AquaEcoLab – a novel indoor laboratory

The AquaEcoLab is a purpose-built indoor experimental facility for controlled studies of aquatic organisms (fish, invertebrates, and algae) under precisely regulated hydrological, thermal, and hydro-chemical conditions. Located at BOKU University Vienna and commissioned in early 2026, the 83 m² large facility provides a highly controlled, micro-scale environment in which individual environmental drivers can be isolated and manipulated.
The AquaEcoLab comprises three identical, independently operated recirculating aquaculture circuits, each with a maximum water throughput of 2.5–3 L s^-1. The circuits can be operated across a temperature range from cold-water (12–20 °C) to warm-water (20–26 °C) conditions, with one circuit equipped with additional cooling capacity for operation down to 8–10 °C, thereby covering the full thermal niche of the target cold-water species and their life stages. Water temperature is regulated automatically via dedicated chiller/heater units, enabling stable long-term thermal treatments as well as programmed temperature scenarios. Each circuit is supplied from three independent water sources — treated recirculated water, well water, and municipal (drinking) water — and is served by its own filtration train comprising a mechanical drum filter, a biological granulate filter, a trickling filter for oxygenation, and UV disinfection (2 × 80 W), with frequency-controlled circulation pumps installed in redundant pairs to ensure uninterrupted operation. The modular design decouples the water-treatment circuits from the holding units, so that tank type, size, and arrangement can be freely adapted to the requirements of a given experiment, allowing control and treatment conditions to be replicated or contrasted across circuits. Continuous monitoring and control instrumentation records water temperature and dissolved oxygen and monitors flow in each circuit, with automated SMS alarms and an automatic emergency water supply safeguarding animal welfare throughout experiments. Two integrated bioreactors support the on-site culture of live food organisms and algae. Together, these features make the AquaEcoLab a flexible testbed for manipulative experiments that isolate the effects of flow, temperature, and water quality on the survival, development, and behavior of aquatic organisms under fully reproducible conditions.