2021 Vol. 43, No. 9
Display Method:
2021, 43(9): 1-7.
doi: 10.12284/hyxb2021148
Abstract:
Marine biotechnology refers to the applied science and technology for large-scale production marine bioproducts and provision of services for industry and community based on sustainable utilization and management of marine bioresources. The 1st International Marine Biotechnology Conference was held in Tokyo, Japan in 1989. Over the last 30 years, the global marine biotechnology had progressed rapidly in promoting the sustainable and healthy development of marine aquaculture, the development of novel marine bioproducts, the conservation of marine environment and bioresources, and the construction of “harmonic ocean” etc. It served not only the upgrade of traditional marine bioindustry of fisheries and aquaculture, but also the growth of many newly emerging industries such as marine pharmaceuticals, marine biomaterials and marine functional foods. The theme of 12th International Marine Biotechnology Conference held in Shizuoka, Japan on 9−13 September 2019, with “the next generation of marine biotechnology” as the theme. The conference served to strengthen the platform for the global exchange of new advances in marine biotechnology and the effective development of cooperations for government, academy and industry. This conference had promoted heavily on the roles of young scientists and entrepreneurs for the advances in marine biotechnology. This review, based on new advances reflected in the conference, proposes notable key directions in marine biotechnology for China over the next 5−10 years, and suggests the priorities of training young talents especially those integrated with entrepreneurs’ skills and to developing the leading strategic position in fostering new industries.
Marine biotechnology refers to the applied science and technology for large-scale production marine bioproducts and provision of services for industry and community based on sustainable utilization and management of marine bioresources. The 1st International Marine Biotechnology Conference was held in Tokyo, Japan in 1989. Over the last 30 years, the global marine biotechnology had progressed rapidly in promoting the sustainable and healthy development of marine aquaculture, the development of novel marine bioproducts, the conservation of marine environment and bioresources, and the construction of “harmonic ocean” etc. It served not only the upgrade of traditional marine bioindustry of fisheries and aquaculture, but also the growth of many newly emerging industries such as marine pharmaceuticals, marine biomaterials and marine functional foods. The theme of 12th International Marine Biotechnology Conference held in Shizuoka, Japan on 9−13 September 2019, with “the next generation of marine biotechnology” as the theme. The conference served to strengthen the platform for the global exchange of new advances in marine biotechnology and the effective development of cooperations for government, academy and industry. This conference had promoted heavily on the roles of young scientists and entrepreneurs for the advances in marine biotechnology. This review, based on new advances reflected in the conference, proposes notable key directions in marine biotechnology for China over the next 5−10 years, and suggests the priorities of training young talents especially those integrated with entrepreneurs’ skills and to developing the leading strategic position in fostering new industries.
2021, 43(9): 33-47.
doi: 10.12284/hyxb2021070
Abstract:
In order to study the growth, death, transport and distribution of early life history of winter-spring cohort of neon flying squid Ommastrephes bartramii in the Northwest Pacific Ocean, parameterized early biological processes, such as growth and death. Used the physical model (FVCOM-Global) to simulate and generate three-dimensional physical field of the North Pacific Ocean (10°−60°N, 120°E−110°W), and adopted the Lagrangian particle tracking method to couple the physical model and the biological model (individual-based model), and constructed an individual-based ecological model of early life history of winter-spring cohort of O. bartramii in the Northwest Pacific Ocean, and used this model to numerically simulate the transport distribution of winter-spring cohort from 1997 to 2010. The simulation results showed that within a certain temperature range, the closer to the optimum water temperature, the faster the growth rate of winter-spring cohort. When the age was 38 days, the mantle length could reach 11.76 millimeters, and then gradually changed from exponential growth to linear growth. The simulative recruitment had interannual fluctuation from 1997 to 2010. Considering the different number of winter-spring cohort parents, the years with the most and the least actual recruitment were 1999 and 2009, respectively. In the simulation stage, the winter-spring cohort was mainly located in the spawning ground, transported to the west in the south of 25°N, and gradually transported to the north and northeast in the north of 25°N, especially affected by the strong current in the later period of transport. In the vertical direction, the larvae within 100 meters water depth accounted for nearly half. This study can lay a foundation for further study of ecological dynamics of winter-spring cohort of O. bartramii in the Northwest Pacific Ocean.
In order to study the growth, death, transport and distribution of early life history of winter-spring cohort of neon flying squid Ommastrephes bartramii in the Northwest Pacific Ocean, parameterized early biological processes, such as growth and death. Used the physical model (FVCOM-Global) to simulate and generate three-dimensional physical field of the North Pacific Ocean (10°−60°N, 120°E−110°W), and adopted the Lagrangian particle tracking method to couple the physical model and the biological model (individual-based model), and constructed an individual-based ecological model of early life history of winter-spring cohort of O. bartramii in the Northwest Pacific Ocean, and used this model to numerically simulate the transport distribution of winter-spring cohort from 1997 to 2010. The simulation results showed that within a certain temperature range, the closer to the optimum water temperature, the faster the growth rate of winter-spring cohort. When the age was 38 days, the mantle length could reach 11.76 millimeters, and then gradually changed from exponential growth to linear growth. The simulative recruitment had interannual fluctuation from 1997 to 2010. Considering the different number of winter-spring cohort parents, the years with the most and the least actual recruitment were 1999 and 2009, respectively. In the simulation stage, the winter-spring cohort was mainly located in the spawning ground, transported to the west in the south of 25°N, and gradually transported to the north and northeast in the north of 25°N, especially affected by the strong current in the later period of transport. In the vertical direction, the larvae within 100 meters water depth accounted for nearly half. This study can lay a foundation for further study of ecological dynamics of winter-spring cohort of O. bartramii in the Northwest Pacific Ocean.
