Abstract: Nutrients in the seaweeds, Enteromorpha, Gracilaria lemaneiformis, Sargassum fusiforme and Laminaria japonica, that were collected from the coastal waters of Fujian were analyzed.The results indicated that the contents of polysaccharide dietary fibers and crude fibers in the seaweeds were more than 50%.Contents of crude protein in Enteromorpha and G.lemaneiformis were 15.6%-38.2%,which were higher than in other seaweeds.The ratios of TAA/protein were 79.8%-91.4%.The essential amino acid compositions of the 4 seaweeds were balanced, i.e., 35.4%-40.0% for EAA/TAA and 0.55-0.67 for EAA/NEAA.The crude fat contents were low for all, but the fatty acids and the ratio of n-3 PUFA/fat were rich.The mineral contents were high as well, especially for Ca, Mg, K, Na and Fe.The contents of Mg, Fe, Zn and Cu in Enteromorpha were higher than other seaweeds.On the other hand, the contents of harmful elements including Pb, Hg, Cd and As were all below the tolerance limits stipulated for fish meal by GB 13078 standard.Therefore, the seaweeds, especially Enteromorpha and G.lemaneiformis, could be considered a safe, natural feedstuff resource rich in dietary fibers, minerals, and proteins, but low in calories.

Key words: Seaweeds, nutrition, feed safety