Seabirds Research Articles

Into the sea: Antimicrobial resistance determinants in the microbiota of little penguins (Eudyptula minor).

Terrestrial and aquatic birds have been proposed as sentinels for the spread of antimicrobial resistant bacteria, but few species have been investigated specifically in the context of AMR in the marine ecosystem. This study contrasts the occurrence of class 1 integrons and associated antimicrobial resistance genes in wild and captive little penguins (Eudyptula minor), an Australian seabird with local population declines. PCR screening of faecal samples (n=448) revealed a significant difference in the prevalence of class 1 integrons in wild and captive groups, 3.2% and 44.7% respectively, with genes that confer resistance to streptomycin, spectinomycin, trimethoprim and multidrug efflux pumps detected. Class 1 integrons were not detected in two clinically relevant bacterial species, Klebsiella pneumoniae or Escherichia coli, isolated from penguin faeces. The presence of class 1 integrons in the little penguin supports the use of marine birds as sentinels of AMR in marine environments.

The Baltic Sea: An ecosystem with multiple stressors

This introductory chapter to our Environment International VSI does not need an abstract and therefore we just include our recommendations below in order to proceed with the resubmission. Future work should examine waterbirds as food web sentinels of multiple stressors as well as Baltic Sea food web dynamics of hazardous substances and how climate change may modify it. Also, future work should aim at further extending the new frameworks developed within BALTHEALTH for energy and contaminant transfer at the population level (Desforges et al., 2018, Cervin et al., 2020/this issue Silva et al., 2020/this issue) and their long term effects on Baltic Sea top predators, such as harbour porpoises, grey seals ringed seals, and white-tailed eagles. Likewise, the risk evaluation conducted for PCB in connection with mercury on Arctic wildlife (Dietz et al., 2019, not a BONUS BALTHEALTH product) could be planned for Baltic Sea molluscs, fish, bird and marine mammals in the future. Finally, future efforts could include stressors not covered by the BONUS BALTHEALTH project, such as food web fluxes, overexploitation, bycatches, eutrophication and underwater noise.

Observation of marine mammal and bird interactions focused around a commercial fishing vessel in central Baffin Bay, Nunavut

A detailed account of a variety of species foraging on Greenland halibut (Reinhardtius hippoglossoides (Walbaum, 1792)) fisheries discards associated with a commercial fishing vessel in central Baffin Bay, Nunavut, Canada is presented. Species observed included three marine mammals: northern bottlenose whales (Hyperoodon ampullatus (Forster, 1770)), sperm whales (Physeter macrocephalus Linnaeus, 1758), and a hooded seal (Cystophora cristata (Erxleben, 1777)), and two marine bird species: northern fulmars (Fulmarus glacialis (Linnaeus, 1761)) and glaucous gulls (Larus hyperboreus Gunnerus, 1767). Interspecies and intraspecies interactions were observed while species were in close proximity to the stern and starboard of a commercial fishing vessel confirming anecdotal reports from boat captains. Improved understanding of marine mammal and bird interactions with fisheries in the Arctic is required to accurately assess financial and ecological (i.e., bycatch) losses, potential for entanglement and to predict the likely impact on energy flow and transport of these resource subsidies throughout the Arctic marine ecosystem.

Inuit knowledge of Arctic Terns (Sterna paradisaea) and perspectives on declining abundance in southeastern Hudson Bay, Canada.

The Arctic Tern (Sterna paradisaea; takatakiaq in Inuttitut) breeds in the circumpolar Arctic and undertakes the longest known annual migration. In recent decades, Arctic Tern populations have been declining in some parts of their range, and this has been a cause of concern for both wildlife managers and Indigenous harvesters. However, limited scientific information is available on Arctic Tern abundance and distribution, especially within its breeding range in remote areas of the circumpolar Arctic. Knowledge held by Inuit harvesters engaged in Arctic Tern egg picking can shed light on the ecology, regional abundance and distribution of this marine bird. We conducted individual interviews and a workshop involving 12 Inuit harvesters and elders from Kuujjuaraapik, Nunavik (northern Québec), Canada, to gather their knowledge of Arctic Tern cultural importance, ecology, and stewardship. Interview contributors reported a regional decline in Arctic Tern numbers which appeared in the early 2000s on nesting islands near Kuujjuaraapik. Six possible factors were identified: (1) local harvest through egg picking; (2) nest disturbance and predation; (3) abandonment of tern nesting areas (i.e., islands that have become connected to the mainland due to isostatic rebound); (4) climate change; (5) natural abundance cycles within the Arctic Tern population; and (6) decline of the capelin (Mallotus villosus) in the region. Recommendations from Inuit contributors related to Arctic Tern stewardship and protection included: (1) conduct more research; (2) let nature take its course; (3) conduct an awareness campaign; (4) implement an egg picking ban; (5) coordinate local egg harvest; (6) start 'tern farming'; (7) protect Arctic Terns across their migration route; and (8) harvest foxes predating on terns. Our study highlighted complementarities between Inuit knowledge and ecological science, and showed that Inuit harvesters can make substantial contributions to ongoing and future Arctic tern research and management initiatives.

