Research

Fish populations in Austrian rivers have declined sharply in recent decades due to hydromorphological degradation, energy-related development and climate change. Meanwhile, the impact of fish-eating predators on these already stressed communities is a hotly debated topic. The project aims to quantify the additional predation pressure while taking ecological conditions into account. To this end, historical and current fish stock data on abundance, biomass and population structure, collected since the return of predators, are analysed and examined by water body type and degree of stress, in order to separate the effects of predation from those of habitat and climate factors. In parallel, cross-state data on the occurrence and population trends of predators are compiled and used for relative trend analyses. Using distribution and feeding ecology data, we estimate the consumed fish biomass and spatiotemporal predation pressure, linking them to fish stock trends. The analysis is conducted across scales, from the national level down to the level of selected case study rivers. The results will provide a scientific basis for managing fish-eating predators in the context of protecting and sustainably using Austrian river fish stocks.

Nature restoration has moved to the centre of public attention as new European rules aim to bring damaged ecosystems back to life. Healthy ecosystems are essential for all of us: they reduce flood risks, improve water quality, support wildlife and help society cope with climate change. Floodplains – the natural areas along rivers that are regularly flooded – play a particularly important role. Yet restoring them is complex, and people working on the ground often lack practical tools and training. This is where FLOODTRAIN comes in. The project focuses on floodplain restoration and brings together scientists, river managers, planners, land users, authorities and the wider public. Its goal is simple but ambitious: to turn the best available scientific knowledge into practical skills that can be used directly in real restoration projects across Europe. FLOODTRAIN develops a comprehensive training programme that helps practitioners plan and implement floodplain restoration at the landscape scale. It asks key questions such as: How can scientific findings be translated into clear, usable guidance? What kind of training really helps bridge the gap between research and everyday practice? And how can working together with local stakeholders improve acceptance and long-term success? The answers shape both the training content and the way stakeholders are involved throughout the project. The training materials are based on the latest scientific knowledge and are made freely available through an online learning platform, linked to initiatives such as the MERLIN Academy. In addition, digital tools support restoration managers in planning projects, finding financing options and monitoring success, enabling informed and transparent decision-making. At its heart, FLOODTRAIN aims to support a real transformation in how floodplains are restored across Europe. By combining science, practical guidance, training and ongoing dialogue with communities and authorities, the project helps ensure that restoration measures are effective, widely accepted and scalable. In doing so, FLOODTRAIN contributes to healthier rivers, safer landscapes and more resilient ecosystems for everyone.

Instrumental water level and discharge measurements in Lower Austria for medium-sized and smaller rivers only date back a little over 100 years. Historical flood statistics are therefore limited in time, which seems insufficient, especially in times of climate change with predicted more frequent and larger extreme floods. For individual rivers, historical floods have been documented and analyzed on the basis of local chronicles and flood marks (see, for example, the work of Heinz Wiesbauer). However, it can be assumed that many documents on historical floods prior to instrumental measurements have not yet been collected and consistently evaluated. The aim of the project is to collect and process information on historical floods in Lower Austria prior to the start of instrumental hydrological recordings. The surveys focus on flood marks, but written sources and historical literature will also be collected and evaluated.