A new assessment of the algal biomass of green tide in the 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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Adaptations of a green tide forming Ulva linza (Ulvophyceae, Chlorophyta) to selected salinity and nutrients conditions mimicking representative environments in the Yellow Sea

Phycologia ◽

10.2216/15-67.1 ◽

2016 ◽

Vol 55 (2) ◽

pp. 210-218 ◽

Cited By ~ 8

Author(s):

Eun Ju Kang ◽

Ju-Hyoung Kim ◽

Keunyong Kim ◽

Kwang Young Kim

Keyword(s):

Yellow Sea ◽

The Yellow Sea ◽

Green Tide ◽

Ulva Linza

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Error analysis on Green Tide monitoring using MODIS data in the Yellow Sea based on GF-1 WFV data

10.1117/12.2235908 ◽

2016 ◽

Author(s):

Fuxiang Xu ◽

Zhiqiang Gao ◽

Jicai Ning ◽

Xiangyu Zheng ◽

Chaoshun Liu ◽

...

Keyword(s):

Error Analysis ◽

Yellow Sea ◽

The Yellow Sea ◽

Green Tide ◽

Modis Data

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Tempo-spatial distribution and species diversity of green algae micro-propagules in the Yellow Sea during the large-scale green tide development

Harmful Algae ◽

10.1016/j.hal.2014.05.013 ◽

2014 ◽

Vol 39 ◽

pp. 40-47 ◽

Cited By ~ 26

Author(s):

Yan Li ◽

Wei Song ◽

Jie Xiao ◽

Zongling Wang ◽

Mingzhu Fu ◽

...

Keyword(s):

Spatial Distribution ◽

Species Diversity ◽

Green Algae ◽

Yellow Sea ◽

Large Scale ◽

The Yellow Sea ◽

Green Tide

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The Yellow Sea green tide: A risk of macroalgae invasion

Harmful Algae ◽

10.1016/j.hal.2018.05.007 ◽

2018 ◽

Vol 77 ◽

pp. 11-17 ◽

Cited By ~ 8

Author(s):

Jin Zhao ◽

Peng Jiang ◽

Ri Qiu ◽

Yingying Ma ◽

Chunhui Wu ◽

...

Keyword(s):

Yellow Sea ◽

The Yellow Sea ◽

Green Tide ◽

Yellow Sea Green Tide

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

National Science Review ◽

10.1093/nsr/nwz026 ◽

2019 ◽

Vol 6 (4) ◽

pp. 825-838 ◽

Cited By ~ 26

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.

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Spatiotemporal Patterns and Morphological Characteristics of Ulva prolifera Distribution in the Yellow Sea, China in 2016–2018

Remote Sensing ◽

10.3390/rs11040445 ◽

2019 ◽

Vol 11 (4) ◽

pp. 445 ◽

Cited By ~ 10

Author(s):

Yingzhi Cao ◽

Yichen Wu ◽

Zhixiang Fang ◽

Xiaojian Cui ◽

Jianfeng Liang ◽

...

Keyword(s):