2021, 43(9): 48-58.
doi: 10.12284/hyxb2021130
Abstract:
Chilean jack mackerel (Trachurus murphyi) is one of the important economic fisheries in the Southeast Pacific Ocean. The stock abundance is inherently affected by recruitment. To find out the status of recruitment is of great significance to the sustainable yield and scientific management of resources. The recruitment of Chilean jack mackerel between 1971 and 2017 is divided into different regimes based on regime test. Then, the Bayesian model averaging is applied to the relationship between recruitment and five environmental factors (sea surface temperature, sea surface salinity, sea surface height, El Niño and Pacific decadal oscillation), and the impact of regime change in recruitment forecast is also discussed. The results show that the first regime (1971−1980) is more disturbed by fishing; in the second regime (1981−1990), El Niño has the highest probability of explaining for the change of recruitment; the environmental factor with the highest explanatory probability is Pacific Decadal Oscillation in the third regime (1991−2001); in the fourth regime (2002−2015), El Niño most likely explains the change in recruitment; comparing the analysis of regime shift and no regime shift models, there is a significant difference between the two. However, the results, with different regimes, are more reasonable to explain the change of recruitment. Recruitment abundance is affected by multiple environmental factors, but in different regimes, the dominant environmental factor changes. The regime shifts of recruitment are induced by the alternation of cold and warm periods of interdecadal Pacific decadal oscillation, and El Niño. It is suggested that different regime shift and their impact factors should be considered in the future assessment and management of Chilean jack mackerel resources.
Chilean jack mackerel (Trachurus murphyi) is one of the important economic fisheries in the Southeast Pacific Ocean. The stock abundance is inherently affected by recruitment. To find out the status of recruitment is of great significance to the sustainable yield and scientific management of resources. The recruitment of Chilean jack mackerel between 1971 and 2017 is divided into different regimes based on regime test. Then, the Bayesian model averaging is applied to the relationship between recruitment and five environmental factors (sea surface temperature, sea surface salinity, sea surface height, El Niño and Pacific decadal oscillation), and the impact of regime change in recruitment forecast is also discussed. The results show that the first regime (1971−1980) is more disturbed by fishing; in the second regime (1981−1990), El Niño has the highest probability of explaining for the change of recruitment; the environmental factor with the highest explanatory probability is Pacific Decadal Oscillation in the third regime (1991−2001); in the fourth regime (2002−2015), El Niño most likely explains the change in recruitment; comparing the analysis of regime shift and no regime shift models, there is a significant difference between the two. However, the results, with different regimes, are more reasonable to explain the change of recruitment. Recruitment abundance is affected by multiple environmental factors, but in different regimes, the dominant environmental factor changes. The regime shifts of recruitment are induced by the alternation of cold and warm periods of interdecadal Pacific decadal oscillation, and El Niño. It is suggested that different regime shift and their impact factors should be considered in the future assessment and management of Chilean jack mackerel resources.
2021, 43(9): 59-70.
doi: 10.12284/hyxb2021052
Abstract:
In order to understand the population dynamics of ichthyoplankton and the changing laws of biodiversity in the Laizhou Bay, four investigations (respectively in spring, summer, autumn and winter) of 20 positions in the Laizhou Bay from 2014 to 2015, the seasonal variations of species composition and community structure of ichthyoplankton in this area, involving its dominant species, community diversity and seasonal turnover rate were studied in this paper. The results showed that 135275 fish eggs and 2456 larvae were collected, total 22 species. Main species of ichthyoplankton changed significantly with the seasons, from Engraulis japonicus and Liza haematocheilus in spring, to Thryssa kammalensis and Allanetta bleekeri in summer, to Protosalanx hyalocranius in autumn, to Zoarces elongates in winter. The richness index (D) and diversity index (H′) were the highest in summer, and the evenness index (J′) was the highest in autumn. The species turnover rate from spring to summer was the lowest. Analysis of the results of clustering using R language with the highest likelihood suggest the existence of three assemblages of ichthyoplankton in the surveyed waters: spring group, summer and autumn group, winter group. The main divergent species of spring group and summer-autumn group, spring group and winter group were Engraulis japonicus. While the main divergent species of summer autumn group and winter group were Zoarces elongates and Thryssa kammalensis. This study shows that there are significant seasonal differences in the species composition, quantity distribution and biodiversity of ichthyoplankton in the Laizhou Bay. The research results supplement the basic data of fish early replenishment resources in the Laizhou Bay and provide basis for fishery resources conservation in the Laizhou Bay.
