Crescimento da macrófita aquática flutuante Salvinia molesta em viveiros de aquicultura com distintos estados tróficos

• Autor(a) principal: Pistori, Raquel Eduarda Trevisan [UNESP]
• Data de Publicação: 2005
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/144149; http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/13-09-2016/000337475.pdf
• topic: Aquicultura; Plantas aquaticas; Viveiros; Eutroficação; Crescimento (Plantas); Eutrophication

Salvinia molesta is a free-floating aquatic macrophyte, which colonize many aquatic environments with distinct physical and chemical characteristics. In this context, effluents from aquaculture activities may contribute to eutrofication of aquatic environments enabling the undesirable development of some aquatic macrophytes, specially the ecological type of free floating. In the Aquaculture Center of UNESP (CAUNESP) - Jaboticabal City, São Paulo State, Brazil, the S. molesta is easily found in many reservoirs. The main aim of this research is to study the growth rates and the chemical composition of S. molesta breeding in two reservoirs in CAUNESP. The first one (R1) does not receive any aquaculture effluents, whereas the second (R2) receive effluents from fish, frog and shrimp breeding tanks. This study was developed from July 2003 to March 2004. Eight square structures of 1 m2 each were set up in each reservoir; four of each had plastic sieves with 3 x 4 mm openings covering inferior part. The other four structures did not have any protection in order to allow fish interference concerning the growth rates. The growth rates in R1 (0,026 day -1) were lower than the values of R2 (0,731 day -1). The fish herbivory and the different trofic levels in the reservoirs (R1 meso-eutrophic and R2 hypereutrophic) were factors that strongly influenced the growth rates. According to the results, we conclude that aquaculture effluents cause eutrofication and, consequently increase the growth of S. molesta