Preliminary Assessment of Microplastic Pollution Index: A Case Study in Marmara Sea

Marine litter is a crucial problem for marine environment, and this problem is generally based on anthropogenic activities. Even though human-induced activities that cause marine litter are well known, they have not been assessed for the microplastic pollution yet. Here, we present the Microplastic Pollution Index (MPI); a fast, convenient, inexpensive and semi-quantitative tool for assessing land- and marinebased pressures on the sampling area. In this preliminary study, MPI were determined for eight different locations in Marmara Sea. The Marmara Sea is under the effect of several pressures, which can be seen from MPI results. Furthermore, currents and coastline morphology affect the retention time of water at the coastal zone. The highest MPI values were obtained from the Izmit and Bandırma gulfs, whereas the lowest value was found at entrance of the Dardanelle Strait. MPI values and manta net abundance values for each station showed a good linear relation (R2 = 0.58; F = 7.113; DF =1, q = 0.045). No correlation was found between the water column and sediment abundance values. MPI is providing information on microplastic pollution, which is useful to create an effective monitoring strategy. Furthermore, environmental managers can use this information to combat, restore and protect coastal waters against the microplastic pollution.