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pdf AMAP 1998 Chapter 2 - Physical/Geographical Characteristics of the Arctic

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AMAP-1998-Chapter 2. Physical_Geographical Cha.pdf

AMAP 1998 Chapter 2 - Physical/Geographical Characteristics of the Arctic

The vast region of the Arctic extends across northern North America, northern Europe and northern Asia, taking in eight countries and the expanses of sea and ocean in between. The terrestrial, freshwater and marine environments throughout this area exhibit considerable variation in climate, meteoro- logy and physical geography. This chapter describes this di- versity as a background to discussions on contaminants and other stressors in these environments.

pdf Arctic Council (2009). Arctic Marine Shipping Assessment 2009 Report No.: 194

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Arctic Council-2009-Arctic Marine Shipping Ass.pdf

Arctic Council (2009). Arctic Marine Shipping Assessment 2009 Report No.: 194
No Abstract Available

pdf Baba, N., M. Kiyota and K. Yoshida (1990). Distribution of marine debris and northern fur seals in the Eastern Bering Sea. The Second International Conference on Marine Debris, Honolulu.

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Baba-1990-Distribution of marine debris and no.PDF

Baba, N., M. Kiyota and K. Yoshida (1990). Distribution of marine debris and northern fur seals in the Eastern Bering Sea. The Second International Conference on Marine Debris, Honolulu.

To obtain basic information about entanglement rate and mortality of the northern fur seal, Callorhinus ursinus, at sea, we conducted sighting surveys of fur seals and marine debris along eight transect lines in 1984 and four in 1985 and 1988 in summer near the Pribilof Islands in the eastern Bering Sea. These southeast to northwest transects were approximately 300-500km long. We observed 710 fur seals and 7 debris items of fisheries origin in 1984, 345 seals and 17 debris items in 1985, and 343 seals and 18 debris items in 1988. In 1985, one dead male fur seal was observed entangled in a trawl net fragment weighing 40 kg. Distributions of both marine debris and fur seals were concentrated in the area along the continental slope west of the Pribilof Islands. It is considered that this co- occurrence is a result of the mutual relationship between fish resources, seals' feeding, fishing grounds of trawlers in the area, and northward-flowingcurrent.

pdf Bråte, I. L. N., D. P. Eidsvoll, C. C. Steindal and K. V. Thomas (2016). Plastic ingestion by Atlantic cod (Gadus morhua) from the Norwegian coast. Mar Pollut Bull, 112(1-2): 105-110 DOI: 10.1016/j.marpolbul.2016.08.034.

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Bråte-2016-Plastic ingestion by Atlantic cod (.pdf

Bråte, I. L. N., D. P. Eidsvoll, C. C. Steindal and K. V. Thomas (2016). Plastic ingestion by Atlantic cod (Gadus morhua) from the Norwegian coast. Mar Pollut Bull, 112(1-2): 105-110 DOI: 10.1016/j.marpolbul.2016.08.034.

This study documents the occurrence of microplastic (b5 mm), mesoplastics (5–20 mm) and macroplastic (N 20 mm) in Atlantic cod (Gadus morhua), a common and economically important species of marine fish in Nor- way. Fish stomachs (n = 302) were examined from six different locations along the coast of Norway. Three per- cent of the individual stomachs contained items identified by Fourier transform infrared spectroscopy (FTIR) as synthetic polymers. Bergen City Harbour was a hotspot with 27% of the cod examined found to contain plastic. Polyester was the most frequently detected polymer. All bar one of the stomachs that contained plastic were full of organic stomach content, suggesting a plastic gut clearance rate similar to the ingested food. It is proposed that stomach fullness is an important metric in order to avoid underestimations when assessing the levels of microplastic ingested by fish.

pdf Cai, L., J. Wang, J. Peng, Z. Tan, Z. Zhan, X. Tan and Q. Chen (2017). Characteristic of microplastics in the atmospheric fallout from Dongguan city, China: preliminary research and first evidence. Environ Sci Pollut Res Int, 24(32): 24928-24935

