Nature protection and biodiversity - Drivers and pressures (Croatia)

Habitat degradation and fragmentation

The most serious threat to wild species in Croatia is degradation and loss of habitats, partly as a consequence of conversion of natural habitats into building or agricultural land, or as a consequence of construction of roads and other communications, which frequently causes habitat fragmentation. All types of infrastructure - rail, roads and waterways - affect the animal habitats they are routed through. Large carnivores, which need vast living space, are particularly sensitive to construction of large road projects. To ensure serviceability of highways, green bridges are built above tunnels and under viaducts. It has to be underlined that Croatia is one of first European countries which started construction of the green bridges and offered practical solutions to the problems arising from the road impact on wild animals, particularly large carnivores. The Ordinance on Green Bridges stipulates the protection measures, determines institutions in charge and method of maintenance of the wild animal crossings over public roads, other roads and other structures crossing over known wild animals migration routes [2].

Invasive alien species

 A number of invasive species found in Croatia is increasing. The oldest example of the introduction of a alien invasive species, dating back to 1910, is the introduction of 11 specimens of Indian mongoose (Herpestes javanicus auropunctatus) into the Island of Mljet. During last century, 16 alien species of fish were introduced into rivers and lakes, which caused great damage to the indigenous ichthyofauna, especially affecting the rivers of the Adriatic Sea basin which harbour a large number of endemic fish species. The plant species Amorpha fruticosa is spreading unstoppably, covering forest fringes and floodplains of the lowland Croatia, creating big problems with the renewal of forest stands. Ambrosia artemisiifolia has spread through mine vegetation habitats throughout Croatia and is known as one of the principal European allergens. The invasive green algae Caulerpa taxifolia and Caulerpa racemosa are the most thoroughly researched invasive species in Croatia so far. These species cause a change in ecological conditions and disappearance of habitats for indigenous species [1]. Established invasive alien species present serious threat to native wild species (competition for food, habitats etc.) [3].