In order to understand the population dynamics of ichthyoplankton and the changing laws of biodiversity in the Laizhou Bay, four investigations (respectively in spring, summer, autumn and winter) of 20 positions in the Laizhou Bay from 2014 to 2015, the seasonal variations of species composition and community structure of ichthyoplankton in this area, involving its dominant species, community diversity and seasonal turnover rate were studied in this paper. The results showed that 135275 fish eggs and 2456 larvae were collected, total 22 species. Main species of ichthyoplankton changed significantly with the seasons, from Engraulis japonicus and Liza haematocheilus in spring, to Thryssa kammalensis and Allanetta bleekeri in summer, to Protosalanx hyalocranius in autumn, to Zoarces elongates in winter. The richness index (D) and diversity index (H′) were the highest in summer, and the evenness index (J′) was the highest in autumn. The species turnover rate from spring to summer was the lowest. Analysis of the results of clustering using R language with the highest likelihood suggest the existence of three assemblages of ichthyoplankton in the surveyed waters: spring group, summer and autumn group, winter group. The main divergent species of spring group and summer-autumn group, spring group and winter group were Engraulis japonicus. While the main divergent species of summer autumn group and winter group were Zoarces elongates and Thryssa kammalensis. This study shows that there are significant seasonal differences in the species composition, quantity distribution and biodiversity of ichthyoplankton in the Laizhou Bay. The research results supplement the basic data of fish early replenishment resources in the Laizhou Bay and provide basis for fishery resources conservation in the Laizhou Bay.
2021, 43(9): 71-80.
doi: 10.12284/hyxb2021152
Abstract:
The benthic macroinvertebrate is the important ecological group in river ecosystem. The study of the community composition and distribution characteristics on the benthic macroinvertebrate can provide theoretical support for river ecosystem management. In June (summer) and November (autumn) 2018, surveys on the benthic macroinvertebrate with trawl and ground cages were carried out in 16 fixed sampling sites in the inland rivers of Chongming Island. The community composition, distribution characteristics and corresponding influencing factors of the benthic macroinvertebrates were analyzed then. A total of 14 species belonging to 5 orders, 8 families of the benthic macroinvertebrates were collected in the surveys. Most of them were arthropods. Among them, 10 species were freshwater type, 3 species were estuarine brackish water type and 1 species was catadromous migration type. And 12, 6 and 11 benthic macroinvertebrate species were recorded in the Beiheng Canal, Nanheng Canal, and the vertical canals respectively. The dominants of the benthic macroinvertebrates were freshwater species, and the common species were Macrobrachium nipponense, and Exopalaemon modestus. The number of species, abundance and biomass of the benthic macroinvertebrates in the Beiheng Canal and the vertical canals were higher than those in the Nanheng Canal. The number of species, abundance and biomass of the benthic macroinvertebrates in the summer were higher than those in the autumn. Seasonal variations were one of the important features of the characteristics of the benthic macroinvertebrate assemblages in the inland rivers of Chongming Island. Add all these together, the inland rivers of Chongming Island had some characteristics of both estuaries and inland rivers, which were related to the geographical location, hydrological conditions, riverine habitats, water quality characteristics and regional human activities of the Chongming Island.
The benthic macroinvertebrate is the important ecological group in river ecosystem. The study of the community composition and distribution characteristics on the benthic macroinvertebrate can provide theoretical support for river ecosystem management. In June (summer) and November (autumn) 2018, surveys on the benthic macroinvertebrate with trawl and ground cages were carried out in 16 fixed sampling sites in the inland rivers of Chongming Island. The community composition, distribution characteristics and corresponding influencing factors of the benthic macroinvertebrates were analyzed then. A total of 14 species belonging to 5 orders, 8 families of the benthic macroinvertebrates were collected in the surveys. Most of them were arthropods. Among them, 10 species were freshwater type, 3 species were estuarine brackish water type and 1 species was catadromous migration type. And 12, 6 and 11 benthic macroinvertebrate species were recorded in the Beiheng Canal, Nanheng Canal, and the vertical canals respectively. The dominants of the benthic macroinvertebrates were freshwater species, and the common species were Macrobrachium nipponense, and Exopalaemon modestus. The number of species, abundance and biomass of the benthic macroinvertebrates in the Beiheng Canal and the vertical canals were higher than those in the Nanheng Canal. The number of species, abundance and biomass of the benthic macroinvertebrates in the summer were higher than those in the autumn. Seasonal variations were one of the important features of the characteristics of the benthic macroinvertebrate assemblages in the inland rivers of Chongming Island. Add all these together, the inland rivers of Chongming Island had some characteristics of both estuaries and inland rivers, which were related to the geographical location, hydrological conditions, riverine habitats, water quality characteristics and regional human activities of the Chongming Island.