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Cai-2017-Characteristic of microplastics in th.pdf

Cai, L., J. Wang, J. Peng, Z. Tan, Z. Zhan, X. Tan and Q. Chen (2017). Characteristic of microplastics in the atmospheric fallout from Dongguan city, China: preliminary research and first evidence. Environ Sci Pollut Res Int, 24(32): 24928-24935

Microplastic pollution has exhibited a global distri- bution, including seas, lakes, rivers, and terrestrial environ- ment in recent years. However, little attention was paid on the atmospheric environment, though the fact that plastic de- bris can escape as wind-blown debris was previously reported. Thus, characteristics of microplastics in the atmospheric fall- out from Dongguan city were preliminarily studied. Microplastics of three different polymers, i.e., PE, PP, and PS, were identified. Diverse shapes of microplastics including fiber, foam, fragment, and film were found, and fiber was the dominant shape of the microplastics. SEM images illustrated that adhering particles, grooves, pits, fractures, and flakes were the common patterns of degradation. The concentrations of non-fibrous microplastics and fibers ranged from 175 to 313 particles/m2/day in the atmospheric fallout. Thus, dust emission and deposition between atmosphere, land surface, and aquatic environment were associated with the transporta- tion of microplastics.

pdf CIESM (2014). Marine litter in the Mediterranean and Black Seas (Executive Summary). CIESM. CIESM Workshop Monographs No. 46. Monaco: 180.

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CIESM-2014-Marine litter in the Mediterranean.pdf

CIESM (2014). Marine litter in the Mediterranean and Black Seas (Executive Summary). CIESM. CIESM Workshop Monographs No. 46. Monaco: 180.

Marine debris is now commonly observed everywhere in the oceans, drastically impacting the Mediterranean Sea which is now one of the most affected areas – if not the most affected area in the World Ocean – as noted by CIESM Director General, Frédéric Briand, in his opening remarks. In welcoming the group of 16 international guests invited on this occasion. He remarked that this was the first time that a CIESM Workshop was held in Albania, signaling the hope that this country would soon join the large family of CIESM Member States.

pdf Cole, M., P. K. Lindeque, E. Fileman, J. Clark, C. Lewis, C. Halsband and T. S. Galloway (2016). Microplastics Alter the Properties and Sinking Rates of Zooplankton Faecal Pellets. Environ Sci Technol, 50(6): 3239-3246

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Cole-2016-Microplastics Alter the Properties a.pdf

Cole, M., P. K. Lindeque, E. Fileman, J. Clark, C. Lewis, C. Halsband and T. S. Galloway (2016). Microplastics Alter the Properties and Sinking Rates of Zooplankton Faecal Pellets. Environ Sci Technol, 50(6): 3239-3246

Plastic debris is a widespread contaminant, prevalent in aquatic ecosystems across the globe. Zooplankton readily ingest microscopic plastic (microplastic, < 1 mm), which are later egested within their faecal pellets. These pellets are a source of food for marine organisms, and contribute to the oceanic vertical flux of particulate organic matter as part of the biological pump. The effects of microplastics on faecal pellet properties are currently unknown. Here we test the hypotheses that (1) faecal pellets are a vector for transport of microplastics, (2) polystyrene microplastics can alter the properties and sinking rates of zooplankton egests and, (3) faecal pellets can facilitate the transfer of plastics to coprophagous biota. Following exposure to 20.6 μm polystyrene microplastics (1000 microplastics mL−1) and natural prey (∼1650 algae mL−1) the copepod Calanus helgolandicus egested faecal pellets with significantly (P < 0.001) reduced densities, a 2.25-fold reduction in sinking rates, and a higher propensity for fragmentation. We further show that microplastics, encapsulated within egests of the copepod Centropages typicus, could be transferred to C. helgolandicus via coprophagy. Our results support the proposal that sinking faecal matter represents a mechanism by which floating plastics can be vertically transported away from surface waters.

pdf Cole, M., P. Lindeque, E. Fileman, C. Halsband and T. S. Galloway (2015). The impact of polystyrene microplastics on feeding, function and fecundity in the marine copepod Calanus helgolandicus. Environ Sci Technol, 49(2): 1130-1137

