8 research outputs found
Microplastics in sea ice and seawater beneath ice floes from the Arctic Ocean
Within the past decade, an alarm was raised about microplastics in the remote and seemingly pristine Arctic Ocean. To gain further insight about the issue, microplastic abundance, distribution and composition in sea ice cores (n = 25) and waters underlying ice floes (n = 22) were assessed in the Arctic Central Basin (ACB). Potential microplastics were visually isolated and subsequently analysed using Fourier Transform Infrared (FT-IR) Spectroscopy. Microplastic abundance in surface waters underlying ice floes (0–18 particles m−3) were orders of magnitude lower than microplastic concentrations in sea ice cores (2–17 particles L−1). No consistent pattern was apparent in the vertical distribution of microplastics within sea ice cores. Backward drift trajectories estimated that cores possibly originated from the Siberian shelves, western Arctic and central Arctic. Knowledge about microplastics in environmental compartments of the Arctic Ocean is important in assessing the potential threats posed by microplastics to polar organisms
Microplastic abundance, distribution and composition along a latitudinal gradient in the Atlantic Ocean
publisher: Elsevier articletitle: Microplastic abundance, distribution and composition along a latitudinal gradient in the Atlantic Ocean journaltitle: Marine Pollution Bulletin articlelink: http://dx.doi.org/10.1016/j.marpolbul.2016.12.025 content_type: article copyright: © 2016 Elsevier Ltd. All rights reserved
Microplastics in sub-surface waters of the Arctic Central Basin
© 2018 Elsevier Ltd Polar oceans, though remote in location, are not immune to the accumulation of plastic debris. The present study, investigated for the first time, the abundance, distribution and composition of microplastics in sub-surface waters of the Arctic Central Basin. Microplastic sampling was carried out using the bow water system of icebreaker Oden (single depth: 8.5 m) and CTD rosette sampler (multiple depths: 8–4369 m). Potential microplastics were isolated and analysed using Fourier Transform Infrared Spectroscopy (FT-IR). Bow water sampling revealed that the median microplastic abundance in near surface waters of the Polar Mixed Layer (PML) was 0.7 particles m −3 . Regarding the vertical distribution of microplastics in the ACB, microplastic abundance (particles m −3 ) in the different water masses was as follows: Polar Mixed Layer (0–375) > Deep and bottom waters (0–104) > Atlantic water (0–95) > Halocline i.e. Atlantic or Pacific (0–83)
Deep sea sediments of the Arctic Central Basin: A potential sink for microplastics
© 2019 Elsevier Ltd Deep sea sediments have emerged as a potential sink for microplastics in the marine environment. The discovery of microplastics in various environmental compartments of the Arctic Central Basin (ACB) suggested that these contaminants were potentially being transported to the deep-sea realm of this oceanic basin. For the first time, the present study conducted a preliminary assessment to determine whether microplastics were present in surficial sediments from the ACB. Gravity and piston corers were used to retrieve sediments from depths of 855–4353 m at 11 sites in the ACB during the Arctic Ocean 2016 (AO16) expedition. Surficial sediments from the various cores were subjected to density flotation with sodium tungstate dihydrate solution (Na 2 WO 4 ·2H 2 O, density 1.4 g cm −3 ). Potential microplastics were isolated and analysed by Fourier Transform Infrared (FT-IR) spectroscopy. Of the surficial samples, 7 of the 11 samples contained synthetic polymers which included polyester (n = 3), polystyrene (n = 2), polyacrylonitrile (n = 1), polypropylene (n = 1), polyvinyl chloride (n = 1) and polyamide (n = 1). Fibres (n = 5) and fragments (n = 4) were recorded in the samples. In order to avoid mis-interpretation, these findings must be taken in the context that (i) sampling equipment did not guarantee retrieval of undisturbed surficial sediments, (ii) low sample volumes were analysed (~10 g per site), (iii) replicate sediment samples per site was not possible, (iv) no air contamination checks were included during sampling and, (v) particles <100 µm were automatically excluded from analysis. While the present study provides preliminary indication that microplastics may be accumulating in the deep-sea realm of the ACB, further work is necessary to assess microplastic abundance, distribution and composition in surficial sediments of the ACB
Chemical contamination assessment in mangrove-lined Caribbean coastal systems using the oyster Crassostrea rhizophorae as biomonitor species
This paper aims to contribute to the use of mangrove
cupped oyster, Crassostrea rhizophorae, as a biomonitor
species for chemical contamination assessment in
mangrove-lined Caribbean coastal systems. Sampling was
carried out in eight localities (three in Nicaragua and five in
Colombia) with different types and levels of contamination.
Oysters were collected during the rainy and dry seasons of
2012–2013 and the tissue concentrations of metals, polycyclic
aromatic hydrocarbons (PAHs), and persistent organic pollutants
(POPs) were determined. Low tissue concentrations of
metals (except Hg) and PAHs; moderate-to-high tissue concentrations
of Hg, hexachlorocyclohexanes (HCHs), and
dichlorodiphenyl-trichloroethanes (DDTs); detectable levels
of chlorpyrifos, polychlorinated biphenyls (PCBs) (mainly
CB28, CB118, CB138 and CB 153) and brominated diphenyl
ethers 85 (BDE85); and negligible levels of musks were recorded
in Nicaraguan oysters. A distinct profile of POPs was
identified in Colombia, where the tissue concentrations of
PCBs and synthetic musk fragrances were low to moderate,
and Ag, As, Cd, Pb, and PAHs ranged from moderate to extremely
high. Overall, the values recorded for HCHs, DDTs
and PCBs in Nicaraguan mangrove cupped oysters greatly
exceeded the reference values in tissues of C. rhizophorae
from the Wider Caribbean Region, whereas only the levels
of PCBs were occasionally surpassed in Colombia. Different
contaminant profiles were distinguished between oysters from
Nicaragua and Colombia in radar plots constructed using the
main groups of contaminants (metals, PAHs, musks, PCBs,
and organochlorine pesticides (OCPs)). Likewise, integrated
pollution indices revealed differences in the levels of contaminants.
Moreover, the profiles and levels in oyster tissues also
varied with season. Thus, principal component analysis clearly
discriminated Nicaraguan and Colombian localities and, especially
in Colombia, seasonal trends in chemical contamination
and differences amongst localities were evidenced. The geographical
and environmental disparity of the studied scenarios
may represent to a large extent the diversity of mangrove-lined
Caribbean coastal systems and therefore the present results
support the use of C. rhizophorae as suitable biomonitor species
at Caribbean regional scale, where seasonal variability
is a major factor controlling pollutant mobility and
bioavailability