2016 Vol. 35, No. 8
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2016, 35(8): .
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2016, 35(8): .
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2016, 35(8): 1-2.
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2016, 35(8): 3-15.
doi: 10.1007/s13131-016-0899-5
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To better evaluate the three-dimensional bay health and predict the dynamic bay health conditions, a concept of numerical bay health was introduced and a method of numerical bay health evaluation (NBHE) was developed. To support the NBHE method, a numerical bay health index (NBHI) system was constructed, which assess the natural and socio-economic effects on the entire bay. Five index groups are combined to formulate the NBHI, including geometry, hydrodynamics and sediment dynamics, bio-ecology, water quality and socio-economy. Each group has different number of indices selected and weighted using AHP method according to their importance. Data were mainly synthesized from a variety of numerical models together with monitoring programs, which provide superior to other approaches in discriminating data integrity and predicting data in future. The NBHE method using NBHI system was applied in the Yueqing Bay during spring tide in April 2007. According to the NBHE results, Sta. A, at the surface level of the estuarine mouth, has a healthy geometry condition, sub-healthy hydrodynamic and sediment dynamic condition, and unhealthy water quality and bioecology conditions. The integrated healthy score at Sta. A indicates its sub-healthy condition.
To better evaluate the three-dimensional bay health and predict the dynamic bay health conditions, a concept of numerical bay health was introduced and a method of numerical bay health evaluation (NBHE) was developed. To support the NBHE method, a numerical bay health index (NBHI) system was constructed, which assess the natural and socio-economic effects on the entire bay. Five index groups are combined to formulate the NBHI, including geometry, hydrodynamics and sediment dynamics, bio-ecology, water quality and socio-economy. Each group has different number of indices selected and weighted using AHP method according to their importance. Data were mainly synthesized from a variety of numerical models together with monitoring programs, which provide superior to other approaches in discriminating data integrity and predicting data in future. The NBHE method using NBHI system was applied in the Yueqing Bay during spring tide in April 2007. According to the NBHE results, Sta. A, at the surface level of the estuarine mouth, has a healthy geometry condition, sub-healthy hydrodynamic and sediment dynamic condition, and unhealthy water quality and bioecology conditions. The integrated healthy score at Sta. A indicates its sub-healthy condition.
2016, 35(8): 16-21.
doi: 10.1007/s13131-016-0846-5
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Harmful algal blooms (HABs) have been increasingly frequent in coastal waters around the world over the last several decades. Accelerated coastal eutrophication, resulting from the increased anthropogenic loadings of nutrients, is commonly assumed to be the primary cause of this increase. However, although important, accelerated coastal eutrophication may not be the only explanation for the increasing blooms or toxic outbreaks in estuarine waters. Changes in riverine material fluxes other than nutrients, such as sediment load, may significantly affect biological activities and HAB incidence in estuarine and coastal waters. A case study off the Changjiang (Yangtze River) Estuary indicated that with the increasing riverine loadings of nutrients, the sediment load from the Changjiang River has been reduced by 70% over the past four decades. A comparison of long-term data revealed that the phytoplankton biomass maximum has expanded to a region of much lower salinity due to the drastic reduction in riverine sediment load and the subsequent improvement in light penetration in the Changjiang River plume. Furthermore, there was an apparent mirror-image relationship between the sediment load from the Changjiang River and the HAB incidence off the Changjiang Estuary over the past four decades, and the number of HAB incidents was significantly negatively correlated with the sediment load. Therefore, it is argued that the drastic decline in sediment load from the Changjiang River reduced turbidity in the Changjiang Estuary and thus contributed to the increased frequency of HABs in the buoyant discharge plumes.
Harmful algal blooms (HABs) have been increasingly frequent in coastal waters around the world over the last several decades. Accelerated coastal eutrophication, resulting from the increased anthropogenic loadings of nutrients, is commonly assumed to be the primary cause of this increase. However, although important, accelerated coastal eutrophication may not be the only explanation for the increasing blooms or toxic outbreaks in estuarine waters. Changes in riverine material fluxes other than nutrients, such as sediment load, may significantly affect biological activities and HAB incidence in estuarine and coastal waters. A case study off the Changjiang (Yangtze River) Estuary indicated that with the increasing riverine loadings of nutrients, the sediment load from the Changjiang River has been reduced by 70% over the past four decades. A comparison of long-term data revealed that the phytoplankton biomass maximum has expanded to a region of much lower salinity due to the drastic reduction in riverine sediment load and the subsequent improvement in light penetration in the Changjiang River plume. Furthermore, there was an apparent mirror-image relationship between the sediment load from the Changjiang River and the HAB incidence off the Changjiang Estuary over the past four decades, and the number of HAB incidents was significantly negatively correlated with the sediment load. Therefore, it is argued that the drastic decline in sediment load from the Changjiang River reduced turbidity in the Changjiang Estuary and thus contributed to the increased frequency of HABs in the buoyant discharge plumes.
2016, 35(8): 22-31.
doi: 10.1007/s13131-016-0897-7
Abstract:
Real-time observations in the field and numerical simulations (with Delft3D) were combined to study the formation, distribution and the relevant influencing factors of turbidity maximum (TM) in the Zhujiang (Pearl River) Estuary (ZE). The spatial distribution pattern of the TM varies with the longitudinal distributions of salinity and suspended sediment concentration (SSC). The SSC is enhanced and the TM is intensified during dry seasons, whereas the center of the TM moves upstream by a distance of 10 km during wet seasons. The formation of the TM is influenced by a complex combination of numerous factors, including tides, river discharges and topography, wherein sediment resuspension and vertical circulation dominate the formations and variability of the TM.