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Cole-2015-The impact of polystyrene microplast.pdf

Cole, M., P. Lindeque, E. Fileman, C. Halsband and T. S. Galloway (2015). The impact of polystyrene microplastics on feeding, function and fecundity in the marine copepod Calanus helgolandicus. Environ Sci Technol, 49(2): 1130-1137

Microscopic plastic debris, termed “micro-plastics”, are of increasing environmental concern. Recent studies have demonstrated that a range of zooplankton, including copepods, can ingest microplastics. Copepods are a globally abundant class of zooplankton that form a key trophic link between primary producers and higher trophic marine organisms. Here we demonstrate that ingestion of micro- plastics can significantly alter the feeding capacity of the pelagic copepod Calanus helgolandicus. Exposed to 20 μm polystyrene beads (75 microplastics mL−1) and cultured algae ([250 μg C L−1) for 24 h, C. helgolandicus ingested 11% fewer algal cells (P = 0.33) and 40% less carbon biomass (P < 0.01). There was a net downward shift in the mean size of algal prey consumed (P < 0.001), with a 3.6 fold increase in ingestion rate for the smallest size class of algal prey (11.6−12.6 μm), suggestive of postcapture or postingestion rejection. Prolonged exposure to polystyrene microplastics significantly decreased reproductive output, but there were no significant differences in egg production rates, respiration or survival. We constructed a conceptual energetic (carbon) budget showing that microplastic-exposed copepods suffer energetic depletion over time. We conclude that microplastics impede feeding in copepods, which over time could lead to sustained reductions in ingested carbon biomass.

pdf Cole, M., P. Lindeque, E. Fileman, C. Halsband, R. Goodhead, J. Moger and T. S. Galloway (2013). Microplastic ingestion by zooplankton. Environ Sci Technol, 47(12): 6646-6655

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Cole-2013-Microplastic ingestion by zooplankto.pdf

Cole, M., P. Lindeque, E. Fileman, C. Halsband, R. Goodhead, J. Moger and T. S. Galloway (2013). Microplastic ingestion by zooplankton. Environ Sci Technol, 47(12): 6646-6655

Small plastic detritus, termed “microplastics”, are a widespread and ubiquitous contaminant of marine ecosystems across the globe. Ingestion of microplastics by marine biota, including mussels, worms, fish, and seabirds, has been widely reported, but despite their vital ecological role in marine food-webs, the impact of microplastics on zooplankton remains under-researched. Here, we show that microplastics are ingested by, and may impact upon, zooplankton. We used bioimaging techniques to document ingestion, egestion, and adherence of microplastics in a range of zooplankton common to the northeast Atlantic, and employed feeding rate studies to determine the impact of plastic detritus on algal ingestion rates in copepods. Using fluorescence and coherent anti-Stokes Raman scattering (CARS) microscopy we identified that thirteen zooplankton taxa had the capacity to ingest 1.7−30.6 μm polystyrene beads, with uptake varying by taxa, life-stage and bead-size. Post-ingestion, copepods egested faecal pellets laden with microplastics. We further observed microplastics adhered to the external carapace and appendages of exposed zooplankton. Exposure of the copepod Centropages typicus to natural assemblages of algae with and without microplastics showed that 7.3 μm microplastics (>4000 mL−1) significantly decreased algal feeding. Our findings imply that marine microplastic debris can negatively impact upon zooplankton function and health.

pdf Davison, P. and R. G. Asch (2011). Plastic ingestion by mesopelagic fishes in the North Pacific Subtropical Gyre. Marine Ecology Progress Series, 432: 173-180 DOI: 10.3354/meps09142.

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Davison-2011-Plastic ingestion by mesopelagic.pdf

Davison, P. and R. G. Asch (2011). Plastic ingestion by mesopelagic fishes in the North Pacific Subtropical Gyre. Marine Ecology Progress Series, 432: 173-180 DOI: 10.3354/meps09142.

