Spatial and temporal variations of litter at the Mediterranean beaches of Morocco mainly due to beach users

摘要

Beach tourism represents a pillar of Morocco economy and must be preserved and improved by enhancing beach attractiveness, e.g. by reducing beach littering. A preliminary step is the characterization of beach litter in order to understand litter-pollution sources/agents. Beach litter was collected, sorted and categorized at fourteen Mediterranean beaches of Morocco, along 100 m in width sectors, during four surveys carried out in the period from autumn 2015 to spring 2017. Mean litter concentration presented an average value of 390.8 +/- 255.3 items per 100 m, or 0.054 +/- 0.036 items m(-2), being more abundant in resorts and urban beaches than villages and rural beaches. Beach litter was slightly more abundant in autumn (436.6 +/- 255.3 items per 100 m; 0.059 +/- 0.032 items m(-2)) than spring (345.0 +/- 144.6 items per 100m; 0.048 +/- 0.026 items m(-2)). The "Clean-Coast Index" value, calculated for every beach and for the four surveys, remained generally low, i.e. presented an average value of 0.93 +/- 0.71 and all beaches fall into the "Very clean" or "Clean" categories. "Beach Grading" was also calculated. It is based on the abundance of nine litter types and classifies beaches from "A" ("Very good"), i.e. very clean, to "D" ("Poor"), i.e. very dirty beaches. Despite beaches appeared clean regarding abundance and density of debris and the CCI index, the biggest part of them showed bad grading with only one beach in a good condition ("B" grading at Jebha, a rural beach). Gross litter, harmful and general litter were the main causes of beaches degradation. Beach litter was mainly composed of Polymer Materials (PM), which represented 83.3% of all collected items and the top three items represented 36.4% of total debris, all them belonging to plastics litter: bottle caps, crisps packets/sweets wrappers and cigarettes butts. Beachgoers impacts on beach littering clearly appear in the high abundance of Coastal/Recreational and Smoking Related Activities debris that accounted for up to 60.5% of all collected debris, being more abundant in urban beaches (80.3%) than village and rural beaches (44.9%). This trend was well marked by Smoking Related Activity debris that were very poorly represented in rural beaches, with an overall mean of 3.2 +/- 5.4 items per 100 in, while in urban beaches their average value was 79.3 +/- 143.6 items per 100 m, it being much more high in autumn (125.6 +/- 190.5) than in spring (33.0 +/- 25.8). Local waste management is within the competences of the Municipalities, which receive technical and financial support from the Ministry of Interior. In addition to the cleaning efforts made by local administrations and NGOs, there exists an urgent need of improve and consolidate beachgoers public awareness since high concentrations of debris, mainly recorded at urban beaches, were related to beachgoers activities.