2016 Vol. 38, No. 12
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2016, 38(12): .
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2016, 38(12): .
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2016, 38(12): 1-10.
doi: 10.3969/j.issn.0253-4193.2016.12.001
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Due to the interaction of runoff and tide, the energy flux of delta's channels contains the runoff energy and the tidal energy. Based on the data of water level and flow measurement in the Pearl River Delta, an interaction model between the runoff and the tide was established to calculate the M2, K1 tidal energy and the tidal energy of high tidal frequency without the signal of river flow. The results showed that about 51.2% of the tidal energy through the Humen into delta, and the tidal energy through Yamen, Jiaomen, Modaomen accounted for about 37%. For the friction effect of topographical and runoff, 148.33 MW energy in the delta is loss. Tidal energy propagated as the convergent type or divergent type along the delta and damped. The unit kinetic energy along the path decay quicker than the tidal potential energy, and semidiurnal tidal energy can decay greater than that of diurnal tide, which is more significant in the upper delta. For the influence of the morphology of Humen-Shiziyang outlet, the attenuation of M2 tidal amplitude (or energy) is the smallest, even the M2 tidal energy increase approximately 0.77% from Humen to Sishengwei. In the two channels system including Humen-Shiziyang outlet and Yamen outlet to Shizui of Tanjiang, the total tidal energy attenuation is greater than the attenuation of unit tidal energy for the tide energy diverge into different branches. But the total tidal energy attenuation is greater than the attenuation of unit tidal energy in the west river delta for the tide energy from Modaom, Jitimen, Hutiaomen and Yamen converge. The tides from Hengmen, Hongqimen and Jiaomen converged and diverged in the middle delta, and the total kinetic energy, M2 tidal energy, K1 tidal energy is less than the tidal potential energy. The tidal potential energy of high frequency including D3 and D4 constituents has increased along the channel.
Due to the interaction of runoff and tide, the energy flux of delta's channels contains the runoff energy and the tidal energy. Based on the data of water level and flow measurement in the Pearl River Delta, an interaction model between the runoff and the tide was established to calculate the M2, K1 tidal energy and the tidal energy of high tidal frequency without the signal of river flow. The results showed that about 51.2% of the tidal energy through the Humen into delta, and the tidal energy through Yamen, Jiaomen, Modaomen accounted for about 37%. For the friction effect of topographical and runoff, 148.33 MW energy in the delta is loss. Tidal energy propagated as the convergent type or divergent type along the delta and damped. The unit kinetic energy along the path decay quicker than the tidal potential energy, and semidiurnal tidal energy can decay greater than that of diurnal tide, which is more significant in the upper delta. For the influence of the morphology of Humen-Shiziyang outlet, the attenuation of M2 tidal amplitude (or energy) is the smallest, even the M2 tidal energy increase approximately 0.77% from Humen to Sishengwei. In the two channels system including Humen-Shiziyang outlet and Yamen outlet to Shizui of Tanjiang, the total tidal energy attenuation is greater than the attenuation of unit tidal energy for the tide energy diverge into different branches. But the total tidal energy attenuation is greater than the attenuation of unit tidal energy in the west river delta for the tide energy from Modaom, Jitimen, Hutiaomen and Yamen converge. The tides from Hengmen, Hongqimen and Jiaomen converged and diverged in the middle delta, and the total kinetic energy, M2 tidal energy, K1 tidal energy is less than the tidal potential energy. The tidal potential energy of high frequency including D3 and D4 constituents has increased along the channel.
2016, 38(12): 11-22.
doi: 10.3969/j.issn.0253-4193.2016.12.002
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River regime is an essential factor of hydrodynamics and salinity intrusion in estuaries. In this paper, the digitized sea chart of the Changjiang Estuary in 1950s and 1970s, and measured data in 2012 were used to analyze the river regime changes of the Changjiang Estuary since 1950s. The Changjiang Estuary is a bifurcated estuary, which had two-order bifurcations in 1950s and the situation of the three-order bifurcations and four outlets into the sea was formed since 1970s. Comparing the Changjiang Estuary in 1970s and in 1950s, the volumes of upper reaches、middle reaches and lower reaches of the North Branch had changed by -64.13×106,-306.60×106 and -639.27×106 m3, the rates were -16.30%,-22.74% and -25.69%, the volume of the North Branch decreased significantly because of the serious siltation; the volumes of upper reaches、middle reaches and lower reaches of the South Branch had changed by -28.61×106,-35.69×106 and 126.43×106 m3, the rates were -1.30%,-2.12% and 4.36%; the volumes of upper reaches and lower reaches of the North Channel had changed by 109.21×106 and -797.14×106 m3, the rates were 5.01% and -15.25%, the volume of lower reaches decreased significantly because of the siltation of Chongming Shoal and Hengsha Shoal; the volumes of upper reaches、north lower reaches and south lower reaches of the South Channel had changed by -238.95×106, 203.58×106 and 153.34×106 m3, the rates were -8.96%, 6.85% and 3.26%, the volume of upper reaches decreased because of the siltation, the volume of northern lower reaches had increased because the cutting off of Tongsha Shoal increased the depth of water. Comparing the Changjiang Estuary in 2012 and in 1970s, the volumes of upper reaches、middle reaches and lower reaches of the North Branch had changed by -199.06×106,-504.61×106 and -654.12×106 m3, the rates were -60.45%,-48.44% and -35.38%, the volume of the North Branch decreased significantly because of the serious siltation and reclamation; the volumes of upper reaches、middle reaches and lower reaches of the South Branch had changed by 92.34×106, 193.01×106 and -163.62×106 m3, the rates were 4.24%, 11.73% and -5.40%; the volumes of upper reaches and lower reaches of the North Channel had changed -154.64×106 and -511.79×106 m3, the rates were -6.75% and -11.55%, the volumes had decreased because of the reclamation of Qingcaosha Reservoir and Hengsha eastern tidal flat; the volumes of upper reaches、north lower reaches and south lower reaches of the South Channel had changed by 136.39×106,-658.28×106 and -1 266.11×106 m3, the rates were 5.62%,-20.73% and -26.06%, the volume of upper reaches had increased because the channel in the upper reaches became deeper and the volume of lower reaches had decreased because of the siltation and reclamation of Jiuduansha and Nanhui tidal flat.
