Exploring the potential use of hydro-drones for freshwater mussels' survey

Long-term monitoring of freshwater taxa is usually hampered by expensive and time-consuming visual surveys. This is the case of freshwater mussels that are rapidly declining due to ecosystem alterations worldwide. Important basic information on them (distribution, habitat preferences, eco-physiological constraints) are scarce. Unfortunately, the possibility to acquire this basic information is impeded by inadequate funding. Exacerbating this problem is the difficulty to track and observe freshwater mussels, because they are often rare and clustered. In addition, mussel surveys are often hampered by restrictive environmental conditions. Although the choice of an appropriate sampling design can improve the likelihood that a survey meets its goals, there is no sampling design that can correct an access problem. To escape this bottle-neck we started exploring the potential use of hydro-drones, developed for this purpose by a recently created start-up company. Hydro-drones are regarded as beneficial tools for obtaining data that cannot be accessed otherwise. However, to date their use for research, monitoring and protection of species surprisingly still not consider them. A pilot project, assessing the efficiency of hydro-drones and their application limits under gradients of environmental constraints, was developed to survey mussels in the recently recolonized Lake Orta