In the Mediterranean Sea, according to experts, approximately 100,000 tons of plastic waste end up annually, a number that has reached alarming levels, against the backdrop of the negative imprint they leave, especially when they are felt in coastal areas both in the water column and at the beach.

Plastics float on the surface of the sea or are distributed in the water column and are then transported by ocean currents, while after often traveling long distances, some of them end up on the bottom posing a significant threat to marine ecosystems and another part of them ends up on the coastline , where it degrades it environmentally and aesthetically.

Speaking to APE-MPE, the director of the Research Technology Foundation’s Coastal and Marine Research Laboratory, Nikos Kampanis, said that “the Aegean region is a particularly interesting region, which has intensive navigation, a complex coastline and many islands. It is also close to coastal megacities which often burden the coastal and marine environment with pollution, a typical type of which is plastics.” He also noted that some of these megacities are in non-EU areas, such as on the coast of Turkey, so they are not subject to European legislation, regulations and provisions that impose restrictive measures. “The problem of marine pollution, whether from plastics or from chemical and biological waste, is cross-border,” pointed out Mr. Kampanis.

The Coastal and Marine Research Laboratory of ITE, in collaboration with the Regional Unit of Lasithi, performed an autopsy on the northern coastline of the Municipality of Ierapetra (Pachia Ammos and surrounding areas), where the problem of marine plastic pollution was identified, which raises the question of how the negative impact from this would ultimately give a negative sign to the tourism development of the region, which is currently showing an upward trend. As the director of the Coastal and Marine Research Laboratory of the ITE pointed out after being informed by the local residents, an autopsy was also carried out in the area of ​​Kalos Chori, in the Municipality of Agios Nikolaos, which showed that the problem exists with high intensity there as well.

The implementation of the relevant research is carried out by the Coastal and Marine Research Laboratory in the context of the relevant research project that it prepares for the Region of Crete. Mathematical modeling of the transport of plastics in the marine environment is carried out, in order to study the possible sources of pollution, their transport routes with marine currents, zones of high concentration of plastics along the coastline (hotspots), as well as seasonality and inter-annual variability of the phenomenon. In addition, data have been collected on the presence of plastics in the coastal zone of the areas where the problem is manifested, from aerial and on-site observations, at the time that points of exceptional natural beauty were recorded in the immediate vicinity, which are strong elements of environmental wealth to be exploited.

To investigate the transport routes of plastic waste in the coastal zone of the Pachia Ammos and Kalos Chori areas, the simulation area spans the entire S. Aegean and the Levantine basin, in order to take into account possible land (coastal settlements, rivers) and marine (sea lanes) sources of pollution. Based on international literature estimates, the most important source of pollution is coastal settlements, contributing 50% of the total mass of plastics entering the marine environment annually, while 30% is attributed to shipping routes and 20% to estuaries.

In order to be able to study the seasonality and inter-annual variability of the phenomenon and to extract average daily and average monthly plastic concentration maps in the study area, as explained by Mr. Kampanis, the years 2019 were chosen as the time period for simulating the transport of plastics -2022, with the note that in addition to sea currents, the effect of waves also plays a role in the transport of plastics. For the modeling done, data on the oceanographic behavior of the S. Aegean and the Levantine basin from the Copernicus Marine Service (CMEMS) were used for the sea currents and waves in geographical cells of about 4 km. Especially, for the nearest sea area of Crete, the plastic transport simulation was based on the Coastal Crete operational marine forecasting service operated by the laboratory, which produces hourly forecasts (meteorological, marine circulation and waves) in 1 km spatial resolution cells.

“The simulation of the phenomenon showed that the most important sources of plastic waste for the region are the Turkish beaches (coastal settlements and sea lanes) in the Levantine basin, from where they move towards the S. Aegean through the surface current. Additional sources are the sea routes in the S. Aegean (mainly the Cyclades) and the Saronic Gulf, from where through the hydrodynamic circulation they move towards the northern Cretan Sea

. The cyclonic and anti-cyclonic circulation in northern Crete creates a recirculation of plastics, which through the sea currents that approach Crete from the NW are transported mainly to the NE coastline of Lasithi, with the beaches of Kalos Chorio, Istro and Pachia Ammos to be among the most burdened” the director of the Laboratory told APE-MPE, adding that the average monthly plastic concentration maps extracted from the simulation show that “the phenomenon is more intense in the spring, in the months of April and May, in the summer June and July, autumn, October and winter, mainly in January, while it is also observed that the transport routes of the plastics from the potential sources of pollution to the coastal areas are relatively short, and no accumulation zones are formed in the Aegean ».

Finally, Mr. Kampanis emphasized that “since no accumulation zones are observed in the Aegean, the largest percentage of plastics flowing in from different sources ends up on the coastline and on the bottom, with an emphasis on the northeastern coastline of Crete”.