Tempo-spatial distribution of green algae micro-propagules in the Yellow Sea after the outbreak of the green tide in 2014

The monthly surveys were conducted along the west coasts of Yellow Sea during October to December 2014 to study the temporal and spatial distribution features of green algae micro-propagules in water and sediment after the large-scale green tide in Yellow Sea.The results showed that there was an evident temporal and spatial variation of the green algae micro-propagules in the survey area.The high values were presented mainly in Dafeng and Rudong area.The spatial distribution of green algae micro-propagules incread gradually from south to north in the invested area.There was no significant change on the abundance in October and November of 2014.However, it significantly increasd at Dafeng and Rudong area in December.In the coastal water of Rudong and Dafeng, the desenties of green algae micro-propagules in the water were 16 and 34 ind/L, respectively, in November and increased to 62 and 72 ind/L in December.The denseties of green algae micro-propagules in the sediment were 7and 10 ind/20 g, respectively, in November and increased to 18 and 28 ind/20 g in December.As shown in this research, the quantity of green algae micro-propagules significantly increasd at the stations of R1、R2、D2 and D3 near the Pyropia aquaculture area.Feuthermore, green algae attached on the Pyropia aquaculture rafts have appeared in December.Therefore, it was suggested that the micro-propagules released from the green algae attached on the Pyropia aquaculture rafts may survive through the winter, and serve as the seed stock for the following spring bloom.