2018 Vol. 40, No. 4
Display Method:
2018, 40(4): .
Abstract:
2018, 40(4): 1-14.
doi: 10.3969/j.issn.0253-4193.2018.04.001
Abstract:
Used the Sea Level Anomaly data during 1994 to 2015, based on the winding-angle eddy detection algorithm, total of 5 899 anticyclonic eddies (AE) and 3 792 cyclonic eddies (CE) in the SCS are identified. With the profiles from the WOD13 and the SCSIO, the 3-D thermohaline anomaly structures are constructed in the SCS and its different area with the objective interpolation approach based on the variational analysis. The results show that the proposed revised interpolation approach can simulate the boundary of eddies effectively, and ensure the correct eddies shape. Generally speaking, AE's intensity are obviously stronger than CE's. AE maintain its main structure till approximately 440 m depth while CE only remain stable above 320 m. Both of the maximum potential temperature anomalies appear in about 80m depth, 2.02℃ for AE and -1.60℃ for CE. The affecting depth of salinity anomaly of eddies reach to 150 m depth around and the maximum anomalies induced by AE and CE are -0.24 and 0.28, respectively, which occur near the depth of 50 m. Meanwhile, the structure of salinity anomaly of AE seems to be positive on the top and negative on the bottom, just opposite to CE,which attributed to the sea water sinking (rising) induced by AE(CE). The temperature anomalies in each area of the SCS are not quite consistent with the salinity anomalies, which may attributed to the background thermohaline fields and different formation mechanism of eddies.
Used the Sea Level Anomaly data during 1994 to 2015, based on the winding-angle eddy detection algorithm, total of 5 899 anticyclonic eddies (AE) and 3 792 cyclonic eddies (CE) in the SCS are identified. With the profiles from the WOD13 and the SCSIO, the 3-D thermohaline anomaly structures are constructed in the SCS and its different area with the objective interpolation approach based on the variational analysis. The results show that the proposed revised interpolation approach can simulate the boundary of eddies effectively, and ensure the correct eddies shape. Generally speaking, AE's intensity are obviously stronger than CE's. AE maintain its main structure till approximately 440 m depth while CE only remain stable above 320 m. Both of the maximum potential temperature anomalies appear in about 80m depth, 2.02℃ for AE and -1.60℃ for CE. The affecting depth of salinity anomaly of eddies reach to 150 m depth around and the maximum anomalies induced by AE and CE are -0.24 and 0.28, respectively, which occur near the depth of 50 m. Meanwhile, the structure of salinity anomaly of AE seems to be positive on the top and negative on the bottom, just opposite to CE,which attributed to the sea water sinking (rising) induced by AE(CE). The temperature anomalies in each area of the SCS are not quite consistent with the salinity anomalies, which may attributed to the background thermohaline fields and different formation mechanism of eddies.
2018, 40(4): 15-29.
doi: 10.3969/j.issn.0253-4193.2018.04.002
Abstract:
To reconstruct 3-D ocean temperature fields using both satellite measurements and in situ observations, the prescribed statistical information estimation in the optimal interpolation (OI) was optimized and the impact mechanisms of these two types of data were analysed. In the OI, two comparative schemes were implemented, with the background field set to a climatology (static scheme) and a synthetic field from satellite surface data (dynamic scheme), respectively. Before the OI, one a posterior diagnosis iterative method was performed to optimize the background error and observation error covariances. After the OI, the two schemes were compared using some diagnostic errors in the observational space and indices on the model grids. The main conclusions include:(1) The analysis error is smaller for the dynamic scheme than for the static one, in which the reduced absolute quantity is determined by the differences in their observation errors (i.e., noises), and the reduced relative extent is determined by the differences in their background errors (i.e., signals). (2) The background term is more important in the high and middle latitudes, and equivalent to the observation term along the equator, which is determined by the qusi-zonally-orientated distributed covariance scales. (3) The dynamic fields have higher spectral energy related to the temperature mesoscale signal features than the static fields by 1-3 orders of magnitude overall, but roughly the same in the tropics. (4) Satellite measurements reduces the total error and increase the effective resolution of the analysis field by resolving the mesoscale features that in situ observations cannot resolve well.
