scholarly journals Improving size selectivity of round pot for Charybdis japonica by configuring escape vents in the Yellow Sea, China

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12282
Author(s):  
Mengjie Yu ◽  
Liyou Zhang ◽  
Changdong Liu ◽  
Yanli Tang
Keyword(s):  
Sustainable Development ◽  
Coastal Waters ◽  
Yellow Sea ◽  
Comparison Method ◽  
The Yellow Sea ◽  
Size Selectivity ◽  
The Sustainable Development ◽  
Charybdis Japonica ◽  
Yellow Sea Of China ◽  
Escape Vent

Sustainable development of the important economic species, Asian paddle crab (Charybdis japonica), has attracted attention in the coastal waters of the Yellow Sea, China. The commonly used round pots are almost nonselective, resulting in severe bycatch of juveniles. In this study, we explored a method to improve the size selectivity for C. japonica by mounting escape vents on the side panels of each pot. The selectivity of pots with escape vent sizes of 70 mm × 20 mm, 70 mm × 25 mm, 70 mm × 30 mm, and 70 mm × 35 mm was tested using a catch comparison method. The estimated minimum landing size (MLS) of carapace height (27 mm), according to the regulated MLS of carapace length (50 mm), was used as a reference point to explain the results. Significant increases in the size of crabs caught by pots were found with the enlargement of escape vent size (Kruskal–Wallis test, P < 0.01). The pots with 70 mm × 20 mm, 70 mm × 25 mm and 70 mm × 30 mm escape vents released nearly 50%, 75% and 95% of undersized individuals, respectively, and these three types of pots retained approximately 90% of legal-sized individuals compared with the control pots without escape vents. The pots with 70 mm × 35 mm escape vents released nearly all undersized individuals, but they also released most legal-sized individuals. Pots with an escape vent size of 70 mm × 30 mm were recommended for the sustainable development of C. japonica in the Yellow Sea of China. The results of this study reiterate the importance of carapace height for determining the size selectivity, which can serve as a reference to formulate management regulations in the coastal waters of the Yellow Sea, China.

scholarly journals Characteristic Volatile Composition of Seven Seaweeds from the Yellow Sea of China

Marine Drugs ◽  
2021 ◽  
Vol 19 (4) ◽  
pp. 192
Author(s):  
Pengrui Wang ◽  
Jiapeng Chen ◽  
Lujing Chen ◽  
Li Shi ◽  
Hongbing Liu
Keyword(s):  
Yellow Sea ◽  
Solid Phase ◽  
Principal Component ◽  
Chemical Diversity ◽  
The Yellow Sea ◽  
Gas Chromatography Mass Spectrometry ◽  
Network Pharmacology ◽  
Receptor Interaction ◽  
Neuropsychiatric Diseases ◽  
Yellow Sea Of China

Plant volatile organic compounds (VOCs) represent a relatively wide class of secondary metabolites. The VOC profiles of seven seaweeds (Grateloupia filicina, Polysiphonia senticulosa, Callithamnion corymbosum, Sargassum thunbergii, Dictyota dichotoma, Enteromorpha prolifera and Ulva lactuca) from the Yellow Sea of China were investigated using multifiber headspace solid phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME/GC–MS), among them, the VOCs of three red algae Grateloupia filicina, Polysiphonia senticulosa, and Callithamnion corymbosum were first reported. Principal component analysis (PCA) was used to disclose characteristic categories and molecules of VOCs and network pharmacology was performed to predict potential biomedical utilization of candidate seaweeds. Aldehyde was found to be the most abundant VOC category in the present study and (E)-β-ionone was the only compound found to exist in all seven seaweeds. The chemical diversity of aldehydes in E. prolifera suggest its potential application in chemotaxonomy and hinted that divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber is more suitable for aldehyde extraction. VOCs in D. dichotoma were characterized as sesquiterpenes and diterpenes and the most relevant pharmacological pathway was the neuroactive ligand–receptor interaction pathway, which suggests that D. dichotoma may have certain preventive and therapeutic values in cancer, especially in lung cancer, in addition to neuropsychiatric diseases.