River regime is an essential factor of hydrodynamics and salinity intrusion in estuaries. In this paper, the digitized sea chart of the Changjiang Estuary in 1950s and 1970s, and measured data in 2012 were used to analyze the river regime changes of the Changjiang Estuary since 1950s. The Changjiang Estuary is a bifurcated estuary, which had two-order bifurcations in 1950s and the situation of the three-order bifurcations and four outlets into the sea was formed since 1970s. Comparing the Changjiang Estuary in 1970s and in 1950s, the volumes of upper reaches、middle reaches and lower reaches of the North Branch had changed by -64.13×106,-306.60×106 and -639.27×106 m3, the rates were -16.30%,-22.74% and -25.69%, the volume of the North Branch decreased significantly because of the serious siltation; the volumes of upper reaches、middle reaches and lower reaches of the South Branch had changed by -28.61×106,-35.69×106 and 126.43×106 m3, the rates were -1.30%,-2.12% and 4.36%; the volumes of upper reaches and lower reaches of the North Channel had changed by 109.21×106 and -797.14×106 m3, the rates were 5.01% and -15.25%, the volume of lower reaches decreased significantly because of the siltation of Chongming Shoal and Hengsha Shoal; the volumes of upper reaches、north lower reaches and south lower reaches of the South Channel had changed by -238.95×106, 203.58×106 and 153.34×106 m3, the rates were -8.96%, 6.85% and 3.26%, the volume of upper reaches decreased because of the siltation, the volume of northern lower reaches had increased because the cutting off of Tongsha Shoal increased the depth of water. Comparing the Changjiang Estuary in 2012 and in 1970s, the volumes of upper reaches、middle reaches and lower reaches of the North Branch had changed by -199.06×106,-504.61×106 and -654.12×106 m3, the rates were -60.45%,-48.44% and -35.38%, the volume of the North Branch decreased significantly because of the serious siltation and reclamation; the volumes of upper reaches、middle reaches and lower reaches of the South Branch had changed by 92.34×106, 193.01×106 and -163.62×106 m3, the rates were 4.24%, 11.73% and -5.40%; the volumes of upper reaches and lower reaches of the North Channel had changed -154.64×106 and -511.79×106 m3, the rates were -6.75% and -11.55%, the volumes had decreased because of the reclamation of Qingcaosha Reservoir and Hengsha eastern tidal flat; the volumes of upper reaches、north lower reaches and south lower reaches of the South Channel had changed by 136.39×106,-658.28×106 and -1 266.11×106 m3, the rates were 5.62%,-20.73% and -26.06%, the volume of upper reaches had increased because the channel in the upper reaches became deeper and the volume of lower reaches had decreased because of the siltation and reclamation of Jiuduansha and Nanhui tidal flat.
2016, 38(12): 23-35.