Real-time observations in the field and numerical simulations (with Delft3D) were combined to study the formation, distribution and the relevant influencing factors of turbidity maximum (TM) in the Zhujiang (Pearl River) Estuary (ZE). The spatial distribution pattern of the TM varies with the longitudinal distributions of salinity and suspended sediment concentration (SSC). The SSC is enhanced and the TM is intensified during dry seasons, whereas the center of the TM moves upstream by a distance of 10 km during wet seasons. The formation of the TM is influenced by a complex combination of numerous factors, including tides, river discharges and topography, wherein sediment resuspension and vertical circulation dominate the formations and variability of the TM.
2016, 35(8): 32-38.
doi: 10.1007/s13131-016-0896-8
Abstract:
Since the concept of "fishing down marine food webs" was first proposed in 1998, mean trophic level of fisheries landings (MTL) has become one of the most widely used indicators to assess the impacts of fishing on the integrity of marine ecosystem and guide the policy development by many management agencies. Recent studies suggest that understanding underlying causes for changes in MTL is vital for an appropriate use of MTL as an indicator of fishery sustainability. Based on the landing data compiled by Food and Agriculture Organization (FAO) and trophic information of relevant species in Fishbase, we evaluated MTL trends in 14 FAO fishing areas and analyzed catches of upper and lower trophic level groups under different trends of MTL and found that both the cases of a recovered MTL trend and a generally increasing MTL trend could be accompanied by decreasing catches of lower trophic level species. Further, community structure and exploitation history should be considered in using MTL after excluding species with trophic levels lower than 3.25 to distinguish "fishingthrough" from "fishing-down". We conclude that MTL used as an indicator to measure fishery sustainability can benefit from a full consideration of both upper and lower trophic level species and masking effects of community structure and exploitation history.
Since the concept of "fishing down marine food webs" was first proposed in 1998, mean trophic level of fisheries landings (MTL) has become one of the most widely used indicators to assess the impacts of fishing on the integrity of marine ecosystem and guide the policy development by many management agencies. Recent studies suggest that understanding underlying causes for changes in MTL is vital for an appropriate use of MTL as an indicator of fishery sustainability. Based on the landing data compiled by Food and Agriculture Organization (FAO) and trophic information of relevant species in Fishbase, we evaluated MTL trends in 14 FAO fishing areas and analyzed catches of upper and lower trophic level groups under different trends of MTL and found that both the cases of a recovered MTL trend and a generally increasing MTL trend could be accompanied by decreasing catches of lower trophic level species. Further, community structure and exploitation history should be considered in using MTL after excluding species with trophic levels lower than 3.25 to distinguish "fishingthrough" from "fishing-down". We conclude that MTL used as an indicator to measure fishery sustainability can benefit from a full consideration of both upper and lower trophic level species and masking effects of community structure and exploitation history.
2016, 35(8): 39-43.
doi: 10.1007/s13131-016-0869-y
Abstract:
Sturgeons are the most important principal market species in the Caspian Sea. In the present study, measurement of blood parameters was carried out with the aim of evaluating the normal value of hematological and serum biochemical parameters of brood stocks Acipenser persicus during spawning season. Blood samples were collected from 36 brood stocks of A. persicus (18 males and 18 females) during the spawning season. Higher value of red blood cells, white blood cells, haemoglobin, haematocrit was observed in male breeders with significant differences between female breeders (p>0.05). Haemoglobin and haematocrit value in this study was within the range of 8.70 to 9.2 g/dL and 29.73% to 30.26%, respectively. The statistically significant differences between mean corpuscular volumes, mean corpuscular haemoglobin, lymphocyte and neutrophil percentages, aspartate aminotransferase, alkaline phosphatase and creatine kinase were observed in the male and female brood stocks. It is concluded from this study, some of the hematological and serum biochemical parameters of male and female A. persicus breeders were significantly varied from each other. In comparative investigation with earlier reports, the values of red blood cells, haemoglobin and haematocrit are highly varied due to age variations of fish. However, further studies are necessary to understand the impact of sexual, age, size, length, and season and habitat variation. Serum biochemical parameters can be used for confirming the maturity of A. persicus and monitoring any changes in the water quality parameters and soil.
Sturgeons are the most important principal market species in the Caspian Sea. In the present study, measurement of blood parameters was carried out with the aim of evaluating the normal value of hematological and serum biochemical parameters of brood stocks Acipenser persicus during spawning season. Blood samples were collected from 36 brood stocks of A. persicus (18 males and 18 females) during the spawning season. Higher value of red blood cells, white blood cells, haemoglobin, haematocrit was observed in male breeders with significant differences between female breeders (p>0.05). Haemoglobin and haematocrit value in this study was within the range of 8.70 to 9.2 g/dL and 29.73% to 30.26%, respectively. The statistically significant differences between mean corpuscular volumes, mean corpuscular haemoglobin, lymphocyte and neutrophil percentages, aspartate aminotransferase, alkaline phosphatase and creatine kinase were observed in the male and female brood stocks. It is concluded from this study, some of the hematological and serum biochemical parameters of male and female A. persicus breeders were significantly varied from each other. In comparative investigation with earlier reports, the values of red blood cells, haemoglobin and haematocrit are highly varied due to age variations of fish. However, further studies are necessary to understand the impact of sexual, age, size, length, and season and habitat variation. Serum biochemical parameters can be used for confirming the maturity of A. persicus and monitoring any changes in the water quality parameters and soil.