2021, 43(9): 81-91.
doi: 10.12284/hyxb2021112
Abstract:
Ten strains of bacteria were isolated from the gut of Mytilus coruscus to study its role in the settlement of larvae and plantigrade by forming biofilms. Results showed that the inducing ability of the biofilms formed by ten bacteria were different, although all of them could induce the settlement of larvae and plantigrade. In larvae, Bacillus sp.4 showed high inducing activity, while Phaeobacter sp.1 had low inducing activity. In plantigrades, Phaeobacter sp.1 showed high inducing activity, while Bacillus sp.4 showed low inducing activity. The polysaccharides and proteins from biofilms formed by Bacillus sp.4 and Phaeobacter sp.1 impacted larval settlement and metamorphosis, and the cell density, thickness and extracellular lipids of biofilm showed no effect on inducing activity of larval settlement and metamorphosis. For plantigrades, biofilm’s bacterial density, thickness and extracellular α-polysaccharide could induce plantigrades to the settlement, and the extracellular lipids and proteins of biofilms did not affect the settlement. This study is helpful for improving the healthy ecological culture of M. coruscus and to understand the settlement mechanism of M. coruscus.
Ten strains of bacteria were isolated from the gut of Mytilus coruscus to study its role in the settlement of larvae and plantigrade by forming biofilms. Results showed that the inducing ability of the biofilms formed by ten bacteria were different, although all of them could induce the settlement of larvae and plantigrade. In larvae, Bacillus sp.4 showed high inducing activity, while Phaeobacter sp.1 had low inducing activity. In plantigrades, Phaeobacter sp.1 showed high inducing activity, while Bacillus sp.4 showed low inducing activity. The polysaccharides and proteins from biofilms formed by Bacillus sp.4 and Phaeobacter sp.1 impacted larval settlement and metamorphosis, and the cell density, thickness and extracellular lipids of biofilm showed no effect on inducing activity of larval settlement and metamorphosis. For plantigrades, biofilm’s bacterial density, thickness and extracellular α-polysaccharide could induce plantigrades to the settlement, and the extracellular lipids and proteins of biofilms did not affect the settlement. This study is helpful for improving the healthy ecological culture of M. coruscus and to understand the settlement mechanism of M. coruscus.
2021, 43(9): 92-101.
doi: 10.12284/hyxb2021116
Abstract:
To study the effect of hypoxia on immune function of juvenile cobia (Rachycentron canadum), the transcription level of immune related genes were detected in gills, liver, intestines, and spleen after exposing to (3.15±0.21) mg/L hypoxia stress for 28 d. The results showed: (1) in gills, the transcription level of tumor necrosis factor α (TNFα) and type 2 interleukin-1 receptor (IL-1R2) extremely decreased (p<0.01) on 1 d and 14 d of stress. On 28 d of stress, TNFα extremely decreased (p<0.01) while IL-1R2 significantly decreased (p<0.05). Tumor necrosis factor alpha induced protein 3 (TNFAIP3) extremely increased (p<0.01) on 1 d and then significantly decreased (p<0.05) on 7 d and extremely decreased (p<0.01) on 14 d. Interleukin-1β (IL-1β) extremely decreased (p<0.01) on 1 d and then extremely increased (p<0.01) . Interleukin-17C (IL-17C) extremely decreased (p<0.01) on 7 d and 14 d, while heat shock protein 70 (HSP70) significantly decreased (p<0.05) on 1 d and extremely decreased (p<0.01) on 14 d and 28 d. (2) In liver, the transcription level of TNFα and IL-1R2 significantly decreased (p<0.05) on 1 d and 28 d and extremely decreased (p<0.01) on 14 d. TNFAIP3 extremely increased (p<0.01) on 1 d and extremely decreased (p<0.01) on 14 d and 28 d. IL-1β extremely increased (p<0.01) at all stress time points, while IL-17C extremely decreased (p<0.01) on 7 d, 14 d and 28 d. HSP70 continued to increase and reached the maximum on 28 d (p<0.01). (3) In the intestine, the transcription level of TNFα, IL-1β, IL-1R2, IL-17C and HSP70 genes were higher (p<0.01) than those in the control group at all stress time points. TNFAIP3 extremely increased (p<0.01) on 1 d and significantly decreased (p<0.05) on 7 d and extremely decreased (p<0.01) on 14 d. (4) In spleen, the transcription level of TNFα and IL-17C extremely decreased (p<0.01) on 1 d, 7 d, 14 d and significantly decreased (p<0.05) on 28 d. IL-1β extremely decreased (p<0.01) on 1 d, 28 d and significantly decreased (p<0.05) on 7 d and 14 d. IL-1R2 extremely decreased (p<0.01) on 1 d, 7 d, 28 d and significantly decreased (p<0.05) on 14 d, while HSP70 extremely decreased (p<0.01) on 1 d, 7 d and 28 d. The results indicated that immune genes of transcription level in juvenile cobia showed significantly change after 28 d of hypoxia stress, suggesting that long-term hypoxia may inhibit the immune function, cause intestinal inflammation, and increase the risk of pathogen infection in cobia.
