2011 Vol. 30, No. 2
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Display Method:
2011, (2): 1-8.
doi: 10.1007/s13131-011-0099-2
Abstract:
Diapycnal mixing plays an important role in the ocean circulation. Internal waves are a kind of bridge relating the diapycnal mixing to external sources of mechanical energy. Difficulty in obtaining eigen solutions of internal waves over curved topography is a limitation for further theoretical study on the generation problem and scattering process. In this study, a kind of transform method is put forward to derive the eigen solutions of internal waves over subcritical topography in twodimensional and linear framework. The transform converts the curved topography in physical space to flat bottom in transform space while the governing equation of internal waves is still hyperbolic if proper transform function is selected. Thus, one can obtain eigen solutions of internal waves in the transform space. Several examples of transform functions, which convert the linear slope, the convex slope, and the concave slope to flat bottom, and the corresponding eigen solutions are illustrated. A method, using a polynomial to approximate the transform function and least squares method to estimate the undetermined coefficients in the polynomial, is introduced to calculate the approximate expression of the transform function for the given subcritical topography.
Diapycnal mixing plays an important role in the ocean circulation. Internal waves are a kind of bridge relating the diapycnal mixing to external sources of mechanical energy. Difficulty in obtaining eigen solutions of internal waves over curved topography is a limitation for further theoretical study on the generation problem and scattering process. In this study, a kind of transform method is put forward to derive the eigen solutions of internal waves over subcritical topography in twodimensional and linear framework. The transform converts the curved topography in physical space to flat bottom in transform space while the governing equation of internal waves is still hyperbolic if proper transform function is selected. Thus, one can obtain eigen solutions of internal waves in the transform space. Several examples of transform functions, which convert the linear slope, the convex slope, and the concave slope to flat bottom, and the corresponding eigen solutions are illustrated. A method, using a polynomial to approximate the transform function and least squares method to estimate the undetermined coefficients in the polynomial, is introduced to calculate the approximate expression of the transform function for the given subcritical topography.
2011, (2): 9-13.
doi: 10.1007/s13131-011-0100-0
Abstract:
Teleconnection between El Nino/La Nina-Southern Oscillation (ENSO) phenomenon and anomalous Antarctic sea-ice variation has been studied extensively. In this study, impacts of sea surface temperature in the Indian Ocean on Antarctic sea-ice change were investigated during Janaury 1979 and October 2009. Based on previous research results, sea areas in the western Indian Ocean (WIO; 50°-70°E, 10°-20°S) are selected for the resreach. All variables showed 1-10 year interannual timescales by Fast Founer Tranaform (FFT) transformation. Results show that i) strong WIO signals emerged in the anomalous changes of Antarctic sea-ice concentration; ii) significant positive correlations occurred around the Antarctic Peninsula, Ross Sea and its northwest peripheral sea region iii) negative correlation occurred in the Indian Ocean section of the Southern Ocean, Amundsen Seas, and the sea area over northern Ross Sea; and iv) the atmospheric anomalies associated with the WIO including wind, meridional heat flux, and surface air temperature over southern high latitudes were the possible factors for the teleconnection.
Teleconnection between El Nino/La Nina-Southern Oscillation (ENSO) phenomenon and anomalous Antarctic sea-ice variation has been studied extensively. In this study, impacts of sea surface temperature in the Indian Ocean on Antarctic sea-ice change were investigated during Janaury 1979 and October 2009. Based on previous research results, sea areas in the western Indian Ocean (WIO; 50°-70°E, 10°-20°S) are selected for the resreach. All variables showed 1-10 year interannual timescales by Fast Founer Tranaform (FFT) transformation. Results show that i) strong WIO signals emerged in the anomalous changes of Antarctic sea-ice concentration; ii) significant positive correlations occurred around the Antarctic Peninsula, Ross Sea and its northwest peripheral sea region iii) negative correlation occurred in the Indian Ocean section of the Southern Ocean, Amundsen Seas, and the sea area over northern Ross Sea; and iv) the atmospheric anomalies associated with the WIO including wind, meridional heat flux, and surface air temperature over southern high latitudes were the possible factors for the teleconnection.
