Abundance and spatial distribution of coastal floating plastic marine debris in the Balearic Islands

Abstract

[eng] Coastal ecosystems are continuously affected by anthropogenic threats such as urbanization, maritime activities, recreational and commercial activities, all of which have been prominent sources of plastic marine litter. During summer of July 2017, the spatial distribution of floating plastics at seven locations across the island using nearshore sea cleaning boats was assessed. One-hundred percent of the samples contained plastic items of varying sizes, ranging from macro- (> 25 mm), meso- (5-25 mm) and microplastics (< 5 mm), composed principally of fragments, films and filaments. Significant differences were found for the abundance and size differences of items between the sampling locations. All samples were collected within one kilometre of the coastline and both the abundance and weight was found to significantly increase closer to the coastline. Plastics smaller than 5 mm were the dominant size class and fragments composed of almost 60% of the items with the main colors being transparent and white. Low variability of polymers were found with polyethylene being the primary plastic polymer type. These preliminary results indicate there is high small scale variability of coastal marine plastic concentrations surrounding the Balearic Islands