doi: 10.3969/j.issn.0253-4193.2016.12.003
Abstract:
IOD-ENSO lag teleconnection in oceanic reanalysis datasets (SODA, ORAS4, and NCEP GODAS) are analyzed and compared with those in observations based on lag correlation analysis. The results show significant lag correlations between the sea surface temperature anomalies (SSTA)/sea surface height anomalies (SSHA) in the southeastern tropical Indian Ocean (STIO) in fall and those in the equatorial Pacific cold tongue in the following fall in the three datasets, which are in agreement with observations. In the subsurface, lag correlations between the STIO SSTA in fall and the temperature anomalies in the equatorial Pacific vertical section show that the significant positive correlations moved eastward in the following winter through fall and outcropped at the cold tongue in the following summer and fall in both observation and assimilation datasets. The significant lag correlations between the STIO and the Pacific cold tongue are attribute to the oceanic channel dynamics, i.e., the IOD induced Indonesian Throughflow transport anomalies results in thermocline anomalies in the equatorial Pacific, driving equatorial Kelvin waves to propagate eastward, thereby contributing to the SSTA in the central-eastern Pacific cold tongue. These significant lag correlations are robust even if the ENSO signal is removed in the SODA and ORAS4 datasets, which are in agreement with those in the observations, suggesting that the oceanic channel dynamics are independent of ENSO. In comparison, the significant lag correlations have disappeared if the ENSO signal is regressed out in the GODAS dataset. Lag correlations between the Indonesian Throughflow (ITF) volume transport anomalies and the Niño 3.4/DMI indices with lag time from -12 to 12 months suggest significant influences of both ENSO and IOD events on the ITF transport in the SODA and ORAS4 datasets, consistent with the analyses of observations. The ITF transport anomalies, however, shows significant correlation only with Niño 3.4 indices in the GODAS dataset, suggesting that the ITF transport is poorly dominated by the IOD anomalies in the GODAS. This explains why the lag correlation of IOD-ENSO teleconnection disappears at one year time lag if ENSO signal was removed in the GODAS dataset.
IOD-ENSO lag teleconnection in oceanic reanalysis datasets (SODA, ORAS4, and NCEP GODAS) are analyzed and compared with those in observations based on lag correlation analysis. The results show significant lag correlations between the sea surface temperature anomalies (SSTA)/sea surface height anomalies (SSHA) in the southeastern tropical Indian Ocean (STIO) in fall and those in the equatorial Pacific cold tongue in the following fall in the three datasets, which are in agreement with observations. In the subsurface, lag correlations between the STIO SSTA in fall and the temperature anomalies in the equatorial Pacific vertical section show that the significant positive correlations moved eastward in the following winter through fall and outcropped at the cold tongue in the following summer and fall in both observation and assimilation datasets. The significant lag correlations between the STIO and the Pacific cold tongue are attribute to the oceanic channel dynamics, i.e., the IOD induced Indonesian Throughflow transport anomalies results in thermocline anomalies in the equatorial Pacific, driving equatorial Kelvin waves to propagate eastward, thereby contributing to the SSTA in the central-eastern Pacific cold tongue. These significant lag correlations are robust even if the ENSO signal is removed in the SODA and ORAS4 datasets, which are in agreement with those in the observations, suggesting that the oceanic channel dynamics are independent of ENSO. In comparison, the significant lag correlations have disappeared if the ENSO signal is regressed out in the GODAS dataset. Lag correlations between the Indonesian Throughflow (ITF) volume transport anomalies and the Niño 3.4/DMI indices with lag time from -12 to 12 months suggest significant influences of both ENSO and IOD events on the ITF transport in the SODA and ORAS4 datasets, consistent with the analyses of observations. The ITF transport anomalies, however, shows significant correlation only with Niño 3.4 indices in the GODAS dataset, suggesting that the ITF transport is poorly dominated by the IOD anomalies in the GODAS. This explains why the lag correlation of IOD-ENSO teleconnection disappears at one year time lag if ENSO signal was removed in the GODAS dataset.
2016, 38(12): 36-45.
doi: 10.3969/j.issn.0253-4193.2016.12.004
Abstract:
From 2008 to 2015, large-scale floating Green Tides have consecutively occurred in the Yellow Sea of China, which have great impacts on the marine environment and economic. Based on the EOS/MODIS remote sensing ocean color data, the NDVI algorithm was adopted to inverse the distribution of Green Tides during May to August. The Green Tides were firstly found from MODIS images in 2007 with the coverage area less than 50 km2 in the Yellow Sea. Seasonally, the Green Tides first appeared during the middle of May to early June, then its coverage grew rapidly and continuously and reached a peak in 30-40 days. In July, the Green Tides depleted gradually and disappeared in August. The maximum coverage areas of the Green Tides were 3 110 km2 and 4 075 km2 in 2008 and 2009 respectively. The Green Tides coverages were in low phase from 2010 to 2012 and the peak areas in these past three years were less than 1 800 km2. Since 2013, the scales of Green Tides increased rapidly, and the peak coverage reached 5 629 km2 in 2015. (The Green Tides covered the regions ranged from 124°E in the east, Lianyungang of Jiangsu Province in the west, Rudong of Jiangsu Province in the south and 37°N in the north). The trajectories of the Green Tides could be divided into three categories:(a) moved northward to 34°30'N, then turned to northwest toward the coast in 2008, 2010 and 2011; (b) moved northward to 35°N, then drifted northeast parallel to the coast in 2009 and 2012; (c) moved northward to the coast of Shandong province, then turned along the coast in 2013, 2014 and 2015.