Marine pollution in fledged Leach's storm-petrels (Hydrobates leucorhous) from Baccalieu Island, Newfoundland and Labrador, Canada

The Leach's storm-petrel (Hydrobates leucorhous) is one of the most abundant and widely distributed marine birds in the North Atlantic but is under global population decline, possibly linked to marine pollution. We determined levels of ingested plastic and hepatic total mercury (THg) in recently fledged juveniles that stranded in Newfoundland and Labrador, Canada, and assessed the relationship to body condition, size and diet. Plastic prevalence was high (87.5%) but hepatic THg was relatively low (mean 486.7 ng/g dry weight) compared to other studies. Levels of neither pollutant were significantly related to body metrics of health. Our data confirm that plastic and mercury are pervasive in the western North Atlantic Ocean, prominent even in young birds.

Penguins and Seals Transport Limiting Nutrients Between Offshore Pelagic and Coastal Regions of Antarctica Under Changing Sea Ice

Large animals such as sea birds and marine mammals can transport limiting nutrients between different regions of the ocean, thereby stimulating and enhancing productivity. In Antarctica this process is influenced by formation and breakup of sea ice and its influence on the feeding behaviour of predators and their prey. We used analyses of bioactive metals (for example, Fe, Co, Mn), macronutrients (for example, N) and stable isotopes (δ13C and δ15N) in the excreta of Adelie (Pygoscelis adeliae) and emperor penguins (Aptenodytes forsteri) as well as Weddell seals (Leptonychotes weddellii) from multiple sites, among multiple years (2012–2014) to resolve how changes in sea ice dynamics, as indicated by MODIS satellite images, were coincident with prey switching and likely changes in nutrient fluxes between the offshore pelagic and coastal zones. We also sampled excreta of the south polar skua (Stercorarius maccormicki), which preys on penguins and scavenges the remains of both penguins and seals. We found strong coincidence of isotopic evidence for prey switching, between euphausiids (Euphausia superba and E. crystallorophias) and pelagic/cryopelagic fishes (for example, Pleuragramma antarcticum) in penguins, and between pelagic/cryopelagic fishes and Antarctic toothfish (Dissostichus mawsoni) in Weddell seals, with changes in sea ice cover among years. Further, prey switching was strongly linked to changes in the concentrations of nutrients (Fe and N) deposited in coastal environments by both penguins and seals. Our findings have important implications for understanding how the roles of large animals in supporting coastal productivity may shift with environmental conditions in polar ecosystems.

`Boats don't fish, people do′- how fishers′ agency can inform fisheries-management on bycatch mitigation of marine mammals and sea birds

Bycatch of seabirds and marine mammals in gillnet fisheries is a major hazard for conservation globally. Measures for bycatch mitigation in fisheries management mostly base on technological and ecological findings and they generally assume fishers as a homogenous group that is supposed to apply new technology or act according to the latest ecological insights. There is often a lack of knowledge about the heterogeneity of fishers′ actions and drivers, despite its importance for effective fisheries management. For the specific case of the German gillnet fleet in the Baltic Sea a qualitative social-science research approach was chosen to generate knowledge that can inform management. In applying the concept of agency, three types of fishers′ actions are distinguished: projective (future-oriented), evaluative (present-oriented) and iterational (past-oriented). Fishers′ attitude towards incidental bycatch differed between viewing bycatch as a normal part of the daily routine or as a disturbing event. These findings are discussed in the context of management instruments, such as closed fishing zones and seasons, brought up during an expert workshop. It is concluded that considering fishers′ agency may be an important contribution to design effective management instruments to mitigate bycatch of seabirds and marine mammals in gillnet fisheries.