2011, (2): 14-24.
doi: 10.1007/s13131-011-0101-z
Abstract:
The relationships between sea surface roughness z0 and wind-wave parameters are analyzed, and spurious self-correlations are found in all of the parameterization schemes. Sea surface drag coefficient CD is fitted by four wind-wave parameters that are wave age, wave steepness, windsea Reynolds number RB and RH, and the analyzed data are divided into laboratory, field and combined data sets respectively. Comparison and analysis of dependence of CD on wind-wave parameters show that RB can fit the CD most appropriately. Wave age and wave steepness are not suitable to fit CD with a narrow range data set. When the value of wave age has a board range, RH is not suitable to fit CD either. Three relationships between CD and RB are integrated into the bulk algorithm COARE to calculate the observational friction velocity, and the results show that the relationship between CD and RB which is fitted with field data set can describe the momentum transfer in the open ocean, under low-moderate wind speed condition, most appropriately.
The relationships between sea surface roughness z0 and wind-wave parameters are analyzed, and spurious self-correlations are found in all of the parameterization schemes. Sea surface drag coefficient CD is fitted by four wind-wave parameters that are wave age, wave steepness, windsea Reynolds number RB and RH, and the analyzed data are divided into laboratory, field and combined data sets respectively. Comparison and analysis of dependence of CD on wind-wave parameters show that RB can fit the CD most appropriately. Wave age and wave steepness are not suitable to fit CD with a narrow range data set. When the value of wave age has a board range, RH is not suitable to fit CD either. Three relationships between CD and RB are integrated into the bulk algorithm COARE to calculate the observational friction velocity, and the results show that the relationship between CD and RB which is fitted with field data set can describe the momentum transfer in the open ocean, under low-moderate wind speed condition, most appropriately.
2011, (2): 25-32.
doi: 10.1007/s13131-011-0102-y
Abstract:
On the basis of the wave action balance equation which incorporates refraction, diffraction, reflection and wave-current interaction, a directional spectral wave transformation model WABED is developed for predicting the irregular wave refraction-diffraction with strongly reflecting structures in coastal regions. In the model, diffraction is taken into account by introducing a term formulated from a parabolic approximation wave equation, and reflection is calculated through a back-marching numerical approach at the reflecting boundary. Two experimental data sets are used to examine the performance of present model with regard to wave characteristics around reflecting coastal structures. One is from a physical experiment at idealized inlet with parallel jetties, while the other is from a laboratory study on a coastal project of the concave breakwater. Reasonably good agreements are found for both cases, revealing the applicability of the present model for predicting combined wave refraction-diffraction processes with strongly reflecting coastal structures.
On the basis of the wave action balance equation which incorporates refraction, diffraction, reflection and wave-current interaction, a directional spectral wave transformation model WABED is developed for predicting the irregular wave refraction-diffraction with strongly reflecting structures in coastal regions. In the model, diffraction is taken into account by introducing a term formulated from a parabolic approximation wave equation, and reflection is calculated through a back-marching numerical approach at the reflecting boundary. Two experimental data sets are used to examine the performance of present model with regard to wave characteristics around reflecting coastal structures. One is from a physical experiment at idealized inlet with parallel jetties, while the other is from a laboratory study on a coastal project of the concave breakwater. Reasonably good agreements are found for both cases, revealing the applicability of the present model for predicting combined wave refraction-diffraction processes with strongly reflecting coastal structures.
Features of aerosol optical depth and its relation to extreme temperatures in China during 1980-2001
2011, (2): 33-45.
