Fish behaviour is one biological organisational level regularly used to assess the state of freshwater ecosystems and can be monitored using fish telemetry methods. The development of activity sensors incorporated into fish telemetered tags allows for non-spatial movement to be detected and is increasingly used to understand the energy budgets and response and fine-scale behaviour of fishes. In addition, detecting tagged fish remotely and in real time highlights the need to process fish activity data in near real time to make it relevant to managers in the water resource sector. Our study on Labeobarbus natalensis, a cyprinid, in the uMngeni River in KwaZulu-Natal, South Africa, adapted and then tested the exponentially weighted moving average (EWMA), as developed for financial predictive modelling, using activity data from fish. To determine changes in behaviour, we compared the EWMA-predicted fish behaviour against the present fish behaviour. We showed that the EWMA could adequately detect changes in behaviour on both individual and population levels. Changes in behaviour are potentially indicative of a change in environmental conditions and thus were developed into management alerts. We conducted further analyses using generalised additive mixed models (GAMM) to determine the relationship between fish activity and the environmental data collected. The GAMMs helped determine the potential drivers for changes in behaviour where the EWMA could detect these in real time. Detecting changes in behaviour in real time as a result of environmental variables can identify thresholds of potential concern influencing management decisions and allow managers to respond, contributing to improving effective freshwater management.

This paper examines the use of both flow control and passive low noise technologies to reduce the aerodynamic noise radiated from a modified LAGOON landing gear, as tested in the EU funded H2020 collaborative research project: INVENTOR, InnoVative dEsign of iNstalled airframe componenTs for aircraft nOise Reduction. At approach to landing, landing gear noise is still a significant contributor to environmental noise in the vicinity of airports. Progress is being made with ambitious projects which aim to develop significantly reconfigured aircraft architectures to reduce airframe noise. The current project examines noise abatement measures which could be retrofit to existing landing gear configurations. Flow control in the form of low TRL "air curtains" which form a fluidic shield or virtual fairing are examined. Amongst the most interesting passive solutions are a selection of higher TRL porous materials in the form of wire mesh, perforated plates and 3D materials. In order to provide a simplified baseline landing gear mock-up on which to test the low noise technologies, the LAGOON NLG is modified with the addition of a torque-link and brakes and is called the "LAGOON-SLG". The porous materials are assessed experimentally in the A-Tunnel aeroacoustic facility in TU Delft, the Netherlands and the air curtains are examined in DLRs AWB aeroacoustic facility in Braunschweig, Germany.

Understanding the biotope requirements of the various aquatic biota is crucial for effective biomonitoring. Yet, the biotope preferences of macroinvertebrates in Afrotropical rivers have been poorly studied. In this study, we investigated the influence of human disturbance and flow-driven biotope changes on the β-diversity and biotope preferences of macroinvertebrates in the Mara River, Kenya. Macroinvertebrates were sampled from various biotopes at seven reference and nine impaired sites in wet and dry seasons. β-Diversity was determined (i) for each biotope and (ii) at the site scale, combining all biotopes sampled, and macroinvertebrate biotope preferences were assessed among biotopes between reference and impaired sites. Minor β-diversity differences were observed between reference and impaired sites based on relative abundance data, but differences were greater when the presence–absence data were used. There were no statistically significant changes in macroinvertebrate biotope preference due to human disturbance, but fidelity to preferred biotopes increased at impaired sites. In fast-flowing waters, Simuliidae, Baetidae, Tricorythidae, and Hydropsychidae dominated stable rocky substrates and were the most sensitive to flow alteration. This study adds valuable information on the effects of biotope reduction/loss and flow alteration on the diversity and biotope preferences of macroinvertebrates in Afrotropical rivers, and contributes to improvement of relevant bioassessment protocols and biodiversity conservation efforts.