scholarly journals Monitoring oyster culture rafts and seagrass meadows in Nagatsura-ura Lagoon, Sanriku Coast, Japan before and after the 2011 tsunami by remote sensing: their recoveries implying the sustainable development of coastal waters

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10727
Author(s):  
Hiroki Murata ◽  
Motoyuki Hara ◽  
Chinatsu Yonezawa ◽  
Teruhisa Komatsu
Keyword(s):  
Remote Sensing ◽  
Sustainable Development ◽  
Coastal Waters ◽  
Coastal Ecosystems ◽  
Oyster Culture ◽  
Sanriku Coast ◽  
The Sustainable Development ◽  
Seagrass Meadows ◽  
Before And After ◽  
Aquaculture Management

Background Coastal ecosystems are blue infrastructures that support coastal resources and also aquaculture. Seagrass meadows, one of coastal ecosystems, provide substrates for epiphytic diatoms, which are food resources for cultured filter feeder organisms. Highly intensive coastal aquaculture degrades coastal environments to decrease seagrass meadows. Therefore, efficient aquaculture management and conservation of seagrass meadows are necessary for the sustainable development of coastal waters. In ria-type bays, non-feeding aquaculture of filter feeders such as oysters, scallops, and ascidians are actively practiced along the Sanriku Coast, Japan. Before the 2011 Great East Japan Earthquake, the over-deployment of oyster culture facilities polluted the bottom environment and formed an hypoxic bottom water layer due to the organic excrements from cultured oysters. The tsunami in 2011 devastated the aquaculture facilities and seagrass meadows along the Sanriku Coast. We mapped the oyster culture rafts and seagrass meadows in Nagatsura-ura Lagoon, Sanriku Coast before and after the tsunami and monitored those and environments after the tsunami by field surveys. Methods We conducted field surveys and monitored the environmental parameters in Nagatsura-ura Lagoon every month since 2014. We used high-resolution satellite remote sensing images to map oyster culture rafts and seagrass meadows at irregular time intervals from 2006 to 2019 in order to assess their distribution. In 2019, we also used an unmanned aerial vehicle to analyze the spatial variability of the position and the number of ropes suspending oyster clumps beneath the rafts. Results In 2013, the number and distribution of the oyster culture rafts had been completely restored to the pre-tsunami conditions. The mean area of culture raft increased after the tsunami, and ropes suspending oyster clumps attached to a raft in wider space. Experienced local fishermen also developed a method to attach less ropes to a raft, which was applied to half of the oyster culture rafts to improve oyster growth. The area of seagrass meadows has been expanding since 2013. Although the lagoon had experienced frequent oyster mass mortality events in summer before the tsunami, these events have not occurred since 2011. The 2011 earthquake and tsunami deepened the sill depth and widened the entrance to enhance water exchange and improve water quality in the lagoon. These changes brought the expansion of seagrass meadows and reduction of mass mortality events to allow sustainable oyster culture in the lagoon. Mapping and monitoring of seagrass meadows and aquaculture facilities via satellite remote sensing can provide clear visualization of their temporal changes. This can in turn facilitate effective aquaculture management and conservation of coastal ecosystems, which are crucial for the sustainable development of coastal waters.

Vertical dynamics in community functioning of biofilm-dwelling ciliates during the colonisation process in coastal waters of the Yellow Sea

2019 ◽  
Vol 70 (11) ◽  
pp. 1611 ◽  
Author(s):  
Xiaoyun Bai ◽  
Congcong Guo ◽  
Mamun Abdullah Al ◽  
Alan Warren ◽  
Henglong Xu
Keyword(s):  
Functional Diversity ◽  
Functional Traits ◽  
Coastal Waters ◽  
Yellow Sea ◽  
Northern China ◽  
Diversity Indices ◽  
Functional Trait ◽  
The Yellow Sea ◽  
Biological Traits ◽  
Trait Distribution