The oceanic convergence zone in the North Pacific Subtropical Gyre acts to accumulate floating marine debris, including plastic fragments of various sizes. Little is known about the ecolog- ical consequences of pelagic plastic accumulation. During the 2009 Scripps Environmental Accumu- lation of Plastics Expedition (SEAPLEX), we investigated whether mesopelagic fishes ingest plastic debris. A total of 141 fishes from 27 species were dissected to examine whether their stomach con- tents contained plastic particles. The incidence of plastic in fish stomachs was 9.2%. Net feeding bias was evaluated and judged to be minimal for our methods. The ingestion rate of plastic debris by mesopelagic fishes in the North Pacific is estimated to be from 12 000 to 24 000 tons yr of plastic ingestion by mesopelagic fishes may occur in other subtropical gyres.

pdf Desforges, J. P., M. Galbraith and P. S. Ross (2015). Ingestion of Microplastics by Zooplankton in the Northeast Pacific Ocean. Arch Environ Contam Toxicol, 69(3): 320-330

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Desforges-2015-Ingestion of Microplastics by Z.pdf

Desforges, J. P., M. Galbraith and P. S. Ross (2015). Ingestion of Microplastics by Zooplankton in the Northeast Pacific Ocean. Arch Environ Contam Toxicol, 69(3): 320-330

Microplastics are increasingly recognized as being widespread in the world’s oceans, but relatively little is known about ingestion by marine biota. In light of the potential for microplastic fibers and fragments to be taken up by small marine organisms, we examined plastic ingestion by two foundation species near the base of North Pacific marine food webs, the calanoid copepod Neo- calanus cristatus and the euphausiid Euphausia pacifia. We developed an acid digestion method to assess plastic ingestion by individual zooplankton and detected microplastics in both species. Encounter rates resulting from ingestion were 1 particle/every 34 copepods and 1/every 17 euphausiids (euphausiids [ copepods; p = 0.01). Consistent with differences in the size selection of food between these two zooplankton species, the ingested particle size was greater in euphausiids (816 ± 108 lm) than in copepods (556 ± 149 lm) (p = 0.014). The contribution of ingested microplastic fibres to total plastic decreased with distance from shore in euphausiids (r2 = 70, p = 0.003), corresponding to pat- terns in our previous observations of microplastics in sea- water samples from the same locations. This first evidence of microplastic ingestion by marine zooplankton indicate that species at lower trophic levels of the marine food web are mistaking plastic for food, which raises fundamental questions about potential risks to higher trophic level species. One concern is risk to salmon: We estimate that consumption of microplastic-containing zooplankton will lead to the ingestion of 2–7 microplastic particles/day by individual juvenile salmon in coastal British Columbia, and B91 microplastic particles/day in returning adults.

pdf Dris, R., J. Gasperi, C. Mirande, C. Mandin, M. Guerrouache, V. Langlois and B. Tassin (2017). A first overview of textile fibers, including microplastics, in indoor and outdoor environments. Environ Pollut, 221: 453-458

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Dris-2017-A first overview of textile fibers.pdf

Dris, R., J. Gasperi, C. Mirande, C. Mandin, M. Guerrouache, V. Langlois and B. Tassin (2017). A first overview of textile fibers, including microplastics, in indoor and outdoor environments. Environ Pollut, 221: 453-458

Sources, pathways and reservoirs of microplastics, plastic particles smaller than 5 mm, remain poorly document- ed in an urban context. While some studies pointed out wastewater treatment plants as a potential pathway of microplastics, none have focused on the atmospheric compartment. In this work, the atmospheric fallout of microplastics was investigated in two different urban and sub-urban sites. Microplastics were collected continu- ously with a stainless steel funnel. Samples were then filtered and observed with a stereomicroscope. Fibers accounted for almost all the microplastics collected. An atmospheric fallout between 2 and 355 particles/m2/ day was highlighted. Registered fluxes were systematically higher at the urban than at the sub-urban site. Chem- ical characterization allowed to estimate at 29% the proportion of these fibers being all synthetic (made with pet- rochemicals), or a mixture of natural and synthetic material. Extrapolation using weight and volume estimates of the collected fibers, allowed a rough estimation showing that between 3 and 10 tons of fibers are deposited by atmospheric fallout at the scale of the Parisian agglomeration every year (2500 km2). These results could serve the scientific community working on the different sources of microplastic in both continental and marine environments.

