Kappaphycus alvarezii, one of the most important sources of raw material for carrageenan production, has been cultivated in a floating-raft system, at Sepetiba Bay, southeast Brazil, with no environmental monitoring studies. The aim of this research was to verify the occurrence and establishment of Kappaphycus alvarezii plantlets and spores in the benthic communities around the biggest Brazilian Kappaphycus alvarezii farm, at Sepetiba Bay (23º03'50"S; 043º52'50"N), to analyze the applicability of the methodology and to propose an environmental monitoring protocol for areas where this cultivation is permitted in Brazil. From May to July/2006, the occurrence of fertile cultivated branches as well the recruitment and establishment of spores were not observed. The occurrence of plantlets outside the system was restricted to the farm boundaries and lost biomass was insignificant in relation to cultivated biomass. Futhermore, the establishment of transplanted seedlings through vegetative growth was suppressed by high suspended particulate material in the water column. These results suggest that Kappaphycus alvarezii introduction has not yet provoked environmental damage in Sepetiba Bay and the methodology used was adequate for this kind of evaluation. Constant application of the method is recommended as a protocol for growing Kappaphycus alvarezii where permitted in Brazil in order to maintain marine biodiversity.
seaweed; seaweed cultivation; species introduction
