2015 Vol. 37, No. 8
Display Method:
2015, 37(8): .
Abstract:
2015, 37(8): 1-8.
doi: 10.3969/j.issn.0253-4193.2015.08.001
Abstract:
pH and its influence by upwelling process off the southern coast of Java Island, Indonesia were examined for the first time using carbonate and related hydrographic data collected from late September to early October 2013. We found that sea surface pH was lower in the upwelling area than in the nearby nonupwelling area. A two end-member mixing model was used to separate the two opposite effects of the upwelling process on pH: physical transport of CO2 rich waters from subsurface layers vs. biological production. Results showed that physical transport at least led to a dissolved inorganic carbon (DIC) increase of 110 μmol/kg, and a pH decrease of about 0.2 units, while strong biological production (chlorophyll a level above 0.4 mg/m3) induced a DIC decrease by up to 70 μmol/kg, and a pH increase by up to 0.15 units. Overall, the physical transport of CO2 rich waters was dominant, leading to a net decrease in pH. Also, we found that surface cooling and salinity increases induced by the upwelling played a relatively minor role in affecting pH (thermodynamically), compared with effects of physical transport and subsequent biological production associated with the upwelling.
pH and its influence by upwelling process off the southern coast of Java Island, Indonesia were examined for the first time using carbonate and related hydrographic data collected from late September to early October 2013. We found that sea surface pH was lower in the upwelling area than in the nearby nonupwelling area. A two end-member mixing model was used to separate the two opposite effects of the upwelling process on pH: physical transport of CO2 rich waters from subsurface layers vs. biological production. Results showed that physical transport at least led to a dissolved inorganic carbon (DIC) increase of 110 μmol/kg, and a pH decrease of about 0.2 units, while strong biological production (chlorophyll a level above 0.4 mg/m3) induced a DIC decrease by up to 70 μmol/kg, and a pH increase by up to 0.15 units. Overall, the physical transport of CO2 rich waters was dominant, leading to a net decrease in pH. Also, we found that surface cooling and salinity increases induced by the upwelling played a relatively minor role in affecting pH (thermodynamically), compared with effects of physical transport and subsequent biological production associated with the upwelling.
2015, 37(8): 9-25.
doi: 10.3969/j.issn.0253-4193.2015.08.002
Abstract:
The dimethylsulfide (DMS), dissolved and particulate dimethylsulfoniopropionate (DMSPd and DMSPp) concentrations were determined in the Norwegian and Greenland Seas during summer of 2012. Surface DMS, DMSPd and DMSPp concentrations in the study area increased significantly from high latitudes to low latitudes, with the average values of 5.36, 15.63 and 96.73 nmol/L, respectively. Moreover, the biological production and consumption rates of DMS were estimated during the cruise, with the average values of 18.19 and 15.67 nmol/(L·d), respectively. Our results showed that the spatial variation of chlorophyll a was consistent with that of DMSPd and DMSPp concentrations, suggesting that phytoplankton biomass might play an important role in controlling the distribution of DMSP in the study area. In the surface water, the biological turnover time of DMS varied from 0.03 to 1.8 days, with an average of 0.49 days, which was about 90-fold faster than the mean DMS sea-air turnover time (28.8 days). Thus, the main sink of DMS in the surface water appears to be microbial consumption.
The dimethylsulfide (DMS), dissolved and particulate dimethylsulfoniopropionate (DMSPd and DMSPp) concentrations were determined in the Norwegian and Greenland Seas during summer of 2012. Surface DMS, DMSPd and DMSPp concentrations in the study area increased significantly from high latitudes to low latitudes, with the average values of 5.36, 15.63 and 96.73 nmol/L, respectively. Moreover, the biological production and consumption rates of DMS were estimated during the cruise, with the average values of 18.19 and 15.67 nmol/(L·d), respectively. Our results showed that the spatial variation of chlorophyll a was consistent with that of DMSPd and DMSPp concentrations, suggesting that phytoplankton biomass might play an important role in controlling the distribution of DMSP in the study area. In the surface water, the biological turnover time of DMS varied from 0.03 to 1.8 days, with an average of 0.49 days, which was about 90-fold faster than the mean DMS sea-air turnover time (28.8 days). Thus, the main sink of DMS in the surface water appears to be microbial consumption.
