Verifying the safe level of visitors’ pressure in aquatic protected areas: surrogate signal species, dummy individuals and bioindication

Aquatic areas within nature reserves can suffer from certain anthropogenic pressures of its visitors. The littoral zone within small rivers and lentic freshwater systems is particularly threatened by water sports, such as swimming and canoeing. The core zone of the Central European National Park is an example of a popular location for visitors and tourists to canoe (Křenová and Kindlmann 2015). Evaluating the direct impact of disturbances on endangered species is often very difficult due to the low number of individuals or the long-lasting impacts; therefore, three methods on how to evaluate anthropogenic disturbance rates are presented. The degree of damage on submerged macrophytes, caused…