Provide your best answer for the following question. Give ONLY the answer, no other words or explanation.
For example:

Answer: <most likely answer, as short as possible; not a complete sentence, just the answer!>.

The question is: Increased nutrient levels in lakes can cause ecological changes that result in the death of many fish. At what point in the hydrological cycle are most nutrients deposited into lakes?
runoff
During runoff.