Karst phenomena, i.e. karst relief, is characteristic of most of the territory of Istria County. Almost 70% of the surface of the Istrian peninsula is located on such a limestone substrate, which, although apparently solid and existing, changes over a long series of years under the influence of water that chemically reacts with the limestone, creating numerous holes and cracks in such rock through which water flows freely. The result of these processes are numerous speleological objects – pits, caverns, caves and sinkholes which, under the influence of water, slowly but constantly change, expand and deepen.
According to estimates, there may be up to 2,000 such facilities in the Istrian County. This is a significant number, given that around 155,000 such facilities are registered in the world. Most of the speleological facilities are a direct connection of surface and underground waters, and their protection is of wider social significance, considering that any pollution or pollution quickly reaches the underground streams through these facilities. Therefore, these facilities are included in the first sanitary protection zone of the source. Speleological objects, especially on karst, are the habitats of many endemic, rare, endangered and protected animal species (Proteus sp., Istriana mirnae, Chiroptera sp. div., etc.).
Speleological objects are owned by the Republic of Croatia and as such are of special interest to the Republic of Croatia and enjoy its special protection. For speleological objects, a cadastre is created which is established and managed by the Institute for Nature Protection of the Ministry of Environmental Protection and Energy.
In the National Strategy for the Protection of Biological and Landscape Diversity (NBSAP), karst ecosystems are rated as a priority that requires action plans for protection. The discovery of each speleological object or its part is reported to the Ministry of Environmental Protection and Energy and HAOP within 8 days of discovery. It is forbidden to damage, destroy and remove sycamores, the living world of speleological objects, fossil, archaeological and other finds, and to change the habitat conditions in the object, its above ground and in the immediate vicinity. For all activities in the speleological object (explorations or interventions in a speleological facility or above ground) it is necessary to obtain permission from the competent authority in accordance with Article 105 of the Nature Protection Act (Official Gazette 80/13, 15/18, 14/19).
Speleological facilities, in the manner prescribed by the Nature Protection Act (Official Gazette 80/13, 15/18, 14/19), are managed by Public Institutions for the Management of Protected Areas of Nature. JU Natura Histrica maintains a database for speleological objects in Istria, and it currently has more than 300 objects.
Unfortunately, many speleological facilities serve as waste disposal sites, despite the ban. In order to prevent such practice, their more active protection and designed, controlled use with respect for all protection measures is necessary. Uncontrolled visiting of speleological objects often leads to their devastation, and the increasing popularity of free climbing and caving further point to the need to devise adequate management plans.
