peer reviewed | Anthropogenic particles (APs), including microplastics, are ingested by a wide variety of marine organisms. Exposure of Clupeiformes (e.g. herrings, anchovies, sardines) is poorly studied despite their economic and ecological importance. This study aims to describe the morphology of the filtration apparatus of three wild-caught Clupeiformes (Sardina pilchardus, Clupea harengus and Engraulis encrasicolus) and to relate the results to ingested APs. Consequently, the species with the more efficient filtration apparatus will be more likely to ingest APs. We hypothesized that sardines were the most exposed species. The filtration area and particle retention threshold were determined in the three species, with sardines displaying the highest filtration area and the closest gill rakers. Sardines ingested more fibers and smaller fragments, confirming that it is the most efficient filtering species. These two results lead to the conclusion that, among the three studied, the sardine is the species most exposed to APs.

peer reviewed | Stable isotopes of carbon and nitrogen are increasingly used in marine ecosystems, for ecological and environmental studies. Here, we examine some applications of stable isotopes as ecological integrators or tracers in seagrass ecosystem studies. We focus on both the use of natural isotope abundance as food web integrators or environmental tracers and on the use of stable isotopes as experimental tools. As ecosystem integrators, stable isotopes have helped to elucidate the general structure of trophic webs in temperate, Mediterranean and tropical seagrass ecosystems. As environmental tracers, stable isotopes have proven their utility in sewage impact measuring and mapping. However, to make such environmental studies more comprehensible, future works on understanding of basic reasons for variations of N and C stable isotopes in seagrasses should be encouraged. At least, as experimental tracers, stable isotopes allow the study of many aspects of N and C cycles at the scale of a plant or at the scale of the seagrass ecosystem. (C) 2004 Elsevier Ltd. All rights reserved.

peer reviewed | A N-15 tracer study was performed during an experimental transplantation trial of natural Posidonia oceanica cuttings. The experiment was done in situ at 17 m depth in the Revellata Bay (Calvi, NW Corsica, France). Despite high survival rates of transplants (>90%) after one year, the weight and the N content of transplants are significantly lower than those of reference plants. In absence of roots, the transplants are not able to meet their N requirement because, leaf uptake is insufficient to replenish the N lost during the natural leaf decay. This could constitute a major cause of long-term failure for transplantation experiments or natural recolonisation processes. The increase of the N-15 content in the roots shows that the plant re-allocates the nitrogen of one organ (i.e. leaves, rhizomes) to ensure the growth of another (i.e. roots). (C) 2003 Elsevier Ltd. All rights reserved. | Novel Marine Technology (NOMATEC)

In the global COVID-19 epidemic, humans are faced with a new challenge. The concept of quarantine as a preventive measure has changed human activities in all aspects of life. This challenge has led to changes in the environment as well. The air quality index is one of the immediate concrete parameters. In this study, the actual potential of quarantine effects on the air quality index and related variables in Tehran, the capital of Iran, is assessed, where, first, the data on the pollutant reference concentration for all measuring stations in Tehran, from February 19 to April 19, from 2017 to 2020, are monitored and evaluated. This study investigated the hourly concentrations of six particulate matters (PM), including PM2.5, PM10, and air contaminants such as nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), and carbon monoxide (CO). Changes in pollution rate during the study period can be due to reduced urban traffic, small industrial activities, and dust mites of urban and industrial origins. Although pollution has declined in most regions during the COVID-19 quarantine period, the PM2.5 rate has not decreased significantly, which might be of natural origins such as dust. Next, the air quality index for the stations is calculated, and then, the interpolation is made by evaluating the root mean square (RMS) of different models. The local and global Moran index indicates that the changes and the air quality index in the study area are clustered and have a high spatial autocorrelation. The results indicate that although the bad air quality is reduced due to quarantine, major changes are needed in urban management to provide favorable conditions. Contaminants can play a role in transmitting COVID-19 as a carrier of the virus. It is suggested that due to the rise in COVID-19 and temperature in Iran, in future studies, the effect of increased temperature on COVID-19 can be assessed. | peer reviewed

peer reviewed | The annual variation in neustonic plastic particles and zooplankton was studied in the Bay of Calvi 23 (Corsica) between 30 August 2011 and 7 August 2012. Plastic particles were classified into three size classes, small microplastics (0.2–2 mm), large microplastics (2–5 mm) and mesoplastics (5–10 mm). 74% of the 38 samples contained plastic particles of varying composition: e.g. filaments, polystyrene, thin plastic films. An average concentration of 6.2 particles/100 m2 was observed. The highest abundance values (69 particles/100 m2) observed occurred during periods of low offshore wind conditions. These values rose in the same order of magnitude as in previous studies in the North Western Mediterranean. The relationships between the abundance values of the size classes between zooplankton and plastic particles were then examined. The ratio for the intermediate size class (2–5 mm) reached 2.73. This would suggest a potential confusion for predators regarding planktonic prey of this size class.

peer reviewed | Microplastic contamination is an emerging issue in the marine environment including the Arctic. However, the occurrence of microplastics in the Arctic fjords remains less understood. Sample collections were conducted by trawling horizontally in surface water (0-0.4-m depth) and trawling vertically in the water column (0-200-m depth) to investigate the abundance, composition, and distribution of microplastics in the Rijpfjorden, Northern Svalbard, in the summer of 2017. Laser Direct Infrared chemical imaging technique was applied for the counting and identification of microplastic particles. A total of 1010 microplastic particles and 14 mesoplastics were identified from 41,038 particles in eight samples from the Rijpfjorden. The abundance of microplastics larger than 300 µm was 0.15 ± 0.19 n/m3 in surface water, and 0.15 ± 0.03 n/m3 in the water column of the Rijpfjorden. The microplastic particles identified in Rijpfjorden water consisted of 10 types of polymers. The dominant microplastics are polyurethane, polyethylene, polyvinyl acetate, polystyrene, polypropylene, and alkyd varnish. Historical ship activities and newly melted sea ice might be major sources of microplastics in the seawater of Rijpfjorden. In general, contamination of microplastics larger than 300 µm in Rijpfjorden water is at a low level in comparison to other polar waters. Further research is needed to confirm the origin and fate of microplastics below 300 µm in Arctic fjords.