Submerged caves of Croatia: distribution, classification and origin

Abstract

Presently, 235 submerged caves and pits have been recorded along the Croatian coast and islands, partly or completely submerged by sea water. Contrary to the inland situation, recorded submerged features are predominantly horizontal (60%), though there are indications that the real situation is similar to that of the continental part where 69% are vertical pits. Completely marine conditions are established in 126 caves and the rest are anchihaline caves and submarine springs. Speleothems are found in more than 140 caves. By their origin, the investigated caves are all continental features formed in Mesozoic and Palaeogene carbonates, subsequently submerged owing to sea transgression. Due to the relatively low wave energy, rapid sea level rise and maturity of the host rock, they do not fit into concepts of a sea cave or a flank margin cave development, but they fulfil several conditions for being the blue holes. Since the term 'blue hole' is mainly associated with the Bahamian karst, our attempt is only to show the possible similarities with no intention of ascribing that term to the Croatian caves. Beside karstological issues, Croatian submerged caves are unique environmental, archaeological and tourism assets.

Increasing heterogeneity of sensitive assemblages as a consequence of human impact in submarine caves

“…The MPA has been established in 2002 and covers an area of about 26 km 2 . The whole area is mostly characterized by rocky reefs (mostly calcarenitic substratum), conducive to the formation of cavities on the cliffs (Suric et al 2010). The MPA has an adequate enforcement and the good relationships between the MPA manager and the local stakeholders insure gathering of realistic information about local human pressures deriving from touristic frequentation on this habitat.…”

World Register of marine Cave Species (WoRCS): a new Thematic Species Database for marine and anchialine cave biodiversity

“…• Vrulja: in Croatia, underground permanent streams discharging under the sea level (Surić et al 2010). …”

Influence of submarine groundwater discharge on seawater properties in Rovanjska-Modrič karst region (Croatia)

“…Tectonically disturbed carbonate deposits, repeatedly exposed to exogenous factors, finally ended as a vast intensively karstified region partially Environ Earth Sci drowned after the late Pleistocene-Holocene transgression. Due to the cyclonic sea current circulation of the Adriatic Sea (Orlić et al 1992), and prevalence of dissolved riverborne matter from the eastern Adriatic rivers (Sekulić and Sondi 1997;Pikelj and Juračić 2013), most of the submerged karst features such as karrens, dolines, caves, etc., are still recognizable on the sea floor, despite thousands of years within the marine environment (Surić et al 2010). Hydrodynamic properties of the landlocked Adriatic Sea are already mitigated along the eastern coast by the numerous island and islets, and the Modrič-Rovanjska region has an additionally sheltered position (Fig.…”