Have you ever thought that the water in the Baltic Sea has a history? The dissolved organic matter (DOM) can be tracked down to soil particles that rivers carry into the sea. The multiDOM researchers study the surface runoff and soil erosion in order to map out this process.
I have put together a simple device for the visual study of the provenience of water. A box made of clear acrylic contains a camera that takes split images of the waterscape. The simultaneous under/over view reveals the colour of the water under the surface (brown indicating the degree of humus = organic matter). And above the vegetation tells about the environment on the sampling site.
My instrument could be used for recording the course of water in the whole catchment area starting from ditches and lakes through rivers into the Baltic Sea. A series of photographs (or videos) would demonstrate how the colour and the turbidity of water vary on its way to the sea.