scholarly journals Temporal variability in zooplankton community in the western Yellow Sea and its possible links to green tides

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6641 ◽  
Author(s):  
Weicheng Wang ◽  
Guangtao Zhang ◽  
Xiaoxia Sun ◽  
Fang Zhang ◽  
Xing Zhang
Keyword(s):  
Yellow Sea ◽  
Temporal Variability ◽  
Zooplankton Community ◽  
Assemblage Structure ◽  
Green Tide ◽  
Zooplankton Abundance ◽  
Green Tides ◽  
Size Diversity ◽  
Tide Period ◽  
Western Yellow Sea

Large-scale macro-algal blooms ofUlva prolifera(also called green tides) have appeared each summer since 2008 in the western Yellow Sea. In this study, we investigated the temporal variability in zooplankton community in the western Yellow Sea and its possible links to green tides using data from a long-term plankton survey off the coast of Qingdao, China. Environmental conditions observed in the study area during the green tide period (GTP: June–August, 2008–2013) were compared to the non-green tide period (NGTP: June–August, 2005–2007), to support the contention that variations observed in zooplankton community may be attributed to the green tides, as opposed to natural climatic or environmental variations. Zooplankton assemblage structure observed during the GTP was then compared to the NGTP. Significant variations were detected both in zooplankton abundance and assemblage structure between the two defined periods. The abundance of zooplankton, mainly copepods, was significantly decreased during the GTP. Meanwhile, the relative abundance of copepods decreased by approximately 10% and that of gelatinous zooplankton, including appendicularians, chaetognaths, and medusae, almost doubled (ca. increased by 6.4%). The dominant species of meroplankton completely changed, specifically, polychaeta, and echinoderm larvae were more dominant than decapod and bivalve larvae. With regard to zooplankton size structure, the NGTP showed a higher size diversity with more small-sized organisms, while the GTP showed a lower size diversity in the community. According to general linear models, the interannual variation in summer zooplankton abundance was significantly correlated with green tides. These results indicate that the temporal changes in zooplankton community may have a close link to the green tides.

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.

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.

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

PeerJ ◽  
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.

scholarly journals A Lagrangian-based Floating Macroalgal Growth and Drift Model (FMGDM v1.0): application in the green tides of the Yellow Sea

2021 ◽  
Author(s):  
Fucang Zhou ◽  
Jianzhong Ge ◽  
Dongyan Liu ◽  
Pingxing Ding ◽  
Changsheng Chen
Keyword(s):  
Remote Sensing ◽  
Yellow Sea ◽  
Surface Wind ◽  
Ocean Model ◽  
Biological Data ◽  
The Yellow Sea ◽  
Green Tide ◽  
Observation Data ◽  
Green Tides ◽  
Drift Model

Abstract. Massive floating macroalgal blooms in the ocean have had an array of ecological consequences; thus, tracking their drifting pattern and predicting their biomass are important for their effective management. However, a high-resolution ecological dynamics model is lacking. In this study, a physical–ecological model, Floating Macroalgal Growth and Drift Model (FMGDM v1.0), was developed to determine the dynamic growth and drift pattern of floating macroalgal, based on the tracking, replication and extinction of Lagrangian particles. The position, velocity, quantity and represented biomass of particles are updated synchronously between the tracking module and the ecological module. The former is driven by ocean flows and sea surface wind, while the latter is controlled by the temperature, salinity, and irradiation. Based on the hydrodynamic models of the Finite-Volume Community Ocean Model and parameterized using a culture experiment of Ulva prolifera, which caused the largest bloom worldwide of the green tide in the Yellow Sea, China, this model was applied to simulate the green tides around the Yellow Sea in 2014 and 2015. The simulation result, distribution and biomass of green tides, was validated using remote sensing observation data and reasonably modeled the entire process of green tide bloom and its extinction from early spring to late summer. Given the prescribed spatial initialization from remote sensing observation, the model could provide accurate short-term (7–8 d) predictions of the spatial and temporal developments of the green tide. With the support of the hydrodynamic model and biological data of macroalgae, this model can forecast floating macroalgae blooms in other regions.

Temporal succession of community structure and biphase ratio in a natural population of Ulva spp. (Chlorophyta) attached to Pyropia rafts in the Yellow Sea, China

2019 ◽  
Vol 62 (6) ◽  
pp. 549-561
Author(s):  
Yu Du ◽  
Yuan Ao ◽  
Yuan He ◽  
Yi Yin ◽  
Yafeng Ma ◽  
...  
Keyword(s):  
Yellow Sea ◽  
Internal Transcribed Spacer ◽  
Algal Blooms ◽  
Null Model ◽  
Ulva Prolifera ◽  
The Yellow Sea ◽  
Green Tide ◽  
Continuous Change ◽  
Green Tides ◽  
Temporal Succession

Abstract Green tide algal blooms occur worldwide, especially in China’s Yellow Sea, and have caused serious damage to local ecological environments and economies. As a dominant agent of green tides, the green macroalga Ulva has caused widespread concern. In this study, phylogenetic clades were constructed among related Ulva species isolated from Pyropia rafts at six sites over 1.5 years based on internal transcribed spacer (ITS) and tufA sequences. In addition, traditional observation ploidy methods and flow cytometry methods were used to analyse continuous change in the biphase and sex ratios of Ulva species and to assess the changes in phase advantages over time. The results showed that the perennial Ulva populations on rafts mainly consisted of Ulva flexuosa and Ulva prolifera, and the biphasic dominance of the attached Ulva populations changed with the seasons: sporophytes were predominant mainly in winter and spring, and gametophytes were predominant mainly in summer and autumn. At the same time, there were some differences in gametophyte and sporophyte frequencies (mainly sporophyte biased) compared to the null model prediction of a √2:1 ratio, while the sex ratio of male and female gametophytes remained 1:1 throughout the year. Our results indicate the presence of both phases of bloom-forming species of Ulva in green tides year round, and that multiple generations coexist and grow continuously.

Semi-enclosed bays serve as hotspots for black carbon burial: A case study in Jiaozhou Bay, western Yellow Sea

2021 ◽  
pp. 149100
Author(s):  
Na Feng ◽  
Weifeng Yang ◽  
Xiufeng Zhao ◽  
Min Chen ◽  
Yusheng Qiu ◽  
...  
Keyword(s):  
Black Carbon ◽  
Yellow Sea ◽  
Jiaozhou Bay ◽  
Carbon Burial ◽  
Western Yellow Sea

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

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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