From 2008 to 2015, large-scale floating Green Tides have consecutively occurred in the Yellow Sea of China, which have great impacts on the marine environment and economic. Based on the EOS/MODIS remote sensing ocean color data, the NDVI algorithm was adopted to inverse the distribution of Green Tides during May to August. The Green Tides were firstly found from MODIS images in 2007 with the coverage area less than 50 km2 in the Yellow Sea. Seasonally, the Green Tides first appeared during the middle of May to early June, then its coverage grew rapidly and continuously and reached a peak in 30-40 days. In July, the Green Tides depleted gradually and disappeared in August. The maximum coverage areas of the Green Tides were 3 110 km2 and 4 075 km2 in 2008 and 2009 respectively. The Green Tides coverages were in low phase from 2010 to 2012 and the peak areas in these past three years were less than 1 800 km2. Since 2013, the scales of Green Tides increased rapidly, and the peak coverage reached 5 629 km2 in 2015. (The Green Tides covered the regions ranged from 124°E in the east, Lianyungang of Jiangsu Province in the west, Rudong of Jiangsu Province in the south and 37°N in the north). The trajectories of the Green Tides could be divided into three categories:(a) moved northward to 34°30'N, then turned to northwest toward the coast in 2008, 2010 and 2011; (b) moved northward to 35°N, then drifted northeast parallel to the coast in 2009 and 2012; (c) moved northward to the coast of Shandong province, then turned along the coast in 2013, 2014 and 2015.
2016, 38(12): 46-54.
doi: 10.3969/j.issn.0253-4193.2016.12.005
Abstract:
To study geochemical behavior of uranium in the Changjiang Estuary (CJE), surface water and surface sediment samples were collected along a salinity gradient during January 2014 and March 2013, respectively. The dissolved uranium concentration (DUC) and 234U/238U activity ratio (AR) were measured by the inductively coupled plasma mass spectrometer (ICP-MS). Sequential extraction experiments of surface sediments (collected from the freshwater end-member to the seaward boundary of the sandbar) were also conducted to analyze spatial distribution of U components and 234U/238U ARs in four fractions:desorption, calcium carbonate, Fe-Mn oxide and organic matter. The results showed that there is an extra source of the dissolved uranium into the CJE by other processes excepting U supplied from the ideal mixing process of river water and seawater. The excess DUC and suspended particle matter (SPM) showed a strong positive correlation (r2=0.96). Around 2 μmol U can be transferred from per kilogram particulate into aqueous phase through the desorption and calcium carbonate dissolution, but this phenomenon did not occur for the Fe-Mn oxides and particulate organic matter. At the low salinity region, the releasable particulate U with low 234U/238U ARs resulted in the measured 234U/238U ARs of the water column below the conservative mixing curve, although the DUC points fell on the conservative mixing line. However, flocculations of the iron hydroxide and fine particle may cause simultaneous depletion of the dissolved uranium. Consequently, when the U input and removal rates were approximately equal at the low salinity region, the dissolved uranium showed apparently conservative phenomenon. At the mid-high salinity region (with high SPM), excess dissolved uranium was observed in the water column, but the U exchange between the particulate and aqueous phases led to that the releasable 234U/238U ARs of the particles were close to the measured 234U/238U ARs in the water column.The excess dissolved uranium flux from the particle was estimated as (3.48±0.41)×105 mol/a which occupied 19.3% particlulate U flux[(1.80±0.17)×106 mol/a] into the CJE. The total flux (i.e., riverine flux plus additional flux) of the dissolved uranium from the CJE[about (2.68±0.13)×106 mol/a] contributed about 11.7% of the DU input to the world ocean.
To study geochemical behavior of uranium in the Changjiang Estuary (CJE), surface water and surface sediment samples were collected along a salinity gradient during January 2014 and March 2013, respectively. The dissolved uranium concentration (DUC) and 234U/238U activity ratio (AR) were measured by the inductively coupled plasma mass spectrometer (ICP-MS). Sequential extraction experiments of surface sediments (collected from the freshwater end-member to the seaward boundary of the sandbar) were also conducted to analyze spatial distribution of U components and 234U/238U ARs in four fractions:desorption, calcium carbonate, Fe-Mn oxide and organic matter. The results showed that there is an extra source of the dissolved uranium into the CJE by other processes excepting U supplied from the ideal mixing process of river water and seawater. The excess DUC and suspended particle matter (SPM) showed a strong positive correlation (r2=0.96). Around 2 μmol U can be transferred from per kilogram particulate into aqueous phase through the desorption and calcium carbonate dissolution, but this phenomenon did not occur for the Fe-Mn oxides and particulate organic matter. At the low salinity region, the releasable particulate U with low 234U/238U ARs resulted in the measured 234U/238U ARs of the water column below the conservative mixing curve, although the DUC points fell on the conservative mixing line. However, flocculations of the iron hydroxide and fine particle may cause simultaneous depletion of the dissolved uranium. Consequently, when the U input and removal rates were approximately equal at the low salinity region, the dissolved uranium showed apparently conservative phenomenon. At the mid-high salinity region (with high SPM), excess dissolved uranium was observed in the water column, but the U exchange between the particulate and aqueous phases led to that the releasable 234U/238U ARs of the particles were close to the measured 234U/238U ARs in the water column.The excess dissolved uranium flux from the particle was estimated as (3.48±0.41)×105 mol/a which occupied 19.3% particlulate U flux[(1.80±0.17)×106 mol/a] into the CJE. The total flux (i.e., riverine flux plus additional flux) of the dissolved uranium from the CJE[about (2.68±0.13)×106 mol/a] contributed about 11.7% of the DU input to the world ocean.
