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Why the sea in Croatia is so blue and clear 

Water quality at Croatian beaches tested – where is the best

Stunning blue sea in Croatia

Croatia’s stunning coastline and islands have been captivating travellers for years.

Croatia’s Adriatic Sea is renowned for its crystal-clear waters and stunning blue hues. This breathtaking body of water is a popular destination for tourists from all over the world.

The Adriatic Sea is fed by several rivers, including the Po, which is the longest river in Italy, and the Neretva in Croatia, which is the largest river in the eastern part of the Adriatic basin. These rivers carry sediment and nutrients that contribute to the colour and clarity of the water.

However, the unique colour and clarity of the sea in Croatia is also influenced by its geographic location and its connection to Africa. The waters of the Adriatic Sea are influenced by the Mediterranean Sea, which is connected to the Atlantic Ocean via the Strait of Gibraltar.

croatian sea clear blue


The Mediterranean Sea is known for its deep blue colour, which is caused by the high concentration of salt in the water. The Adriatic Sea in Croatia also has a high salt concentration, which contributes to its blue colour.

In addition to the salt concentration, the water is also influenced by the winds and currents that come from Africa. The African continent is located to the south of the Mediterranean Sea, and the winds and currents that come from this direction carry warm water and nutrients towards Croatia’s Adriatic.

These warm waters and nutrients stimulate the growth of phytoplankton, which are microscopic organisms that are the foundation of the marine food chain. Phytoplankton require sunlight to grow, and the clear waters of the Adriatic Sea allow plenty of sunlight to penetrate the water, promoting their growth.

Water quality at Croatian beaches

The island of Rab

As the phytoplankton grow and multiply, they release oxygen and absorb carbon dioxide, which helps to maintain the water’s clarity. In addition, the microscopic organisms are eaten by zooplankton, which are then eaten by larger fish, creating a thriving ecosystem.

The Adriatic Sea’s connection to Africa also brings a diverse range of marine life to the area. The warm waters from the African coast attract fish and other marine animals, which migrate to the Adriatic Sea during different seasons of the year.

Not only is Croatia’s sea clear and blue, it is also the cleanest in Europe. According to date from the European Statistical Office, when it comes to having the most places to swim with excellent quality water, Croatia is number one.

Why is the sea in Croatia so blue and clear? 

Croatia also has the cleanest waters for swimming in Europe

More than 99% of beaches monitored across Croatia were judged as having excellent sea quality for swimming. Malta, with 96.6% and Greece with 95.8% are the next best behind Croatia.

Croatia’s clear clean and blue waters are the result of a combination of factors, including its high salt concentration, its geographic location, and its connection to Africa. These factors contribute to the growth of phytoplankton and a thriving marine ecosystem, making Croatian beaches a unique and beautiful destination for travellers from around the world.

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