doi: 10.1007/s13131-011-0103-x
Abstract:
Based on Total Ozone Mapping Spectrometer (TOMS) monthly aerosol optical thickness (AOT) measurements in 1980-2001 a study is made of space/time patterns and difference between land and sea of AOT 0.50 μm thick over China, which are put into correlation analysis with synchronous extreme temperature indices (warm/cold day and night). Results suggest that 1) the long-term mean AOT over China is characterized by typical geography, with pronounced land-sea contrast. And AOT has significant seasonality and its seasonal difference is diminished as a function of latitude. 2) On the whole, the AOT displays an appreciably increasing trend, with the distinct increase in the eastern Qinghai-Tibetan plateau and SW China, North China, the mid-lower Changjiang (MiLY) valley as well as the South China Sea, but marginal decrease over western/northern Xinjiang and part of South China. 3) The AOT over land and sea is marked by conspicuous intra-seasonal and -yearly oscillations, with remarkable periods at one-, two-yr and more (as interannual periods). 4) Land AOT change is well correlated with extremely temperature indexes. Generally, the correlations of AOT to the extreme temperature indices are more significant in Eastern China with 110°E as the division. Their high-correlation regions are along the Southern China coastline, the Loess Plateau and the Sichuan Basin, and even higher in North China Plain and the mid-lower Changjiang River reaches. 5) Simulations of LMDZ-regional model indicate that aerosol effects may result in cooling all over China, particularly in Eastern China. The contribution of aerosol change may result in more decrease in the maximum temperature than the minimum, with decrease of 0.11/0.08 K for zonal average, respectively.
Based on Total Ozone Mapping Spectrometer (TOMS) monthly aerosol optical thickness (AOT) measurements in 1980-2001 a study is made of space/time patterns and difference between land and sea of AOT 0.50 μm thick over China, which are put into correlation analysis with synchronous extreme temperature indices (warm/cold day and night). Results suggest that 1) the long-term mean AOT over China is characterized by typical geography, with pronounced land-sea contrast. And AOT has significant seasonality and its seasonal difference is diminished as a function of latitude. 2) On the whole, the AOT displays an appreciably increasing trend, with the distinct increase in the eastern Qinghai-Tibetan plateau and SW China, North China, the mid-lower Changjiang (MiLY) valley as well as the South China Sea, but marginal decrease over western/northern Xinjiang and part of South China. 3) The AOT over land and sea is marked by conspicuous intra-seasonal and -yearly oscillations, with remarkable periods at one-, two-yr and more (as interannual periods). 4) Land AOT change is well correlated with extremely temperature indexes. Generally, the correlations of AOT to the extreme temperature indices are more significant in Eastern China with 110°E as the division. Their high-correlation regions are along the Southern China coastline, the Loess Plateau and the Sichuan Basin, and even higher in North China Plain and the mid-lower Changjiang River reaches. 5) Simulations of LMDZ-regional model indicate that aerosol effects may result in cooling all over China, particularly in Eastern China. The contribution of aerosol change may result in more decrease in the maximum temperature than the minimum, with decrease of 0.11/0.08 K for zonal average, respectively.
2011, (2): 46-52.
doi: 10.1007/s13131-011-0104-9
Abstract:
By using the TRMM and QuikSCAT datathe characteristics of the 2-8 day high frequency atmospheric variability over the South China Sea are studied in this paper. It's found that:(1) the 2-8 day high frequency signals are significant not only during the periods of the South China Sea Summer Monsoon (SCSSM), but also after the retreat of the SCSSM. It reaches its peak around July to August; (2) the 2-8 day high frequency signals exhibit strong intermittent features; (3) During El Nino years, the 2-8 day high frequency signals are active only in the periods of the SCSSM. During La Nina years, the 2-8 day high frequency signals are obviously not only in periods of the SCSSM, but also after the retreat of the SCSSM. During the SCSSM periods, the 2-8 day high frequency signals in El Nino years are much stronger than that in La Nina years; (4) During spring to early summer, most of 2-8 day signals propagate southward and eastward, during midsummer to autumn, however, most of 2-8-day signals propagate northward and westward; (5) The 2-8 day northward and westward propagation signals is probably related to the activities of high-frequency vortex over the SCS.
By using the TRMM and QuikSCAT datathe characteristics of the 2-8 day high frequency atmospheric variability over the South China Sea are studied in this paper. It's found that:(1) the 2-8 day high frequency signals are significant not only during the periods of the South China Sea Summer Monsoon (SCSSM), but also after the retreat of the SCSSM. It reaches its peak around July to August; (2) the 2-8 day high frequency signals exhibit strong intermittent features; (3) During El Nino years, the 2-8 day high frequency signals are active only in the periods of the SCSSM. During La Nina years, the 2-8 day high frequency signals are obviously not only in periods of the SCSSM, but also after the retreat of the SCSSM. During the SCSSM periods, the 2-8 day high frequency signals in El Nino years are much stronger than that in La Nina years; (4) During spring to early summer, most of 2-8 day signals propagate southward and eastward, during midsummer to autumn, however, most of 2-8-day signals propagate northward and westward; (5) The 2-8 day northward and westward propagation signals is probably related to the activities of high-frequency vortex over the SCS.
