History of the Adriatic. Egidio Ivetic

limit following the criteria of the International Hydrographic Organization.¹ The Strait of Otranto, which is 72 kilometres wide, is conventionally recognized as being the gateway to the Adriatic. The average width of the sea is 248 kilometres, with a minimum width of 100 kilometres at the 45° parallel, between Istria and the Po Delta, and a maximum width of 355 kilometres between Vasto and Bar (Antivari). Airline routes fly the length of the Adriatic in less than an hour and its width in 20 minutes. This is the surface of the Adriatic. Underground there is also a geological Adriatic, which is more widespread, and is where the Adriatic lithospheric plate extends in a long narrow bow shape from eastern Sicily to the western Alps, between the Eurasian, African and Aegean plates, colliding with them.² It is almost an island surrounded by more or less active faults, corresponding to the seismic zones (including Friuli, Abruzzo, Montenegro and the Ionian coasts) that follow the mountainous coasts along the sea and the Po Plain.

      Following hydrographic criteria, the Adriatic lies in the eastern basin of the Mediterranean Sea. Nevertheless, in his weighty study of the geography of the Western Mediterranean, James Houston places the Adriatic in the west, with the exception of the Albanian coast.³ This book will observe the criteria of the International Hydrographic Organization and therefore considers the Adriatic as a segment of the Eastern Mediterranean. Its geography points to it, as do its navigational routes and times. In comparison to Atlantic navigation, the Adriatic is slightly marginal as it is separated from the ocean by three entrances: Gibraltar, the Strait of Sicily and the Strait of Otranto. No comparison can be made between the Adriatic marine traffic and that in the North Sea, or even with that in the Western Mediterranean, for example Marseilles or Genoa. Conversely, for a ship that sets sail from Alessandra, Suez, Jaffa or Izmir, the Adriatic is a short passage to the heart of Europe, and today it only a 30–40-hour voyage. Moreover, Gibraltar is 1,258 nautical miles distant from the Strait of Otranto, which is 885 miles distant from Port Said and 594 miles from the Dardanelles.

It might be more appropriate to see the Adriatic–Ionian basin as playing a central role in the Mediterranean regional system. In fact, the Mediterranean can be interpreted in another manner, as a system of three macroregions: a Mediterranean Europe, including the coastal areas from Andalusia to Thrace; the Eastern Mediterranean, from the Marmara Sea to the Suez Canal; and Mediterranean Africa, from Suez to Gibraltar. Or, alternatively, a system of four macroregions: Western Europe (Spain, France and Italy), the Ionian Adriatic, the Eastern Mediterranean (Aegean and the Levant) and Mediterranean Africa. Clearly, the Ionian Adriatic is the central gulf, the focus of Mediterranean Europe. Within the EU Maritime Strategy Framework Directive, established in 2008, the Adriatic Sea is labelled as a specific maritime area of Europe, one of the four areas into which the Mediterranean is divided.

      The Adriatic is a contained sea with a surface area of 138,000 km². Hence it is decidedly smaller than the Black Sea (436,000 km²), the Baltic Sea (377,000 km²), the Red Sea (438,000 km²) or the Californian Gulf (160,000 km²). Yet, comparing it with countries, it is larger than England (130,395 km²) or Greece (131,957 km²). The Adriatic coastlines stretch out for 1,836 kilometres, half of which are in Italy. However, what is most striking is the total length of the continental and island coasts which, including all bays and inlets, measure 7,841 kilometres. In other words, the African coastline in the Mediterranean, from Gibraltar to the Suez Canal, is 5,829 kilometres long, while the Eastern Mediterranean coastline, from İskenderun to the Gaza strip, is 719 kilometres long. This is due to the eastern Adriatic shore, to the archipelago of Dalmatian islands: between Duino and Corfu lies the fourth most indented coastline in Europe, after the Scandinavian peninsula, Great Britain and Greece, and the second longest in the Mediterranean. The Croatian coast alone measures 5,835 kilometres, of which 4,058 kilometers are the 1,246 islands and islets with countless inlets. However, the total surface area of the islands along the eastern coasts (ex-Yugoslavia) is 3,177 km², less than the 3,600 km² of Majorca. The Italian Adriatic shoreline is 1,272 kilometres long, Albania 406, Montenegro 284, Slovenia 46, Greece 41, and Bosnia and Herzegovina 21.

