Occurrence and spatial distribution of microplastics in sediments from Norderney

Area of Science:

• Environmental Science
• Marine Biology
• Chemistry

Background:

• Microplastic pollution is a growing concern in marine environments.
• Understanding the distribution of small potential microplastics (SPM) is crucial for assessing ecological risks.
• Beach sediments act as sinks for microplastics, influencing their environmental fate.

Purpose of the Study:

• To investigate the spatial distribution of small potential microplastics (SPM) (<1 mm) in beach sediments.
• To examine the correlation between SPM and visible plastic debris (VPD) (>1 mm).
• To identify the types of polymers and additives present in the microplastics.

Main Methods:

• Sampling of 36 one kg sediment samples from a 500 m stretch of Norderney beach.
• Extraction and analysis of SPM using visual microscopic inspection.
• Identification of polymers and additives using thermal desorption pyrolysis gas chromatography/mass spectrometry (TD-Py-GC/MS).

Main Results:

• SPM were found at mean concentrations of 1.7, 1.3, and 2.3 particles per kg dry sediment across three sites.
• Identified polymers included polypropylene, polyethylene, PET, PVC, polystyrene, and polyamide.
• Detected additives comprised phthalates, phenols, and benzophenone.
• SPM distribution was homogenous and showed no correlation with VPD presence.

Conclusions:

• Small potential microplastics are present in North Sea beach sediments, with diverse polymer compositions.
• The homogenous distribution suggests widespread input or transport mechanisms.
• The lack of correlation with visible plastic debris indicates that larger debris is not a reliable indicator for the presence of smaller microplastics.