2011, (2): 53-61.
doi: 10.1007/s13131-011-0105-8
Abstract:
Obvious tendency and periodicity of the air temperature can be detected over the North Pole area. They are reflected as follows:a. the air temperature at the earth surface and in the middle layer of the stratosphere tends to be increased either in winter or in summer. The air temperature has increased 1.3℃ for about 50 years at a speed about 0.025℃/year in January, and 0.013℃/year in July. The air temperature in the middle layer of the stratosphere (10 hPa) in January has increased 10℃. The temperature rising speed in July is 0.14℃/year. Generally speaking, the temperature rising speed is quicker in winter than in summer and quicker in the upper layer than at the earth surface. b. The air temperature at the top layer of the troposphere (100 hPa) over the North Pole area tends to be increased either in winter or in summer. The air temperature in January has decreased 5.0℃ for about 50 years at a temperature decreasing speed about 0.094℃/year, and at a temperature decreasing speed about 0.032℃/year in July. The speed of the temperature decreasing is greater in winter than in summer. c. Periodicity. The air temperature respectively at different altitudes over the North Pole possesses interdecadal variation with a period of 22 years. In July the amplitude of the variation with a period of 22 years decreases rapidly from the high altitude to the low. This means that the 22-year's period is more obvious at the high altitude than at the low altitude. At the earth surface layer in North Pole there also is obvious decadal variation with a period of 11 years. The analysis indicates that the 22-years' period temperature variation is associated with the periodic variation of the solar magnetic field. The 11-year period temperature variation is corresponding to 11 year' period of the variation of the sunspot number.
Obvious tendency and periodicity of the air temperature can be detected over the North Pole area. They are reflected as follows:a. the air temperature at the earth surface and in the middle layer of the stratosphere tends to be increased either in winter or in summer. The air temperature has increased 1.3℃ for about 50 years at a speed about 0.025℃/year in January, and 0.013℃/year in July. The air temperature in the middle layer of the stratosphere (10 hPa) in January has increased 10℃. The temperature rising speed in July is 0.14℃/year. Generally speaking, the temperature rising speed is quicker in winter than in summer and quicker in the upper layer than at the earth surface. b. The air temperature at the top layer of the troposphere (100 hPa) over the North Pole area tends to be increased either in winter or in summer. The air temperature in January has decreased 5.0℃ for about 50 years at a temperature decreasing speed about 0.094℃/year, and at a temperature decreasing speed about 0.032℃/year in July. The speed of the temperature decreasing is greater in winter than in summer. c. Periodicity. The air temperature respectively at different altitudes over the North Pole possesses interdecadal variation with a period of 22 years. In July the amplitude of the variation with a period of 22 years decreases rapidly from the high altitude to the low. This means that the 22-year's period is more obvious at the high altitude than at the low altitude. At the earth surface layer in North Pole there also is obvious decadal variation with a period of 11 years. The analysis indicates that the 22-years' period temperature variation is associated with the periodic variation of the solar magnetic field. The 11-year period temperature variation is corresponding to 11 year' period of the variation of the sunspot number.
2011, (2): 62-74.
