ABSTRACT. – An evaluation of the characteristics of the influent and effluent water of a semiintensive shrimp farm of Sonora that operated with one cycle of six months, a mean water exchange of 12.7 %·d^-1 and had mean final yields of 2,000 ± 85 kg·ha^-1 (FCR = 2.15 ± 0.21), showed that during that cycle the farm discharged 547 kg N·ha^-1 and 73 kg P·ha^-1. The respective net exports were 122 kg N·ha^-1 and 14 kg P·ha^-1. The total solids discharged were 20.8 tons·ha^-1 (73.4 % inorganic) and the net amounts exported were 7.52 tons·ha^-1 of inorganic particulates and 0.92 tons ·ha^-1 of organic suspended matter. The water body that receives these discharges is the Moroncarit lagoon, which has an estimated mean water residence time of 3 to 5 d and receives also agricultural drains and sediments of marine origin. For this reason, the nutrients and the sediments discharged by this farm could contribute significantly to the evolution of this lagoon, as well as to its trophic status.