To study the effect of hypoxia on immune function of juvenile cobia (Rachycentron canadum), the transcription level of immune related genes were detected in gills, liver, intestines, and spleen after exposing to (3.15±0.21) mg/L hypoxia stress for 28 d. The results showed: (1) in gills, the transcription level of tumor necrosis factor α (TNFα) and type 2 interleukin-1 receptor (IL-1R2) extremely decreased (p<0.01) on 1 d and 14 d of stress. On 28 d of stress, TNFα extremely decreased (p<0.01) while IL-1R2 significantly decreased (p<0.05). Tumor necrosis factor alpha induced protein 3 (TNFAIP3) extremely increased (p<0.01) on 1 d and then significantly decreased (p<0.05) on 7 d and extremely decreased (p<0.01) on 14 d. Interleukin-1β (IL-1β) extremely decreased (p<0.01) on 1 d and then extremely increased (p<0.01) . Interleukin-17C (IL-17C) extremely decreased (p<0.01) on 7 d and 14 d, while heat shock protein 70 (HSP70) significantly decreased (p<0.05) on 1 d and extremely decreased (p<0.01) on 14 d and 28 d. (2) In liver, the transcription level of TNFα and IL-1R2 significantly decreased (p<0.05) on 1 d and 28 d and extremely decreased (p<0.01) on 14 d. TNFAIP3 extremely increased (p<0.01) on 1 d and extremely decreased (p<0.01) on 14 d and 28 d. IL-1β extremely increased (p<0.01) at all stress time points, while IL-17C extremely decreased (p<0.01) on 7 d, 14 d and 28 d. HSP70 continued to increase and reached the maximum on 28 d (p<0.01). (3) In the intestine, the transcription level of TNFα, IL-1β, IL-1R2, IL-17C and HSP70 genes were higher (p<0.01) than those in the control group at all stress time points. TNFAIP3 extremely increased (p<0.01) on 1 d and significantly decreased (p<0.05) on 7 d and extremely decreased (p<0.01) on 14 d. (4) In spleen, the transcription level of TNFα and IL-17C extremely decreased (p<0.01) on 1 d, 7 d, 14 d and significantly decreased (p<0.05) on 28 d. IL-1β extremely decreased (p<0.01) on 1 d, 28 d and significantly decreased (p<0.05) on 7 d and 14 d. IL-1R2 extremely decreased (p<0.01) on 1 d, 7 d, 28 d and significantly decreased (p<0.05) on 14 d, while HSP70 extremely decreased (p<0.01) on 1 d, 7 d and 28 d. The results indicated that immune genes of transcription level in juvenile cobia showed significantly change after 28 d of hypoxia stress, suggesting that long-term hypoxia may inhibit the immune function, cause intestinal inflammation, and increase the risk of pathogen infection in cobia.
2021, 43(9): 102-114.
doi: 10.12284/hyxb2021108
Abstract:
Aegiceras corniculatum is one of the pioneering mangroves. The coupling process involving A. corniculatum development and tidal flat geomorphological evolution is one of the core contents of mangrove bio-morphodynamic and ecological restoration research. Based on high-resolution remote sensing images between 2005−2019, monthly sediment and A. corniculatum population samples from October 2019 to October 2020, the variation characteristics of A. corniculatum distributed over the tidal flat of the Nanliu River Estuary were analyzed. Meanwhile, the coupling mechanism between the morphological changes of tidal flat erosion/accretion and the population expansion of A. corniculatum was discerned. The main results can be shown as follows: (1) it is found that the main grown area of A. corniculatum is the outer sides of the levees of Nanliu River Estuary. The distribution of the adult, youth and embryos of A. corniculatum presented bandy features along the high tidal flat, middle tidal flat and the area near mean sea level, respectively. Furtherly, tidal flat elevation of 0.07 m above the mean sea level is the growth limit of annual seedling. (2) A. corniculatum of the Nanliu River Estuarine flat expanded rapidly from northwest to southeast, which is in coincidence with development tendency of tidal flat. Tidal flat height is elevated with possibility for mangrove habitation, which should be necessary for A. corniculatum promoted seaward progradation. (3) A. corniculatum that induced wave attenuation can mitigate hydrodynamics forcing with benefit to tidal flat sedimentation, which can furtherly have tidal flat accreted seaward. Moreover, the low tidal flat can be elevated into the middle-high tidal flat by silting, which provides growth and development conditions for A. corniculatum.