2016, 35(8): 44-50.
doi: 10.1007/s13131-016-0889-7
Abstract:
Viral hemorrhagic septicemia virus (VHSV) and marine birnavirus (MABV) are the causative pathogens for some of the most explosive epidemics of emerging viral diseases in many Asian countries, leading to huge economic losses in aquaculture. Rapid molecular detection for surveillance or diagnosis has been a critical component in reducing the prevalence of pathogen infection. The loop-mediated isothermal amplification (LAMP) of DNA is currently one of the most commonly used molecular diagnostic tools, as it is simple, quick, and easy to amplify target DNA under isothermal conditions. In the present study, a novel and highly specific LAMP assay for the sensitive and rapid detection of VHSV and MABV infection in fish was developed. Using a set of synthesized primers matching a specific region of the genome, the efficiency and specificity of the LAMP assay were optimized in terms of the reaction temperature and DNA polymerase concentration, as they are the main determinants of the sensitivity and specificity of the LAMP assay. In particular, we demonstrated that our assay could be applied to efficient detection of VHSV and MABV infection in the wild fish, Paralichthys olivaceus. Our results demonstrate the simplicity and convenience of this method for the detection of viral infection in aquatic organisms.
Viral hemorrhagic septicemia virus (VHSV) and marine birnavirus (MABV) are the causative pathogens for some of the most explosive epidemics of emerging viral diseases in many Asian countries, leading to huge economic losses in aquaculture. Rapid molecular detection for surveillance or diagnosis has been a critical component in reducing the prevalence of pathogen infection. The loop-mediated isothermal amplification (LAMP) of DNA is currently one of the most commonly used molecular diagnostic tools, as it is simple, quick, and easy to amplify target DNA under isothermal conditions. In the present study, a novel and highly specific LAMP assay for the sensitive and rapid detection of VHSV and MABV infection in fish was developed. Using a set of synthesized primers matching a specific region of the genome, the efficiency and specificity of the LAMP assay were optimized in terms of the reaction temperature and DNA polymerase concentration, as they are the main determinants of the sensitivity and specificity of the LAMP assay. In particular, we demonstrated that our assay could be applied to efficient detection of VHSV and MABV infection in the wild fish, Paralichthys olivaceus. Our results demonstrate the simplicity and convenience of this method for the detection of viral infection in aquatic organisms.
2016, 35(8): 51-56.
doi: 10.1007/s13131-016-0830-0
Abstract:
Eight microsatellite markers were used to analyze genetic diversity, level of inbreeding, and effective population size of spawner and recaptured populations of Chinese shrimp (Fenneropenaeus chinensis) during stock enhancement in the Bohai Bay in 2013. A total of 254 and 238 alleles were identified in the spawner and recaptured populations, respectively, and the numbers of alleles (Na) were 8-63 and 6-60, respectively. The numbers of effective alleles (Ne) were 2.52-21.60 and 2.67-20.72, respectively. The polymorphism information content ranged from 0.529 to 0.952. The observed heterozygosity (Ho) values (0.638-0.910 and 0.712-0.927) were lower than the expected heterozygosity (He) values (0.603-0.954 and 0.625-0.952), which indicated that the two populations possessed a rich genetic diversity. In 16 tests (2 populations×8 loci), 13 tests deviated from the HardyWeinberg equilibrium. Fis values were positive at seven loci and the inbreeding coefficients (F) of the two populations estimated by trioML were 13.234% and 11.603%, suggesting that there was a relatively high degree of inbreeding. A certain level of inbreeding depression had occurred in the Chinese shrimp population. Fst values ranged from 0 to 0.059, with a mean of 0.028, displaying a low level of genetic differentiation in the two populations. Effective population sizes (3 060.2 and 3 842.8) were higher than the minimum number suggested for retaining the evolutionary potential to adapt to new environmental conditions. For enhancement activity in 2014, the ideal number of captured shrimp spawners should have ranged from 7 686 to 19 214 to maintain genetic diversity and effective population size. Further strategies to adjust the balance of economic cost, fishing effort and ideal number of shrimp spawners to maintain a satisfactory effective population size for ensuring the sustainability of Chinese shrimp are proposed.
Eight microsatellite markers were used to analyze genetic diversity, level of inbreeding, and effective population size of spawner and recaptured populations of Chinese shrimp (Fenneropenaeus chinensis) during stock enhancement in the Bohai Bay in 2013. A total of 254 and 238 alleles were identified in the spawner and recaptured populations, respectively, and the numbers of alleles (Na) were 8-63 and 6-60, respectively. The numbers of effective alleles (Ne) were 2.52-21.60 and 2.67-20.72, respectively. The polymorphism information content ranged from 0.529 to 0.952. The observed heterozygosity (Ho) values (0.638-0.910 and 0.712-0.927) were lower than the expected heterozygosity (He) values (0.603-0.954 and 0.625-0.952), which indicated that the two populations possessed a rich genetic diversity. In 16 tests (2 populations×8 loci), 13 tests deviated from the HardyWeinberg equilibrium. Fis values were positive at seven loci and the inbreeding coefficients (F) of the two populations estimated by trioML were 13.234% and 11.603%, suggesting that there was a relatively high degree of inbreeding. A certain level of inbreeding depression had occurred in the Chinese shrimp population. Fst values ranged from 0 to 0.059, with a mean of 0.028, displaying a low level of genetic differentiation in the two populations. Effective population sizes (3 060.2 and 3 842.8) were higher than the minimum number suggested for retaining the evolutionary potential to adapt to new environmental conditions. For enhancement activity in 2014, the ideal number of captured shrimp spawners should have ranged from 7 686 to 19 214 to maintain genetic diversity and effective population size. Further strategies to adjust the balance of economic cost, fishing effort and ideal number of shrimp spawners to maintain a satisfactory effective population size for ensuring the sustainability of Chinese shrimp are proposed.
