Description: Microplastics (MP) are recognized as a growing environmental hazard and have been identified as far as the remote Polar Regions, with particularly high concentrations of microplastics in sea ice. Little is known regarding the horizontal variability of MP within sea ice and how the underlying water body affects MP composition during sea ice growth. Here we show that sea ice MP has no uniform polymer composition and that, depending on the growth region and drift paths of the sea ice, unique MP patterns can be observed in different sea ice horizons. Thus even in remote regions such as the Arctic Ocean, certain MP indicate the presence of localized sources. Increasing exploitation of Arctic resources will likely lead to a higher MP load in the Arctic sea ice and will enhance the release of MP in the areas of strong seasonal sea ice melt and the outflow gateways.

Description: Although the Arctic covers 6% of our planet’s surface and plays a key role in the Earth’s climate it remains one of the least explored ecosystems. The global change induced decline of sea ice has led to increasing anthropogenic presence in the Arctic Ocean. Exploitation of its resources is already underway, and Arctic waters are likely important future shipping lanes as indicated by already increasing numbers of fishing vessels, cruise liners and hydrocarbon prospecting in the area over the past decade. Global estimates of plastic entering the oceans currently exceed results based on empirical evidence by up to three orders of magnitude highlighting that we have not yet identified some of the major sinks of plastic in our oceans. Fragmentation into microplastics could explain part of the discrepancy. Indeed, microplastics were identified from numerous marine ecosystems globally, including the Arctic. Here, we analysed horizons of ice cores from the western and eastern Fram Strait by focal plane array based micro-Fourier transform infrared spectroscopy to assess if sea ice is a sink of microplastic. Ice cores were taken from land-locked and drifting sea ice to distinguish between local entrainment of microplastics vs long-distance transport. Mean concentrations of 2 x 106 particles m-3 in pack ice and 6 x 105 particles m-3 in land-locked ice were detected (numbers of fibers will soon be added). Eleven different polymer types were identified; polyethylene (PE) was the most abundant one. Preliminary results from four further ice cores from the central Arctic range in a similar order but the microplastics composition was very different. Calculation of drift trajectories by back-tracking of the ice floes sampled indicates multiple source areas, which explains the differences in the microplastic composition. Preliminary analysis of snow samples taken from ice floes in the Fram Strait showed numerous fibers of yet unknown but most likely anthropogenic origin indicating atmospheric fallout as a possible pathway. Our results exceed concentrations from the North Pacific by several orders of magnitudes. This can be explained partly by the process of ice formation, during which (organic) particles tend to concentrate by 1-2 orders of magnitude compared with ambient seawater. However, the magnitude of the difference indicates that Arctic sea ice is a temporal sink for microplastics. Increasing quantities of small plastic litter items on the seafloor nearby, which is located in the marginal ice zone corroborate the notion that melting sea ice releases entrained plastic particles and that sea ice acts as a vector of transport both horizontally and vertically to underlying ecosystem compartments.

Description: The global change induced decline of sea ice has led to increasing anthropogenic presence in the Arctic Ocean. The Fram Strait is likely to become an important shipping lane as indicated by increasing numbers of fishing vessels and cruise liners in this area. One footprint of anthropogenic activities in the oceans is litter pollution, especially long-lived plastic, which is recognised as a global problem of growing concern given annual global production rates of 299 million t. Litter affects 〉580 marine species primarily by entanglement and ingestion, through which it can also enter food webs. Although recent reports indicate that anthropogenic waste has made it to the remotest parts of our oceans, there is still only limited information about temporal trends and its distribution, especially in polar and deep seas. Still less information is available about the contamination with microplastics, a degradation product of larger fragmented litter items. Mean litter densities from the water surface recorded during ship- and helicopter-based surveys in the Fram Strait (2012) were 0.0062 items km-1, which is comparable with observations from Antarctica. Despite the notion that plastic floats at the water surface, 50% of municipal waste exceeds the density of seawater and sinks. Repeated camera transects from the seafloor of two stations of the HAUSGARTEN observatory (2500 m depth) showed that litter densities increased from 3,523 in 2002 to 6,566 items km-2 in 2014, comparable to densely populated European seas. There was also an increase in smaller-sized items, indicating fragmentation. Differences in litter type and size between the two stations may suggest different pathways of litter to the deep seafloor. For example, the northern station experienced longer periods of sea ice cover, which may explain the higher densities of small-sized plastics, released from sea ice upon melting. Microplastic concentrations in two sea ice cores from the FRAM Strait were analysed by FT-IR Imaging technology and exceeded those from previous reports in the Arctic by four orders of magnitude. The upper sections of the core contained far more microplastics compared to those in direct contact with the underlying seawater corroborating the assumption that sea ice is a source for microplastic in the Fram Strait. Considering the ever increasing production rates of plastic (ca.4% p.a.) and the failure of solid waste management practice, our footprints are likely to become larger unless serious mitigating actions are taken to reduce the amounts of litter entering the oceans.

