Description: The ingestion of microplastics has been shown for a great variety of marine organisms. However, benthic marine mesoherbivores such as the common periwinkle Littorina littorea have been largely disregarded in studies about the effects of microplastics on the marine biota, probably because the pathway for microplastics to this functional group of organisms was not obvious. In laboratory experiments we showed that the seaweed Fucus vesiculosus retains suspended microplastics on its surface. The numbers of microplastics that adhered to the algae correlated with the concentrations of suspended particles in the water. In choice feeding assays L. littorea did not distinguish between algae with adherent microplastics and clean algae without microplastics, indicating that the snails do not recognize solid nonfood particles in the submillimeter size range as deleterious. In periwinkles that were feeding on contaminated algae, microplastics were found in the stomach and in the gut. However, no microplastics were found in the midgut gland, which is the principle digestive organ of gastropods. Microplastics in the fecal pellets of the periwinkles indicate that the particles do not accumulate rapidly inside the animals but are mostly released with the feces. Our results provide the first evidence that seaweeds may represent an efficient pathway for microplastics from the water to marine benthic herbivores.

Description: Our objective for this study was to evaluate the influence of preindustrial and expected future atmospheric CO2 concentrations (280 μatm and 700 μatm pCO2, respectively) on different life-cycle stages of the kelp Laminaria hyperborea from Helgoland (Germany, North Sea). Zoospore germination, gametogenesis, vegetative growth, sorus formation and photosynthetic performance of vegetative and fertile tissue were examined. The contribution of external carbonic anhydrase (exCA) to C-supply for net-photosynthesis (net-PS) and the Chla- and phlorotannin content were investigated. Female gametogenesis and vegetative growth of sporophytes were significantly enhanced under the expected future pCO2. rETR(max) and net-PS of young vegetative sporophytes tended to increase performance at higher pCO2. The trend towards elevated net-PS vanished after inhibition of exCA. In vegetative sporophytes, phlorotannin content and Chla content were not significantly affected by pCO2.

Description: The ingestion of microplastics has been shown for a great variety of marine organisms. However, benthic marine mesoherbivores such as the common periwinkle Littorina littorea have been largely disregarded in studies about the effects of microplastics on the marine biota, probably because the pathway for microplastics to this functional group of organisms was not obvious. In laboratory experiments we showed that the seaweed Fucus vesiculosus retains suspended microplastics on its surface. The numbers of microplastics that adhered to the algae correlated with the concentrations of suspended particles in the water. In choice feeding assays L. littorea did not distinguish between algae with adherent microplastics and clean algae without microplastics, indicating that the snails do not recognize solid nonfood particles in the submillimeter size range as deleterious. In periwinkles that were feeding on contaminated algae, microplastics were found in the stomach and in the gut. However, no microplastics were found in the midgut gland, which is the principle digestive organ of gastropods. Microplastics in the fecal pellets of the periwinkles indicate that the particles do not accumulate rapidly inside the animals but are mostly released with the feces. Our results provide the first evidence that seaweeds may represent an efficient pathway for microplastics from the water to marine benthic herbivores.

Description: Understanding the distribution and structure of biotopes is essential for marine conservation according to international legislation, such as the European Marine Strategy Framework Directive (MSFD). The biotope 'Sea Pen and Burrowing Megafuna Communities' is included in the OSPAR list of threatened and/or declining habitats. Accordingly, the MSFD prescribes a monitoring of this biotope by the member states of the EU. In the German North Sea, however, the distribution and spatial extent of this biotope as well as the structuring of its benthic species inventory is unknown. We used an extensive geo-referenced dataset on occurrence, abundance and biomass of the benthic infauna of the south-eastern North Sea to estimate the distribution of the biotope and to characterize the associated infauna assemblages. Sediment preferences of the burrowing megafauna, comprising decapod crustaceans and echiurids, were identified and the core distribution areas of the burrowing megafauna were modelled using Random Forests. Clusters of benthic infauna inside the core distribution areas were identified by fuzzy clustering. The burrowing megafauna occurred on a wide range of sediments with varying mud contents. The core distribution area of the burrowing megafauna was characterized by elevated mud content and a water depth of 25-55 m. The analysis of the benthic communities and their relation to sedimentological conditions identified four infauna clusters of slightly varying species composition. The biotope type 'Sea Pen and Burrowing Megafuna Communities' is primarily located inside the paleo valley of the river Elbe and covers an area of 4980 km2. Dedicated monitoring will have to take into account the spatial extent and the structural variability of the biotope. Our results can provide a baseline for the evaluation of the future development of the environmental status of the biotope. The maps generated herein will facilitate the communication of information relevant for environmental management to authorities and policy makers.

Description: A new report commissioned by WWF provides the most comprehensive account to date of the extent to which plastic pollution is affecting the global ocean, the impacts it’s having on marine species and ecosystems, and how these trends are likely to develop in future. The report by researchers from the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI) reveals a serious and rapidly worsening situation that demands immediate and concerted international action: ● Today almost every species group in the ocean has encountered plastic pollution, with scientists observing negative effects in almost 90% of assessed species. ● Not only has plastic pollution entered the marine food web, it is significantly affecting the productivity of some of the world’s most important marine ecosystems like coral reefs and mangroves. ● Several key global regions – including areas in the Mediterranean, the East China and Yellow Seas and Arctic sea ice – have already exceeded plastic pollution thresholds beyond which significant ecological risks can occur, and several more regions are expected to follow suit in the coming years. ● If all plastic pollution inputs stopped today, marine microplastic levels would still more than double by 2050 – and some scenarios project a 50-fold increase by 2100.

Description: The seventh edition of the »World Ocean Review« focuses on the effects of climate change on the physics of the ocean and on its biotic communities; the consequences of fishing, shipping, resource extraction, energy production, and marine pollution; and the questions of how active substances from the ocean can be used and how the ocean can be managed in the future in such a way that both its protection and the participation of as many people as possible in its services and goods are ensured.

Description: Im Fokus der siebten Ausgabe des »World Ocean Review« stehen die Auswirkungen des Klimawandels auf die Physik des Meeres und auf seine Lebensgemeinschaften; die Folgen von Fischerei, Schifffahrt, Ressourcenabbau, Energiegewinnung und Meeresverschmutzung sowie die Fragen, wie sich Wirkstoffe aus dem Meer nutzen lassen und wie der Ozean künftig so verwaltet werden kann, dass sowohl sein Schutz als auch die Teilhabe möglichst aller Menschen an seinen Leistungen und Gütern gewährleistet sind.