To reconstruct 3-D ocean temperature fields using both satellite measurements and in situ observations, the prescribed statistical information estimation in the optimal interpolation (OI) was optimized and the impact mechanisms of these two types of data were analysed. In the OI, two comparative schemes were implemented, with the background field set to a climatology (static scheme) and a synthetic field from satellite surface data (dynamic scheme), respectively. Before the OI, one a posterior diagnosis iterative method was performed to optimize the background error and observation error covariances. After the OI, the two schemes were compared using some diagnostic errors in the observational space and indices on the model grids. The main conclusions include:(1) The analysis error is smaller for the dynamic scheme than for the static one, in which the reduced absolute quantity is determined by the differences in their observation errors (i.e., noises), and the reduced relative extent is determined by the differences in their background errors (i.e., signals). (2) The background term is more important in the high and middle latitudes, and equivalent to the observation term along the equator, which is determined by the qusi-zonally-orientated distributed covariance scales. (3) The dynamic fields have higher spectral energy related to the temperature mesoscale signal features than the static fields by 1-3 orders of magnitude overall, but roughly the same in the tropics. (4) Satellite measurements reduces the total error and increase the effective resolution of the analysis field by resolving the mesoscale features that in situ observations cannot resolve well.
2018, 40(4): 30-40.
doi: 10.3969/j.issn.0253-4193.2018.04.003
Abstract:
A physical-biological coupled model (ROMS-NPZD) was built with climatological forcing conditions in the Taiwan Strait (TWS). Comparison between the model and remote sensing data shown the model could capture the climatological characteristics of temperature and chlorophyll in the strait. The model result identified that, the east and west routes of the nutrient transportation that were coincident with the intrusive routes of South China Sea (SCS) subsurface water in the TWS in summer; by contrast the nutrients were source from the Min-Zhe coastal water and the intrusive SCS subsurface water via the Penghu Channel in winter. The model result illustrated the nitrogenous contribution from the strait to the East China Sea (ECS) was mainly composed by PON in summer; in winter the Min-Zhe coastal water supplied abundant nutrient from the ECS to the strait and northern SCS. In addition to that, the nutrients fluxes from the SCS subsurface water into the TWS were comparative between in summer and winter.
A physical-biological coupled model (ROMS-NPZD) was built with climatological forcing conditions in the Taiwan Strait (TWS). Comparison between the model and remote sensing data shown the model could capture the climatological characteristics of temperature and chlorophyll in the strait. The model result identified that, the east and west routes of the nutrient transportation that were coincident with the intrusive routes of South China Sea (SCS) subsurface water in the TWS in summer; by contrast the nutrients were source from the Min-Zhe coastal water and the intrusive SCS subsurface water via the Penghu Channel in winter. The model result illustrated the nitrogenous contribution from the strait to the East China Sea (ECS) was mainly composed by PON in summer; in winter the Min-Zhe coastal water supplied abundant nutrient from the ECS to the strait and northern SCS. In addition to that, the nutrients fluxes from the SCS subsurface water into the TWS were comparative between in summer and winter.
2018, 40(4): 41-50.
doi: 10.3969/j.issn.0253-4193.2018.04.004
Abstract:
Wind directions are necessary to sea surface wind speed retrieval from SAR image by Geophysical Model Function (GMF). In this paper, a method of sea wind directions retrieval from SAR images by using the feature of footprints of rain cells on SAR image with brighter in downwind direction and darker in upwind direction is applied on sea surface wind retrieval. The root mean square errors (RMSE) of wind directions retrieved from 4 case studied RADARSAT-2 SAR images compared with wind directions of ASCAT are all less than 16 degrees. The wind speed retrieval results from these 4 SAR images by using GMF of CMOD5 with wind directions retrieved from rain cells are nearly the same as that with wind directions of ASCAT scatterometer, the differences of RMSEs are no more than 0.3 m/s. The method of wind directions retrieval from the feature of rain cell footprints on SAR image developed in this paper can be applied in SAR wind speeds retrieval.
Wind directions are necessary to sea surface wind speed retrieval from SAR image by Geophysical Model Function (GMF). In this paper, a method of sea wind directions retrieval from SAR images by using the feature of footprints of rain cells on SAR image with brighter in downwind direction and darker in upwind direction is applied on sea surface wind retrieval. The root mean square errors (RMSE) of wind directions retrieved from 4 case studied RADARSAT-2 SAR images compared with wind directions of ASCAT are all less than 16 degrees. The wind speed retrieval results from these 4 SAR images by using GMF of CMOD5 with wind directions retrieved from rain cells are nearly the same as that with wind directions of ASCAT scatterometer, the differences of RMSEs are no more than 0.3 m/s. The method of wind directions retrieval from the feature of rain cell footprints on SAR image developed in this paper can be applied in SAR wind speeds retrieval.