Aegiceras corniculatum is one of the pioneering mangroves. The coupling process involving A. corniculatum development and tidal flat geomorphological evolution is one of the core contents of mangrove bio-morphodynamic and ecological restoration research. Based on high-resolution remote sensing images between 2005−2019, monthly sediment and A. corniculatum population samples from October 2019 to October 2020, the variation characteristics of A. corniculatum distributed over the tidal flat of the Nanliu River Estuary were analyzed. Meanwhile, the coupling mechanism between the morphological changes of tidal flat erosion/accretion and the population expansion of A. corniculatum was discerned. The main results can be shown as follows: (1) it is found that the main grown area of A. corniculatum is the outer sides of the levees of Nanliu River Estuary. The distribution of the adult, youth and embryos of A. corniculatum presented bandy features along the high tidal flat, middle tidal flat and the area near mean sea level, respectively. Furtherly, tidal flat elevation of 0.07 m above the mean sea level is the growth limit of annual seedling. (2) A. corniculatum of the Nanliu River Estuarine flat expanded rapidly from northwest to southeast, which is in coincidence with development tendency of tidal flat. Tidal flat height is elevated with possibility for mangrove habitation, which should be necessary for A. corniculatum promoted seaward progradation. (3) A. corniculatum that induced wave attenuation can mitigate hydrodynamics forcing with benefit to tidal flat sedimentation, which can furtherly have tidal flat accreted seaward. Moreover, the low tidal flat can be elevated into the middle-high tidal flat by silting, which provides growth and development conditions for A. corniculatum.
2021, 43(9): 115-125.
doi: 10.12284/hyxb2021120
Abstract:
Phycobilisomes are photosynthetic light-harvesting antenna complexes unique to red algae and cyanobacteria. Allophycocyanin (APC) is the main component of the core structure of phycobilisomes. In this experiment, recombinant allophycocyanin (rAPC) was used as the material, and the structure conformation and energy transfer process of rAPC were studied through steady-state spectroscopy, circular dichroic spectroscopy, and ultrafast time-resolved spectroscopy. The results show that rAPC can maintain the same spectral characteristics and active conformation as natural APC under the test conditions; after rAPC monomers are assembled into trimer, the results confirmed that α84PCB and β84PCB can form an exciton pigment pair which can improve the energy transfer efficiency of the rAPC trimer through exciton splitting; ultrafast time-resolved spectroscopy results show that the energy transfer time from 620 nm to 650 nm is 300−600 fs, and there is also a 19 fs exciton state electronic decoherence process. These results provide a data basis for revealing the efficient energy transfer mechanism of phycobilisomes.
Phycobilisomes are photosynthetic light-harvesting antenna complexes unique to red algae and cyanobacteria. Allophycocyanin (APC) is the main component of the core structure of phycobilisomes. In this experiment, recombinant allophycocyanin (rAPC) was used as the material, and the structure conformation and energy transfer process of rAPC were studied through steady-state spectroscopy, circular dichroic spectroscopy, and ultrafast time-resolved spectroscopy. The results show that rAPC can maintain the same spectral characteristics and active conformation as natural APC under the test conditions; after rAPC monomers are assembled into trimer, the results confirmed that α84PCB and β84PCB can form an exciton pigment pair which can improve the energy transfer efficiency of the rAPC trimer through exciton splitting; ultrafast time-resolved spectroscopy results show that the energy transfer time from 620 nm to 650 nm is 300−600 fs, and there is also a 19 fs exciton state electronic decoherence process. These results provide a data basis for revealing the efficient energy transfer mechanism of phycobilisomes.
2021, 43(9): 8-20.
doi: 10.12284/hyxb2021128
Abstract:
The CO2 flux at the sea-air interface, which is equal to the product of the gas transfer velocity, solubility, and the CO2 partial pressure difference between sea and the atmosphere, is estimated using the bulk equation, where the gas transfer velocity is usually associated with the wind speed. Different authors have proposed different parameterization schemes, in which the gas transfer velocity is a polynomial of different powers of the wind speed. In this paper, we summarize the main findings on the gas transfer velocity as a function of wind speed. We discover that the observation method has a greater influence on the gas transfer velocity than the power of the wind speed polynomial. On this basis, this paper calculates the global CO2 flux from 1982−2018 using several different parametric formulas for the gas exchange rate. The ocean is a sink for atmospheric CO2, the equatorial sea area is a source, and the ocean near 40° in the northern and southern hemispheres forms a strong absorption zone along the latitudinal direction. The annual average value of oceanic CO2 absorption (in terms of carbon) over 1982−2018 is (−1.53±0.15)Pg/a. The oceanic absorption decreases year by year until 1999, reaching a minimum in 1999, after which the oceanic absorption begins to increase, with the increase in oceanic absorption occurring mainly in the Southern Ocean.
The CO2 flux at the sea-air interface, which is equal to the product of the gas transfer velocity, solubility, and the CO2 partial pressure difference between sea and the atmosphere, is estimated using the bulk equation, where the gas transfer velocity is usually associated with the wind speed. Different authors have proposed different parameterization schemes, in which the gas transfer velocity is a polynomial of different powers of the wind speed. In this paper, we summarize the main findings on the gas transfer velocity as a function of wind speed. We discover that the observation method has a greater influence on the gas transfer velocity than the power of the wind speed polynomial. On this basis, this paper calculates the global CO2 flux from 1982−2018 using several different parametric formulas for the gas exchange rate. The ocean is a sink for atmospheric CO2, the equatorial sea area is a source, and the ocean near 40° in the northern and southern hemispheres forms a strong absorption zone along the latitudinal direction. The annual average value of oceanic CO2 absorption (in terms of carbon) over 1982−2018 is (−1.53±0.15)Pg/a. The oceanic absorption decreases year by year until 1999, reaching a minimum in 1999, after which the oceanic absorption begins to increase, with the increase in oceanic absorption occurring mainly in the Southern Ocean.
