The total length of the Greek coastal zone is approximately 16,200 km, making it the longest coastal zone among European countries.

The coastal zone hosts significant habitats, contributing to the survival of genetic resources of flora and fauna.

Marine ecosystems also play a major role in climate regulation by storing carbon dioxide, while various processes of the phytoplankton reservoir emit significant amounts of oxygen into the atmosphere.

Coastal areas help create and maintain microclimates. The presence of coastal forests and wetlands ensures the minimization of flooding, erosion, and other natural disasters, providing valuable regulatory and supporting ecosystem services.

From all the aforementioned, it can be inferred that the coastal zone is a significant natural resource that requires respect and protection.

The threats to the Greek coastal and marine environment stem either from natural hazards (e.g., erosion) or, primarily, from anthropogenic influences (e.g., over-exploitation of natural resources, urbanization, pollution, eutrophication, the invasion of non-native species, etc.).

The most significant problem of the coastal zone is the high rate of shoreline erosion. Over 20% of the total coastline (EUROSION, 2004) is threatened, ranking Greece as the 4th most vulnerable country in terms of coastal vulnerability among the 22 EU member states with coastal territories. The main causes of increased erosion are the particularly strong winds and storm-induced wave action in the Aegean Sea, the vulnerability caused to the coasts by human interventions (e.g., dams that reduce sediment supply (Llasat et al., 2010)), and the geomorphological substrate of the coastline: 2,400 km (15% of the total coastline) correspond to recent soft sediments, while 960 km (6% of the total coastline) correspond to coastal delta regions.

Erosion is expected to intensify in the near future (Velegrakis, 2010) due to (a) the projected rise in average sea level, (b) the worsening of extreme wave phenomena, and (c) the further reduction in river sediment supply due to changes in precipitation and the construction of river management works. Additionally, Monioudi et al. (2014) specifically quantified the shoreline retreat on beaches under future sea-level rise scenarios. Their research showed that for a sea-level rise of 0.48 cm, and according to the lowest estimates, more than 60% of Greek beaches would retreat by 20% of their maximum width, and about 15% by half of this width. However, based on higher estimates, the impacts would be much more significant, as about two-thirds of the beaches are at risk of being completely submerged (GGET, BeachTour_11SYN_8_1466). Furthermore, the sea’s encroachment inland will cause salinization of underground waters and soils, in combination with changes in land use. The salinization of coastal aquifers cannot be avoided due to the increase in hydraulic load on the sea and could possibly be minimized by reducing or eliminating coastal freshwater withdrawals.