WaterWebTools’ Post

Even shallow lakes stratify! In fact, they can stratify quite often - sometimes with dire consequences for the life they support. Warming from a couple of nice sunny days with low wind speeds can oftentimes be enough to cause stratification in shallow lakes. For nutrient rich lakes, hypoxia (low oxygen) in the bottom waters can form shortly after the onset of stratification - forcing much of the aquatic life in a lake to move upwards to a more oxygen rich habitat. In some bad cases, we see severe fish kills, where oxygen levels are low from top to bottom of the water column - leaving no room to escape hypoxia. An event of stratification, followed by hypoxia formation and then complete water column mixing can be short-lived in shallow lakes, and typically span from a single day to a few weeks. Traditional water sampling, such as that carried out to comply with the EU Water Framework Directive, will very often not be sufficient to capture these short-lived events. Sampling is typically carried out once per month, or bi-weekly at the most. But to capture these short-lived events, you need high-frequency data – for example data collected automatically every 15 min. through sensors installed on a floating buoy. The picture shows an example of high-frequency oxygen profiles recorded by a data buoy this summer in a typical shallow (max depth 2.6 m) Danish lake. Having such sensor system installed and running operationally through WaterWebTools can help you understand the system dynamics much better, including identifying whether an observed fish kill was caused by hypoxia, or due to other factors. If you would like to learn more about how a sensor system can be designed by WaterITech and installed in your system, please feel free to reach out, or check out our website at: https://lnkd.in/dYyeWwBR.