2016, 35(8): 57-64.
doi: 10.1007/s13131-016-0878-x
Abstract:
The adductor muscle scar (AMS) is the fixation point of adductor muscle to the shell. It is an important organicinorganic interface and stress distribution area. Despite recent advances, our understanding of the structure and composition of the AMS remain limited. Here, we report study on the AMS of three bivalves:Mytilus coruscus, Chlamys farreri and Ruditapes philippinarum. Results showed that there were significant differences among their AMS structures. Both M. coruscus and C. farreri were found to have a columnar layer above the nacreous platelet shell structure at the AMS and this layer was more organized in M. coruscus. There was no distinguishable twolayer structure in R. philippinarum. Atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FT-IR) results showed that the AMS was much smoother than the nacreous inner shell in all the three species and the AMS had minor different compositions from the nacreous shell layer. SDS-PAGE (sodium dodecyl-sulfate polyacrylamide gel electophoresis) study of the proteins isolated from the interface indicated that there was a 70 kDa protein which seemed to be specifically located to the highly organized columnar AMS structure in Mytilus coruscus. Further analysis of this protein showed it contained high level of Asx (Asp+Asn), Glx (Glu+Gln) and Gly. The special structure and composition of the AMS might play important roles in the stability, adhesion and function at this stress distribution site.
The adductor muscle scar (AMS) is the fixation point of adductor muscle to the shell. It is an important organicinorganic interface and stress distribution area. Despite recent advances, our understanding of the structure and composition of the AMS remain limited. Here, we report study on the AMS of three bivalves:Mytilus coruscus, Chlamys farreri and Ruditapes philippinarum. Results showed that there were significant differences among their AMS structures. Both M. coruscus and C. farreri were found to have a columnar layer above the nacreous platelet shell structure at the AMS and this layer was more organized in M. coruscus. There was no distinguishable twolayer structure in R. philippinarum. Atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FT-IR) results showed that the AMS was much smoother than the nacreous inner shell in all the three species and the AMS had minor different compositions from the nacreous shell layer. SDS-PAGE (sodium dodecyl-sulfate polyacrylamide gel electophoresis) study of the proteins isolated from the interface indicated that there was a 70 kDa protein which seemed to be specifically located to the highly organized columnar AMS structure in Mytilus coruscus. Further analysis of this protein showed it contained high level of Asx (Asp+Asn), Glx (Glu+Gln) and Gly. The special structure and composition of the AMS might play important roles in the stability, adhesion and function at this stress distribution site.
2016, 35(8): 65-73.
doi: 10.1007/s13131-016-0829-6
Abstract:
Catalase is an important antioxidant protein that can protect organisms against various forms of oxidative damage by eliminating hydrogen peroxide. In this study, the catalase cDNA of Paphia textile (PtCAT) was cloned using RTPCR and rapid amplification of cDNA ends (RACE). PtCAT is 1921 bp long and consists of a 5'-UTR of 50 bp, a 3'-UTR of 349 bp, and an ORF of 1 542 bp that encodes 513 amino acids with a molecular weight of 58.4 kD and an estimated isoelectric point of 8.2. Sequence alignment indicated that PtCAT contained a highly conserved catalytic signature motif (61FNRERIPERVVHAKGAG77), a proximal heme-ligand signature sequence (352RLFSYSDP359), and three catalytic amino acid residues (H72, N145, and Y356). PtCAT also contains two putative N-glycosylation sites (34NKT36 and 437439) and a peroxisome-targeting signal (511AQL513). Furthermore, PtCAT shares 53%-88% identity and 29%-89% similarity with other catalase amino acid sequences. PtCAT mRNA was present in all tested organs, including the heart, digestive gland, adductor muscle, gonad, gill, and mantle, but its expression was highest in the digestive gland. High-temperature-induced stress produced two expression patterns of PtCAT mRNA:first, an initial up-regulation followed by a down-regulation in the heart, digestive gland, and gonad and, second, consistent down-regulation in all other organs. These results demonstrate that PtCAT is a typical member of the catalase family and might be involved in the responses to harmful environmental factors.
Catalase is an important antioxidant protein that can protect organisms against various forms of oxidative damage by eliminating hydrogen peroxide. In this study, the catalase cDNA of Paphia textile (PtCAT) was cloned using RTPCR and rapid amplification of cDNA ends (RACE). PtCAT is 1921 bp long and consists of a 5'-UTR of 50 bp, a 3'-UTR of 349 bp, and an ORF of 1 542 bp that encodes 513 amino acids with a molecular weight of 58.4 kD and an estimated isoelectric point of 8.2. Sequence alignment indicated that PtCAT contained a highly conserved catalytic signature motif (61FNRERIPERVVHAKGAG77), a proximal heme-ligand signature sequence (352RLFSYSDP359), and three catalytic amino acid residues (H72, N145, and Y356). PtCAT also contains two putative N-glycosylation sites (34NKT36 and 437439) and a peroxisome-targeting signal (511AQL513). Furthermore, PtCAT shares 53%-88% identity and 29%-89% similarity with other catalase amino acid sequences. PtCAT mRNA was present in all tested organs, including the heart, digestive gland, adductor muscle, gonad, gill, and mantle, but its expression was highest in the digestive gland. High-temperature-induced stress produced two expression patterns of PtCAT mRNA:first, an initial up-regulation followed by a down-regulation in the heart, digestive gland, and gonad and, second, consistent down-regulation in all other organs. These results demonstrate that PtCAT is a typical member of the catalase family and might be involved in the responses to harmful environmental factors.
