BIOLOGICAL MONITORING IN CAVES
David C. Culver, Boris Sket - (31/1,2002)
In 1999, we described the twenty caves and karst wells that have 20 or more species of obligate cave organisms living in them. Among these caves five are developed as tourist caves &emdash, Postojna-Planina Cave System (Slovenia), Baget - Sainte Catherine System (France), Shelta Cave (Alabama, USA), Mammoth Cave (Kentucky, USA), and Vjetrenica Cave (Bosnia & Herzegovina). For these and other tourist caves, there is a special responsibility to protect this fauna. The very fact that caves with large numbers of visitors and with modifications to the cave can have high species diversity shows that the two are not incompatible. Many of the standard sampling techniques, may work in some caves only, they are of restricted use. Pollution may be either directly detrimental to the cave fauna or may enable surface species to outcompete the endemic cave fauna. Therefore, changes in the quantity of fauna have to be monitored as well as changes in its taxonomic composition. In the case of new tourist installations, the local cave and surface fauna has to be investigated prior to any modifications. For biological monitoring, we recommend one of the following: 1. minimum-time census, rather than minimum-area census, 2. baiting in both terrestrial and aquatic habitats, 3. pitfall traps (baited or unbaited) in terrestrial habitats.