Distribution and composition patterns of plastic pollution in small islands subjected to different human pressures along the highly connected waters of the NW Mediterranean Sea.

One of the tools to protect Mediterranean biodiversity was the creation of an extensive network of Marine Protected Areas. That those areas are not exempt from plastic pollution has extensively been demonstrated whether they are characterized by a specific plastic composition if compared to not protected areas is currently a topic of discussion. This research aims to evaluate plastic spatial distribution and composition patterns along the surface waters of small islands of the Western Mediterranean Basin subjected to different human pressures and protection status. We studied the spatial distribution of floating plastics by performing 65 surface trawls, carried out using a Hydro-bios manta net coupled with a 335-μm mesh, along the coastal waters of a remote protected archipelago, Columbretes Islands (NW Mediterranean Sea), a protected archipelago located in a high anthropized environment, Cabrera MPA (Balearic Sea), and protected and unprotected areas of two touristic Islands, Mallorca and Menorca in the Balearic Sea. 10637 plastics were identified along the study area and a subset was categorized according to shape, size and polymer. Plastics were found at each sampling site and in all samples. No microscale nor mesoscale variability in plastics abundance was encountered throughout the study area where similar values were found in remote protected areas with no local land-based contamination sources [0.04 (±0.03) items/m2] and in anthropized areas [0.04 (±0.07) items/m2]. Results suggest that floating plastics, in a region such as the NW Mediterranean Sea, strongly exposed to human stressors and highly connected waters, are homogeneously distributed regardless of land uses. Differences were found in plastic size, shape, and polymer composition. Remote islands showed the highest number of fragments reaching percentages higher than 90%, the lowest percentage of film summing up to less than 3%, a lower microscale variability, and the presence of small items with sizes ranging from 2900 μm to 163000 μm not detected in the more anthropized areas. The percentage of film and plastic size increase according to the level of human pressure. Small fragments are the product of fragmentation processes, driven by photooxidation, of larger plastics to smaller ones. Films, due to their volume/surface ratio are suitable for biofouling favoring their faster removal from the sea surface to the seafloor. The lower abundance of film observed in the studied remote protected areas combined with a consistent abundance of small fragments suggest that plastics detected within these waters could be more aged and be arriving from distant sources when compared to plastics detected in more anthropized areas, such as of the Balearic Archipelago, closer to potential marine debris sources and previously described as plastics “retention area”. Remote areas showed a different polymer composition, with a higher percentage of polystyrene, extensively used in the fishing industry that could represent an important contamination source for those areas. Finally, data from this research can contribute to consolidating scientific evidence available for the elaboration and monitoring of future management plans focused on the mitigation and prevention of plastic pollution in marine protected areas

Distributed DNN serving in the network data plane

© 2022 ACM.Programmable networks have received tremendous attention recently. Apart from exciting network innovations, in-network computing has been explored as a means to accelerate a variety of distributed systems concerns, by leveraging programmable network devices. In this paper, we extend in-network computing to an important class of applications called deep neural network (DNN) serving. In particular, we propose to run DNN inferences in the network data plane in a distributed fashion and make our programmable network a powerful accelerator for DNN serving. We demonstrate the feasibility of this idea through a case study with a real-world DNN on a typical data center network architecture

Marine plastics in Mediterranean islands: Evaluating the distribution and composition of plastic pollution in the surface waters along four islands of the Western Sea Basin

To study the spatial distribution of sea surface plastics in marine protected and non-protected areas, 65 sea surface trawls were carried out using a Hydro-bios manta net coupled with a 335-μm mesh. A total of 19 sampling sites along the coastal waters of Mallorca, the “Parque Nacional Marítimo-Terrestre del Archipi´elago de Cabrera” and Menorca in the Balearic Islands as well as along coastal waters of The Natural Park of Columbretes Islands (NW Mediterranean Sea) were sampled. A total of 10,637 plastic items were identified and a subset of these items was categorized by shape, color, size and polymer composition. Plastic particles were found at each sampling site and in all samples. No microscale nor mesoscale variability in floating marine plastics abundance (particles/m2) was encountered throughout the study area where similar values were found in protected areas with no local land-based contamination sources, such as Columbretes [0.04 (±0.03) particles/m2], and in high anthropized areas, such as the island of Mallorca [0.04 (±0.07) particles/m2]. However, differences were found in characteristics of plastic items (shape, polymer, and size range), with the protected area of Columbretes characterized by the presence of the highest density of very small plastic items composed mainly of fragments (93%). Quantified plastics from the marine environment were composed mainly of polyethylene (PE, 63.3%), polypropylene (PP; 24.9%), polycarbonate (PC; 4.6%) and polystyrene (PS, 3.3%). The polymer composition showed a homogenous composition between islands and differences were detected only amongst Columbretes and the other islands. Results from this study provide further evidence of the ubiquity of plastics in the marine environment and highlight that remote and protected areas, such as Columbretes, are not exempt from plastic pollution, but receptor areas for small and aged floating plastics composed mainly by fragments, which might have potentially harmful effects on protected ecosystems.En prens