Marine litter in the Croatian part of the middle Adriatic Sea: Simultaneous assessment of floating and seabed macro and micro litter abundance and composition

In this study, abundance, distribution and composition of floating and seabed macro and micro litter in the Central Adriatic Sea were assessed. Floating macro litter observations were made. Floating and seabed micro litter were sampled with manta net and Van Veen grab, respectively. Micro litter particles visually found under the microscope were chemically analyzed with Fourier Transform Infrared microscope. Average calculated concentrations of floating macro (175 items/km²), floating micro (127 thousand particles/km²) and seabed micro litter (36 particles/100 g dry weight) show similar values as other published studies from the Mediterranean Sea. A statistically significant (p < 0.01) correlation between the floating micro and macro litter concentrations was found for the sites located in the channel waters. Disagreement between model and observations revealed gaps in our knowledge concerning the sea circulation and litter sources. Simultaneous samplings and observations of marine litter in different marine compartments proved possible, efficient and informative.

Levels of trace metals on microplastic particles in beach sediments of the island of Vis, Adriatic Sea, Croatia

The aim of this study was to determine the levels of trace metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) in plastic pellets collected from two sandy beaches on the island of Vis, Croatia. A total of 92 pellets in a sediment volume of 3965 mL were collected at the investigated sampling sites. Concentrations of pellets in sediment samples ranged from 6 to 36 particles dm^-3 of wet sediment. Mean particle weight of the collected beached pellets ranged from 17 mg to 31 mg. Trace metal concentrations in plastic pellets were greater than the concentrations reported for seawater in the investigated area, which indicates that plastic pellets sorb metals from the marine environment. The adsorbed trace metals may enter the food chain due to incidental ingestion of microplastic particles by marine animals, which presents a potential human health risk due to consumption of seafood.

Assessment on marine litter ingested by fish in the Adriatic and NE Ionian Sea macro-region (Mediterranean)

This study presents data on the marine litter occurrence in the stomachs of fish species living in different marine habitats for the Adriatic and NE Ionian Sea macro-region. "Macro-litter" was examined in 614 specimens belonging to 11 species, while micro-litter in 230 specimens belonging to 7 species. The study highlights for the first time the presence of litter in the stomachs of the fish species Citharus linguatula. The occurrence of "macro-litter" in the guts of fish was <3% in both the NE Ionian and N Adriatic but reached 26% in the S Adriatic Sea. Micro-litter occurrence was 40 for the NE Ionian and increased to 87% in the N Adriatic (Slovenian Sea). The ingested "macro" and micro-litter differed among the areas. The marine habitat was found to affect the "macro"-litter ingestion but not the micro-litter.