Per- and polyfluoroalkyl substances in Chinese and German river water - Point source- and country-specific fingerprints including unknown precursors.

This study aimed at comparing source-specific fingerprints of per- and polyfluoroalkyl substances (PFASs) in river water from China and Germany, selected as countries with different histories of PFAS production. Samples were collected from up- and downstream of seven suspected point sources in autumn 2018. Amongst the 29 analyzed legacy and emerging PFASs, 24 were detected, with a sum ranging from 2.

Predation risk triggers copepod small-scale behavior in the Baltic Sea.

Predators not only have direct impact on biomass but also indirect, non-consumptive effects on the behavior their prey organisms. A characteristic response of zooplankton in aquatic ecosystems is predator avoidance by diel vertical migration (DVM), a behavior which is well studied on the population level. A wide range of behavioral diversity and plasticity has been observed both between- as well as within-species and, hence, investigating predator-prey interactions at the individual level seems therefore essential for a better understanding of zooplankton dynamics.

Photochemistry of oxidized Hg(I) and Hg(II) species suggests missing mercury oxidation in the troposphere.

Mercury (Hg), a global contaminant, is emitted mainly in its elemental form Hg to the atmosphere where it is oxidized to reactive Hg compounds, which efficiently deposit to surface ecosystems. Therefore, the chemical cycling between the elemental and oxidized Hg forms in the atmosphere determines the scale and geographical pattern of global Hg deposition. Recent advances in the photochemistry of gas-phase oxidized Hg and Hg species postulate their photodissociation back to Hg as a crucial step in the atmospheric Hg redox cycle.

Influence of Aviation Emission on the Particle Number Concentration near Zurich Airport.

In addition to the much-publicized environmental impact of CO emission by air traffic, aviation particulate emission also deserves attention. The abundant ultrafine particles in the aviation exhaust with diameters less than 100 nm may penetrate deep into the human respiratory system and cause adverse health effects. Here, we quantified the detailed aviation particle number emission from Zurich Airport and evaluated its influences on the annual mean particle number concentrations in the surrounding communities.

Bioaccumulation and changes of trace metals over the last two decades in marine organisms from Guangdong coastal regions, South China.

Trace metal (Cr, Ni, Cu, Zn, Cd and Pb) exposures, distribution and bioaccumulation were investigated in marine organisms from Guangdong coastal regions, South China. The results showed that all of the selected metals were observed in marine organisms with a predomination of Cu and Zn. The metal exposure levels exhibited obvious variations between species with the decreasing order of crab>shellfish>shrimp>fish.

Ecological and conceptual consequences of Arctic pollution.

Although the effect of pollution on forest health and decline received much attention in the 1980s, it has not been considered to explain the 'Divergence Problem' in dendroclimatology; a decoupling of tree growth from rising air temperatures since the 1970s. Here we use physical and biogeochemical measurements of hundreds of living and dead conifers to reconstruct the impact of heavy industrialisation around Norilsk in northern Siberia. Moreover, we develop a forward model with surface irradiance forcing to quantify long-distance effects of anthropogenic emissions on the functioning and productivity of Siberia's taiga.

Training deep neural density estimators to identify mechanistic models of neural dynamics.

Mechanistic modeling in neuroscience aims to explain observed phenomena in terms of underlying causes. However, determining which model parameters agree with complex and stochastic neural data presents a significant challenge. We address this challenge with a machine learning tool which uses deep neural density estimators-trained using model simulations-to carry out Bayesian inference and retrieve the full space of parameters compatible with raw data or selected data features.

Experimental Characterization of Single-Color Power LEDs Used as Photodetectors.

Semiconductor-based light emitting diodes can be used for photon emission as well as for detection of photons. In this paper, we present a fair comparison between off-the-shelf power Light emitting diodes (LEDs) and a silicon photodetector with respect to their spectral, temporal, and spatial properties. The examined LED series features unexpected good sensitivity and distinct optical bandpass characteristic suitable for daylight filtering or color selectivity.

