These authors contributed equally to this work.
Diluted seawater promoted the green tide of Ulva prolifera (Chlorophyta, Ulvales)
Article first published online: 11 OCT 2011
© 2011 Japanese Society of Phycology
Volume 59, Issue 4, pages 295–304, October 2011
How to Cite
Lin, A.-P., Wang, C., Pan, G.-H., Song, L.-Y., Gao, S., Xie, X.-J., Wang, Z.-Y., Niu, J.-F. and Wang, G.-C. (2011), Diluted seawater promoted the green tide of Ulva prolifera (Chlorophyta, Ulvales). Phycological Research, 59: 295–304. doi: 10.1111/j.1440-1835.2011.00629.x
Communicating editor: W. Nelson.
- Issue published online: 11 OCT 2011
- Article first published online: 11 OCT 2011
- Received 23 March 2011; accepted 4 August 2011.
- algal drift;
- Changjiang River;
- diluted water;
- green tide;
Ulva prolifera (Müller) J. Agardh is the main causative species of the 2008 Yellow Sea green tide incident. We investigated the influences of diluted seawater on the vegetative growth and reproductive cell formation of the alga. The thalli that were cultivated under low salinities (10‰ and 20‰) and low pH values (pH around 7.0) showed obvious and steady biomass gain, while those cultivated under high salinities (40‰) and relatively higher pH conditions (pH around 8.0) manifested significant biomass loss. The trend was, however, completely the opposite for reproductive cell formation and there were indications that enrichment, over very wide concentration ranges of both nitrogen and phosphate, could significantly promote vegetative growth. Results also indicated that relatively low salinity and low pH regimes boosted vegetative growth but were unfavorable for reproductive cell formation and vice versa. Based on these results, the possible origin and development mechanisms of the green tide event are discussed. Eutrophication in the Changjiang River estuary and adjacent sea areas, as well as extremely high freshwater inflows before, and during, the flood of 2007 – due to the full operation of large-scale water facilities in the area – may have both played an important role in the formation and development of the green tide event.