Growth responses of Ulva prolifera to inorganic and organic nutrients: Implications for macroalgal blooms in the southern Yellow Sea, China

Abstract

The marine macrophyte Ulva prolifera is the dominant green-tide-forming seaweed in the southern Yellow Sea, China. Here we assessed, in the laboratory, the growth rate and nutrient uptake responses of U. prolifera to different nutrient treatments. The growth rates were enhanced in incubations with added organic and inorganic nitrogen [i.e. nitrate (NO3−), ammonium (NH4+), urea and glycine] and phosphorus [i.e. phosphate (PO43−), adenosine triphosphate (ATP) and glucose 6-phosphate (G-6-P)], relative to the control. The relative growth rates of U. prolifera were higher when enriched with dissolved organic nitrogen (urea and glycine) and phosphorus (ATP and G-6-P) than inorganic nitrogen (NO3− and NH4+) and phosphorus (PO43−). In contrast, the affinity was higher for inorganic than organic nutrients. Field data in the southern Yellow Sea showed significant inverse correlations between macroalgal biomass and dissolved organic nutrients. Our laboratory and field results indicated that organic nutrients such as urea, glycine and ATP, may contribute to the development of macroalgal blooms in the southern Yellow Sea.

Cloning and characterization of nitrate reductase gene in Ulva prolifera (Ulvophyceae, Chlorophyta)

“…Although it is accepted widely that the N content in the Yellow Sea is essential to supporting the world's largest green tide, it is unclear which form of N triggers the blooming of U. prolifera, including nitrate (Smetacek and Zingone 2013), ammonium (Wu et al 2013) or urea (Li et al 2016). This work provides UpNR as a gene-sensor to probe N assimilation by U. prolifera in the field.…”

“…) or urea (Li et al. ). This work provides UpNR as a gene‐sensor to probe N assimilation by U. prolifera in the field.…”

Adsorptive removal of polycyclic aromatic hydrocarbons by detritus of green tide algae deposited in coastal sediment

“…These processes are of great importance for the biogeochemical cycle of coastal contaminants. The algae possess higher ratio of surface to volume and different functional groups including the carboxyl, hydroxyl and sulphate groups, which provides them with the potential of substantially removing pollutants such as nutrients (nitrogen and phosphorus) (Fan et al, 2014;Li et al, 2016;Luo et al, 2012;Sun et al, 2015) and metals (Sarı and Tuzen, 2008a) from seawater. In many previous studies, the fresh algae were often dried (Gao et al, 2018) and/or modified by ferric chloride (Son et al, 2018), sulfuric acid (Xiong et al, 2013) and formaldehyde (Yang and Chen, 2008) to improve the surface physico-chemical characteristics of algal biomass for reinforcing their sorption performance.…”

Removal of phenanthrene from coastal waters by green tide algae Ulva prolifera

“…In every spring and early summer since 2007, green tides persistently flourish along the coastal regions of the northern Yellow Sea, Jiangsu Province of China (Shi et al, 2015), and then floated northward until landed on seashore of Shandong Province with 6 million kg algae biomass, which brought negative effects on local economy and coastal ecosystems . As a kind of dominant species, Ulva prolifera (U. prolifera) can inhabit in the inshore and estuaries as well as brackish and fresh waters which contain enriched nutrients from agriculture and animal aquaculture (Li et al, 2016). These algae consist of filamentous shoots with monostromatic hollow cylinders and have higher ratio of surface to volume (S/V), which endows them with high nutrient (nitrogen and phosphorus) uptake capability and the potential to remove pollutants when exposed to contaminated aquatic environment (Gao et al, 2016).…”