POLLUTION

Đula – Medvedica špiljski sustav (Cave System) is the largest cave in Croatia, which stretches under the City of Ogulin. Both entrances are covered with garbage and since Ogulin does not have any sewerage system, all waste waters flow directly into the subterranean. The cave is also a type locality of two species, but also the habitat to the sponge, which has not been found there since 1998.

The Privis jama (Pit) and Vrelić špilja (Cave) were researched by the members of the Speleological Club “Ozren Lukić”, who found both speleological objects polluted with oil and oil derivatives. The pollution was most likely caused by traffic accidents, resulting in spilling of hazardous substances into nature and the subterranean. These substances can remain in the subterranean for a very long time and thus these two caves may be considered permanently devastated. The Privis jama (Pit) is a type locality of one cave planarian.

The Ponor Rupečice (Sinkhole) is just one of a set of speleological objects used like a dumping site in this region. The sinkhole is a habitat to the Ogulin cave sponge and other endemics. It is also a dwelling site of the most numerous olm populations. In the framework of its educational activities in 2007 the Croatian Biospeleological Society organised a sinkhole cleaning action together with many cave researchers and local inhabitants.

PHYSICAL DEVASTATION

Špilja u kamenolomu Tounj (Cave in Tounj Quarry) with practically 8500 m in length is the third longest cave in Croatia. Unfortunately, the activities of the quarry situated directly above this cave result in destruction of the cave and its valuable geological phenomena and decorations. Although the cave was placed under temporary protection in 2008, its devastation has continued. The preparations are undergoing to place this cave under permanent protection.

HYDROTECHNICAL PROJECTS

Gojak Hydropower Plant
The construction of the Gojak Hydropower Plant in the 1960’s resulted in many modifications of the hydrological regime in the Ogulin region. We have no knowledge about the effects of these modifications on the subterranean and the subterranean fauna since this huge project was finished before any speleological or biospeleological research had been undertaken in this region.

Lešće Hydropower Plant
The construction of the Lešće Hydropower Plant was finished in 2010. It consists of a 13 km long storage reservoir, which was to sink 8 speleological objects completely and another 6 speleological objects partially. In fact, it sank more than the Croatian Power Company (HEP) experts had predicted because the water came out in the round karst valleys nearby the Village of Špehari, nearly 2 km away from the storage reservoir. This type of devastation which exceeds any predictions is another warning that karst should not be used like a construction site for hydropower plants since sinking of karst results in destruction of an area which occupies much more space than the space occupied by the hydro-storage reservoir, but also in destruction of an extremely large number of habitats. The Dobra River Canyon sinking irretrievably destroyed the only known habitats of the species Calconiscellus gottscheensis and Niphargus costozzae in Croatia and partially destroyed populations of another 14 important cave taxa.

OTHER PROJECTS

The lowland railway line and the marshalling yard in Drežničko polje (Field)
The construction of a lowland railway line is foreseen for the Ogulin Region. This railway line will run nearby the Rupečica River and Jama Klisura (Pit), which could have adverse effects on the exceptional fauna that lives there. Hence, these speleological objects are about to be proclaimed protected. In addition, a marshalling yard is to be constructed in the Lug Field nearby Drežnica. This is disastrous option since the Lug Field is an intact natural oasis and a habitat to many rare and endangered flora and fauna species (not only subterranean). Moreover, any damage might affect the springs at the foot of Kapela (Mountain Range), which are hydrologically connected with the sinkholes in Drežničko polje (Field). These sinkholes are used as a source of drinking water for the entire Ogulin region.