Geodiversity of the Togean Islands National Park, Central Sulawesi Province for Geopark Assessment

The Togean Islands National Park is located at the Gulf of Tomini, Central Sulawesi Province, Indonesia. The islands officially become National Park in 2007, initiated by the government of the Tojo Una-Una district in 2004. There is a variety of geodiversity within the Togean Islands National Park, such as active volcano, ophiolitic pillow lava, beautiful beaches and islands formed by lithology of volcanic deposits, igneous intrusions and quaternary limestone formation. Four geodiversity areas are provided within the national park, according to lithological and geomorphological aspects. Those are the Una-Una Island active volcano, karst topography of limestone around the Batudaka Island, the lava dome at the Togean Island and the ophiolite complex of Walea Islands. The Una-Una volcano island is unique based on the location and anomaly in magma affinities. The Soliter volcano separated from the volcanic belt along the North Sulawesi Arm and has the adakite signature compared to tholeiitic - calk-alkaline as dominant affinities from the North Sulawesi island arc province. The Batudaka Island - karst topography offers sailing and cruiser to the beautiful shape and scenery of karst topography of limestone formation, cave, sandy beaches and blue ocean. The lava dome of the Togean Island: provides a geomorphological landscape that represents the dome of trachytic igneous rock above sea level. The Walea ophiolite: of a geoheritage showing rock formation, consists of ophiolitic pillow lava and the tectonic fossil of subduction between tectonic plates around Sulawesi Islands. Overall, the Togean Islands National Park proposes many adventure sites for diving, snorkelling, surfing, fishing, sea birds and dolphin watching and also conservation of reef, fish and geoheritage sites. Several facilities are already available inside of the National Park, such as resorts and cottages for accommodation, sailing and diving rental for leisure activities.

Hydrology-hydrochemical researches of the Caspian Sea in July-August 2019

Comprehensive research information on hydrology-hydrochemical structure of the Middle Caspian Sea in July-August 2019 on board of R/V “Issledovatel’ Kaspiya” is presented in the article. Data on dissolved oxygen, hydrogen sulfide, basic nutrients (ammonium, nitrite and nitrate nitrogen; mineral phosphorus) and dissolved organic carbon were obtained in four quasi-latitudinal sections using the probing complex SBE19 plus Sea Bird, equipped with a series of sensors and twelve Niskin bathometers. It is shown, that the distribution patterns of determined elements and vertical structure correspond to average annual values of the summer season. Despite the sea level decline, the thickness of hydrogen sulfide layer of the Caspian Sea hasn’t decreased.

Simple method to extend the range of ECO-BB for waters with high backscattering coefficient.

The ECO-BB (Sea Bird Scientific) is a popular instrument used by water optics researchers to measure the backscattering coefficient of waters in the visible to near-infrared wavelengths. The ECO-BB is calibrated by default for oceanic waters where the backscattering coefficient is typically low. In inland and coastal waters however, there is a tendency for the ECO-BB to reach saturation due to the high number of suspended particles. In the paper, a simple method is presented to extend the range of the ECO-BB instrument in such waters using a nephelometric turbidimeter. The method was first tested on powdered calcium carbonate in pure freshwater, followed by collected water samples from the Singapore Straits and the Lupar River in Sarawak. All three tests confirm the correlation between the ECO-BB and turbidimeter and show that the turbidimeter is a good proxy for backscattering coefficient measurements in turbid waters.

A review of a decade of lessons from one of the world’s largest MPAs: conservation gains and key challenges

Given the recent trend towards establishing very large marine protected areas (MPAs) and the high potential of these to contribute to global conservation targets, we review outcomes of the last decade of marine conservation research in the British Indian Ocean Territory (BIOT), one of the largest MPAs in the world. The BIOT MPA consists of the atolls of the Chagos Archipelago, interspersed with and surrounded by deep oceanic waters. Islands around the atoll rims serve as nesting grounds for sea birds. Extensive and diverse shallow and mesophotic reef habitats provide essential habitat and feeding grounds for all marine life, and the absence of local human impacts may improve recovery after coral bleaching events. Census data have shown recent increases in the abundance of sea turtles, high numbers of nesting seabirds and high fish abundance, at least some of which is linked to the lack of recent harvesting. For example, across the archipelago the annual number of green turtle clutches (Chelonia mydas) is ~ 20,500 and increasing and the number of seabirds is ~ 1 million. Animal tracking studies have shown that some taxa breed and/or forage consistently within the MPA (e.g. some reef fishes, elasmobranchs and seabirds), suggesting the MPA has the potential to provide long-term protection. In contrast, post-nesting green turtles travel up to 4000 km to distant foraging sites, so the protected beaches in the Chagos Archipelago provide a nesting sanctuary for individuals that forage across an ocean basin and several geopolitical borders. Surveys using divers and underwater video systems show high habitat diversity and abundant marine life on all trophic levels. For example, coral cover can be as high as 40–50%. Ecological studies are shedding light on how remote ecosystems function, connect to each other and respond to climate-driven stressors compared to other locations that are more locally impacted. However, important threats to this MPA have been identified, particularly global heating events, and Illegal, Unreported and Unregulated (IUU) fishing activity, which considerably impact both reef and pelagic fishes.