doi: 10.1007/s13131-011-0106-7
Abstract:
Dissolved inorganic phosphorus (DIP), dissolved organic phosphorus (DOP), particulate inorganic phosphorus (PIP) and particulate organic phosphorus (POP) in the Jiaozhou Bay (JZB) and its adjacent major rivers were analyzed during 2001-2003. DIP was the major form of dissolved phosphorus in JZB, representing 62%-83% of the total dissolved phosphorus (TDP), and the PIP concentration generally exceeded the POP concentration. The concentrations of phosphorus were higher in the north than in the south of the bay, which were related to the fluvial input and water exchange rate. The dissolved phosphorus concentrations were higher in the autumn and spring than in the summer, while the seasonal variation of particulate phosphorus showed opposite pattern. The distribution of phosphorus is mainly affected by the growth of phytoplankton, desorption/adsorption of DIP from and to particulates, and anthropogenic activities. A preliminary phosphorus budget was established. In JZB, riverine input and water exchange flow between JZB and the Huanghai (Yellow) Sea are the major sources of phosphorus, followed by industrial and domestic waste transport, and then atmospheric deposition. Phosphorus burial efficiency is estimated to be 91%. About 52.2×106 mol/a of phosphorus were assimilated by phytoplankton, of which about 68% was recycled in the water column and sediment.
Dissolved inorganic phosphorus (DIP), dissolved organic phosphorus (DOP), particulate inorganic phosphorus (PIP) and particulate organic phosphorus (POP) in the Jiaozhou Bay (JZB) and its adjacent major rivers were analyzed during 2001-2003. DIP was the major form of dissolved phosphorus in JZB, representing 62%-83% of the total dissolved phosphorus (TDP), and the PIP concentration generally exceeded the POP concentration. The concentrations of phosphorus were higher in the north than in the south of the bay, which were related to the fluvial input and water exchange rate. The dissolved phosphorus concentrations were higher in the autumn and spring than in the summer, while the seasonal variation of particulate phosphorus showed opposite pattern. The distribution of phosphorus is mainly affected by the growth of phytoplankton, desorption/adsorption of DIP from and to particulates, and anthropogenic activities. A preliminary phosphorus budget was established. In JZB, riverine input and water exchange flow between JZB and the Huanghai (Yellow) Sea are the major sources of phosphorus, followed by industrial and domestic waste transport, and then atmospheric deposition. Phosphorus burial efficiency is estimated to be 91%. About 52.2×106 mol/a of phosphorus were assimilated by phytoplankton, of which about 68% was recycled in the water column and sediment.
2011, (2): 75-83.
doi: 10.1007/s13131-011-0107-6
Abstract:
The grain-size of suspended particulate matter (SPM) in the Huanghe Estuary and its adjacent sea area was investigated with an in situ laser particle size analyzer (LISST-100) in November 2006. The spatial distribution of the grain-size parameters was very complicated. The results show that (1) the mean particle size of SPM ranged from 3.00Φ to 6.41Φ, with an average value of 4.66Φ; (2) the frequency distribution patterns of the SPM grain-size showed three different types, which were mono-mode, dual-mode and tri-mode, respectively; (3) C-M chart suggested that the transportation-processes of the SPM not only included suspended mode, but also the bed load transportation mode. The bed load transportation mode mainly occurred at the bottom layer. The characteristics and space distribution of SPM grain-size might be mainly controlled by sediment discharge of the Huanghe River, hydrodynamics condition, surface sediment types, and biological process within the study area.
The grain-size of suspended particulate matter (SPM) in the Huanghe Estuary and its adjacent sea area was investigated with an in situ laser particle size analyzer (LISST-100) in November 2006. The spatial distribution of the grain-size parameters was very complicated. The results show that (1) the mean particle size of SPM ranged from 3.00Φ to 6.41Φ, with an average value of 4.66Φ; (2) the frequency distribution patterns of the SPM grain-size showed three different types, which were mono-mode, dual-mode and tri-mode, respectively; (3) C-M chart suggested that the transportation-processes of the SPM not only included suspended mode, but also the bed load transportation mode. The bed load transportation mode mainly occurred at the bottom layer. The characteristics and space distribution of SPM grain-size might be mainly controlled by sediment discharge of the Huanghe River, hydrodynamics condition, surface sediment types, and biological process within the study area.