The Adriatic is not a deep sea; its seabeds slope from north-west to south-east.⁴ North of the Ancona–Pula (Pola) line, it is only 52 metres deep; between Istria and Venice, it is only 35–40 metres deep. Here, if a cruise ship were to sink, a third of it would still emerge. The depth increases to an average of 240 metres in the depression off the coast of Pescara. It then drops again near Palagruža (Pelagosa) with an average depth of 130 metres, which divides the sea in two. The southern section, between Apulia and Montenegro, forms a trench of over 1,400 metres, while the Strait of Otranto is 742 metres deep. The waters of the Adriatic have a high level of salinity (38%), which is higher than the Western Mediterranean and the Ionian, despite the numerous rivers that flow into the sea on the west coast, including the Po and the Adige rivers. The surface temperature is consistent with the rest of the Mediterranean: an average of 8–9 degrees in the winter and 25 degrees in the summer. As elsewhere in the Mediterranean, the surface currents along the coast flow in an anti-clockwise direction. After Otranto, the current ascends along the eastern shore before mainly changing direction at the level of Ancona and slightly sheering off to reach the Venetian lagoons. In the Adriatic, unlike the rest of the Mediterranean, the tides are stronger, with a range of more than half a metre between Venice and Trieste. These elements – depth, salinity, currents and seabeds – have helped make the Adriatic for centuries one of the internal Mediterranean seas richest in fish.⁵

      The Adriatic climate matches the parameters of the Mediterranean climate.⁶ Summers are hot and dry, and are affected by the Azores anticyclone (an influence that has been diminishing in recent years), whereas winters are generally wet and warm. The subtropical temperate climate and the hot climate extend approximately from Apulia to Pesaro. Temperate subcontinental weather stretches from Romagna to Trieste, where moderate heat starts again. This part of the coast is a break into the Mediterranean of the temperate climate; it is a unique case and an atypical area compared to the rest of the basin. The Mediterranean climate starts up again in Istria; the southernmost part of the peninsula is the northernmost point of the essential Mediterranean environment and climate. There are, however, specific characteristics. In the north-eastern quadrant, between November and February, a strong cold wind – bora – blows, with gusts up to 150 kilometres an hour. The bora blows down in cascades on clear days from the karst tablelands to Trieste and along the Velebit Mountians and in Dalmatia, hindering shipping and road traffic. In winter, currents of cold air from the Siberian anticyclone regularly make their way into the Balkans and often bring snow and low temperatures to the mid-Adriatic, Marche and Abruzzo. In autumn and winter months, on days of low atmospheric pressure, the scirocco, a warm wet wind, brings grains of sand from the Sahara to the foot of the Venetian Pre-Alps. Rainfall in the Dalmatian hinterland reaches high levels, similar to Scotland and Scandinavia. There is therefore no lack of contrast.

Olive trees, the very essence of the Mediterranean character, are not found everywhere in the Adriatic. There is a large area to the north-west, roughly between Pesaro and Duino, which corresponds to the temperate subcontinental climate, where olive trees had not taken root until recently. This is an area of floodplains and sandy sediments, of wet winters on the Po Plain. On the opposite coast in Istria, including Trieste, olive trees flourish; this is the northernmost point, in terms of latitude, at which they have grown since antiquity. Between the islands of Cres-Lošinj (Cherso-Lussino) and southern Istria grow evergreen scrub, broom, fig and almond trees, typical of the Mediterranean landscape. This is the northernmost extremity of the ‘classical’ Mediterranean which embeds itself in a continental context, thanks to the influence of the sea. This creates considerable climate contrasts that occur in the span of a few kilometres between the coast and the interior. The latitude here is 45° north, level with Ferrara, Turin and Bordeaux; it is north of Hokkaido, and of Halifax in Nova Scotia and of Vermont. Moving southwards to the lower Adriatic, the inland Mediterranean is found on the Dalmatian islands and in Apulia, especially Salento. Dry, clear, brilliant: this is a foretaste of the Eastern Mediterranean and African coasts.

      The Apennines, the Alps, the Dinaric Alps, the Albanian mountains and the Pindus mountain range surround the sea and shape its perspective.⁷ The two openings, the Po Plain and the Strait of Otranto, represent a passage between