Namibia's way to Marine Spatial Planning - Using existing practices or instigating its own approach?

The territorial waters and EEZ of Namibia are part of the Benguela Current Large Marine Ecosystem in the South-East Atlantic. Growing demands and conflicts emerge although the area is not as intensely used as marine areas elsewhere. Namibia has chosen Marine Spatial Planning (MSP) as an integrated approach to facilitate sustainable ocean development and improved ocean governance.

Altered tropical seascapes influence patterns of fish assemblage and ecological functions in the Western Indian Ocean.

The arrangement and composition of habitats within landscapes and fine-scale habitat characteristics influence community structure and ecological processes. These aspects can be altered by anthropogenic activities, thus influencing associated assemblages. Farming of macroalgae is a common practice in tropical settings and alters the natural composition of seascapes by introducing monoculture patches.

Substituting HF by HBF- an optimized digestion method for multi-elemental sediment analysis via ICP-MS/MS.

Determination of elemental mass fractions in sediments plays a major role in evaluating the environmental status of aquatic ecosystems. Herewith, the optimization of a new total digestion protocol and the subsequent analysis of 48 elements in different sediment reference materials (NIST SRM 2702, GBW 07313, GBW 07311 and JMC-2) based on ICP-MS/MS detection is presented. The developed method applies microwave acid digestion and utilizes HBF as fluoride source for silicate decomposition.

A metrologically traceable protocol for the quantification of trace metals in different types of microplastic.

The presence of microplastic (MP) particles in aquatic environments raised concern about possible enrichment of organic and inorganic pollutants due to their specific surface and chemical properties. In particular the role of metals within this context is still poorly understood. Therefore, the aim of this work was to develop a fully validated acid digestion protocol for metal analysis in different polymers, which is a prerequisite to study such interactions.

Holocene global mean surface temperature, a multi-method reconstruction approach.

An extensive new multi-proxy database of paleo-temperature time series (Temperature 12k) enables a more robust analysis of global mean surface temperature (GMST) and associated uncertainties than was previously available. We applied five different statistical methods to reconstruct the GMST of the past 12,000 years (Holocene). Each method used different approaches to averaging the globally distributed time series and to characterizing various sources of uncertainty, including proxy temperature, chronology and methodological choices.

Occurrence of legacy and emerging organic contaminants in snow at Dome C in the Antarctic.

Concentrations of 9 organophosphate esters (OPEs), 16 perfluoroalkylated substances (PFASs) and 17 polycyclic aromatic hydrocarbons (PAHs) were investigated in surface snow samples collected at Dome C on the Antarctic Plateau in summer 2016. Tris(1-chloro-2-propyl) phosphate (TCPP), tris-(2-chloroethyl) phosphate (TCEP) and tri-n-butylphosphate (TnBP) were the dominant compounds of OPEs, with mean concentrations of 8157 ± 4860, 1128 ± 928 and 1232 ± 1147 pg/L. Perfluorooctanoic acid (PFOA, mean: 358 ± 71 pg/L) was the dominant compound of PFASs, and following by perfluoro-n-hexanoic acid (PFHxA, mean: 222 ± 97 pg/L), perfluoro-n-heptanoic acid (PFHpA, 183 ± 60 pg/L) and perfluoro-n-pentanoic acid (PFPeA, 175 ± 105 pg/L).

Uncovering the intricacies of microbial community dynamics at Helgoland Roads at the end of a spring bloom using automated sampling and 18S meta-barcoding.

In May 2016, the remote-controlled Automated Filtration System for Marine Microbes (AUTOFIM) was implemented in parallel to the Long Term Ecological Research (LTER) observatory Helgoland Roads in the German Bight. We collected samples for characterization of dynamics within the eukaryotic microbial communities at the end of a phytoplankton bloom via 18S meta-barcoding. Understanding consequences of environmental change for key marine ecosystem processes, such as phytoplankton bloom dynamics requires information on biodiversity and species occurrences with adequate temporal and taxonomic resolution via time series observations.