Individual specialization in the use of space by frugivorous bats.

Natural populations are not homogenous systems but sets of individuals that occupy subsets of the species' niche. This phenomenon is known as individual specialization. Recently, several studies found evidence of individual specialization in animal diets. Diet is a critical dimension of a species' niche that affects several other dimensions, including space use, which has been poorly studied under the light of individual specialization. In this study, which harnesses the framework of the movement ecology paradigm and uses yellow-shouldered bats Sturnira lilium as a model, we ask how food preferences lead individual bats of the same population to forage mainly in different locations and habitats. Ten individual bats were radiotracked in a heterogeneous Brazilian savanna. First, we modelled intraspecific variation in space use as a network of individual bats and the landscape elements visited by them. Second, we developed two novel metrics, the spatial individual specialization index (SpatIS) and the spatial individual complementary specialization index (SpatICS). Additionally, we tested food-plant availability as a driver of interindividual differences in space use. There was large interindividual variation in space use not explained by sex or weight. Our results point to individual specialization in space use in the studied population of S. lilium, most probably linked to food-plant distribution. Individual specialization affects not only which plant species frugivores consume, but also the way they move in space, ultimately with consequences for seed dispersal and landscape connectivity.

Mercury concentrations provide an indicator of marine foraging in coastal birds

The transfer of nutrients between marine and terrestrial systems has important ecological consequences, and animal movement is an important driver of nutrient transfer. Coastal birds forage in marine environments and breed in terrestrial habitats, and thus serve as vectors moving nutrients from the sea to the land. However, urbanization can influence the extent to which coastal birds forage in marine or terrestrial environments due to the availability of human subsidies. Establishing a reliable and straightforward indicator of marine foraging would be useful for assessing changes in the use of terrestrial vs. marine habitats in the face of urbanization and broader environmental change, and for understanding the flow of nutrients and energy between terrestrial and marine environments. Mercury (Hg) is a highly toxic heavy metal which bioaccumulates in marine food webs, and is a potential indicator of marine foraging. Methylmercury (MeHg), is present only in aquatic ecosystems and reaches elevated concentrations in the prey species of marine birds. Thus, high concentrations of MeHg would be expected for birds foraging in marine environments in comparison to those foraging on terrestrial sources. We hypothesized that the degree of marine foraging influences Hg uptake in coastal birds. To test this hypothesis, we combined GPS tracking data with measurements of Hg concentrations in the blood of herring gulls (Larus argentatus) along an urban gradient in the northeast United States. We examined Hg concentrations for 51 individual herring gulls tracked with GPS tags at study sites representing high, medium and low degrees of urbanization. Our results showed a strong and significant positive relationship between Hg concentrations and the proportion of herring gull foraging locations occurring in offshore waters. Hg concentrations differed significantly between herring gulls whose primary foraging habitat occurred in marine vs. terrestrial environments. Gulls in more urban colonies spent less time foraging in marine environments, and had significantly lower Hg concentrations than those at the more remote study. Our results suggest that Hg concentrations in blood can be used to reflect the extent of marine foraging for animals using both marine and terrestrial habitats. Hg concentrations could be valuable monitoring tool to assess how the use of marine foraging habitats changes through time (dietary shifts) or relative to environmental change such as urbanization.

