Temporal and spatial distributions of green algae micro-propagules in the coastal waters of the Subei Shoal, China

The blooms of large-scale green tides in the Yellow Sea have become a focus of marine research in China. Micro-propagules, as the propagule source of green algae, played an important role in the formation of green tides. In this study, monthly surveys in the coastal area of the Subei Shoal were conducted from October 2010 to October 2011. The temporal and spatial distributions of green algae micro-propagules in the water column and sediment were investigated. Green algae micro-propagules were widely distributed in the waters and sediments throughout the year, and their distribution significantly corresponded to Porphyra aquaculture activities. The abundance of the micro-propagules decreased gradually from inshore to offshore. The average number of micro-propagules reached a maximum in late April and was low during the winter and summer. The source of the micro-propagules was the green algae attached to the Porphyra aquaculture rafts. The green algae micro-propagules might serve as the seed stock of the raft-attached green algae and provide the initial conditions for the formation of green tides. (C) 2014 Elsevier Ltd. All rights reserved.