2016, 35(8): 74-81.
doi: 10.1007/s13131-016-0881-2
Abstract:
The community characteristics of macrobenthos in the Huanghe (Yellow River) Estuary is influenced by a combination of natural and anthropogenic factors. Here, we investigated short-term changes (1-month) in macrobenthic community structure in response to water and sediment discharge regulation (WSDR) in 2011. Specifically, we sampled the macrobenthos at 18 sampling stations situated at four distances (5, 10, 20, and 40 km) from the mouth of the Huanghe Estuary before (mid-June), during (early-July), and after (mid-July) WSDR. The results showed that a total of 73, 72, and 85 species were collected before, during, and after WSDR, respectively. Then, 13, 1, and 16 dominant species were detected at this three periods. Four phyla were primarily detected at all three periods (Annelida, Mollusca, Arthropoda, and Echinodermata). However, while Mollusca and Annelida were the most important phyla in our study, Echinodermata and Annelida were the most important phyla in 1982, demonstrating major changes to community structure over a 3-decadal period. All stations were of high quality BOPA index before WSDR, whereas two and three stations were of reduced quality BOPA index during and after WSDR, respectively. The results of ABC curves showed that had incurred disturbed conditions after human activities WSDR. Most important of all, multivariate analyses and RDA analysis indicated that the structure of the macrobenthic community was closely linked to environment factors, including that organic content factor caused the distribution of macrobenthic community mostly during WSDR, while water depth after WSDR affected the macro benthos community structure seriously, and during WSDR, the environment factor influencing it was not single, including organic content, sulfide content, Hg and As. These differences may have been due to changes in water transparency negatively impacting the growth and development of macrobenthos, due to specific lifehistory requirements. Our results demonstrate that anthropogenic activity is having both long-term (3 decadal) and short term (1-month) impacts on the structure of the macrobenthic community of the Huanghe Estuary. In conclusion, human activities WSDR influence the habitat environment of macro benthos, including the water temperature, nutrients, bioturbation, and so on. Therefore, we suggest the necessity to strengthen regulations of land-derived organic pollutant input to maintain the ecological balance of the Huanghe Estuary.
The community characteristics of macrobenthos in the Huanghe (Yellow River) Estuary is influenced by a combination of natural and anthropogenic factors. Here, we investigated short-term changes (1-month) in macrobenthic community structure in response to water and sediment discharge regulation (WSDR) in 2011. Specifically, we sampled the macrobenthos at 18 sampling stations situated at four distances (5, 10, 20, and 40 km) from the mouth of the Huanghe Estuary before (mid-June), during (early-July), and after (mid-July) WSDR. The results showed that a total of 73, 72, and 85 species were collected before, during, and after WSDR, respectively. Then, 13, 1, and 16 dominant species were detected at this three periods. Four phyla were primarily detected at all three periods (Annelida, Mollusca, Arthropoda, and Echinodermata). However, while Mollusca and Annelida were the most important phyla in our study, Echinodermata and Annelida were the most important phyla in 1982, demonstrating major changes to community structure over a 3-decadal period. All stations were of high quality BOPA index before WSDR, whereas two and three stations were of reduced quality BOPA index during and after WSDR, respectively. The results of ABC curves showed that had incurred disturbed conditions after human activities WSDR. Most important of all, multivariate analyses and RDA analysis indicated that the structure of the macrobenthic community was closely linked to environment factors, including that organic content factor caused the distribution of macrobenthic community mostly during WSDR, while water depth after WSDR affected the macro benthos community structure seriously, and during WSDR, the environment factor influencing it was not single, including organic content, sulfide content, Hg and As. These differences may have been due to changes in water transparency negatively impacting the growth and development of macrobenthos, due to specific lifehistory requirements. Our results demonstrate that anthropogenic activity is having both long-term (3 decadal) and short term (1-month) impacts on the structure of the macrobenthic community of the Huanghe Estuary. In conclusion, human activities WSDR influence the habitat environment of macro benthos, including the water temperature, nutrients, bioturbation, and so on. Therefore, we suggest the necessity to strengthen regulations of land-derived organic pollutant input to maintain the ecological balance of the Huanghe Estuary.