2011, (2): 84-95.
doi: 10.1007/s13131-011-0108-5
Abstract:
The study was conducted during two cruises of June-August 2006 (summer), and January-February 2007 (winter) in the Huanghai (Yellow) Sea and East China Sea. Spatial and temporal variations of zooplankton abundance, biomass and community structure and its relation to currents and water masses over the continental shelf were examined. A total of 584 zooplankton species/taxa and 28 planktonic larvae were identified during the two surveys. Copepods were the most abundant component among these identified groups. Zooplankton abundance and biomass fluctuated widely and showed distinct heterogeneity in the shelf waters. Five zooplankton assemblages were identified with hierarchical cluster analysis during this study, and they were Huanghai Sea Assemblage, Changjiang Estuary Assemblage, Coastal Assemblage, East China Sea Mixed-water Assemblage and East China Sea Offshore Assemblage. Seasonal changes of zooplankton community composition and its geographical distribution were detected, and the locations of the faunistic areas overlap quite well with water masses and current systems. So we suggest that the zooplankton community structure and its changes were determined by the water masses in the Huanghai Sea and East China Sea. The results of this research can provide fundamental information for the long-term monitoring of zooplankton ecology in the shelf of Huanghai Sea and East China Sea.
The study was conducted during two cruises of June-August 2006 (summer), and January-February 2007 (winter) in the Huanghai (Yellow) Sea and East China Sea. Spatial and temporal variations of zooplankton abundance, biomass and community structure and its relation to currents and water masses over the continental shelf were examined. A total of 584 zooplankton species/taxa and 28 planktonic larvae were identified during the two surveys. Copepods were the most abundant component among these identified groups. Zooplankton abundance and biomass fluctuated widely and showed distinct heterogeneity in the shelf waters. Five zooplankton assemblages were identified with hierarchical cluster analysis during this study, and they were Huanghai Sea Assemblage, Changjiang Estuary Assemblage, Coastal Assemblage, East China Sea Mixed-water Assemblage and East China Sea Offshore Assemblage. Seasonal changes of zooplankton community composition and its geographical distribution were detected, and the locations of the faunistic areas overlap quite well with water masses and current systems. So we suggest that the zooplankton community structure and its changes were determined by the water masses in the Huanghai Sea and East China Sea. The results of this research can provide fundamental information for the long-term monitoring of zooplankton ecology in the shelf of Huanghai Sea and East China Sea.
2011, (2): 96-102.
doi: 10.1007/s13131-011-0109-4
Abstract:
In this study, the authors investigated the effects of residual chlorine on mortality, grazing and respiration of Labidocera euchaeta in laboratory. The grazing rate was evaluated by subtraction method of food concentration and respiration rate was measured using oxygen electrode. It was found that the lethal effect of residual chlorine on L. euchaeta increased with enhanced concentration and prolonged duration. The medium lethal concentration (LC50) of chlorine for L. euchaeta in 24 h was about 0.58 mg/L and the safe concentration was about 0.21 mg/L. However, the grazing and respiration of L. euchaeta decreased by 32.6% and 18.9% when exposed to 0.2 mg/L residual chlorine for 4 h. It indicated that the physiological activities of zooplankton could be suppressed by the residual chlorine less than the safety concentration. Therefore, both survival and physiological activities of the organisms living in the thermal (nuclear) power plant discharging waters should be considered when carrying out the ecological risks assessment.
In this study, the authors investigated the effects of residual chlorine on mortality, grazing and respiration of Labidocera euchaeta in laboratory. The grazing rate was evaluated by subtraction method of food concentration and respiration rate was measured using oxygen electrode. It was found that the lethal effect of residual chlorine on L. euchaeta increased with enhanced concentration and prolonged duration. The medium lethal concentration (LC50) of chlorine for L. euchaeta in 24 h was about 0.58 mg/L and the safe concentration was about 0.21 mg/L. However, the grazing and respiration of L. euchaeta decreased by 32.6% and 18.9% when exposed to 0.2 mg/L residual chlorine for 4 h. It indicated that the physiological activities of zooplankton could be suppressed by the residual chlorine less than the safety concentration. Therefore, both survival and physiological activities of the organisms living in the thermal (nuclear) power plant discharging waters should be considered when carrying out the ecological risks assessment.
