The project Natura 2000 – Scientific analysis of subterranean species (Congeria kusceri and Leptodirus hochenwartii) listed in Annex II of the Habitats Directive (Council Directive 92/43/EEC of 21 May 1992 on the conservation of natural habitats and of wild fauna and flora) was conducted from 2007 to 2009. The project was financed by the State Institute for Nature Protection, and Branko Jalžić was the project leader. The first part of the project included the collection of all available data on these two species followed by extensive field research. Primary research was biogeographical, but a part of the fieldwork was focused on the inspection of known sites and determination of the status of habitats and populations of these two species in them.
Genus Congeria with three known species (Congeria kusceri, Congeria jalzici and Congeria mulaomerovici) is the only cave bivalve in the world. Genus is endemic to Dinarides and it lives in Slovenia, Croatia and Bosnia and Herzegovina. It has been placed on the European list of protected species at the request of Slovenia in which only shells were found in just one locality. In Croatia, the species was reported from a total of 15 sites. However, on most sites only shells were found and live populations were recorded from just 5 sites until this research. Unfortunately, this research revealed that two populations are missing and that only 3 populations remain today in Croatia. These populations are highly endangered. The one from Markov ponor has been severely influenced by the hydrological interventions for the hydroelectric power plant HE Senj, and a planned construction of HE Kosinj will have further impact. Groundwater in the Jama u Predolcu cave is exposed to a series of pollution, and furthermore, a population of bivalves that lives in it could be completely wiped out if the planned bypass around the city of Metković is constructed.
Although the distribution of the species was most intensely researched, complex hydrogeological relationships in karst, and a finding of one population in Lika region leave space for the discovery of new populations on almost the entire Croatian karst area. Also, detailed studies have been conducted from Imotski to the area south of the Metković but the speleological map of the area is incomplete and we certainly do not know all the caves where you can get to the groundwater level. Given that one can enter deeply underground only in a limited number of sites, it would be important to explore all existing and future caverns that will open during the construction grips in the area and beyond.
Leptodirus hochenwartii Schmidt, 1832 was also placed on the European list of protected species at the request of Slovenia. Four subspecies are living in Croatia, three of which are endemic. This species was recorded on a total of 47 localities. Although biogeographical research has been carried out for many years, it has not been systematic and the degree of exploration of certain areas is dependent on the interest of researchers and varies for different areas. In addition, most data is gathered in the one-time research and some of the older data is quite arguably or the situation in the area has changed. The presence of this species in some localities (eg, Lasić špilja, Jelar ponor) was not confirmed in the research for this project. It would be necessary to repeatedly put live-traps with baits over a longer period of time to know whether Leptodirus hochenwartii dwells on these sites still.
A good part of the data was collected due to unselfish help from fellow cavers and we owe a big thanks to: Tomica Rubinić for information on the findings of Leptodirus hochenwartii in Žumberak and Risnjak, Dalibor Reš for information on the findings in the hinterland of Rijeka, Nenad Kuzmanović for help with the decipherment of the localities on Ćićarija Mountain, Hrvoje Cvitanović for information about the findings in Jelar ponor and Mladen Kuhta and PhD. Srećko Božićević for assistance with the hydrogeological situation in the field.
Branko Jalžić – email@example.com
Helena Bilandžija – firstname.lastname@example.org
Fanica Kljaković Gašpić and
Robert Baković (CBSS, SKS)
Jana Bedek (CBSS, SOV)
Petra Bregović (CBSS; SOŽ)
Tvrtko Dražina (CBSS; SOL)
Goran Gašparac (CBSS)
Aleksandar Hadeljan (CBSS, SOV)
Vedran Jalžić (CBSS, SOŽ)
Alen Kirin (CBSS, SKS)
Fanica Kljaković Gašpić (CBSS, SOŽ)
Petra Kovač Konrad (CBSS)
Marko Lukić (CBSS, SOV)
Martina Pavlek (CBSS, SOŽ)
Domagoj Tomašković (SKS) and
Ivna Vukšić (CBSS, SOŽ).