(17) demonstrated ethanol production from green algae at a 10 g/l (12.7 ml/l) level. As for seagrass, Viola et al. (18) produced ethanol at a 47 ml/l level from eel grass (Zostera marina). As for freshwater plants, water-hyacinth (Eichhornia crassipes) is known to be suitable as a substrate for fermentation 19, 20 and 21.