidad de aves marinas producida por la luz son: la estimación de la mortalidad y los efectos sobre la población; la determinación de umbrales de niveles de luz y de distancias seguras a las fuentes de luz; el estudio del destino de las aves rescatadas; la mejora de las campañas de rescate, particularmente en términos de incrementar las tasas de recogida y el nivel de cuidado; y la investigación sobre las características de la luz para reducir la atracción de las aves marinas.This research was supported by a Marie Curie Intra European Fellowship within the 7th European Community Framework Programme (Project ID: 330655 FP7-PEOPLE-2012-IOF)info:eu-repo/semantics/publishedVersio

Future directions in conservation research on petrels and shearwaters

Shearwaters and petrels (hereafter petrels) are highly adapted seabirds that occur across all the world's oceans. Petrels are a threatened seabird group comprising 124 species. They have bet-hedging life histories typified by extended chick rearing periods, low fecundity, high adult survival, strong philopatry, monogamy and long-term mate fidelity and are thus vulnerable to change. Anthropogenic alterations on land and at sea have led to a poor conservation status of many petrels with 52 (42%) threatened species based on IUCN criteria and 65 (52%) suffering population declines. Some species are well-studied, even being used as bioindicators of ocean health, yet for others there are major knowledge gaps regarding their breeding grounds, migratory areas or other key aspects of their biology and ecology. We assembled 38 petrel conservation researchers to summarize information regarding the most important threats according to the IUCN Red List of threatened species to identify knowledge gaps that must be filled to improve conservation and management of petrels. We highlight research advances on the main threats for petrels (invasive species at breeding grounds, bycatch, overfishing, light pollution, climate change, and pollution). We propose an ambitious goal to reverse at least some of these six main threats, through active efforts such as restoring island habitats (e.g., invasive species removal, control and prevention), improving policies and regulations at global and regional levels, and engaging local communities in conservation efforts

Global assessment of marine plastic exposure risk for oceanic birds

Plastic pollution is distributed patchily around the world’s oceans. Likewise, marine organisms that are vulnerable to plastic ingestion or entanglement have uneven distributions. Understanding where wildlife encounters plastic is crucial for targeting research and mitigation. Oceanic seabirds, particularly petrels, frequently ingest plastic, are highly threatened, and cover vast distances during foraging and migration. However, the spatial overlap between petrels and plastics is poorly understood. Here we combine marine plastic density estimates with individual movement data for 7137 birds of 77 petrel species to estimate relative exposure risk. We identify high exposure risk areas in the Mediterranean and Black seas, and the northeast Pacific, northwest Pacific, South Atlantic and southwest Indian oceans. Plastic exposure risk varies greatly among species and populations, and between breeding and non-breeding seasons. Exposure risk is disproportionately high for Threatened species. Outside the Mediterranean and Black seas, exposure risk is highest in the high seas and Exclusive Economic Zones (EEZs) of the USA, Japan, and the UK. Birds generally had higher plastic exposure risk outside the EEZ of the country where they breed. We identify conservation and research priorities, and highlight that international collaboration is key to addressing the impacts of marine plastic on wide-ranging species

Global assessment of marine plastic exposure risk for oceanic birds

Plastic pollution is distributed patchily around the world's oceans. Likewise, marine organisms that are vulnerable to plastic ingestion or entanglement have uneven distributions. Understanding where wildlife encounters plastic is crucial for targeting research and mitigation. Oceanic seabirds, particularly petrels, frequently ingest plastic, are highly threatened, and cover vast distances during foraging and migration. However, the spatial overlap between petrels and plastics is poorly understood. Here we combine marine plastic density estimates with individual movement data for 7137 birds of 77 petrel species to estimate relative exposure risk. We identify high exposure risk areas in the Mediterranean and Black seas, and the northeast Pacific, northwest Pacific, South Atlantic and southwest Indian oceans. Plastic exposure risk varies greatly among species and populations, and between breeding and non-breeding seasons. Exposure risk is disproportionately high for Threatened species. Outside the Mediterranean and Black seas, exposure risk is highest in the high seas and Exclusive Economic Zones (EEZs) of the USA, Japan, and the UK. Birds generally had higher plastic exposure risk outside the EEZ of the country where they breed. We identify conservation and research priorities, and highlight that international collaboration is key to addressing the impacts of marine plastic on wide-ranging species.B.L.C., C.H., and A.M. were funded by the Cambridge Conservation Initiative’s Collaborative Fund sponsored by the Prince Albert II of Monaco Foundation. E.J.P. was supported by the Natural Environment Research Council C-CLEAR doctoral training programme (Grant no. NE/S007164/1). We are grateful to all those who assisted with the collection and curation of tracking data. Further details are provided in the Supplementary Acknowledgements. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.Peer reviewe