DISTURBANCE OF THE PHOSPHORUS CYCLE - A CASE OF INDIRECT EFFECTS OF HUMAN ACTIVITY

Phosphorus (P) often limits primary productivity of aquatic systems. Humans have altered the P cycle in aquatic systems, directly, by mining P-rich rock, and indirectly, through the manipulation of other element cycles and the alteration of aquatic food webs. Aquatic ecologists are becoming increasingly aware of the importance of these indirect alterations to biogeochemical cycles. Quantitative predictions of these indirect effects will be an important focus of future studies.