Dr. Jenny Deakin:

The first thing to say is that we will always need the source of nutrients, which is a critical starting point. We have to have the source. The rainfall is the vector or the method by which the nutrients are moved from the land into the waters. For phosphorus, the pathway is over land, so there is a very close correlation between rainfall and phosphorus run-off, and that impacts on our fresh waters. When it comes to nitrate, the pathway is down into the ground and horizontally into the rivers. Absolutely, rainfall is a vector but we always need that source. If we do not have a source, we do not have a problem.