2011, (2): 103-112.
doi: 10.1007/s13131-011-0110-y
Abstract:
For the population genetics analysis of the naturally grown brown seaweed Laminaria japonica (Laminariales, Phaeophyta) sampled from Dalian, Yantai, Weihai, Rongcheng and Qingdao in China, ten primers were employed to produce 88 bands as revealed by randomly amplified polymorphic DNA (RAPD) markers, and all these bands were polymorphic. According to these band patterns, there were 94 distinct phenotypes occurred in 100 samples indicating the high heterozygosity of this kelp. Dalian population samples showed the highest percentage of polymorphism (71.67%), and also the higher diversity estimated on the basis of the Shannon's index (8.498), suggesting that this population could be chosen as the best resource for genetic breeding. The highest diversity of Yantai population possibly resulted from the introduction of L. longissima used for interspecific cross breeding with L. japonica cultivated in China. From Dalian southwards to Qingdao, the genetic variation of the five populations became less with a decrease in latitude, possibly due to the natural selection especially of high temperature. The genetic distance (ΦST values) of the five populations was a little significantly correlated with the geographical distance (r=0.496) at P=0.05 by Mantel's test. Weihai, Rongcheng and Yantai populations were closely grouped genetically together by Neighbor-joining cluster analysis probably in that the dispersal of the kelp by propagules more easily occurring in the range of relatively short distance. The analysis of molecular variance (AMOVA) also demonstrated that the relatively higher variation occurred among populations (71.49%) at an extremely significant level (P <0.000 1). All these evidence showed that there was a relatively distinct genetic differentiation among the sampled kelp populations, and L. japonica grown in China was also rather heterozygous in heredity.
For the population genetics analysis of the naturally grown brown seaweed Laminaria japonica (Laminariales, Phaeophyta) sampled from Dalian, Yantai, Weihai, Rongcheng and Qingdao in China, ten primers were employed to produce 88 bands as revealed by randomly amplified polymorphic DNA (RAPD) markers, and all these bands were polymorphic. According to these band patterns, there were 94 distinct phenotypes occurred in 100 samples indicating the high heterozygosity of this kelp. Dalian population samples showed the highest percentage of polymorphism (71.67%), and also the higher diversity estimated on the basis of the Shannon's index (8.498), suggesting that this population could be chosen as the best resource for genetic breeding. The highest diversity of Yantai population possibly resulted from the introduction of L. longissima used for interspecific cross breeding with L. japonica cultivated in China. From Dalian southwards to Qingdao, the genetic variation of the five populations became less with a decrease in latitude, possibly due to the natural selection especially of high temperature. The genetic distance (ΦST values) of the five populations was a little significantly correlated with the geographical distance (r=0.496) at P=0.05 by Mantel's test. Weihai, Rongcheng and Yantai populations were closely grouped genetically together by Neighbor-joining cluster analysis probably in that the dispersal of the kelp by propagules more easily occurring in the range of relatively short distance. The analysis of molecular variance (AMOVA) also demonstrated that the relatively higher variation occurred among populations (71.49%) at an extremely significant level (P <0.000 1). All these evidence showed that there was a relatively distinct genetic differentiation among the sampled kelp populations, and L. japonica grown in China was also rather heterozygous in heredity.
2011, (2): 113-119.
doi: 10.1007/s13131-011-0111-x
Abstract:
The effect of UV-B radiation enhancement at experimental doses of 0.00, 0.24, 0.48, 0.72, 0.96, and 1.20 kJ/m2 on the population dynamics of the rotifer Brachionus urceus feeding on the alga Chlorella sp. was studied under controlled laboratory conditions using clonal culture and life-table techniques. The results show that UV-B radiation treatment significantly shortened the survival time of the rotifer (P <0.05):The longest survival time (336 h) occurred in the control (0.00 kJ/m2) while the shortest (222 h) occurred when exposed to the highest UV-B radiation treatment (1.20 kJ/m2). The fecundity of the rotifer B. urceus was enhanced by the lower UV-B radiation treatment (0.24 and 0.48 kJ/m2) but inhibited by the higher treatments (0.96 and 1.20 kJ/m2). Life expectancy also was obviously affected by UV-B radiation (P <0.05). The highest life expectancy occurred in the control (0.00 kJ/m2), and it became shorter with increasing doses of UV-B radiation. The resutls in the present study indicate that the life expectancy of the rotifer B. urceus can be used as an indicator for UV-B radiation enhancement.
