Cave fauna survey campaigns: first step into guideline setting on cave biodiversity monitoring

Monitoring of subterranean biodiversity in Europe with focus on invertebrates still lack a standardized strategy protocol of sampling. Although there is a well established protocol for bats, cave invertebrates that include typical cave dwellers with specific adaptations to subterranean realm (i.e., eyeless, depigmented, slow metabolism and adapted physiology to live in a reduced food resources environment and saving energy for main processes), is still lacking. Such species includes several troglobites terrestrial beetles (Coleoptera), spiders and aquatic stygobite crustaceans (i.e., isopods, copepods, amphipods, syncarids, decapods) is still lacking. The main aim of Sub-BioMon is to fill this gap and develop a protocol of sampling to evaluate the biodiversity within caves not open to the public (8310), as they are defined cf. the EU Habitat Directive. Hence, a first step to know the current state of fauna biodiversity in caves is to explore what species reside in new caves or still reside in those caves intensively investigated in the past. During the summer of 2025 several trips has been performed in the three Romanian caves selected for monitoring, Closani Cave located in the southern Carpathians and two other caves located in the Apuseni Mountains (northwest Romania), Pestera cu Apa din Valea Lesului & Pestera din Poiana Varasoaia (V11). We are aiming to understand the biodiversity within each cave, to detect species preferences for a certain type of habitat along the cave, to find potential new species and evaluate the potential threats that may affect their survival on long term. In the Apuseni Natural Park we will explore the cave fauna in one of the most emblematic karst areas located under the Padis plateau – Varasoaia cave system, that will be our playground field for the next 2 years. We found new species in all three caves, mainly crustaceans, either new for science or new for Romania, enlarging our ongoing cave fauna database and species distribution at the country and regional level.