Abundance and composition of marine litter on the coasts of the Dardanelles (Canakkale Strait, Turkey)

The amount of human-origin litter in sea surface water, sediment, and beaches has been increasing for decades. Initially described in marine coastal systems in the 1960s, marine litter (ML) is nowadays commonly observed in all marine systems. There is even a gigantic island consisting of garbage in the gyre area of the Atlantic Ocean. In relation to this significant problem, ML was collected from seven stations on beaches along the Dardanelles for the first time in the period May 2017–May 2018 and was seasonally and regionally analyzed in terms of densities and weights. ML was categorized by material type (plastic, rubber, paper, etc.) and field of use (mixed packaging wastes, personal use products, fishing wastes, etc.). Total numbers and weights of ML during the study were 5751 items and 115.7 kg in an area of 15,980 m2, respectively. Density and weight of ML ranged from 0.050 to 1.182 items/m2 and from 0.446 to 78.46 g/m2, respectively. The main ML component was plastic items in terms of both density (90.95%) and weight (53.76%) according to material type. Additionally, mixed packaging wastes (MPW) were the most common ML items in terms of density (82.14%) and weight (49.38%) according to usage. According to the clean-coast index, while Kilya (St.2) and Kepez (St.5) beaches were dirty, Seddulbahir (St.1) beach was clean. The beaches in other stations were neither dirty nor clean (medium) according to the index. At the end of the study, suggestions for a regional strategy were made.