Azevedo, José M. N.Valente, A.Gonçalves, VitorVieira, N.2014-05-272014-05-272005Azevedo, J.M.N., A. Valente, V. Gonçalves, N. Vieira (2005). Biomanipulation of the Furnas Lake (Azores, Portugal). 5th International Symposium on Shallow Lakes, Dalfsen, The Netherlands, 5-9 June. Book of Abstracts, p. 69-70.http://hdl.handle.net/10400.3/30375th International Symposium on Shallow Lakes, Dalfsen, The Netherlands, 5-9 June, 2005.The Furnas Lake is located in the island of São Miguel, Azores. lt is a small lake (area, 1.92 km2;average depth, 6.9 m) with agricultura as the main activity in the catchment area (12.45 Km² ). Water temperaturas range from 10 °C to 24 °C. The water is turbid (Secchi disc depth is rarely > 1 m) and with a relatively high nutrient load (total N up to 2 mg.l ̄ ¹. total P up to 0.1 mg.l ̄ ¹ Turbid water and the frequent algae blooms caused by agricultura! runoff are considered a nuisance for tourism. The Regional Government has taken a series of measures of improve nutrient control, both upstream and in the water mass, but the problem has persisted. A two-year biomanipulation project started in March 2005 is aimed at reducing the cyprinid density (carp, Cyprinus carpio and roach, Rutilus rutilus) of the lake from 150 to about 20 kg.ha ̄ ¹ , and at monitoring the effects of this measure on water quality, macrophytes, zooplankton and the fish communities. The project work plan includes 1). the production of public information campaigns directed to ali lake users; 2). a survey of the initial state of the distribution and biomass of macrophytes, and species, size and biomass of zooplankton; 3). an intensiva removal of carp and roach during the reproductive season, employing gill and seine nets; and 4). to monitor the effects of biomanipulation on the water quality and biota.engFurnas Lake (Azores)Nutrient ControlCyprinus carpioRutilus rutilusconference object