2015, 37(8): 26-38.
doi: 10.3969/j.issn.0253-4193.2015.08.003
Abstract:
The organic geochemical characteristics and molecular biomarker are tests analyzed by gas chromatography-mass spectrometry which are soluble extracted from the bottom surface sediments in the northeast waters to Antarctic Peninsula. Results show that the average contents of TOC (total organic carbon) of the surface sediment in the study is higher than the average contents of organic matter in modern deep-sea sediments. δ13 Corg (Organic carbon isotope) values change means that the source of sediment organic carbon has feature of marine aquatic organisms mixed with terrigenous material input. The combination parameters of n-alkanes peak type distribution, n-alkanes main carbon peak, the saturated hydrocarbon radio of ∑C21-/∑C22+ and (C21+C22)/(C28+C29), sterane combination and hopance combination parameters confirm that the source of surface sediment organic matter of west part in the study area is given priority to with terrigenous higher plants, which maybe come from the Antarctic Peninsula and South Shetland Islands; conversely, the organic matter source of the east part are given priority to marine origin, the lower plankton, algae and bacteria, and the like. CPI (Carbon preference index), OEP (Odd-even Predominance) and sterane C29ααα20S/(20S+20R) ratio show that the sediment organic matter of position D1-7 and D5-9 has higher evolution degree, and the sediment organic matter of position D5-2 and D2-4 has lower evolution degree-immature, other positions between the intermediate state-low mature. The saturated hydrocarbon compositions of pristance, phytance and their ratio (Pr/Ph) show that the sedimentary environment in west part of study area is oxidation and weak reduction-environment, mainly affected by high temperature and low salt current: Bellingshausen Sea Water and nearby volcanic eruption. Oppositely, the east part sedimentary environment is reducing environment-strong reducing environment, which may being caused by WSBW (Weddell Sea Bottom Water) and WSDW (Weddell Sea Deep Water) with low temperature and high salt.
The organic geochemical characteristics and molecular biomarker are tests analyzed by gas chromatography-mass spectrometry which are soluble extracted from the bottom surface sediments in the northeast waters to Antarctic Peninsula. Results show that the average contents of TOC (total organic carbon) of the surface sediment in the study is higher than the average contents of organic matter in modern deep-sea sediments. δ13 Corg (Organic carbon isotope) values change means that the source of sediment organic carbon has feature of marine aquatic organisms mixed with terrigenous material input. The combination parameters of n-alkanes peak type distribution, n-alkanes main carbon peak, the saturated hydrocarbon radio of ∑C21-/∑C22+ and (C21+C22)/(C28+C29), sterane combination and hopance combination parameters confirm that the source of surface sediment organic matter of west part in the study area is given priority to with terrigenous higher plants, which maybe come from the Antarctic Peninsula and South Shetland Islands; conversely, the organic matter source of the east part are given priority to marine origin, the lower plankton, algae and bacteria, and the like. CPI (Carbon preference index), OEP (Odd-even Predominance) and sterane C29ααα20S/(20S+20R) ratio show that the sediment organic matter of position D1-7 and D5-9 has higher evolution degree, and the sediment organic matter of position D5-2 and D2-4 has lower evolution degree-immature, other positions between the intermediate state-low mature. The saturated hydrocarbon compositions of pristance, phytance and their ratio (Pr/Ph) show that the sedimentary environment in west part of study area is oxidation and weak reduction-environment, mainly affected by high temperature and low salt current: Bellingshausen Sea Water and nearby volcanic eruption. Oppositely, the east part sedimentary environment is reducing environment-strong reducing environment, which may being caused by WSBW (Weddell Sea Bottom Water) and WSDW (Weddell Sea Deep Water) with low temperature and high salt.
2015, 37(8): 39-46.
doi: 10.3969/j.issn.0253-4193.2015.08.004
Abstract:
Concentrations and sources of polycyclic aromatic hydrocarbons (PAHs) and black carbon (BC) were investigated based on a sediment core collected in the mud area of the central northern Yellow Sea. Results showed that: (1) The concentration of PAHs were in the value of 207 to 611 ng/g, and the values for BC were 0.560 to 1.32 mg/g.(2)The comparison of low-molecular-weighted(LMW) and high-molecular-weighed (HMW) PAHs indicated that biomass burning with relatively low temperature was their main source prior to 1980s, and shifted to fossil fuels with higher combustion temperature after 1980s. (3) Before 1920s, the concentration of PAHs and BC remained in stable and lower levels. In 1920s-1980s, PAHs concentrations began to increase which could be largely contributed to the rapid industrialization and coal usage in adjacent areas. After 1980s, the increase of energy consumption and vehicle population account for the continued increase of PAHs and BC concentrations, which reached to their maximum values about 1996, But the use of clean energy made them decreased since 1990s. (4) Before 1920s and 1920s-1980s, there are no correlation between PAHs and BC (r=-0.25, P>0.05, n=34; r=0.06, P>0.06, n=11). After 1980, there is a strong association of PAHs and BC (r=0.90, P=0.04, n=5).
