Geraldes, Ana MariaBoavida, Maria José2010-12-222010-12-221999Geraldes, Ana Maria, Boavida, M.J. (1999). Limnological comparison of a new reservoir with one almost 40 years old which had been totally emptied and refilled. Lakes & Reservoirs: Research & Management. ISSN 1440-1770. 4:1-2, p. 15–221440-1770http://hdl.handle.net/10198/2933In the present study, several limnological characteristics of a reservoir filled for the first time are compared with those of another reservoir totally emptied after being full for almost 40 years and then refilled. Three phases were considered during the study, determined by the filling and emptying in the oldest reservoir: (i) filling phase, from August to October 1994; (ii) regular water-level phase, from December 1994 to April 1995; and (iii) emptying phase, from May to July 1995. Several forms of phosphorus, phosphatase, chlorophyll a, and phytoplankton and zooplankton composition were determined. Trophic states of the two reservoirs were compared. Major limnological differences were not found between these two artificial lakes. In fact, physical factors such as temperature, chemical parameters such as the several forms of phosphorus measured, and biologically derived variables such as chlorophyll a and phosphatase activity exhibited similar patterns and values in both reservoirs, as well as practically the same relationships among thoseengEmptying reservoirNew reservoirOld reservoir phosphorusjournal article10.1046/j.1440-1770.1999.00075.x