The effect of UV-B radiation enhancement at experimental doses of 0.00, 0.24, 0.48, 0.72, 0.96, and 1.20 kJ/m2 on the population dynamics of the rotifer Brachionus urceus feeding on the alga Chlorella sp. was studied under controlled laboratory conditions using clonal culture and life-table techniques. The results show that UV-B radiation treatment significantly shortened the survival time of the rotifer (P <0.05):The longest survival time (336 h) occurred in the control (0.00 kJ/m2) while the shortest (222 h) occurred when exposed to the highest UV-B radiation treatment (1.20 kJ/m2). The fecundity of the rotifer B. urceus was enhanced by the lower UV-B radiation treatment (0.24 and 0.48 kJ/m2) but inhibited by the higher treatments (0.96 and 1.20 kJ/m2). Life expectancy also was obviously affected by UV-B radiation (P <0.05). The highest life expectancy occurred in the control (0.00 kJ/m2), and it became shorter with increasing doses of UV-B radiation. The resutls in the present study indicate that the life expectancy of the rotifer B. urceus can be used as an indicator for UV-B radiation enhancement.
2011, (2): 120-125.
doi: 10.1007/s13131-011-0112-9
Abstract:
In May of 2007, the second generation selected (SS) and control (SC) groups of pearl oyster Pinctada martensii were established by selecting 10% breeders with the largest and mean shell length, respectively, from the first generation selected group. Growth performance of the SS and SC groups were compared on the basis of measurement data at Days 8, 18, 60, 95, 195 and 365. On Day 365, 100 individuals (60.0-75.0 mm at shell length) were sampled from each group and then subjected to the experiment where physiological parameters such as filtrate rate, oxygen consumption and ammonia excretion were measured at 15, 20, 25 and 30 ℃. The results show that the SS group had significantly larger mean shell length and shell height than the SC group at Days 8, 18, 60, 95, 195 and 365 (P <0.05). The genetic gains at different ages varied from 6.0% to 17.0% for shell length and 5.7% to 14.6% for shell height, respectively. At 15, 20, 25 and 30 ℃, the SS groups had significantly larger filtrate rate than the SC group (P <0.05). At 15 and 25 ℃, the differences in oxygen consumption rate between the SS and SC groups were not significant (P >0.05). At 20 and 30 ℃, however, the oxygen consumption rate of the SS group was significantly larger than the SC group (P <0.05). At 15, 20, 25 and 30 ℃, there were no significant differences in am- monia excretion rate between the SS and SC groups (P >0.05). The present results indicate that there existed considerable genetic variability in the base population and a further selection could be likely fruitful. Mass selection for faster growth might produce animals that had higher intake of metabolizable energy by virtue of faster filtrating behavior.
In May of 2007, the second generation selected (SS) and control (SC) groups of pearl oyster Pinctada martensii were established by selecting 10% breeders with the largest and mean shell length, respectively, from the first generation selected group. Growth performance of the SS and SC groups were compared on the basis of measurement data at Days 8, 18, 60, 95, 195 and 365. On Day 365, 100 individuals (60.0-75.0 mm at shell length) were sampled from each group and then subjected to the experiment where physiological parameters such as filtrate rate, oxygen consumption and ammonia excretion were measured at 15, 20, 25 and 30 ℃. The results show that the SS group had significantly larger mean shell length and shell height than the SC group at Days 8, 18, 60, 95, 195 and 365 (P <0.05). The genetic gains at different ages varied from 6.0% to 17.0% for shell length and 5.7% to 14.6% for shell height, respectively. At 15, 20, 25 and 30 ℃, the SS groups had significantly larger filtrate rate than the SC group (P <0.05). At 15 and 25 ℃, the differences in oxygen consumption rate between the SS and SC groups were not significant (P >0.05). At 20 and 30 ℃, however, the oxygen consumption rate of the SS group was significantly larger than the SC group (P <0.05). At 15, 20, 25 and 30 ℃, there were no significant differences in am- monia excretion rate between the SS and SC groups (P >0.05). The present results indicate that there existed considerable genetic variability in the base population and a further selection could be likely fruitful. Mass selection for faster growth might produce animals that had higher intake of metabolizable energy by virtue of faster filtrating behavior.