2016, 38(12): 55-65.
doi: 10.3969/j.issn.0253-4193.2016.12.006
Abstract:
The benthic exchange rates of dissolved silicate (DSi) at the sediment-water interface in Jiaozhou Bay were measured by intact sediment cores incubation. Further, the impacts of environmental factors on the exchange rate were also discussed. Silicate transported from sediment to overlying water, and the exchange rate ranged from 947 to 4 889 μmol/(m2·d) with a mean of 1 819 μmol/(m2·d). Total organic carbon (TOC) and chlorophyll a(Chl a) in surface sediment which were relative with the biological activity were the dominant factors controlling the exchange rate of DSi. Moreover, water ratio(φ), biogenic silicate(BSi), clay content of sediment and DSi in the pore water also had important effects on the exchange process. As a result, the exchange of DSi at the sediment-water interface in Jiaozhou Bay was a consequence of dissolution-dilution process which was dominantly controlled by biological activity. Grain diameter of sediment and DSi in bottom water, however, were not relatively important when compared with those factors.
The benthic exchange rates of dissolved silicate (DSi) at the sediment-water interface in Jiaozhou Bay were measured by intact sediment cores incubation. Further, the impacts of environmental factors on the exchange rate were also discussed. Silicate transported from sediment to overlying water, and the exchange rate ranged from 947 to 4 889 μmol/(m2·d) with a mean of 1 819 μmol/(m2·d). Total organic carbon (TOC) and chlorophyll a(Chl a) in surface sediment which were relative with the biological activity were the dominant factors controlling the exchange rate of DSi. Moreover, water ratio(φ), biogenic silicate(BSi), clay content of sediment and DSi in the pore water also had important effects on the exchange process. As a result, the exchange of DSi at the sediment-water interface in Jiaozhou Bay was a consequence of dissolution-dilution process which was dominantly controlled by biological activity. Grain diameter of sediment and DSi in bottom water, however, were not relatively important when compared with those factors.
2016, 38(12): 66-75.
doi: 10.3969/j.issn.0253-4193.2016.12.007
Abstract:
According to production statistics from tuna purse seine fishery during 1995 to 2010, cluster analysis of purse seine fishery by year and month different time scale is analyzed. Combined with sea surface temperature (SST) and Niño 3.4 zone index, the causes of different fishing ground type are discussed. The studies shown that the frequency distribution of abnormal weather events (El Niño and La Niña events)are closely related to the class of clustering results of fishing ground in a monthly time scale, which can be divided into the following phases, i.e. January to March, April to June, July to September and October to December, this results is basically consistent with the time range of clustering results of fishing ground. Compared with center of clustering fishing ground and classification statistical of El Niño and La Niña events, it is found that the type of abnormal climate event associated with the results of clustering. Under the same category, the first category is in 1995 and 1997 with strong El Niño years, the second category is 1998, 2007 and 2009 with normal year, the third category is 2010 with a strong La Niña year, the fourth category is 1999, 2000 and 2001 with La Niña years, the fifth category is 1996 and 2008 with La Niña Year, and category VI is 2002 and 2004 with El Niño years. It is concluded that the changing annual fishing grounds has a strong correlation with the occurrence of El Niño and La Niña events, the index of the El Niño and La Niña can be used to predict the changes of fishing grounds at year and month scales.
According to production statistics from tuna purse seine fishery during 1995 to 2010, cluster analysis of purse seine fishery by year and month different time scale is analyzed. Combined with sea surface temperature (SST) and Niño 3.4 zone index, the causes of different fishing ground type are discussed. The studies shown that the frequency distribution of abnormal weather events (El Niño and La Niña events)are closely related to the class of clustering results of fishing ground in a monthly time scale, which can be divided into the following phases, i.e. January to March, April to June, July to September and October to December, this results is basically consistent with the time range of clustering results of fishing ground. Compared with center of clustering fishing ground and classification statistical of El Niño and La Niña events, it is found that the type of abnormal climate event associated with the results of clustering. Under the same category, the first category is in 1995 and 1997 with strong El Niño years, the second category is 1998, 2007 and 2009 with normal year, the third category is 2010 with a strong La Niña year, the fourth category is 1999, 2000 and 2001 with La Niña years, the fifth category is 1996 and 2008 with La Niña Year, and category VI is 2002 and 2004 with El Niño years. It is concluded that the changing annual fishing grounds has a strong correlation with the occurrence of El Niño and La Niña events, the index of the El Niño and La Niña can be used to predict the changes of fishing grounds at year and month scales.
