Marine Pollution

Marine debris is a marine pollution component, the importance of which has been underestimated. The seriousness of marine debris as a potential pollution factor of the ocean has been recognized only during the last two decades. Marine debris are responsible for the death of animals which is caused by entanglement and ingestions. Furthermore, the marine debris on the beaches and nearshore zone are responsible for aesthetic pollution thus decreasing the recreational value of the beach and consequently the socio-economic development of the area.
In the Mediterranean Sea studies related to the frequency, distribution and source of marine debris are very few and all of them are focused on selected beaches.
The Laboratory the last three years has undertaken an extensive research over the Greek shelf in the Ionian Sea concerning the distribution, frequency and extend of marine debris on the seafloor. Preliminary results from the Patras gulf, has shown that the average concentration of marine debris on the seafloor is 240 item/km2. Plastic material dominates the composition of seafloor debris with a mean abundance of 82%. The classification of the debris in terms of its original use shows that general packaging material (plastic bags, containers e.t.c) are the most abundant 45% followed by beverage packaging 33.5% and food packaging 11.5%.

Underwater archaeological surveying (Navarino Bay, Greece and Alexandria, Egypt)

Since the appearance of mankind on earth, the marine environment has been used for habitation (coastal villages, towns, cities), food resources, migration and goods transport. Many coastal towns and cities are at present submerged under water due to eustatic and isostatic movements, furthermore many thousands of wrecks are assumed to be lying on the seafloor or buried in the sediments on the seabed.
During the last three years, the Laboratory has been involved in underwater archaeological prospecting using marine geophysical techniques in Navarino (Pylos) Bay and Alexandria Egypt. In Navarino Bay, the marine geophysical surveying using sub-bottom profiling, side scan sonar and R.O.V inspection of the seafloor, has shown the presence of wrecks on the seafloor, which may be part of the Turkish fleet. Furthermore, the survey has shown that the seafloor has been ploughed by the anchors of the tankers which moor in the bay. The anchor ploughing causes disintegration of the wrecks.
In Alexandria the sonar imaging of the seafloor has shown the presence of targets, which may represent man-made objects and structures of archaeological importance.

Submarine Landslides

Evidence of submarine landsliding exists across the entire breadth of the European continental shelf / slope. Many of the detected landslides have occurred in the near past and some of them had an impact on man’s activities. The potential impact of submarine landslides on humanity increases as man reaches farther into the ocean to exploit the marine resources.

Marine Geophysical surveys over the Aegean and Ionian Seas, which have been carried out by the Laboratory has shown the presence of many recent submarine landslides. In the gulf of Corinth (Greece), which is characterized by high seismicity, there is evidence that submarine landslides occur at a rate of 1 every 2 or 3 years.

The 6.2R Aegion earthquake in 1995 simultaneously triggered coastal and submarine landslides in at least 5 sites, which were within a 10km radius from the earthquake’s epicenter.

The ancient town Helice, which disappeared in 473 BC from the earth’s surface, is considered to have been destroyed by coastal landslide.

Paleoclimatic changes in Eastern Mediterranean

The prediction of global climatic changes which may occur during the next millennia is one of the most important goals of society.

To predict future climatic changes, it is necessary to know the climatic variability in the past. These past changes can be identified in the sedimentary records from lakes and marine basins.

The Laboratory’s involvement in this worldwide effort for the prediction of the climatic changes is focused on the identification of climatic changes, which have occurred in the last 50,000 years in the Eastern Mediterranean. Specific targets include the identification of the magnitude, frequencies and mechanism of climatic changes on time scales from decadal through centennial to millennial.