Contribution to attenuation coefficient

The application shows to what extent substances present in water contribute to the availability of light under water. From this, the user may draw the conclusion that a reduction the optical active substances in the water leads to the quantified reduction of the light extinction coefficient.

This is not necessarily true, e.g. in water systems in which primary production is limited by light. If e.g. inorganic suspended matter is removed in such system, the water will initially be more transparent. But, as a result of that the amount of algae is increased and the improvement in the light of climate will be temporary.

The presented contribution of optically active substances to light attenuation is thus only valid for the present composition of water, not necessarily for the future situation after remedial measures have been implemented. Limiting factors for the growth of algae determine the amount of algae which can produced. Knowledge of these limiting factors is necessary for predictions of the future light climate. This type of information can be obtained from studies using mathematical simulations models (such as BLOOM).