Concentrations and sources of polycyclic aromatic hydrocarbons (PAHs) and black carbon (BC) were investigated based on a sediment core collected in the mud area of the central northern Yellow Sea. Results showed that: (1) The concentration of PAHs were in the value of 207 to 611 ng/g, and the values for BC were 0.560 to 1.32 mg/g.(2)The comparison of low-molecular-weighted(LMW) and high-molecular-weighed (HMW) PAHs indicated that biomass burning with relatively low temperature was their main source prior to 1980s, and shifted to fossil fuels with higher combustion temperature after 1980s. (3) Before 1920s, the concentration of PAHs and BC remained in stable and lower levels. In 1920s-1980s, PAHs concentrations began to increase which could be largely contributed to the rapid industrialization and coal usage in adjacent areas. After 1980s, the increase of energy consumption and vehicle population account for the continued increase of PAHs and BC concentrations, which reached to their maximum values about 1996, But the use of clean energy made them decreased since 1990s. (4) Before 1920s and 1920s-1980s, there are no correlation between PAHs and BC (r=-0.25, P>0.05, n=34; r=0.06, P>0.06, n=11). After 1980, there is a strong association of PAHs and BC (r=0.90, P=0.04, n=5).
2015, 37(8): 47-62.
doi: 10.3969/j.issn.0253-4193.2015.08.005
Abstract:
Major and ICP-MS trace element compositions have been determined for 14 fresh mid-ocean ridge basalts (MORBs) dredged from Carlsberg Ridge to investigate the nature of mantle source and magmatic process beneath this ridge. These basalts can be classified into the typical normal MORB derived from depleted mantle source and basalts with different geochemistry experienced variable degree of fractional crystallization which is mainly dominated by olivine fractionation, a few of basalts have experienced clinopyroxene fractionation and no significant plagioclase fractionation. The basaltic magma is derived from the depleted spinel lherzolite mantle melting and has no obvious major and trace element geochemical evidence suggested the enriched component mixing into the mantle source. The distinct geochemical characteristics for basalts are mainly controlled by various degree of mantle melting and the subsequently different magmatic evolution processes, and the independent magmatic process in different segments is the main dominating factor for differences of magmatism in this ridge. Major and trace element compositions of MORBs from Carlsberg Ridge are very similar to the average composition of global normal mid-ocean ridge basalt (N-MORB), there are no significant differences for compositions of mantle sources, and the average degree and depth of mantle melting among segments of Carlsberg Ridge, and this homogeneity feature continues southward to the northern section of the CIR.
Major and ICP-MS trace element compositions have been determined for 14 fresh mid-ocean ridge basalts (MORBs) dredged from Carlsberg Ridge to investigate the nature of mantle source and magmatic process beneath this ridge. These basalts can be classified into the typical normal MORB derived from depleted mantle source and basalts with different geochemistry experienced variable degree of fractional crystallization which is mainly dominated by olivine fractionation, a few of basalts have experienced clinopyroxene fractionation and no significant plagioclase fractionation. The basaltic magma is derived from the depleted spinel lherzolite mantle melting and has no obvious major and trace element geochemical evidence suggested the enriched component mixing into the mantle source. The distinct geochemical characteristics for basalts are mainly controlled by various degree of mantle melting and the subsequently different magmatic evolution processes, and the independent magmatic process in different segments is the main dominating factor for differences of magmatism in this ridge. Major and trace element compositions of MORBs from Carlsberg Ridge are very similar to the average composition of global normal mid-ocean ridge basalt (N-MORB), there are no significant differences for compositions of mantle sources, and the average degree and depth of mantle melting among segments of Carlsberg Ridge, and this homogeneity feature continues southward to the northern section of the CIR.