Characterization of alloying components in galvanic anodes as potential environmental tracers for heavy metal emissions from offshore wind structures.

The impact of offshore constructions on the marine environment is unknown in many aspects. The application of Al- and Zn-based galvanic anodes as corrosion protection results in the continuous emission of inorganic matter (e.g.

Overall comparison and source identification of PAHs in the sediments of European Baltic and North Seas, Chinese Bohai and Yellow Seas.

An international sampling campaign was carried out to comprehensively investigate the occurrence of polycyclic aromatic hydrocarbons (PAHs) in the marine sediments from the European Baltic and North Seas, Chinese Bohai and Yellow Seas. The concentrations of ∑PAHs in the samples from these four seas were in the range of 0.91-5361 ng/g dry weight (dw), 0.

Algal Accumulation Decreases Sediment Nitrogen Removal by Uncoupling Nitrification-Denitrification in Shallow Eutrophic Lakes.

In eutrophic lakes, the decay of settled algal biomass generates organic carbon and consumes oxygen, favoring sediment nitrogen loss via denitrification. However, persistent winds can cause algae to accumulate into dense mats, with uncertain impacts on sediment nitrogen removal. In this study, we investigated the effects of algal accumulation on sediment nitrogen removal in a shallow and eutrophic Chinese lake, Taihu.

Spatial and seasonal variations of organic corrosion inhibitors in the Pearl River, South China: Contributions of sewage discharge and urban rainfall runoff.

While organic corrosion inhibitors are ubiquitous in aquatic environments, knowledge on their occurrence, sources and transport in urban surface water is still scarce. In this study, the spatial and seasonal variations of organic corrosion inhibitors and their potential sources were investigated in the Pearl River Delta (PRD), one of the most highly urbanized watersheds in China. A total of 8 compounds belonging to benzothiazole (BTH) and benzotriazole (BTR) groups respectively, were identified in the Pearl River.

Persulfate-based degradation of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) in aqueous solution: Review on influences, mechanisms and prospective.

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) have attracted global attention due to their chemical durability, wide distribution, biotoxicity and bioaccumulative properties. Persulfate is a promising alternative to HO for advanced oxidation processes and effective for organic removal. In this review, persulfate activation methods and operational factors in persulfate-based PFOA / PFOS degradation are analyzed and summarized.

Maker Buoy Variants for Water Level Monitoring and Tracking Drifting Objects in Remote Areas of Greenland.

Meltwater runoff from the Greenland Ice Sheet changes water levels in glacial lakes and can lead to glacial lake outburst flooding (GLOF) events that threaten lives and property. Icebergs produced at Greenland's marine terminating glaciers drift into Baffin Bay and the North Atlantic, where they can threaten shipping and offshore installations. Thus, monitoring glacial lake water levels and the drift of icebergs can enhance safety and aid in the scientific studies of glacial hydrology and iceberg-ocean interactions.

An affordable and miniature ice coring drill for rapid acquisition of small iceberg samples.

Icebergs account for approximately half of the freshwater flux from the Greenland Ice Sheet and they can impact marine ecosystems by releasing nutrients and sediments into the ocean as they drift and melt. Parameterizing iceberg fluxes of nutrients and sediments to fjord and ocean waters remains a difficult task due to the complexity of ice-ocean interactions and is complicated by a lack of observations. Acquiring iceberg samples can be difficult and dangerous, as icebergs can break apart and roll without warning.

Vertical migration by bulk phytoplankton sustains biodiversity and nutrient input to the surface ocean.

Phytoplankton subsumes the great variety of unicellular photoautotrophs that perform roughly half of Earth's primary production. They achieve this despite their challenging oceanic habitat, with opposing vertical gradients of nutrients (which often limit their growth near the surface) and light (which becomes limiting with increasing depth). Most phytoplankton species are commonly assumed to be incapable of moving actively between the zones of light and nutrient availability, which are separated vertically by from 30-120 m.