Anchialine caves of the Krka River estuary, Croatia

摘要: Anchialine caves have been the subject of increasing research in recent years due to their interesting aquatic environment, which combines the characteristics of a subterranean estuary (stratified water body) and a deep ocean (lack of light and oxygen, chemosynthesis, slow water exchange). In the Republic of Croatia, along the Adriatic coast and on the islands, almost one hundred and fifty anchialine speleological objects are known, of which only a few have been partially explored. Due to the freshwater surface layer, many of them served as a source of drinking water throughout history, which is why we find archaeological finds in or near them. In the last 15 years, preliminary exploration of 7 anchialine speleological objects (" Špilja pod Orljakom"," Špilja Čapljina" also known as a Sarcophagus cave," Vodena jama na Srimi"," Izvor Litno"," Špilja u uvali Vidrovača"," Bićinska pećina"," Špilja Mandalina") have been carried out along the estuary of the Krka River. The physico-chemical characteristics of the water column were determined in all newly discovered caves and the caves have been mapped by standard topographical methods. The concentrations and trace metals (Hg, Cd, Pb, Cu, Zn, Ni and Co) were determined for the first time in the water column of these caves. The concentrations of organic matter and nutrients were also determined, and the aquatic fauna was studied. In some caves the Microeukaryotic and prokaryotic communities were studied. In order to assess the caves' connections with the estuary or the surrounding sea, the movement of the water level in the caves was studied. In the last 15 years, preliminary archaeological …