Assessing the exposure of three diving bird species to offshore wind areas on the U.S. Atlantic Outer Continental Shelf using satellite telemetry

AbstractAimThe United States Atlantic Outer Continental Shelf (OCS) has considerable offshore wind energy potential. Capturing that resource is part of a broader effort to reduce CO2 emissions. While few turbines have been constructed in U.S. waters, over a dozen currently planned offshore wind projects have the potential to displace marine birds, potentially leading to effective habitat loss. We focused on three diving birds identified in Europe to be vulnerable to displacement. Our research aimed to determine their potential exposure to areas designated or proposed for offshore wind development along the Atlantic OCS.MethodsSatellite tracking technology was used to determine the spatial and temporal use and movement patterns of Surf Scoters (Melanitta perspicillata), Red‐throated Loons (Gavia stellata) and Northern Gannets (Morus bassanus), and calculate their exposure to each offshore wind area. We tagged 236 adults in 2012–2015 on the Atlantic OCS from New Jersey to North Carolina; an additional 147 birds tagged in previous tracking studies were integrated into our analyses. Tracking data were analysed in two‐week intervals using dynamic Brownian bridge movement models to develop composite spatial utilization distributions. For each species, these distributions were then used to calculate the spatio‐temporal exposure to each offshore wind area.ResultsSurf Scoters and Red‐throated Loons were exposed to offshore wind areas almost exclusively during migration because these species were distributed among coastal and inshore waters during winter months. In contrast, Northern Gannets ranged over a much larger area, reaching farther offshore and south in winter, thus exhibited the greatest exposure to extant offshore wind areas.ConclusionsResults of this study provide better understanding of how diving birds use current and potential future offshore wind areas on the Atlantic OCS, and can inform permitting, risk assessment and pre‐ and post‐construction impact assessments of offshore energy infrastructure.

Estimating the breeding population size and confirming the status of invasive rodents at the newly discovered colonies of Japanese Murrelets, Mugi-cho, Tokushima Prefecture, Japan ―Marine Bird Restoration Group―

Estimating the breeding population size and confirming the status of invasive rodents at the newly discovered colonies of Japanese Murrelets, Mugi-cho, Tokushima Prefecture, Japan ―Marine Bird Restoration Group―

Conservation genetics of a small population of Ancient murrelts breeding on the Teuri Island, Hokkaido, Japan ―Research Group for Conservation of Sea Birds in the West Pacific―

Conservation genetics of a small population of Ancient murrelts breeding on the Teuri Island, Hokkaido, Japan ―Research Group for Conservation of Sea Birds in the West Pacific―

Methylmercury biomagnification in coastal aquatic food webs from western Patagonia and western Antarctic Peninsula

Mercury (Hg) is a global pollutant of concern because its organic and more toxic form, methylHg (MeHg), bioaccumulates and biomagnifies through aquatic food webs to levels that affect the health of fish and fish consumers, including humans. Although much is known about trophic transfer of MeHg in aquatic food webs at temperate latitudes in the northern hemisphere, it is unclear whether its fate is similar in biota from coastal zones of the southeastern Pacific. To assess this gap, MeHg, total Hg and food web structure (using δ13C and δ15N) were measured in marine macroinvertebrates, fishes, birds, and mammals from Patagonian fjords and the Antarctic Peninsula. Trophic magnification slopes (TMS; log MeHg versus δ15N) for coastal food webs of Patagonia were high when compared with studies in the northern hemisphere, and significantly higher near freshwater inputs as compared to offshore sites (0.244 vs 0.192). Similarly, in Antarctica, the site closer to glacial inputs had a significantly higher TMS than the one in the Southern Shetland Islands (0.132 vs 0.073). Composition of the food web also had an influence, as the TMS increased when mammals and seabirds were excluded (0.132–0.221) at a coastal site. This study found that both the composition of the food web and the proximity to freshwater outflows are key factors influencing the TMS for MeHg in Patagonian and Antarctic food webs.

Fate of Common (Sterna hirundo) and Roseate Terns (S. dougallii) with Satellite Transmitters Attached with Backpack Harnesses

Miniature transmitters now permit ornithologists to track the annual cycle of smaller (< 150 g) marine birds. To assess annual movements of Common Terns (Sterna hirundo) and endangered Roseate Terns (S. dougallii), 2.5 g satellite transmitters were attached with backpack harnesses. Using the same capture techniques and investigator to fit harnesses, five Common Terns were tagged in Maine in 2017, and 10 Roseate Terns in New York, USA in 2018. Common Terns were tracked from 102 – 652 days to destinations as far as Brazil with no documented adverse impacts. Three of five Common Terns returned to Maine, USA one year after tagging, and non-functioning tags were recovered from two Common Terns in 2018 and 2019. In contrast, Roseate Terns were tracked for only 1 – 72 days before transmissions ceased, with only two birds tracked for > 7 days. We detected three Roseate Terns with their bill stuck in the harness material, with one documented mortality. Common Terns tolerated the tags and provided useful data on annual movements but were not a suitable surrogate for predicting the effects of backpack mounted transmitters on Roseate Terns. Researchers considering tracking Roseate Terns should avoid using backpack harnesses.