2016, 35(8): 82-88.
doi: 10.1007/s13131-016-0870-5
Abstract:
Marine zooplankton responds sensitively to elevated seawater CO2 concentration. However, the underlying physiological mechanisms have not been studied well. We therefore investigated the effects of elevated CO2 concentration (0.08%, 0.20%, 0.50% and 1.00%) on antioxidant defense components, as well as two detoxification enzymes of Calanus sinicus (copepod). The results showed that glutathione peroxidase (GPx) activity exposed to CO2-acidified seawater was significantly stimulated while other antioxidant components, including glutathione-Stransferase (GST) activity, superoxide dismutase (SOD) activity decreased significantly with reduced glutathione (GSH) level and GSH/oxidized glutathione (GSSG) value. CO2-acidified seawater exhibited stimulatory effects on adenosine triphosphatase (ATPase) activity and acetylcholinesterase (AchE) activity was inhibited. Moreover, the results of principal component analysis indicated that 75.93% of the overall variance was explained by the first two principal components. The elevated CO2 concentration may affect the metabolism and survivals of copepods through impacts these enzymes activities. Further studies are needed to focus on the synergistic effects of elevated CO2 concentration and other environmental factors on copepods.
Marine zooplankton responds sensitively to elevated seawater CO2 concentration. However, the underlying physiological mechanisms have not been studied well. We therefore investigated the effects of elevated CO2 concentration (0.08%, 0.20%, 0.50% and 1.00%) on antioxidant defense components, as well as two detoxification enzymes of Calanus sinicus (copepod). The results showed that glutathione peroxidase (GPx) activity exposed to CO2-acidified seawater was significantly stimulated while other antioxidant components, including glutathione-Stransferase (GST) activity, superoxide dismutase (SOD) activity decreased significantly with reduced glutathione (GSH) level and GSH/oxidized glutathione (GSSG) value. CO2-acidified seawater exhibited stimulatory effects on adenosine triphosphatase (ATPase) activity and acetylcholinesterase (AchE) activity was inhibited. Moreover, the results of principal component analysis indicated that 75.93% of the overall variance was explained by the first two principal components. The elevated CO2 concentration may affect the metabolism and survivals of copepods through impacts these enzymes activities. Further studies are needed to focus on the synergistic effects of elevated CO2 concentration and other environmental factors on copepods.
2016, 35(8): 89-98.
doi: 10.1007/s13131-016-0880-3
Abstract:
The exploitation of different plant materials for the biosynthesis of nanoparticles is considered a green technology because it does not involve any harmful chemicals. In this study, iron oxide nanoparticles (Fe3O4-NPs) were synthesized using a completely green biosynthetic method by reduction of ferric chloride solution using brown seaweed water extracts. The two seaweeds Padina pavonica (Linnaeus) Thivy and Sargassum acinarium (Linnaeus) Setchell 1933 were used in this study. The algae extract was used as a reductant of FeCl3 resulting in the phytosynthesis of Fe3O4-NPs. The phytogenic Fe3O4-NPs were characterized by surface plasmon band observed close to 402 nm and 415 nm; the obtained Fe3O4-NPs are in the particle sizes ranged from 10 to 19.5 nm and 21.6 to 27.4 nm for P. pavonica and S. acinarium, respectively. The strong signals of iron were reported in their corresponding EDX spectra. FTIR analyses revealed that sulphated polysaccharides are the main biomolecules in the algae extracts that do dual function of reducing the FeCl3 and stabilizing the phytogenic Fe3O4-NPs. The biosynthesized Fe3O4-NPs were entrapped in calcium alginates beads and used in Pb adsorption experiments. The biosynthesized Fe3O4-NPs alginate beads via P. pavonica (Linnaeus) Thivy had high capacity for bioremoval of Pb (91%) while that of S. acinarium (Linnaeus) Setchell 1933 had a capacity of (78%) after 75 min. The values of the process parameters for the maximum Pb removal efficiency by Fe3O4-NPs alginate beads synthesized via P. pavonica (Linnaeus) Thivy were also estimated.
The exploitation of different plant materials for the biosynthesis of nanoparticles is considered a green technology because it does not involve any harmful chemicals. In this study, iron oxide nanoparticles (Fe3O4-NPs) were synthesized using a completely green biosynthetic method by reduction of ferric chloride solution using brown seaweed water extracts. The two seaweeds Padina pavonica (Linnaeus) Thivy and Sargassum acinarium (Linnaeus) Setchell 1933 were used in this study. The algae extract was used as a reductant of FeCl3 resulting in the phytosynthesis of Fe3O4-NPs. The phytogenic Fe3O4-NPs were characterized by surface plasmon band observed close to 402 nm and 415 nm; the obtained Fe3O4-NPs are in the particle sizes ranged from 10 to 19.5 nm and 21.6 to 27.4 nm for P. pavonica and S. acinarium, respectively. The strong signals of iron were reported in their corresponding EDX spectra. FTIR analyses revealed that sulphated polysaccharides are the main biomolecules in the algae extracts that do dual function of reducing the FeCl3 and stabilizing the phytogenic Fe3O4-NPs. The biosynthesized Fe3O4-NPs were entrapped in calcium alginates beads and used in Pb adsorption experiments. The biosynthesized Fe3O4-NPs alginate beads via P. pavonica (Linnaeus) Thivy had high capacity for bioremoval of Pb (91%) while that of S. acinarium (Linnaeus) Setchell 1933 had a capacity of (78%) after 75 min. The values of the process parameters for the maximum Pb removal efficiency by Fe3O4-NPs alginate beads synthesized via P. pavonica (Linnaeus) Thivy were also estimated.
