Quarterly variability of floating plastic debris in the marine protected area of the Menorca Channel (Spain)

Plastic pollution is widespread in all the oceans and seas, representing a significant threat to most of their ecosystems even in marine protected areas (MPAs). This study determines the floating plastic distribution in four different periods between 2014 and 2015 in the recently approved Menorca Channel MPA (Balearic Islands). Plastic debris were persistent during all sampling periods on the surface of the Channel, composed mainly by the microplastic sizes. Average particle abundances ranged from 138,293 items⋅km⁻² in autumn to 347,793 items⋅km⁻² during the spring, while weight densities varied from 458.15 g(DW)⋅km⁻² in winter to 2016.67 g(DW)⋅km⁻² in summer. Rigid plastics were the most frequent particles in all the periods analysed (from 89.40%-winter to 94.54%-spring). The high-resolution and particle distribution models corroborated that the oceanographic variability shapes different patterns of presence of plastics, and in particular the existence of areas with almost no plastics. Floating plastic debris in the MPA of the Menorca Channel were present along four different sampling periods influenced by circulation patterns that would shape its spatial distribution.