Fish stock survey in Johnsbach - Postmonitoring

The Institute of Hydrobiology and Water Management at BOKU was commissioned to carry out the fish ecological monitoring in Johnsbach as part of the EU Life project. The fish-ecological post-monitoring took place in September 2009. Since the fish fitability was not guaranteed at the time of post-monitoring, a master thesis was awarded in addition to the existing contract with a focus on the investigation of the fish fitability of converted sole steps. Since the entry into force of the EU Water Framework Directive (WFD) in December 2000, new legal frameworks for an ecologically oriented handling of waters have been in place throughout Europe. The WFD is to be implemented in the respective national legislations and stipulates good ecological status for the member states as a binding target (by 2016). In addition to chemical and physical components, the current state is determined by the composition of the biocenosis of the waters. Fish deposits in species and individual numbers also play an important role in this. If these differ from the (original) water type-specific status, it must be examined in which form (e.g. with regard to quality, morphology, hydrology, continuum) action is required and with which measures it can be met. The Institute of Hydrobiology and Water Management (Department of Water Atmosphere Environment) of the University of Natural Resources and Life Sciences Vienna was commissioned with the implementation of the fish ecological monitoring in the Johnsbach as part of the EU Life project Nature Conservation Strategies for Forest and Wild River in the Gesäuse (LIFE05NAT/A/78). In addition to post-monitoring (state after implementation of measures), a comparison to pre-monitoring (Wiesner et al. 2006) is carried out. The LIFE project included the restoration of the water continuum in the Johnsbach from the Enns to the Silberreith (interim wall section, NATURA 2000 area) by conversion or dissolution of several sole steps. This life project was carried out from 2005 to 2009 in cooperation with the National Park Gesäuse GmbH with the Styrian state government, Department 19B and the Forestry Service for torrent and avalanche development. Funding is provided by the above-mentioned bodies and from EC and LIFE Nature Programme funds. The fish ecological pre-monitoring took place from 17 to 18 November 2005, the post-monitoring from 16 to 17 September 2009. Since the fish fitability was not guaranteed even at the time of post-monitoring, a master thesis was awarded in addition to the existing contract with a focus on the investigation of the fish fitability of converted sole steps (Kammerhofer 2010). The necessary measurements were taken on 14, 15 and 18 September 2009 and on 20 to 23 and 31 September 2009. It was held in December 2009.