2016, 35(8): 99-105.
doi: 10.1007/s13131-016-0866-1
Abstract:
Vast declines in Zostera marina seagrass beds demand effective methods of rehabilitation. In this study, we developed a practical method by reducing salinity to induce seed germination followed with recovering salinity to facilitate seedling production of Z. marina. The results showed that Z. marina seeds collected from natural seawater (salinity 30) were induced to germinate at reduced salinities. Percent germination (GR) was higher and mean-time-to-germinate (MTG) was shorter at lower salinities. The highest GR and shortest MTG occurred at salinity 0 (deionized freshwater). After germination in freshwater, seeds could develop into seedlings at salinities 5-30 and continue the growth. Viability or development of germinated seeds was not significantly different during the 40 d of post-germination incubation at salinities 5-15 after 1-20 d of germination in freshwater. However, during the process of translating germinated seeds from salinity 0 and 5 to salinity 30, reducing the gradients of post-germination acclimation facilitated more seeds forming seedlings in less time. On average, after 60 d of static incubation, including 20 d in freshwater for germination followed with immediate shift to salinity 5 and increasing to salinity 30 at increment of 5 every two days until cultivation at constant salinity 30, 33% of Z. marina seeds produced healthy seedlings. The results indicate that the salinity-manipulation based method of artificial germination and seedling production is practical and effective in supporting rehabilitation of Z. marina bed.
Vast declines in Zostera marina seagrass beds demand effective methods of rehabilitation. In this study, we developed a practical method by reducing salinity to induce seed germination followed with recovering salinity to facilitate seedling production of Z. marina. The results showed that Z. marina seeds collected from natural seawater (salinity 30) were induced to germinate at reduced salinities. Percent germination (GR) was higher and mean-time-to-germinate (MTG) was shorter at lower salinities. The highest GR and shortest MTG occurred at salinity 0 (deionized freshwater). After germination in freshwater, seeds could develop into seedlings at salinities 5-30 and continue the growth. Viability or development of germinated seeds was not significantly different during the 40 d of post-germination incubation at salinities 5-15 after 1-20 d of germination in freshwater. However, during the process of translating germinated seeds from salinity 0 and 5 to salinity 30, reducing the gradients of post-germination acclimation facilitated more seeds forming seedlings in less time. On average, after 60 d of static incubation, including 20 d in freshwater for germination followed with immediate shift to salinity 5 and increasing to salinity 30 at increment of 5 every two days until cultivation at constant salinity 30, 33% of Z. marina seeds produced healthy seedlings. The results indicate that the salinity-manipulation based method of artificial germination and seedling production is practical and effective in supporting rehabilitation of Z. marina bed.
2016, 35(8): 106-113.
doi: 10.1007/s13131-016-0887-9
Abstract:
The accurate measurement of gene expression via quantitative real-time reverse transcription PCR (qRT-PCR) heavily relies on the choice of valid reference gene(s) for data normalization. Resting cyst is the dormant stage in the life cycle of dinoflagellate, which plays crucial roles in HAB-forming dinoflagellate ecology. However, only limited investigations have been conducted on the reference gene selection in dinoflagellates. Gap remained in our knowledge about appropriate HKGs for normalizing gene expression in different life stages, which laid obstacles for the application of qRT-PCR to the HAB-forming group. In this study, six candidate reference genes, 18S ribosomal RNA (18S), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), α-tubulin (TUA), β-tubulin (TUB), actin (ACT) and cytochrome oxidase subunit 1 (COX1), were evaluated for their expression stability with qRT-PCR and three statistical algorithms (GeNorm, NormFinder, and BestKeeper) for the cosmopolitan, harmful algal bloom-forming dinoflagellate Akashiwo sanguinea. Expression patterns were observed across 18 biological samples, including cells at resting stages (resting cysts), different growth stages, in darkness, exposed to abscisic acid (ABA) and exposed to temperature stress. The results indicated that TUA, 18S and GAPDH were relatively stable across all tested scenarios. While the best-recommended reference genes differed across experimental groups, the pairs of ACT and TUA, 18S and GAPDH were the most reliable for cells at different growth stages and darkness treatment. The combination of TUA and TUB was the best choice for normalization in resting cysts and in ABA treatment, respectively. The pair of ACT and COX1 was suitable for temperature treatments. This study was the first to investigate the stable internal reference genes in dinoflagellates at different stages of life cycle, particularly in resting cysts. Our results provided useful information for selection of reference genes in dinoflagellates regarding quantification of gene expression at different experimental scenarios, which will facilitate more accurate and widespread use of qRT-PCR in gene analysis of dinoflagellates and help to design primers targeting orthologous genes in other algal species.
The accurate measurement of gene expression via quantitative real-time reverse transcription PCR (qRT-PCR) heavily relies on the choice of valid reference gene(s) for data normalization. Resting cyst is the dormant stage in the life cycle of dinoflagellate, which plays crucial roles in HAB-forming dinoflagellate ecology. However, only limited investigations have been conducted on the reference gene selection in dinoflagellates. Gap remained in our knowledge about appropriate HKGs for normalizing gene expression in different life stages, which laid obstacles for the application of qRT-PCR to the HAB-forming group. In this study, six candidate reference genes, 18S ribosomal RNA (18S), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), α-tubulin (TUA), β-tubulin (TUB), actin (ACT) and cytochrome oxidase subunit 1 (COX1), were evaluated for their expression stability with qRT-PCR and three statistical algorithms (GeNorm, NormFinder, and BestKeeper) for the cosmopolitan, harmful algal bloom-forming dinoflagellate Akashiwo sanguinea. Expression patterns were observed across 18 biological samples, including cells at resting stages (resting cysts), different growth stages, in darkness, exposed to abscisic acid (ABA) and exposed to temperature stress. The results indicated that TUA, 18S and GAPDH were relatively stable across all tested scenarios. While the best-recommended reference genes differed across experimental groups, the pairs of ACT and TUA, 18S and GAPDH were the most reliable for cells at different growth stages and darkness treatment. The combination of TUA and TUB was the best choice for normalization in resting cysts and in ABA treatment, respectively. The pair of ACT and COX1 was suitable for temperature treatments. This study was the first to investigate the stable internal reference genes in dinoflagellates at different stages of life cycle, particularly in resting cysts. Our results provided useful information for selection of reference genes in dinoflagellates regarding quantification of gene expression at different experimental scenarios, which will facilitate more accurate and widespread use of qRT-PCR in gene analysis of dinoflagellates and help to design primers targeting orthologous genes in other algal species.