2016, 38(12): 76-85.
doi: 10.3969/j.issn.0253-4193.2016.12.008
Abstract:
Small yellow croaker, Larimichthys polyactis, is an important marine fish species and widely distributed throughout the Bohai Sea, the Yellow Sea, and the East China Sea of the Northwest Pacific Ocean. To investigate the effect of water temperature on L. polyactis, the survival, activities of antioxidant enzymes (i.e. Superoxide dismutase, SOD, and Catalase, CAT) and digestive enzymes (i.e. Lipase, LPS, and Amylase, AMS) of 4.5 month-old L. polyactis at different temperatures (27℃, 29℃, 31℃, 32℃ and 33℃) were compared. The results showed that the mortality rate of L. polyactis was zero at the temperatures of 27℃, 29℃, and 31℃, and the mortality was 16.67% at the temperature of 32℃. Nevertheless, the survival rate was 75.56% at the temperature of 33℃. This study indicated that the temperature of 32℃ may be the upper limit for L. polyactis. The water temperature significantly affected the activities of antioxidant and digestive enzymes of liver and intestine of L. polyactis(except the activities of intestine CAT). The SOD, CAT, LPS and AMS activities increased and then declined with increasing water temperature in the temperature range of 27-33℃. A quadratic regression was fit to describe the relationship between the SOD, CAT, LPS, AMS activities and the water temperature, and only the R2 of regression models of liver and intestine LPS and temperature were higher than 0.85 (R2 was 0.89 and 0.93 respectively), which were meaningful. Moreover, SOD and CAT activities in liver were higher than those of intestine. Conversely, LPS and AMS activities in liver were lower than those of intestine. There were highly significant correlation between the body weight and LPS activities of liver. There were high activities of antioxidant and digestive enzymes and high survival rate of L. polyactis at the temperature of 29℃ and 31℃, which means those temperatures conductive to culture L. polyactis. Those results would be good references for healthy culture of L. polyactis.
Small yellow croaker, Larimichthys polyactis, is an important marine fish species and widely distributed throughout the Bohai Sea, the Yellow Sea, and the East China Sea of the Northwest Pacific Ocean. To investigate the effect of water temperature on L. polyactis, the survival, activities of antioxidant enzymes (i.e. Superoxide dismutase, SOD, and Catalase, CAT) and digestive enzymes (i.e. Lipase, LPS, and Amylase, AMS) of 4.5 month-old L. polyactis at different temperatures (27℃, 29℃, 31℃, 32℃ and 33℃) were compared. The results showed that the mortality rate of L. polyactis was zero at the temperatures of 27℃, 29℃, and 31℃, and the mortality was 16.67% at the temperature of 32℃. Nevertheless, the survival rate was 75.56% at the temperature of 33℃. This study indicated that the temperature of 32℃ may be the upper limit for L. polyactis. The water temperature significantly affected the activities of antioxidant and digestive enzymes of liver and intestine of L. polyactis(except the activities of intestine CAT). The SOD, CAT, LPS and AMS activities increased and then declined with increasing water temperature in the temperature range of 27-33℃. A quadratic regression was fit to describe the relationship between the SOD, CAT, LPS, AMS activities and the water temperature, and only the R2 of regression models of liver and intestine LPS and temperature were higher than 0.85 (R2 was 0.89 and 0.93 respectively), which were meaningful. Moreover, SOD and CAT activities in liver were higher than those of intestine. Conversely, LPS and AMS activities in liver were lower than those of intestine. There were highly significant correlation between the body weight and LPS activities of liver. There were high activities of antioxidant and digestive enzymes and high survival rate of L. polyactis at the temperature of 29℃ and 31℃, which means those temperatures conductive to culture L. polyactis. Those results would be good references for healthy culture of L. polyactis.
2016, 38(12): 86-94.
doi: 10.3969/j.issn.0253-4193.2016.12.009
Abstract:
Saggita crassa is one of the most important dominant zooplankton species in temperate China seas. Based on samples collected during monthly investigation (July 2009 to June 2010) around the Zhanagzi Island, we demonstrated annual variation of abundance and its correlation with environmental conditions. In our study, its abundance averaged in 22.6 ind/m3on annual cycle, with monthly maximum in December (47.5 ind/m3) and minimum (7.8 ind/m3) in August. Spatially, the abundance was higher at stations near the island comparing to those in open waters in all months but August. The difference was statistically significant in October and February (P<0.05). As a carnivore, temporal and spatial distribution of S. crassa was influenced by not only water temperature and salinity but also that of prey populations (mainly copepods). Thus, we propose that different annual patterns of S. crassa over various geographical regions were impacted by that of prey communities.