Yellow Sea ◽

Vegetation Index ◽

Morphological Changes ◽

Surface Wind ◽

Morphological Characteristics ◽

Ulva Prolifera ◽

Spatiotemporal Patterns ◽

The Yellow Sea ◽

Green Tide ◽

Sea Surface Wind

The world’s largest macroalgal blooms, Ulva prolifera, have appeared in the Yellow Sea every summer on different scales since 2007, causing great harm to the regional marine economy. In this study, the Normalized Difference of Vegetation Index (NDVI) index was used to extract the green tide of Ulva prolifera from MODIS images in the Yellow Sea in 2016–2018, to investigate its spatiotemporal patterns and to calculate its occurrence probability. Using the standard deviational ellipse (SDE), the morphological characteristics of the green tide, including directionality and regularity, were analyzed. The results showed that the largest distribution and coverage areas occurred in 2016, with 57,384 km2 and 2906 km2, respectively and that the total affected region during three years was 163,162 km2. The green tide drifted northward and died out near Qingdao, Shandong Province, which was found to be a high-risk region. The coast of Jiangsu Province was believed to be the source of Ulva prolifera, but it was probably not the only one. The regularity of the boundary shape of the distribution showed a change that was opposite to the variation of scale. Several sharp increases were found in the parameters of the SDE in all three years. In conclusion, the overall situation of Ulva prolifera was still severe in recent years, and the sea area near Qingdao became the worst hit area of the green tide event. It was also shown that the sea surface wind played an important part in its migration and morphological changes.

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Remote sensing of early-stage green tide in the Yellow Sea for floating-macroalgae collecting campaign

Marine Pollution Bulletin ◽

10.1016/j.marpolbul.2018.05.035 ◽

2018 ◽

Vol 133 ◽

pp. 150-156 ◽

Cited By ~ 15

Author(s):

Qianguo Xing ◽

Lingling Wu ◽

Liqiao Tian ◽

Tingwei Cui ◽

Lin Li ◽

...

Keyword(s):

Remote Sensing ◽

Yellow Sea ◽

Early Stage ◽

The Yellow Sea ◽

Green Tide

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Validation of MODIS-based monitoring for a green tide in the Yellow Sea with the aid of unmanned aerial vehicle

Journal of Applied Remote Sensing ◽

10.1117/1.jrs.11.012007 ◽

2017 ◽

Vol 11 (1) ◽

pp. 012007 ◽

Cited By ~ 5

Author(s):

Fuxiang Xu ◽

Zhiqiang Gao ◽

Weitao Shang ◽

Xiaopeng Jiang ◽

Xiangyu Zheng ◽

...

Keyword(s):

Unmanned Aerial Vehicle ◽

Yellow Sea ◽

The Yellow Sea ◽

Green Tide ◽

Aerial Vehicle

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Distribution and species diversity of the floating green macroalgae and micro-propagules in the Subei Shoal, southwestern Yellow Sea

PeerJ ◽

10.7717/peerj.10538 ◽

2020 ◽

Vol 8 ◽

pp. e10538

Author(s):

Xiaoxiang Miao ◽

Jie Xiao ◽

Qinzeng Xu ◽

Shiliang Fan ◽

Zongling Wang ◽

...

Keyword(s):

Species Diversity ◽

Environmental Factors ◽

Yellow Sea ◽

Source Region ◽

The Yellow Sea ◽

Green Tide ◽

Distributional Pattern ◽

Green Tides ◽

Green Macroalgae ◽

Subei Shoal

Massive floating green macroalgae have formed harmful green tides in the Yellow Sea since 2007. To study the early development and the associated environmental factors for the green tide, a field survey was carried out in the Subei Shoal, southwestern Yellow Sea. Multiple species were identified in both floating green macroalgae and micro-propagules , while their abundances showed distinct spatial variations. The floating macroalgal biomass was widespread in the northern Subei Shoal and most abundant at 34°N. Ulva prolifera dominated (91.2% in average) the floating macroalgae, and the majority (88.5%) of U. prolifera was the ‘floating type’. In comparison, the micro-propagules were most abundant around the aquaculture rafts, and decreased significantly with the distance to the rafts. The dominant species of micro-propagules was U. linza (48.5%), followed by U. prolifera (35.1%). Their distinct distribution patterns and species diversity suggested little direct contribution of micro-propagules for the floating macroalgae. The spatial variation of the floating macroalgae was probably a combined result from the biomass source and environmental factors, while the abundance of micro-propagules was closely associated with the rafts. A positive correlation between the floating macroalgae and DO was observed and suggested active photosynthesis of the initial biomass in Subei Shoal. This study revealed specific distributional pattern and relationships among the floating macroalgae, micro-propagules and the environmental factors in the source region, which helps understanding the early blooming dynamics of the green tides in Yellow Sea.

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