pdf Eisted, R. and T. H. Christensen (2011). Waste management in Greenland: current situation and challenges. Waste Manag Res, 29(10): 1064-1070

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Eisted-2011-Waste management in Greenland_ cur.pdf

Eisted, R. and T. H. Christensen (2011). Waste management in Greenland: current situation and challenges. Waste Manag Res, 29(10): 1064-1070

Waste management in Greenland (56 000 inhabitants) is characterized by landfilling, incineration and export to Denmark of small quantities of metals and hazardous waste. The annual amount of waste is estimated to about 50 000 tons but actual data are scarce. Data on the waste composition is basically lacking. The scattered small towns and settlements, the climate and the long transport distances between towns and also to recycling industries abroad constitute a complex situation with respect to waste management. The landfills have no collection of gas and leachate and the incinerators are small and equipped with only moderate flue gas cleaning technology. This report summarizes the current waste management situation in Greenland and identifies important challenges in improving the waste management.

pdf Feldkamp, S. D., D. P. Costa and G. K. DeKrey (1989). Energetic and behavioral effects of net entanglement on juvenile northern fur seals, Callorhinus ursinus. Fisheries Bulletin U.S., 87: 85-94.

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Feldkamp-1989-Energetic and behavioral effects.pdf

Feldkamp, S. D., D. P. Costa and G. K. DeKrey (1989). Energetic and behavioral effects of net entanglement on juvenile northern fur seals, Callorhinus ursinus. Fisheries Bulletin U.S., 87: 85-94.

The energetic costs and behavioral changes associated with net entanglement were studied in three cap- tive juvenile male northern fur seals, Callorkin'U8 ursi'll'US. Rates of energy expenditure were highly depen- dent upon swim velocity and size of the net fragment. At a speed of 1.1 mfs, northern fur seals expended a mean (±SD) of 6.5 (±0.7) Wlkg before entanglement. 9.7 (±3.8) Wlkg when entangled in 100 g nets, and 13.8 WIkg with 200 g nets. These results showed that a free-ranging animal entangled in a net frag- ment of 200 g or larger will experience considerable difficulty swimming.

The northern fur seals' average daily metabolic rates (ADMR) were measured with doubly labeled water over 6 day periods before and during entanglement in 225 g net fragments. Concurrent behavioral observations revealed a 75% reduction in time spent swimming and a 138% increase in time spent resting due to entanglement. Nevertheless. the northern fur seals' mean ADMR rose from 8.0 (±0.4) Wlkg to 9.3 (± 1.9) WIkg. While this increase was primarily due to one animal's performance, it suggests that entanglement may also elevate the costs of resting and grooming.

At 17 months of age, the northern fur seals had averaged head diameters (±SD) of 14.7 (±0.2) em, making them most susceptible to entanglement in nets with stretched mesh sizes of 23 em or more. Obser- vations showed that these juvenile fur seals were naturally inquisitive and rapidly became entangled upon their first encounter with a floating net. Subsequent entanglements depended more upon each animal's behavior than upon net fragment size. Captive animals were unable to free themselves from the entangling fragments.

pdf Finley, K. J. (2001). Natural History and Conservation of the Greenland Whale, or Bowhead, in the Northwest Atlantic. Arctic, 54(1)

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Finley-2001-Natural History and Conservation o.pdf

Finley, K. J. (2001). Natural History and Conservation of the Greenland Whale, or Bowhead, in the Northwest Atlantic. Arctic, 54(1)

