Fauna - Microplastics interactions: Empirical insights from benthos community exposure to marine plastic waste.

Microplastic deposition in soft marine sediments raises concerns on their role in sediment habitats and unknown effects on resident macrobenthic communities. To assess the reciprocal influence that MPs and macrobenthos might have on each other, we performed a mesocosm experiment with ambient concentrations of environmental Polyethylene (PE) and a non-manipulated, natural macrobenthic community from the Belgian part of the North Sea (BPNS). Our results show that PE fragments increase mortality of abundant bivalves (specifically Abra alba) after 30 days of exposure but not for the most abundant polychaete Owenia fusiformis, possibly due to its predominant suspension feeding behavior. Fast burial of surface MPs exposes deep-dwelling burrowers to the pollutant, however reducing the amount of MPs interacting with (sub) surface living fauna. We conclude that macrobenthos promotes the sequestration of deposited MPs, counteracting resuspension, and can have cascading effects on biodiversity due to their effect on abundant and functionally important species.

Selenium in Hungary. The rock-soil-human system.

Selenium (Se) status of Hungarian rock-soil systems has been poorly investigated. The goal of this study was to get general information on the main features of Se geochemistry, and to have a brief look into the human Se status in Hungary, developing an appropriate method for a forthcoming systematic regional investigation. A multistage program was applied: 1. stream sediment sampling; 2. investigation of rock-soil profiles typical in Hungary; and 3. extraction of mobile Se fractions from soils. Human serum samples from apparently healthy blood donors residing in both urban and rural areas were collected from three districts in Hungary. It was concluded that Hungarian rock-soil systems, especially the acid igneous rocks and the widely distributed young sediments (loess and sand formations) with most of the agricultural activity, are low in Se, and the mean serum Se level of the blood samples were also low.