The Adriatic Sea and islands

The Adriatic Sea is the most indented section of the Mediterranean Sea on the continent of Europe. In its present shape, it was formed by the rising of the sea level by 96 metres following the last ice age in the Pleistocene period, when valleys and basins were submerged, and the dry land emerged as elongated islands, separated by sea channels. The Croatian Adriatic coastline is 1,777 km long and occupies most of the eastern Adriatic shoreline.

It is only 526 km from the most northerly to the most southerly point as the crow flies, but due to many bays and coves, it is among the three most indented shorelines in Europe. The elongated islands extend parallel to the shore, separated by channels, and counting the island shorelines as well, the total is 5,835 km, which is almost three-quarters of the total Adriatic shoreline. In terms of its length, the Croatian shoreline is the third-longest in Mediterranean, after Greece's and Italy's. Due to its indentation and geological structural characteristics, this type of shoreline is known in professional literature as Dalmatian.

The Adriatic Sea is relatively shallow, with an average depth of about 173 metres. The north part is shallower than 100 metres, and the deepest part (1,228 m) is in the south (known as the South Adriatic basin). Average sea temperatures in the summer months are between 22 °C and 27 °C, and the lowest temperature is in winter, by the shore (about 7 °C). Salinity in the south is 38‰, which is higher than the world average, though this decreases towards the north. Tides are higher in the north (up to about 0.8 m) than in the south. The sea current enters the Adriatic along the Albanian coastline, and flows along the Croatian coastline, restricted by the islands, in a northwesterly direction.

The clarity of the seawater rises from around 20 metres in the north to a maximum of 56 metres in the south, and is greater in the open sea than by the shore. The seawater reflects different shades of blue, depending on position. In general, the Adriatic Sea along the Croatian coastline is characterised by a particular clarity and intense colour, which contributes to the uniqueness of the landscape, along with the picturesque shoreline. There are fishing grounds (white and oily fish) offshore and off the outer islands, while the water is rich in different types of crustaceans. Red coral can be found in habitats at greater depths.

The natural beauty and picturesqueness of the Croatian coastline is accentuated by the mild Mediterranean climate, with between 2,400 and 2,800 hours of sunshine per year, which makes it one of the sunniest coastlines in Europe.

There are 78 islands, 524 islets and 642 reefs along the coastline, so Croatia may justly be called the 'land of a thousand islands'. Although the islands amount to only 5.8% of the total surface area of the country, their importance for the geographical identity of the country is much greater. Most are limestone, like the coast. The exceptions are the outer islands of Jabuka and Brusnik, which are volcanic in origin, and the sandy island of Susak. About fifty islands are inhabited (most have several settlements). Although island life is traditional linked to the sea (fishing, sailing, boatbuilding), each inhabited island is a miniature cosmos in itself.

Its position on the long, indented Adriatic coast, with its unique archipelago, has enabled Croatia to engage in maritime travel and trade since ancient times. Among the Slavic countries, Croatia is the only one whose maritime and Mediterranean orientation has become deeply rooted in the traditions and daily lives of its people.

In accordance with the UN Convention on Law of the Sea, Croatia holds sovereignty over the part of the Adriatic Sea which belongs to its coastline, internal sea waters and territorial waters (about 31,000 km²), and in 2003, declared an Ecological and Fisheries Protection Zone, which covers a further 23,870 km².