Description: Microplastics (MP) are recognized as a growing environmental hazard and have been identified as far as the remote Polar Regions, with particularly high concentrations of microplastics in sea ice. Little is known regarding the horizontal variability of MP within sea ice and how the underlying water body affects MP composition during sea ice growth. Here we show that sea ice MP has no uniform polymer composition and that, depending on the growth region and drift paths of the sea ice, unique MP patterns can be observed in different sea ice horizons. Thus even in remote regions such as the Arctic Ocean, certain MP indicate the presence of localized sources. Increasing exploitation of Arctic resources will likely lead to a higher MP load in the Arctic sea ice and will enhance the release of MP in the areas of strong seasonal sea ice melt and the outflow gateways

Description: Although the Arctic covers 6% of our planet’s surface and plays a key role in the Earth’s climate it remains one of the least explored ecosystems. The global change induced decline of sea ice has led to increasing anthropogenic presence in the Arctic Ocean. Exploitation of its resources is already underway, and Arctic waters are likely important future shipping lanes as indicated by already increasing numbers of fishing vessels, cruise liners and hydrocarbon prospecting in the area over the past decade. Global estimates of plastic entering the oceans currently exceed results based on empirical evidence by up to three orders of magnitude highlighting that we have not yet identified some of the major sinks of plastic in our oceans. Fragmentation into microplastics could explain part of the discrepancy. Indeed, microplastics were identified from numerous marine ecosystems globally, including the Arctic. Here, we analysed horizons of ice cores from the western and eastern Fram Strait by focal plane array based micro-Fourier transform infrared spectroscopy to assess if sea ice is a sink of microplastic. Ice cores were taken from land-locked and drifting sea ice to distinguish between local entrainment of microplastics vs long-distance transport. Mean concentrations of 2 x 106 particles m-3 in pack ice and 6 x 105 particles m-3 in land-locked ice were detected (numbers of fibers will soon be added). Eleven different polymer types were identified; polyethylene (PE) was the most abundant one. Preliminary results from four further ice cores from the central Arctic range in a similar order but the microplastics composition was very different. Calculation of drift trajectories by back-tracking of the ice floes sampled indicates multiple source areas, which explains the differences in the microplastic composition. Preliminary analysis of snow samples taken from ice floes in the Fram Strait showed numerous fibers of yet unknown but most likely anthropogenic origin indicating atmospheric fallout as a possible pathway. Our results exceed concentrations from the North Pacific by several orders of magnitudes. This can be explained partly by the process of ice formation, during which (organic) particles tend to concentrate by 1-2 orders of magnitude compared with ambient seawater. However, the magnitude of the difference indicates that Arctic sea ice is a temporal sink for microplastics. Increasing quantities of small plastic litter items on the seafloor nearby, which is located in the marginal ice zone corroborate the notion that melting sea ice releases entrained plastic particles and that sea ice acts as a vector of transport both horizontally and vertically to underlying ecosystem compartments.

Description: Since the mass production of plastic started in the 1950’s, the accumulation of plastic litter as well as plastic particles known as microplastics (MP) in aquatic habitats was reported. The primarily examined habitats concerning MP are the marine environment as well as riverine systems and lakes. MP pollution of remote areas like polar regions is currently widely unknown. Until now only one published study proved the abundance of MP in arctic sea ice. This thesis aims to fill this gap of knowledge with an emphasis on MP pollution of sea ice deriving from the Fram Strait, a passage between Greenland and Svalbard. As a first step, an appropriate preparation procedure of ice cores regarding MP analysis was developed. The second step consisted of the identification and quantification of MP via FPA (focal plane array) – based micro – Fourier transformed infrared (FTIR) spectroscopy. In total four ice cores sampled in Fram Strait in 2014 at two different locations were examined. The surface of the ice cores in contact with the driller was removed by scraping and flushing with MilliQ. The cores were cut into pieces, melted, concentrated on Anodisc filters and finally subjected to micro – FTIR spectroscopy. Mean concentrations of 2 x 106 particles m-3 in pack ice and 6 x 105 particles m-3 land-fast ice were detected. Thereby the highest concentration exceeded that of the previously published study on MP in sea ice by 4 orders of magnitude. In total 11 different polymer types were identified, whereas polyethylene (PE) was the most abundant one.