Saggita crassa is one of the most important dominant zooplankton species in temperate China seas. Based on samples collected during monthly investigation (July 2009 to June 2010) around the Zhanagzi Island, we demonstrated annual variation of abundance and its correlation with environmental conditions. In our study, its abundance averaged in 22.6 ind/m3on annual cycle, with monthly maximum in December (47.5 ind/m3) and minimum (7.8 ind/m3) in August. Spatially, the abundance was higher at stations near the island comparing to those in open waters in all months but August. The difference was statistically significant in October and February (P<0.05). As a carnivore, temporal and spatial distribution of S. crassa was influenced by not only water temperature and salinity but also that of prey populations (mainly copepods). Thus, we propose that different annual patterns of S. crassa over various geographical regions were impacted by that of prey communities.
2016, 38(12): 95-105.
doi: 10.3969/j.issn.0253-4193.2016.12.010
Abstract:
To explore the pattern of functional feeding groups of macrozoobenthos and their response to environmental factors in Xiamen coastal waters, including Weitou Bay, Dadeng, Jiulong River estuary and Tongan Bay, samples were collected at 60 stations in May and November 2013. A total of 411 species of macrozoobenthos were identified, which belonged to 9 phyla and 160 families. The macrozoobenthos were categorized into five functional groups based on feeding types including the camivorous group(C), the planktophagous group(Pl), the detritivorous group(D), the omnivorous group(O) and the phytophagous group (Ph), which contained 152, 102, 103, 48 and 6 species in the sea area, respectively. Ruditapes philippinarum and Prionospio malmgreni were the prominent species in Spring and Autumn respectively. The groups of C and D dominated in Weitou Bay; the groups of C and Pl dominated in Dadeng; the group of D and Pl dominated in Jiulong River estuary and Tongan Bay. The results of canonical correspondence analysis indicated that water depth and water temperature were the important environmental factors impacting the spatial distribution pattern of macrozoobenthos functional feeding groups, and that active phosphate, salinity, organic matter and chlorophyll a also modestly influenced the distribution of macrozoobenthos functional feeding groups.
To explore the pattern of functional feeding groups of macrozoobenthos and their response to environmental factors in Xiamen coastal waters, including Weitou Bay, Dadeng, Jiulong River estuary and Tongan Bay, samples were collected at 60 stations in May and November 2013. A total of 411 species of macrozoobenthos were identified, which belonged to 9 phyla and 160 families. The macrozoobenthos were categorized into five functional groups based on feeding types including the camivorous group(C), the planktophagous group(Pl), the detritivorous group(D), the omnivorous group(O) and the phytophagous group (Ph), which contained 152, 102, 103, 48 and 6 species in the sea area, respectively. Ruditapes philippinarum and Prionospio malmgreni were the prominent species in Spring and Autumn respectively. The groups of C and D dominated in Weitou Bay; the groups of C and Pl dominated in Dadeng; the group of D and Pl dominated in Jiulong River estuary and Tongan Bay. The results of canonical correspondence analysis indicated that water depth and water temperature were the important environmental factors impacting the spatial distribution pattern of macrozoobenthos functional feeding groups, and that active phosphate, salinity, organic matter and chlorophyll a also modestly influenced the distribution of macrozoobenthos functional feeding groups.
2016, 38(12): 106-117.
doi: 10.3969/j.issn.0253-4193.2016.12.011
Abstract:
Ark-shell Anadara broughtonii is one of the most important commercial bivalve species in Northern China. Raft culture of ark-shell has been developing rapidly. Stable isotope (δ13C and δ15N) analysis was conducted on Anadara broughtonii in raft culture and three potential food sources:surface particular organic matter (SPOM), bottom particular organic matter (BPOM) and attached microalgae (AM) in the raft culture area, Lingshan Bay of Qingdao, in four seasons, from May 2014 to January 2015. Meanwhile, the composition of food sources for the cultured ark-shell was investigated in relation to season by using stable isotopes and stomach content analysis. The results showed that, the δ13C and δ15N values of ark-shell and their food sources varied significantly with season. The δ13C values of ark-shell (-19.6‰ to -19.2‰) were higher than those of SPOM (-23.3‰ to -21.8‰) and BPOM (-22.1‰ to -21.2‰), but lower than those of AM (-17.0‰ to -16.0‰). The δ15N values mainly ranged from 8.7‰ to 9.9‰. In addition, the ark-shell in winter had significantly depleted δ13C and enriched δ15N. The particulate organic matter (mainly phytoplankton) in water column was the principle food source for ark-shell, with a contribution of about 60.0%-77.8% (with the highest contribution in summer). Meanwhile, the contribution of BPOM resulting from resuspension in this area remained a high level (about 30.8%-47.1%), and the AM on culture cages took up about 22.1%-40.0% contribution in diets. These results indicate that A. broughtonii feeds on a mixture diet of particulate organic matter and attached microalgae, and the AM on cages can treat as important supplemental food sources in raft culture area.