2021, 43(9): 21-32.
doi: 10.12284/hyxb2021124
Abstract:
As a typical high-turbidity bay, the carbonate systems in the Hangzhou Bay are not well documented. In this paper, the spatial distributions of inorganic carbonate paramenters in the Hangzhou Bay were analyzed based on data collected from two summer surveys in 2018 and 2019. The results showed that dissolved inorganic carbon (DIC) concentration and total alkalinity (TA) in surface layer of the Hangzhou Bay ranged from 1 553 μmol/kg to 1 964 μmol/kg and from 1 577 μmol/kg to 2 101 μmol/kg, respectively, which were lower than that of the Changjiang River Estuary (1 407−2 110 μmol/kg and 1 752−2 274 μmol/kg). The spatial distributions of DIC concentration and TA were controlled by the mixing of fresh water and offshore sea water. They were affected by strong tide, which gradually increased DIC concentration from inner bay to outlet of the bay. Air-sea carbon exchange and biological respiration led to decrease and increase of DIC concentration, with the contributions of (−42.3±11.7)% and (34.2±14.3)%, respectively. Such two compensate processes resulted in a net balanced state. The average surface pCO2 in the Hangzhou Bay was 799 μatm (675−932 μatm), indicating that bay waters were source of atmospheric CO2. The revelle factor in the Hangzhou Bay varied from 12.8 to 23.8, suggesting a weaker CO2 buffering capacity than the adjacent East China Sea (the mean value was 11.9). Compared with other estuaries/gulfs, the characteristics of high turbidity and strong tides in the Hangzhou Bay made the spatial distributions of the carbonate system in the bay water had regional specificity.
As a typical high-turbidity bay, the carbonate systems in the Hangzhou Bay are not well documented. In this paper, the spatial distributions of inorganic carbonate paramenters in the Hangzhou Bay were analyzed based on data collected from two summer surveys in 2018 and 2019. The results showed that dissolved inorganic carbon (DIC) concentration and total alkalinity (TA) in surface layer of the Hangzhou Bay ranged from 1 553 μmol/kg to 1 964 μmol/kg and from 1 577 μmol/kg to 2 101 μmol/kg, respectively, which were lower than that of the Changjiang River Estuary (1 407−2 110 μmol/kg and 1 752−2 274 μmol/kg). The spatial distributions of DIC concentration and TA were controlled by the mixing of fresh water and offshore sea water. They were affected by strong tide, which gradually increased DIC concentration from inner bay to outlet of the bay. Air-sea carbon exchange and biological respiration led to decrease and increase of DIC concentration, with the contributions of (−42.3±11.7)% and (34.2±14.3)%, respectively. Such two compensate processes resulted in a net balanced state. The average surface pCO2 in the Hangzhou Bay was 799 μatm (675−932 μatm), indicating that bay waters were source of atmospheric CO2. The revelle factor in the Hangzhou Bay varied from 12.8 to 23.8, suggesting a weaker CO2 buffering capacity than the adjacent East China Sea (the mean value was 11.9). Compared with other estuaries/gulfs, the characteristics of high turbidity and strong tides in the Hangzhou Bay made the spatial distributions of the carbonate system in the bay water had regional specificity.
2021, 43(9): 126-136.
doi: 10.12284/hyxb2021146
Abstract:
Salinity is an important parameter to characterize physical and biogeo-chemical processes. Optical satellite images with high resolution can avoid radio frequency interference, and provide a feasible way to monitor sea surface salinity (SSS) in coastal regions. Using an extensive dataset of ship-based SSS and MODIS estimated remote sensing reflectance (Rrs) at 412 nm, 443 nm, 488 nm, 555 nm and 667 nm and sea surface temperature (SST) a random forest (RF) model has been utilized to retrieve the SSS. Based on the predicted SSS, we analyze the spatiotemporal heterogeneity of SSS in the Gulf of Mexico and contribution of each factor with correlations coefficient. The results show that: (1) the RF model can accurately estimate the SSS in the Gulf of Mexico (RMSE=0.335, R2=0.931); (2) the spatial distribution pattern of SSS shows a ring-shaped inward value increase, which is affected by river discharge, wind forcing and circulation; (3) there is a strong correlation between SSS and SST, and SST significantly impact in retrieving SSS; (4) the correlation between SST, Rrs and SSS appears spatial heterogeneity.
Salinity is an important parameter to characterize physical and biogeo-chemical processes. Optical satellite images with high resolution can avoid radio frequency interference, and provide a feasible way to monitor sea surface salinity (SSS) in coastal regions. Using an extensive dataset of ship-based SSS and MODIS estimated remote sensing reflectance (Rrs) at 412 nm, 443 nm, 488 nm, 555 nm and 667 nm and sea surface temperature (SST) a random forest (RF) model has been utilized to retrieve the SSS. Based on the predicted SSS, we analyze the spatiotemporal heterogeneity of SSS in the Gulf of Mexico and contribution of each factor with correlations coefficient. The results show that: (1) the RF model can accurately estimate the SSS in the Gulf of Mexico (RMSE=0.335, R2=0.931); (2) the spatial distribution pattern of SSS shows a ring-shaped inward value increase, which is affected by river discharge, wind forcing and circulation; (3) there is a strong correlation between SSS and SST, and SST significantly impact in retrieving SSS; (4) the correlation between SST, Rrs and SSS appears spatial heterogeneity.