2015, 37(8): 63-75.
doi: 10.3969/j.issn.0253-4193.2015.08.006
Abstract:
Based on the monitoring data from 1988 to 2014, combined with the ecological environment condition of Xiangshan Bay, a scientific evaluation method of marine ecological environment in Xiangshan Bay was established.The results showed that:(1)The evaluation index system in Xiangshan Bay was composed of biology and ecology, water quality, water power and water mass. The determination of water quality index was on the comprehensive consideration of the over standard rate, fluctuation and trend.(2)The base year of phosphate and inorganic in Xiangshan bay was 1993 and 1992 by data statistical analysis from the E2 section of east sea and the mouth of Xiangshan Bay. And then combined with the frequency analysis the recommended reference values of phosphate and inorganic nitrogen in Xiangshan Bay was 0.023 mg/L and 0.50 mg/L.(3)Three evaluation classes was determined by the present ecological environment situation and the partition, while the 25% and 75% of the nutrient concentration values was chose for the classification basis.(4) The marine environment evaluation results was "perfect"、"good"、"general" or "poor" in Xiangshan Bay, which can be divided into 3-4 different areas. The comprehensive environment of 2, 4, 5, 7, 8, 9 zones in 2014 was poorer than 2011.
Based on the monitoring data from 1988 to 2014, combined with the ecological environment condition of Xiangshan Bay, a scientific evaluation method of marine ecological environment in Xiangshan Bay was established.The results showed that:(1)The evaluation index system in Xiangshan Bay was composed of biology and ecology, water quality, water power and water mass. The determination of water quality index was on the comprehensive consideration of the over standard rate, fluctuation and trend.(2)The base year of phosphate and inorganic in Xiangshan bay was 1993 and 1992 by data statistical analysis from the E2 section of east sea and the mouth of Xiangshan Bay. And then combined with the frequency analysis the recommended reference values of phosphate and inorganic nitrogen in Xiangshan Bay was 0.023 mg/L and 0.50 mg/L.(3)Three evaluation classes was determined by the present ecological environment situation and the partition, while the 25% and 75% of the nutrient concentration values was chose for the classification basis.(4) The marine environment evaluation results was "perfect"、"good"、"general" or "poor" in Xiangshan Bay, which can be divided into 3-4 different areas. The comprehensive environment of 2, 4, 5, 7, 8, 9 zones in 2014 was poorer than 2011.
2015, 37(8): 76-87.
doi: 10.3969/j.issn.0253-4193.2015.08.007
Abstract:
Six surveys were conducted during 2011-2013 to assess the benthic ecological status of the stressed Wuyuan Bay (Xiamen, China) by the AZTI'S Marine Biotic Index (AMBI) and multivariate-AMBI (M-AMBI). A total of 193 species of macrobenthos were identified, which were belonged to 9 phyla and 106 families. The dominated ones were polychaetes, crustaceans and mollusks, which have 83, 53, and 25 species, respectively. The dominant species of polychaetes were Pista brevibranchia, Ruditapes philippinarum, Tharyx sp., Amaeana trilobata, Prionospio malmgreni, Terebellides stroemii, Melita longidactyla, Austinogebia wuhsienweni and Amaeana occidentalis. The average density and biomass (mean ± SD across all stations) of the total macrobenthos were (518±292) ind/m2 and (54.8±88.9) g/m2, respectively. The results showed that most sampling stations were slightly disturbed, and the benthic ecological status of Wuyuan Bay were between "moderate" and "good". Compared with the results of 2005, the average taxa numbers, the average density, biodiversity and M-AMBI values in the stressed Wuyuan Bay were increased, which might benefit from the uncork rebuilt of Wuyuan and Gaoji Causeway, treatment of marine environmental and improvement of water exchange in Wuyuan Bay and Xiamen area.
Six surveys were conducted during 2011-2013 to assess the benthic ecological status of the stressed Wuyuan Bay (Xiamen, China) by the AZTI'S Marine Biotic Index (AMBI) and multivariate-AMBI (M-AMBI). A total of 193 species of macrobenthos were identified, which were belonged to 9 phyla and 106 families. The dominated ones were polychaetes, crustaceans and mollusks, which have 83, 53, and 25 species, respectively. The dominant species of polychaetes were Pista brevibranchia, Ruditapes philippinarum, Tharyx sp., Amaeana trilobata, Prionospio malmgreni, Terebellides stroemii, Melita longidactyla, Austinogebia wuhsienweni and Amaeana occidentalis. The average density and biomass (mean ± SD across all stations) of the total macrobenthos were (518±292) ind/m2 and (54.8±88.9) g/m2, respectively. The results showed that most sampling stations were slightly disturbed, and the benthic ecological status of Wuyuan Bay were between "moderate" and "good". Compared with the results of 2005, the average taxa numbers, the average density, biodiversity and M-AMBI values in the stressed Wuyuan Bay were increased, which might benefit from the uncork rebuilt of Wuyuan and Gaoji Causeway, treatment of marine environmental and improvement of water exchange in Wuyuan Bay and Xiamen area.