Multifunctional trait analysis is increasingly recognised as an effective tool for assessing ecosystem function and environmental quality. Here, a baseline study was performed at four depths (i.e. 1, 2, 3.5 and 5m) in Yellow Sea coastal waters of northern China in order to determine the optimal depth for bioassessment using biological traits of biofilm-dwelling ciliates. Community-weighted means (CWM) from functional traits system were used to summarise the trait distribution and functional diversity of ciliates among the four depths during a 1-month colonisation period. Functional trait distribution revealed a clear temporal variation among the four depths. In total, 3 of 17 functional traits (i.e. feeding type, body size and flexibility) showed significant temporal patterns. Bootstrapped averaging and permutational multivariate analysis of variance (PERMANOVA) tests demonstrated that the colonisation pattern of biofilm-dwelling ciliates as expressed by CWM at 1 and 2m differed significantly from those at 3.5 and 5m. Functional diversity indices showed lower variability at 1 and 2m than at 3.5 and 5m. These results suggest that 1 and 2m are the preferred sampling depths for bioassessment of marine water quality using biological traits of biofilm-dwelling ciliates.

scholarly journals Source spectrum model for merchant ship radiated noise in the Yellow Sea of China

2020 ◽  
Vol 216 ◽  
pp. 107607 ◽  
Author(s):  
Pengfei Jiang ◽  
Jianheng Lin ◽  
Junping Sun ◽  
Xuejuan Yi ◽  
Yuanchun Shan
Keyword(s):  
Yellow Sea ◽  
The Yellow Sea ◽  
Source Spectrum ◽  
Radiated Noise ◽  
Merchant Ship ◽  
Yellow Sea Of China ◽  
Spectrum Model

scholarly journals A barrier to gene flow in the Asian paddle crab, Charybdis japonica, in the Yellow Sea

2015 ◽  
Vol 72 (5) ◽  
pp. 1440-1448 ◽  
Author(s):  
Zhiqiang Han ◽  
Wei Zheng ◽  
Wenbin Zhu ◽  
Cungen Yu ◽  
Bonian Shui ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Yellow Sea ◽  
Population Expansion ◽  
The Yellow Sea ◽  
Northwestern Pacific ◽  
Factors Affecting ◽  
Haizhou Bay ◽  
Coastal Species ◽  
Charybdis Japonica

Abstract Three primary factors affecting genetic patterns of marine species in the Northwestern Pacific Ocean have been proposed: isolation and population expansion during Pleistocene glacial cycles, ocean currents facilitating the gene flow, and the Yangtze River outflow imposing a physical barrier to gene flow. Here, we examined these factors affecting population structuring of the Asian paddle crab, Charybdis japonica, in the Yellow Sea, East China Sea, and adjacent areas. Genetic variation in nine populations of C. japonica (n = 169) was determined from partial mitochondrial cytochrome c oxidase subunit I sequences. Among the 14 haplotypes identified, a dominant haplotype H1 was present in all populations, and a relatively abundant localized haplotype H2 was found in four of the northern populations. Furthermore, the frequency of the common haplotype H1 decreased from south to north. A genetic discontinuity was detected in Haizhou Bay, which divided species into two groups (north group and south group). The lack of genetic structure in the south and north groups indicates high dispersal of C. japonica within groups. Local marine gyres in Haizhou Bay might be responsible for the divergence of the north and south groups. Our study highlights the importance of local marine gyres for influencing genetic structure in marine coastal species in the Northwestern Pacific, especially in species spawning inshore.

The sound velocity and bulk properties of sediments in the Bohai Sea and the Yellow Sea of China

2016 ◽  
Vol 35 (7) ◽  
pp. 76-86 ◽  
Author(s):  
Jiewen Zheng ◽  
Baohua Liu ◽  
Guangming Kan ◽  
Guanbao Li ◽  
Yanliang Pei ◽  
...  
Keyword(s):  
Sound Velocity ◽  
Yellow Sea ◽  
Bohai Sea ◽  
The Yellow Sea ◽  
Bulk Properties ◽  
The Bohai Sea ◽  
Yellow Sea Of China
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