scholarly journals Numerical Study on the Massive Outbreak of the Ulva prolifera Green Tides in the Southwestern Yellow Sea in 2021

2021 ◽  
Vol 9 (11) ◽  
pp. 1167
Author(s):  
Bin Wang ◽  
Lei Wu
Keyword(s):  
Yellow Sea ◽  
Numerical Study ◽  
Ulva Prolifera ◽  
Changjiang River ◽  
Nutrient Inputs ◽  
Green Tides ◽  
Easterly Wind ◽  
Average Value ◽  
The Changjiang River

The most massive outbreak on record of the Ulva prolifera green tides in the southwestern Yellow Sea occurred in summer of 2021. The environmental factors were investigated based on observations and simulations. The results suggested that the significantly enhanced discharge of the Changjiang River since winter 2020–2021 was crucial for the outbreak of the Ulva prolifera green tides in the southwestern Yellow Sea, which could significantly have contributed to the nutrient enrichment off the Subei coast. Additionally, the southerly wind stress anomaly during winter 2020–2021 favored the upwind transport of Changjiang water. Numerical experiments showed that the remaining winter freshwater coming from the Changjiang River, which persisted in the Subei coast’s upper layer until spring 2021, exceeded the long-term average value by 20%. We demonstrated that these large amount of nutrient inputs, as an effective supplement, were the reason the green tides sharply emerged as an extensive outbreak in 2021. The easterly wind anomaly during spring 2021 contributed to the landing of Ulva prolifera off the Lunan coast.

scholarly journals Ulva prolifera green-tide outbreaks and their environmental impact in the Yellow Sea, China

2019 ◽  
Vol 6 (4) ◽  
pp. 825-838 ◽  
Author(s):  
Yongyu Zhang ◽  
Peimin He ◽  
Hongmei Li ◽  
Gang Li ◽  
Jihua Liu ◽  
...  
Keyword(s):  
Yellow Sea ◽  
Red Tide ◽  
Abiotic Factors ◽  
Management Strategies ◽  
Ulva Prolifera ◽  
The Yellow Sea ◽  
Green Tide ◽  
Biological Interactions ◽  
Green Tides ◽  
Carbon Cycles

Abstract The Ulva prolifera green tides in the Yellow Sea, China, which have been occurring since 2007, are a serious environmental problem attracting worldwide attention. Despite extensive research, the outbreak mechanisms have not been fully understood. Comprehensive analysis of anthropogenic and natural biotic and abiotic factors reveals that human activities, regional physicochemical conditions and algal physiological characteristics as well as ocean warming and biological interactions (with microorganism or other macroalgae) are closely related to the occurrence of green tides. Dynamics of these factors and their interactions could explain why green tides suddenly occurred in 2007 and decreased abruptly in 2017. Moreover, the consequence of green tides is serious. The decay of macroalgal biomass could result in hypoxia and acidification, possibly induce red tide and even have a long-lasting impact on coastal carbon cycles and the ecosystem. Accordingly, corresponding countermeasures have been proposed in our study for future reference in ecosystem management strategies and sustainable development policy.

A numerical study of the Ulva prolifera biomass during the green tides in China - toward a cleaner Porphyra mariculture

2020 ◽  
Vol 161 ◽  
pp. 111805
Author(s):  
Ke Sun ◽  
Junchuan Sun ◽  
Qing Liu ◽  
Zhan Lian ◽  
Jeffrey S. Ren ◽  
...  
Keyword(s):  
Numerical Study ◽  
Ulva Prolifera ◽  
Green Tides

A dynamic growth model of Ulva prolifera: Application in quantifying the biomass of green tides in the Yellow Sea, China

2020 ◽  
Vol 428 ◽  
pp. 109072 ◽  
Author(s):  
Ke Sun ◽  
Jeffrey S. Ren ◽  
Tao Bai ◽  
Jihong Zhang ◽  
Qing Liu ◽  
...  
Keyword(s):  
Growth Model ◽  
Yellow Sea ◽  
Ulva Prolifera ◽  
The Yellow Sea ◽  
Green Tides ◽  
Dynamic Growth

scholarly journals Assessing Herbivorous Impacts of Apohale sp. on the Ulva prolifera Green Tide in China

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaoxiang Miao ◽  
Jie Xiao ◽  
Shiliang Fan ◽  
Yu Zang ◽  
Xuelei Zhang ◽  
...  
Keyword(s):  
Yellow Sea ◽  
Algal Biomass ◽  
Large Scale ◽  
Algal Growth ◽  
Ulva Prolifera ◽  
The Yellow Sea ◽  
Green Tide ◽  
Species Identity ◽  
Green Tides ◽  
The Southern Yellow Sea

An epiphytic gammarid species, Apohyale sp., was abundant in the floating Ulva prolifera (U. prolifera), which forms large-scale green tides in the Yellow Sea (YSGT). Field observation and laboratory experiments were subsequently conducted to study the species identity, abundance, and grazing effects on the floating algal biomass. The abundance of Apohyale sp. showed great spatial variation and varied from 0.03 to 1.47 inds g−1 in the YSGT. In average, each gram of Apohyale sp. body mass can consume 0.43 and 0.60 g algal mass of U. prolifera per day, and the grazing rates varied among the algae cultured with different nutritional seawaters. It was estimated that grazing of Apohale sp. could efficiently reduce ~0.4 and 16.6% of the algal growth rates in Rudong and Qingdao, respectively. The U. prolifera fragments resulting from gnawing of Apohyale sp. had a higher growth rate and similar photosynthetic activities compared to the floating algae, indicating probably positive feedback on the floating algal biomass. This research corroborated the significant impact of Apohyale sp. on the floating algal mass of YSGT through the top-down control. However, further research is needed to understand the population dynamics of these primary predators and hence their correlation with the expansion or decline of YSGT, especially under the complex food webs in the southern Yellow Sea.

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