2015, 37(8): 88-95.
doi: 10.3969/j.issn.0253-4193.2015.08.008
Abstract:
In this study, according to the Chinese squid fishing production data during the main fishing season (January to May) from 2003 to 2005, and 2011, combined with sea surface temperature (SST) and sea surface height (SSH) , We attempt to forecast fishing ground of Illex argentinus based on habitat suitability models with different weights. The suitability index was built by external envelope method, and the arithmetic weighted model (AWM) with different weights were compared and the best habitat suitability index (HSI) model was selected based on the percentage of fishing efforts (fishing days) and catch. Results show that, when HSI value was greater than 0.6, the percentage of fishing efforts was 93.23% and the percentage of catch was 89.28%, and when HSI value was less than 0.4, the percentage of fishing efforts was 2.12% and the percentage of catch was 3.35% by using AWM (a=0.3, the weights of SST and SSH are 0.3 and 0.7 respectively). Compared with AWM with other four weights, the percentage of fishing efforts and of catch were larger when HSI value was greater than 0.6, and the percentage of fishing efforts and catch were smaller when HSI value was less than 0.4. Therefore, given to the percentage of fishing efforts and the percentage of catch, the AWM (a=0.3) was selected to be the best HSI model, defined as HSI=0.3SISST+0.7SISSH, indicating that SSH is more important than SST in estimating the HSI of squid. According to the data from January to May in 2011, we found that the main fishing ground is distributed in the waters with HSI more than 0.6 from the AWM(a=0.3), and the percentage of fishing efforts reached more than 91% and the percentage of catch were above 95%. The results indicate that SSH is more important than SST in the formation of fishing ground of Illex argentinus, and the AWM (a=0.3) based on SST and SSH can better forecast the fishing grounds of Illex argentinus in the southwest Atlantic.
In this study, according to the Chinese squid fishing production data during the main fishing season (January to May) from 2003 to 2005, and 2011, combined with sea surface temperature (SST) and sea surface height (SSH) , We attempt to forecast fishing ground of Illex argentinus based on habitat suitability models with different weights. The suitability index was built by external envelope method, and the arithmetic weighted model (AWM) with different weights were compared and the best habitat suitability index (HSI) model was selected based on the percentage of fishing efforts (fishing days) and catch. Results show that, when HSI value was greater than 0.6, the percentage of fishing efforts was 93.23% and the percentage of catch was 89.28%, and when HSI value was less than 0.4, the percentage of fishing efforts was 2.12% and the percentage of catch was 3.35% by using AWM (a=0.3, the weights of SST and SSH are 0.3 and 0.7 respectively). Compared with AWM with other four weights, the percentage of fishing efforts and of catch were larger when HSI value was greater than 0.6, and the percentage of fishing efforts and catch were smaller when HSI value was less than 0.4. Therefore, given to the percentage of fishing efforts and the percentage of catch, the AWM (a=0.3) was selected to be the best HSI model, defined as HSI=0.3SISST+0.7SISSH, indicating that SSH is more important than SST in estimating the HSI of squid. According to the data from January to May in 2011, we found that the main fishing ground is distributed in the waters with HSI more than 0.6 from the AWM(a=0.3), and the percentage of fishing efforts reached more than 91% and the percentage of catch were above 95%. The results indicate that SSH is more important than SST in the formation of fishing ground of Illex argentinus, and the AWM (a=0.3) based on SST and SSH can better forecast the fishing grounds of Illex argentinus in the southwest Atlantic.