2016, 35(8): 114-125.
doi: 10.1007/s13131-016-0872-3
Abstract:
Phytoplanktonic ecological provinces of the Yellow Sea (31.20°-39.23°N, 121.00°-125.16°E) is derived in terms of species composition and hydrological factors (temperature and salinity). 173 samples were collected from 40 stations from April 28 to May 18, 2014, and a total of 185 phytoplanktonic algal species belonging to 81 genera of 7 phyla were identified by Utermöhl method. Phytoplankton abundance in surface waters is concentrated in the west coast of Korean Peninsula and Korea Bay, and communities in those areas are mainly composed of diatoms and cyanobacteria with dominant species ofCylindrotheca closterium, Synechocystis pevalekii, Chroomonas acuta, Paralia sulcata, Thalassiosira pacifica and Karenia mikimotoi, etc. The first ten dominant species of the investigation area are analyzed by multidimensional scaling (MDS) and cluster analysis, then the Yellow Sea is divided into five provinces from Province I (P-I) to Province V (P-V). P-I includes the coastal areas near southern Liaodong Peninsula, with phytoplankton abundance of 35 420×103-36 163×103 cells/L and an average of 35 791×103 cells/L, and 99.84% of biomass is contributed by cyanobacteria. P-Ⅱ is from Shandong Peninsula to Subei coastal area. Phytoplankton abundance is in a range of 2×103-48×103 cells/L with an average of 24×103 cells/L, and 63.69% of biomass is contributed by diatoms. P-Ⅲ represents the Changjiang (Yangtze River) Diluted Water. Phytoplankton abundance is 10×103-37×103 cells/L with an average of 24×103 cells/L, and 73.14% of biomass is contributed by diatoms. P-IV represents the area affected by the Yellow Sea Warm Current. Phytoplankton abundance ranges from 6×103 to 82×103 cells/L with an average of 28×103 cells/L, and 64.17% of biomass is contributed by diatoms. P-V represents the cold water mass of northern Yellow Sea. Phytoplankton abundance is in a range of 41×103-8 912×103 cells/L with an average of 1 763×103 cells/L, and 89.96% of biomass is contributed by diatoms. Overall, structures of phytoplankton community in spring are quite heterogeneous in different provinces. Canonical correspondence analysis (CCA) result illustrates the relationship between dominant species and environmental factors, and demonstrates that the main environmental factors that affect phytoplankton distribution are nitrate, temperature and salinity.
Phytoplanktonic ecological provinces of the Yellow Sea (31.20°-39.23°N, 121.00°-125.16°E) is derived in terms of species composition and hydrological factors (temperature and salinity). 173 samples were collected from 40 stations from April 28 to May 18, 2014, and a total of 185 phytoplanktonic algal species belonging to 81 genera of 7 phyla were identified by Utermöhl method. Phytoplankton abundance in surface waters is concentrated in the west coast of Korean Peninsula and Korea Bay, and communities in those areas are mainly composed of diatoms and cyanobacteria with dominant species ofCylindrotheca closterium, Synechocystis pevalekii, Chroomonas acuta, Paralia sulcata, Thalassiosira pacifica and Karenia mikimotoi, etc. The first ten dominant species of the investigation area are analyzed by multidimensional scaling (MDS) and cluster analysis, then the Yellow Sea is divided into five provinces from Province I (P-I) to Province V (P-V). P-I includes the coastal areas near southern Liaodong Peninsula, with phytoplankton abundance of 35 420×103-36 163×103 cells/L and an average of 35 791×103 cells/L, and 99.84% of biomass is contributed by cyanobacteria. P-Ⅱ is from Shandong Peninsula to Subei coastal area. Phytoplankton abundance is in a range of 2×103-48×103 cells/L with an average of 24×103 cells/L, and 63.69% of biomass is contributed by diatoms. P-Ⅲ represents the Changjiang (Yangtze River) Diluted Water. Phytoplankton abundance is 10×103-37×103 cells/L with an average of 24×103 cells/L, and 73.14% of biomass is contributed by diatoms. P-IV represents the area affected by the Yellow Sea Warm Current. Phytoplankton abundance ranges from 6×103 to 82×103 cells/L with an average of 28×103 cells/L, and 64.17% of biomass is contributed by diatoms. P-V represents the cold water mass of northern Yellow Sea. Phytoplankton abundance is in a range of 41×103-8 912×103 cells/L with an average of 1 763×103 cells/L, and 89.96% of biomass is contributed by diatoms. Overall, structures of phytoplankton community in spring are quite heterogeneous in different provinces. Canonical correspondence analysis (CCA) result illustrates the relationship between dominant species and environmental factors, and demonstrates that the main environmental factors that affect phytoplankton distribution are nitrate, temperature and salinity.