One of the longest-living mammals, the Greenland whale or bowhead (Balaena mysticetus) is specialized to filter small crustaceans, especially Calanus copepods, from barren Arctic seas. Brought to near extinction by commercial whaling, the North Atlantic ‘meta-population’ remains at less than 5% of its former abundance, and none of its three constituent stocks has shown demonstrable recovery during the last century. Two of these stocks, the Baffin Bay and Hudson Bay populations, occur in coastal waters of the Eastern Canadian Arctic during summer. Each of these two stocks numbers in the low hundreds and exists in isolated groups segregated by age and sex, showing strong fidelity to essential habitats. A skewed age distribution, predation by killer whales (Orcinus orca), hunting, net entanglement, tourism, climate change, habitat loss, and inbreeding suppression are some of the factors that may affect the bowhead’s recovery. We need local and historical knowledge to understand the bowhead’s natural history. Together with scientific data, such knowledge is also useful in evaluating the status of the species and prescribing a management plan. A recovery plan must employ the precautionary principle, both within the international ‘meta-population’ context and at the sub-population level; it must take a historical view and seek to protect abandoned habitats. Canada has conducted whaling activities that violate international agreements and diminish the effectiveness of the International Whaling Commission.

pdf Fowler, C. W., J. D. Baker, R. Ream, B. W. Robson and M. Kiyota (1993). Entanglement studies on juvenile male northern fur seals, St. Paul Island, 1992. Alaska Fisheries Center. AFSC Processed Report No. 93-03.

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Fowler-1993-Entanglement studies on juvenile m.pdf

Fowler, C. W., J. D. Baker, R. Ream, B. W. Robson and M. Kiyota (1993). Entanglement studies on juvenile male northern fur seals, St. Paul Island, 1992. Alaska Fisheries Center. AFSC Processed Report No. 93-03.

During ,fuIy and early August of lggT, entanglement of juvenile male northern fur seals (calrorhinus ursinus) in marine debris was studied on st. paur rsland, Araska, in the Bering sea. Estimates of entanglement-caused mortality, incidence ofentanglemenE, and the kinds and sizes of debris were determined for seals in 94 roundups.

The proportion of entangled seals obsen¡ed in 1992 was greater than in 1991 but was comparable Èo that obsen¡ed during the previous several years. The entanglement rate since i-9g7 has remained lower than that obse:r¡ed during 1967-96. The proportion of juvenile males obsen¡ed ent,angled in 1-992 was O.2gZ. Although the proport,ion of entangled animals found in fragnnents of trawl webbing increased over that, obsen¡ed in 1gg1, the frequency of occurrence of Èraw1 webbing among entangling debrís in 1992 was about one-harf that obsen¡ed prior to 1998. The proportion ofseals entangled ín other Èlæes of debris did not change.

The L992 studies confirm earlier esÈimates that the annual sun¡ival of seals entangled in small debris is about one-half that of nonentangled seals. Seals from which debris was removed had significantly higher surr¡ival than those which remainedentangled.

During the 1,992 roundups, 10 entangled male seals too large to be part of the entanglement study were captured and the debris was removed.

pdf Galloway, T. S., M. Cole and C. Lewis (2017). Interactions of microplastic debris throughout the marine ecosystem. Nat Ecol Evol, 1(5): 116

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Galloway-2017-Interactions of microplastic deb.pdf

Galloway, T. S., M. Cole and C. Lewis (2017). Interactions of microplastic debris throughout the marine ecosystem. Nat Ecol Evol, 1(5): 116

Marine microscopic plastic (microplastic) debris is a modern societal issue, illustrating the challenge of balancing the con­ venience of plastic in daily life with the prospect of causing ecological harm by careless disposal. Here we develop the con­ cept of microplastic as a complex, dynamic mixture of polymers and additives, to which organic material and contaminants can successively bind to form an ‘ecocorona’, increasing the density and surface charge of particles and changing their bio­ availability and toxicity. Chronic exposure to microplastic is rarely lethal, but can adversely affect individual animals, reducing feeding and depleting energy stores, with knock-on effects for fecundity and growth. We explore the extent to which ecological processes could be impacted, including altered behaviours, bioturbation and impacts on carbon flux to the deep ocean. We discuss how microplastic compares with other anthropogenic pollutants in terms of ecological risk, and consider the role of science and society in tackling this global issue in the future.