Plastics in the Pacific: Assessing risk from ocean debris for marine birds in the California Current Large Marine Ecosystem

Understanding the impact of plastic debris on marine birds is important for conservation of some species, and assessing risk from this anthropogenic threat requires high-quality distribution data for both marine birds and plastic debris. We applied a risk assessment framework to explore the relative risk for 19 marine bird species posed by plastic debris in the California Current Large Marine Ecosystem. We estimated exposure for each species by combining scores from (1) spatial overlap of predicted marine bird densities from habitat-association models and predicted density of marine plastics from terrestrial input and ocean circulation models, (2) species' foraging behavior, and (3) species' residence time in the California Current Large Marine Ecosystem. We estimated sensitivity for each species by combining scores for (1) mortality/sub-lethal effects of ingested plastic debris, (2) off-loading of plastics via regurgitation, (3) fecundity, and (4) age of breeding maturity. Overall risk from marine debris was greatest for more pelagic species and lowest for nearshore coastal species and generally agreed with published plastic ingestion studies. Notably, marine plastic debris densities are greatest at the western edge and offshore of the study domain, which likely explains the greater risk we observed in more pelagic species. This study is the first to look specifically at plastic debris risk to marine birds in the California Current Large Marine Ecosystem, and our results suggest that any attempts to mitigate the impacts of plastic debris on marine birds will likely require assessment and actions beyond the California Current into the broader Pacific basin.

Organohalogen compounds of emerging concern in Baltic Sea biota: Levels, biomagnification potential and comparisons with legacy contaminants

While new chemicals have replaced major toxic legacy contaminants such as polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT), knowledge of their current levels and biomagnification potential in Baltic Sea biota is lacking. Therefore, a suite of chemicals of emerging concern, including organophosphate esters (OPEs), short-chain, medium-chain and long-chain chlorinated paraffins (SCCPs, MCCPs, LCCPs), halogenated flame retardants (HFRs), and per- and polyfluoroalkyl substances (PFAS), were analysed in blue mussel (Mytilus edulis), viviparous eelpout (Zoarces viviparus), Atlantic herring (Clupea harengus), grey seal (Halichoerus grypus), harbor seal (Phoca vitulina), harbor porpoise (Phocoena phocoena), common eider (Somateria mollissima), common guillemot (Uria aalge) and white-tailed eagle (Haliaeetus albicilla) from the Baltic Proper, sampled between 2006 and 2016. Results were benchmarked with existing data for legacy contaminants. The mean concentrations for ΣOPEs ranged from 57 to 550 ng g−1 lipid weight (lw), for ΣCPs from 110 to 640 ng g−1 lw for ΣHFRs from 0.42 to 80 ng g−1 lw, and for ΣPFAS from 1.1 to 450 ng g−1 wet weight. Perfluoro-4-ethylcyclohexanesulfonate (PFECHS) was detected in most species. Levels of OPEs, CPs and HFRs were generally similar or higher than those of polybrominated diphenyl ethers (PBDEs) and/or hexabromocyclododecane (HBCDD). OPE, CP and HFR concentrations were also similar to PCBs and DDTs in blue mussel, viviparous eelpout and Atlantic herring. In marine mammals and birds, PCB and DDT concentrations remained orders of magnitude higher than those of OPEs, CPs, HFRs and PFAS. Predator-prey ratios for individual OPEs (0.28–3.9) and CPs (0.40–5.0) were similar or somewhat lower than those seen for BDE-47 (5.0–29) and HBCDD (2.4–13). Ratios for individual HFRs (0.010–37) and PFAS (0.15–47) were, however, of the same order of magnitude as seen for p,p′-DDE (4.7–66) and CB-153 (31–190), indicating biomagnification potential for many of the emerging contaminants. Lack of toxicity data, including for complex mixtures, makes it difficult to assess the risks emerging contaminants pose. Their occurence and biomagnification potential should trigger risk management measures, particularly for MCCPs, HFRs and PFAS.