Three major phosphorus sources have contributed to the degradation of water quality in the Chesapeake Bay: land driven phosphorus, mobilized phosphorus from bay sediments, and imported phosphorus from ocean. One of the challenges faced is to interpret some of our present results is that we do not have sufficient information on the differences and variations of different land driven phosphorus sources. Previous results show that the bulk of agriculturally driven phosphorus retained in the particulate matter remains as unreactive phosphorus in the sediment in the Chesapeake Bay. Phosphorus derived from dead phytoplankton is the most predominant phosphorus source that sustains dead zone and...