2021, 43(9): 137-145.
doi: 10.12284/hyxb2021136
Abstract:
The composition and distribution of mangrove species are crucial to the protection and restoration of mangrove wetland ecosystems. In this study, mangrove species distribution was identified by unmanned aerial vehicle (UAV) hyperspectral images from Zhangjiangkou mangrove national nature reserve. Spectral characteristics, spectral differential, and spectral continuum removal were analyzed, 17 spectral parameters of 911 group spectral data from different vegetation species were obtained. Furthermore, 13 parameters for decision tree construction were selected by stepwise discriminant analysis. As a result, an accurate distribution map of mangrove species in the study area was obtained through C5.0 decision tree classification model. The vegetation species present different distribution types from top to bottom in the Zhangjiangkou mangrove national nature reserve. The upper part of the study area was dominated by the mixed type of Aegiceras corniculatum and Kandelia obovata. The middle area showed symbiosis status of three different mangrove species Avicennia marina, Aegiceras corniculatum and Kandelia obovata. The lower part of the study area was dominated by Avicennia marina, and a small amount of Kandelia obovata. Through the confusion matrix, the overall classification accuracy is 87.95% and the Kappa coefficient is 83.81%, showed a satisfactory precision. Therefore, our mangrove species identification results from UAV hyperspectral images could be used as a reference for ecological protection of regional mangrove wetland, and also as a identification method reference for mangrove species.
The composition and distribution of mangrove species are crucial to the protection and restoration of mangrove wetland ecosystems. In this study, mangrove species distribution was identified by unmanned aerial vehicle (UAV) hyperspectral images from Zhangjiangkou mangrove national nature reserve. Spectral characteristics, spectral differential, and spectral continuum removal were analyzed, 17 spectral parameters of 911 group spectral data from different vegetation species were obtained. Furthermore, 13 parameters for decision tree construction were selected by stepwise discriminant analysis. As a result, an accurate distribution map of mangrove species in the study area was obtained through C5.0 decision tree classification model. The vegetation species present different distribution types from top to bottom in the Zhangjiangkou mangrove national nature reserve. The upper part of the study area was dominated by the mixed type of Aegiceras corniculatum and Kandelia obovata. The middle area showed symbiosis status of three different mangrove species Avicennia marina, Aegiceras corniculatum and Kandelia obovata. The lower part of the study area was dominated by Avicennia marina, and a small amount of Kandelia obovata. Through the confusion matrix, the overall classification accuracy is 87.95% and the Kappa coefficient is 83.81%, showed a satisfactory precision. Therefore, our mangrove species identification results from UAV hyperspectral images could be used as a reference for ecological protection of regional mangrove wetland, and also as a identification method reference for mangrove species.
2021, 43(9): 146-156.
doi: 10.12284/hyxb2021058
Abstract:
The cumulative human impact assessment of marine ecosystems is an ecological method to scientifically recognize the response and feedback laws of the system to external disturbances. In order to explore and reveal the inherent mechanisms, the region of coastal seas of China as the research scope in this article, selecting 16 ecological factors in four aspects, marine fishery, marine shipping, land-based and offshore pressures, and climate change. And by spatial quantization and standardization, the cumulative exposure and impact assessment of the 9 marine habitat types in the study area are carried out under the 1 km×1 km spatial grid scale. The results show that the cumulative exposure in the study area is generally higher in the coastal seas than in the pelagic, and gradually decreases to the far ocean; the coastal seas ecosystem is mainly affected by land-based pollution and fishing, and overall climate change contributes the most; 22.8% and 7.6% of China’s coastal seas are respectively highly and extremely highly affected, among which the Changjiang River Delta is the most affected by human activities.
The cumulative human impact assessment of marine ecosystems is an ecological method to scientifically recognize the response and feedback laws of the system to external disturbances. In order to explore and reveal the inherent mechanisms, the region of coastal seas of China as the research scope in this article, selecting 16 ecological factors in four aspects, marine fishery, marine shipping, land-based and offshore pressures, and climate change. And by spatial quantization and standardization, the cumulative exposure and impact assessment of the 9 marine habitat types in the study area are carried out under the 1 km×1 km spatial grid scale. The results show that the cumulative exposure in the study area is generally higher in the coastal seas than in the pelagic, and gradually decreases to the far ocean; the coastal seas ecosystem is mainly affected by land-based pollution and fishing, and overall climate change contributes the most; 22.8% and 7.6% of China’s coastal seas are respectively highly and extremely highly affected, among which the Changjiang River Delta is the most affected by human activities.
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