2015, 37(8): 96-104.
doi: 10.3969/j.issn.0253-4193.2015.08.009
Abstract:
The abundance and production of bacterioplankton with their correlations with environmental factors were investigated in the Chukchi Sea and its northern border areas in 2012 summer. The abundances of bacterioplankton in and near the Chukchi Sea range from 0.56×108 to 6.41×108 cells/dm3, with an average of 2.25×108 cells/dm3. Bacterial productions are between 0.042 mg/(m3·d) (in carbon) and 1.92 mg/(m3·d) (in carbon), with an average of 0.54 mg/(m3·d) (in carbon). These results are similar with previous studies in the Arctic Ocean. In the shelf region, the abundances and productions of bacteria are obviously higher than those in the northern border areas, but the specific bacterial production is lower. The environmental correlation analysis shows that bacterial abundance is positively correlation with temperature and Chl a concentration (p<0.01), indicating that both the increase of water temperature and phytoplankton biomass will enhance the growth of bacterioplankton in the Chukchi Sea which will further promote the role of bacteria in the marine ecosystem and carbon cycle. On the contrary, bacterial production has no correlation with environmental factors in the shelf region, but shows a significant positive correlation with Chl a in northern border area (p<0.01), suggesting that the growth of bacteria mainly depends on DOC released by phytoplankton in border area. The simplicity of carbon source may restrict the productivity of bacteria in the northern border area, and the DOC released from melting ice will stimulate the bacterial activity.
The abundance and production of bacterioplankton with their correlations with environmental factors were investigated in the Chukchi Sea and its northern border areas in 2012 summer. The abundances of bacterioplankton in and near the Chukchi Sea range from 0.56×108 to 6.41×108 cells/dm3, with an average of 2.25×108 cells/dm3. Bacterial productions are between 0.042 mg/(m3·d) (in carbon) and 1.92 mg/(m3·d) (in carbon), with an average of 0.54 mg/(m3·d) (in carbon). These results are similar with previous studies in the Arctic Ocean. In the shelf region, the abundances and productions of bacteria are obviously higher than those in the northern border areas, but the specific bacterial production is lower. The environmental correlation analysis shows that bacterial abundance is positively correlation with temperature and Chl a concentration (p<0.01), indicating that both the increase of water temperature and phytoplankton biomass will enhance the growth of bacterioplankton in the Chukchi Sea which will further promote the role of bacteria in the marine ecosystem and carbon cycle. On the contrary, bacterial production has no correlation with environmental factors in the shelf region, but shows a significant positive correlation with Chl a in northern border area (p<0.01), suggesting that the growth of bacteria mainly depends on DOC released by phytoplankton in border area. The simplicity of carbon source may restrict the productivity of bacteria in the northern border area, and the DOC released from melting ice will stimulate the bacterial activity.
2015, 37(8): 105-116.
doi: 10.3969/j.issn.0253-4193.2015.08.010
Abstract:
Mercuric reductase gene merA had a potential role in mercuric reduction and detoxification in environment. During 2011-2012, surface sediments were collected from wastewater discharge of Dagu River in Tianjin Binhai New Area from Bohai Bay, near shore of Bohai Bay and Kenli aquaculture facility from Laizhou Bay. Clone libraries of merA from Actinomycete, Firmicutes, α-Proteobacteria and β/γ-Proteobacteria were constructed and the sequences were determined. Deduced MerA protein sequences of merA gene were then analyzed. The results showed that Bohai Sea sedimentary environment contained high diversity of MerA, and MerA diversity within Firmicutes, α-Proteobacteria and α/β/γ-Proteobacteria from wastewater discharge and aquaculture facility were higher than that in near shore of Bohai Bay. The MerA composition in different locations also differed, and within Firmicutes, the highest total abundance of MerAs that had the highest similarity with Bacillus sp. MB2021 was found in aquaculture facility(24.3%), while, the highest total abundance of MerAs that had the highest similarity with Paenisporosarcina sp. TG20 was found in wastewater discharge(46.3%). Different environment context, exogenous merA gene input, and co-selection caused by mercury and other heavy metal pollutants might together lead to the change of merA diversity, community composition in Bohai Sea sedimentary environment.
Mercuric reductase gene merA had a potential role in mercuric reduction and detoxification in environment. During 2011-2012, surface sediments were collected from wastewater discharge of Dagu River in Tianjin Binhai New Area from Bohai Bay, near shore of Bohai Bay and Kenli aquaculture facility from Laizhou Bay. Clone libraries of merA from Actinomycete, Firmicutes, α-Proteobacteria and β/γ-Proteobacteria were constructed and the sequences were determined. Deduced MerA protein sequences of merA gene were then analyzed. The results showed that Bohai Sea sedimentary environment contained high diversity of MerA, and MerA diversity within Firmicutes, α-Proteobacteria and α/β/γ-Proteobacteria from wastewater discharge and aquaculture facility were higher than that in near shore of Bohai Bay. The MerA composition in different locations also differed, and within Firmicutes, the highest total abundance of MerAs that had the highest similarity with Bacillus sp. MB2021 was found in aquaculture facility(24.3%), while, the highest total abundance of MerAs that had the highest similarity with Paenisporosarcina sp. TG20 was found in wastewater discharge(46.3%). Different environment context, exogenous merA gene input, and co-selection caused by mercury and other heavy metal pollutants might together lead to the change of merA diversity, community composition in Bohai Sea sedimentary environment.