Ark-shell Anadara broughtonii is one of the most important commercial bivalve species in Northern China. Raft culture of ark-shell has been developing rapidly. Stable isotope (δ13C and δ15N) analysis was conducted on Anadara broughtonii in raft culture and three potential food sources:surface particular organic matter (SPOM), bottom particular organic matter (BPOM) and attached microalgae (AM) in the raft culture area, Lingshan Bay of Qingdao, in four seasons, from May 2014 to January 2015. Meanwhile, the composition of food sources for the cultured ark-shell was investigated in relation to season by using stable isotopes and stomach content analysis. The results showed that, the δ13C and δ15N values of ark-shell and their food sources varied significantly with season. The δ13C values of ark-shell (-19.6‰ to -19.2‰) were higher than those of SPOM (-23.3‰ to -21.8‰) and BPOM (-22.1‰ to -21.2‰), but lower than those of AM (-17.0‰ to -16.0‰). The δ15N values mainly ranged from 8.7‰ to 9.9‰. In addition, the ark-shell in winter had significantly depleted δ13C and enriched δ15N. The particulate organic matter (mainly phytoplankton) in water column was the principle food source for ark-shell, with a contribution of about 60.0%-77.8% (with the highest contribution in summer). Meanwhile, the contribution of BPOM resulting from resuspension in this area remained a high level (about 30.8%-47.1%), and the AM on culture cages took up about 22.1%-40.0% contribution in diets. These results indicate that A. broughtonii feeds on a mixture diet of particulate organic matter and attached microalgae, and the AM on cages can treat as important supplemental food sources in raft culture area.
2016, 38(12): 118-131.
doi: 10.3969/j.issn.0253-4193.2016.12.012
Abstract:
The Chinese surf clam (Mactra chinensis) is an economically important clam, distributed in Liaoning Province and Shandong Province. In recently years, because of coastal environmental deterioration and overfishing, the natural population of M. chinensis have considerably declined. In this paper, we studied the microRNA transcriptome of gills, and control and experimental group were sequenced through Illumina Hiseq 2500 CE. The differential expression andlysis was used to find the functional microRNA response to the Cd2+ exposure. Through Illumina Hi-seq 2500 CE, a total of 14 415 256 clean reads and 15 570 111 clean reads were yielded in the gill of control and experimental group respectively. A total of 14 584 077 small RNA, including 187 859 unique small RNA were yielded. The distribution of the small RNA length in the two library was similar, most of them were 26-27 nt. 27 nt was the most abundant length in control group, followded by 28 nt, 26 nt, and 23 nt; 26 nt was the most abundant length in experimental group, and followed by 27 nt, 28 nt and 23 nt. 50 microRNA was found in unique small RNA, including 38 conserved and 12 novel genes. The most abundant length of microRNA in the two library was the same, 23 nt. Through the analyze of differential expression analysis, the expression of 5 microRNA was induced with significantly difference, other 45 microRNA was regulated up or down without significantly difference. 542 target genes were yielded when the 50 microRNA were hit to mRNA genome. And the target genes of differential expression microRNA were annotated by hitting to the NCBI database, and 4 genes hit to the COG, 1 genes hit to the GO, 5 genes hit to the KEGG and 11 genes hit to the nr database. The genes hit to the NCBI database included E3 ubiquitin-protein ligase, Wnt signaling pathway and Regulator of G-protein signaling 22.
The Chinese surf clam (Mactra chinensis) is an economically important clam, distributed in Liaoning Province and Shandong Province. In recently years, because of coastal environmental deterioration and overfishing, the natural population of M. chinensis have considerably declined. In this paper, we studied the microRNA transcriptome of gills, and control and experimental group were sequenced through Illumina Hiseq 2500 CE. The differential expression andlysis was used to find the functional microRNA response to the Cd2+ exposure. Through Illumina Hi-seq 2500 CE, a total of 14 415 256 clean reads and 15 570 111 clean reads were yielded in the gill of control and experimental group respectively. A total of 14 584 077 small RNA, including 187 859 unique small RNA were yielded. The distribution of the small RNA length in the two library was similar, most of them were 26-27 nt. 27 nt was the most abundant length in control group, followded by 28 nt, 26 nt, and 23 nt; 26 nt was the most abundant length in experimental group, and followed by 27 nt, 28 nt and 23 nt. 50 microRNA was found in unique small RNA, including 38 conserved and 12 novel genes. The most abundant length of microRNA in the two library was the same, 23 nt. Through the analyze of differential expression analysis, the expression of 5 microRNA was induced with significantly difference, other 45 microRNA was regulated up or down without significantly difference. 542 target genes were yielded when the 50 microRNA were hit to mRNA genome. And the target genes of differential expression microRNA were annotated by hitting to the NCBI database, and 4 genes hit to the COG, 1 genes hit to the GO, 5 genes hit to the KEGG and 11 genes hit to the nr database. The genes hit to the NCBI database included E3 ubiquitin-protein ligase, Wnt signaling pathway and Regulator of G-protein signaling 22.
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