Abstract
We will describe the potential usefulness of jellyfish (Aurelia aurita and Chrysaora melanaster), which have increased rapidly in coastal waters, as a fertilizer for vegetable fields. The jellyfish were found, by means of absorptiometry, flame photometry or ICP emission spectroscopy, to have five principal components of fertilizers: nitrogen, phosphorus, potassium, magnesium, and calcium. Concentrations of total nitrogen, total phosphorus, and potassium in Chrysaora melanaster (954, 153, and 667 mg/kg in fresh weight) were 2.8, 3.3, and 1.3 times higher than those in Aurelia aurita (336, 46, and 501 mg/kg), respectively. Concentrations of sodium, potassium, magnesium, and calcium were almost identical to those in seawater. Concentrations of chromium andcadmium in jellyfish were lower than the limit of quantification for ICP emission spectroscopy. Three kinds of vegetables, chingentsuai (a Chinese vegetable), green soybeans, and perilla were cultivated using a suspension of jellyfish as a izer. Jellyfish are inferred to be effective for growth of vegetables, especially chingentsuai.