pdf Gjøsæter, H., P. H. Wiebe, T. Knutsen and R. B. Ingvaldsen (2017). Evidence of Diel Vertical Migration of Mesopelagic Sound-Scattering Organisms in the Arctic. Frontiers in Marine Science, 4

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Gjøsæter-2017-Evidence of Diel Vertical Migrat.pdf

Gjøsæter, H., P. H. Wiebe, T. Knutsen and R. B. Ingvaldsen (2017). Evidence of Diel Vertical Migration of Mesopelagic Sound-Scattering Organisms in the Arctic. Frontiers in Marine Science, 4

While sound scattering layers (SSLs) have been described previously from ice-covered waters in the Arctic, the existence of a viable mesopelagic community that also includes mesopelagic fishes in the Arctic has been questioned. In addition, it has been hypothesized that vertical migration would hardly exist in these areas. We wanted to check if deep scattering layers (DSLs) was found to the west and north of Svalbard (79◦30′ N−82◦10′ N) during autumn 2015, and if present; whether organisms in such DSLs undertook vertical migrations. Our null hypothesis was that there would be no evidence of diel vertical migration. Multi-frequency acoustic observations by hull mounted echo sounder (18, 38, and 120 kHz) revealed a DSL at depths ∼210–510 m in areas with bottom depths exceeding ∼600 m. Investigating eight geographical locations that differed with respect to time periods, light cycle and sea ice conditions, we show that the deeper layer of DSL displayed a clear ascending movement during night time and a descending movement during daytime. The high-light weighted mean depth (WMD) (343–514m) with respect to backscattered energy was statistically deeper than the low-light WMD (179–437m) for the locations studied. This behavior of the DSL was found to be consistent both when the sun was continuously above the horizon and after it started to set on 1 September, and both in open water and sea ice covered waters. The WMD showed an increasing trend, while the nautical area backscattering strength from the DSL showed a decreasing trend from south to north among the studied locations. Hydrographic observations revealed that the diel migration was found in the lower part of the north-flowing Atlantic Water, and was disconnected from the surface water masses above the Atlantic Water during day and night. The organisms conducting vertical migrations were studied by vertical and oblique hauls with zooplankton nets and pelagic trawls. These data suggest that these organisms were mainly various mesopelagic fishes, some few larger fishes, large zooplankton like krill and amphipods, and various gelatinous forms.

pdf Gregory, M. R. (2009). Environmental implications of plastic debris in marine settings-- entanglement, ingestion, smothering, hangers-on, hitch-hiking and alien invasions. Philosophical Transactions of the Royal Society B: Biological Sciences, 364(1526):

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Gregory-2009-Environmental implications of pla.pdf

Gregory, M. R. (2009). Environmental implications of plastic debris in marine settings-- entanglement, ingestion, smothering, hangers-on, hitch-hiking and alien invasions. Philosophical Transactions of the Royal Society B: Biological Sciences, 364(1526):

Over the past five or six decades, contamination and pollution of the world’s enclosed seas, coastal waters and the wider open oceans by plastics and other synthetic, non-biodegradable materials (generally known as ‘marine debris’) has been an ever-increasing phenomenon. The sources of these polluting materials are both land- and marine-based, their origins may be local or distant, and the environmental consequences are many and varied. The more widely recognized problems are typically associated with entanglement, ingestion, suffocation and general debilitation, and are often related to stranding events and public perception. Among the less frequently recognized and recorded problems are global hazards to shipping, fisheries and other maritime activities. Today, there are rapidly developing research interests in the biota attracted to freely floating (i.e. pelagic) marine debris, commonly known as ‘hangers-on and hitch-hikers’ as well as material sink- ing to the sea floor despite being buoyant. Dispersal of aggressive alien and invasive species by these mechanisms leads one to reflect on the possibilities that ensuing invasions could endanger sensitive, or at-risk coastal environments (both marine and terrestrial) far from their native habitats.