INDUSTRIAL CHAIN OF PYROPIA AQUACULTURE AND BIOREMEDIATION IN JIANGSU PROVINCE COASTS, CHINA  

The red seaweed Pyropia is the most valuable maricultured seaweed (approximately US$ 18 million/t dry biomass) in the world, and annual market value was over US$1.4 billion in 2005. In China, Pyropia yezoensis cultivation is very important for both economic efficiency and ecological efficiency. Since 80's of 20th Century, P. yezoensis cultivation has developed for about 40 years in Jiangsu province, and its cultivation scale reached up to34.5 kha (450 kMu). The yield was about about 800 kg (dry weight)/ha throughout the cultivation season. And the biomass P. yezoensis cultivation was up to 132 k tons (dry weight) or 4.4 billion sheets in Jiangsu province in 2015. The industrial chain includes breeding, cultivation, primary proceeding, second proceeding, storing, trading.

P. yezoensis has been considered to be a good bioremediation candidate for reducing marine eutrophication. We studied the bioremediation effection of about 15 kha (200 kMu) of P. yezoensis cultivation in the radial sandbanks waters of Jiangsu province in 2012-2013. These results indicate that large-scale cultivation of P. yezoensis can be used to efficiently alleviate eutrophication and control harmful algae blooms in open sea.Mean nutrient concentration in the P. yezoensis cultivation area were significantly lower than those in the non-cultivation area, especially during the cultivation season (p < 0.05), the seawater quality belonged to Grade II for P and Grade III for N. Tissue nitrogen and phosphorus contents of baldes were 5.99-6.80 % (dry weight) and 0.16-0.19 % (dry weight), respectively. For biomass of P. yezoensis was about 59 kt (dry weight), about 3.7 kt of tissue nitrogen and 0.1 kt of tissue phosphorus were uptaked by harvesting. The richness index of the red tide species Skeleton emacostatum declined from 0.32 to 0.05 during the P. yezoensis cultivation season.