2015, 37(8): 117-125.
doi: 10.3969/j.issn.0253-4193.2015.08.011
Abstract:
Stable isotope analysis has been used powerfully in tracing animal dietary sources. In the recent decades, many mixing models have been exploited to calculate source proportional contributions to a mixture based on stable isotope analyses. Here we present a case study by using Euclidean, Linear and Bayesian stable isotope mixing models to calculate proportion of Euphausia superba, Electrona antarctica and Gymnoscopelus nicholsi in Antarctic fur seal (Arctocephalus gazelle) diets over the 20th century. The Euphausia superba proportions in fur seal diets obtained from formula (1) and (2) of Euclidean method show a rising trend over the 20th century, similar to those δ15N of fur seal hairs. While the results given by formula (3) of Euclidean, Linear and Bayesian models show a declining trend, which are in accord with those recent changes in regional climate, sea ice extent and the observational Euphausia superba density. The results here can be used to study the biological response to climate change in a long time period. The calculated decline of krill proportion in seal diets over the past century indicates a decreasing trend of Euphausia superba population which is very likely due to the recent rapid regional warming and sea ice loss. Our results suggest that recent warming in the West Antarctic Peninsula has had an obvious impact on the regional marine food chains.
Stable isotope analysis has been used powerfully in tracing animal dietary sources. In the recent decades, many mixing models have been exploited to calculate source proportional contributions to a mixture based on stable isotope analyses. Here we present a case study by using Euclidean, Linear and Bayesian stable isotope mixing models to calculate proportion of Euphausia superba, Electrona antarctica and Gymnoscopelus nicholsi in Antarctic fur seal (Arctocephalus gazelle) diets over the 20th century. The Euphausia superba proportions in fur seal diets obtained from formula (1) and (2) of Euclidean method show a rising trend over the 20th century, similar to those δ15N of fur seal hairs. While the results given by formula (3) of Euclidean, Linear and Bayesian models show a declining trend, which are in accord with those recent changes in regional climate, sea ice extent and the observational Euphausia superba density. The results here can be used to study the biological response to climate change in a long time period. The calculated decline of krill proportion in seal diets over the past century indicates a decreasing trend of Euphausia superba population which is very likely due to the recent rapid regional warming and sea ice loss. Our results suggest that recent warming in the West Antarctic Peninsula has had an obvious impact on the regional marine food chains.
2015, 37(8): 126-133.
doi: 10.3969/j.issn.0253-4193.2015.08.012
Abstract:
A new species of Euphilomedes (Ostracoda: Philomedidae), Euphilomedes spinulosa sp. nov., is described and the differences between the new species and its similar species are also discussed. All type specimens are deposited in the Third Institute of Oceanography, State Oceanic Administration. The specific diagnoses of new species is as follows: Euphilomedes spinulosa sp. nov. (Fig.1-2).The new species is distinguished by the 13 clusters of spines on the middle of ventral infold of left valve. Each lamella of furca has 11 claws: claws1, 2, 4, 6 are primary, remaining claws secondary. Third and fifth claws are secondary claws inserted between primary claws. One peg present opposite of the terminal comb of seventh limb.
A new species of Euphilomedes (Ostracoda: Philomedidae), Euphilomedes spinulosa sp. nov., is described and the differences between the new species and its similar species are also discussed. All type specimens are deposited in the Third Institute of Oceanography, State Oceanic Administration. The specific diagnoses of new species is as follows: Euphilomedes spinulosa sp. nov. (Fig.1-2).The new species is distinguished by the 13 clusters of spines on the middle of ventral infold of left valve. Each lamella of furca has 11 claws: claws1, 2, 4, 6 are primary, remaining claws secondary. Third and fifth claws are secondary claws inserted between primary claws. One peg present opposite of the terminal comb of seventh limb.
Email alert
RSS