2018, 40(4): 51-60.
doi: 10.3969/j.issn.0253-4193.2018.04.005
Abstract:
Water depth is one of the important parameters of the marine environment,and water depth remote sensing is an important means of water depth measurement. EMD can eliminate small-scale wave information,leaving large-scale underwater terrain information. The paper uses the EMD to scale the GF-1 WFV image. The spectral fidelity analysis of the remaining layer images was carried out by using spectral correlation coefficient,spectral angle mapper,spectral error and spectral relative error. The paper uses the improved logarithmic transformation ratio model to carry out the water depth inversion of the original image and the remaining layer image,and carry on the correlation analysis and the accuracy evaluation. Research indicates:(1)The evaluation index shows that the image has considerable spectral fidelity after the EMD transformation. Analysis of spatial section shows that the EMD removes the small-scale noise information and retains the underwater terrain change information. (2)The uniform distribution of the checkpoints to verify that,the correlation between the depth of the original image and the measured water depth is better the correlation coefficient is above 0.75,and the MAE and MRE of the two kinds of band combination are not more than 2.42 m and 8.5%. (3)A water depth inversion was performed on all 10 layers of EMD remaining layer. The MAE and MRE of the combination of blue and green bands are not higher than 1.62 m and 5.8%. The MAE and MRE of the combination of green and red bands are no more than 1.93 m and 6.9%. (4) For different combinations of bands,the effect of blue-green band combination in the remaining layers is superior to the green-red band,and the water depth inversion accuracy is improved significantly after EMD. (5)The inversion accuracy of 20-30 m water depth is higher than 30-40 m,which indicates that the model is more suitable for shallow water depth.
Water depth is one of the important parameters of the marine environment,and water depth remote sensing is an important means of water depth measurement. EMD can eliminate small-scale wave information,leaving large-scale underwater terrain information. The paper uses the EMD to scale the GF-1 WFV image. The spectral fidelity analysis of the remaining layer images was carried out by using spectral correlation coefficient,spectral angle mapper,spectral error and spectral relative error. The paper uses the improved logarithmic transformation ratio model to carry out the water depth inversion of the original image and the remaining layer image,and carry on the correlation analysis and the accuracy evaluation. Research indicates:(1)The evaluation index shows that the image has considerable spectral fidelity after the EMD transformation. Analysis of spatial section shows that the EMD removes the small-scale noise information and retains the underwater terrain change information. (2)The uniform distribution of the checkpoints to verify that,the correlation between the depth of the original image and the measured water depth is better the correlation coefficient is above 0.75,and the MAE and MRE of the two kinds of band combination are not more than 2.42 m and 8.5%. (3)A water depth inversion was performed on all 10 layers of EMD remaining layer. The MAE and MRE of the combination of blue and green bands are not higher than 1.62 m and 5.8%. The MAE and MRE of the combination of green and red bands are no more than 1.93 m and 6.9%. (4) For different combinations of bands,the effect of blue-green band combination in the remaining layers is superior to the green-red band,and the water depth inversion accuracy is improved significantly after EMD. (5)The inversion accuracy of 20-30 m water depth is higher than 30-40 m,which indicates that the model is more suitable for shallow water depth.
2018, 40(4): 61-75.
doi: 10.3969/j.issn.0253-4193.2018.04.006
Abstract:
The 63.5°E hydrothermal field was the first ultramafic-hosted hydrothermal system on the super-slow spreading ridge-South West Indian Ridge (SWIR). In this study, we report the detailed mineralogical and geochemical characteristics of hydrothermal metal sulfides recovered from this are. The results show that the mineral assemblage were highly weathered, characterized by a large number of intermediate Fe-hydroxides filling in the vugs or fractures. Marcasite is the main mineral (there are two generations marcasite), followed by the isocubanite, and a small amount of covellite, sphalerite and pyrite were not identified. Four distinctive mineralization stages have been identified:(1) low-temperature stage consisting largely of marcasite; (2) high temperature stage distinguished by isocubanite;(3)low-temperature stage consisting mainly of euhedral marcasite stage; (4) weathering stage characterized by minor Cu-sulfides (covellite), mass Fe-ox hydroxides. For the Fe-sulfide, there only observed marcasite, which could be due to the strong reducing environment resulted from the serpentinization of peridotite. Geochemical analysis indicates that the hydrothermal sulfides relative enrichment of Fe(31.57%-44.59%), a small amount of Cu(0.16%-7.24%), however, the Zn(0.01%-0.11%) content is relatively low. As for trace elements, enrichment of Co(328×10-6-2 400×10-6)and Mn(48.47×10-6-1 730×10-6) content. The high content of Fe and Co is comparable to results from seafloor massive sulfides collected from other ultramafic-hosted sites, significantly higher than that of collected from other mafic-hosted hydrothermal systems. The unique mineral and elements characteristics of hydrothermal sulfide in coincidence with the widely exposed mantle rock and the extensive development of detachment faults at this field.
The 63.5°E hydrothermal field was the first ultramafic-hosted hydrothermal system on the super-slow spreading ridge-South West Indian Ridge (SWIR). In this study, we report the detailed mineralogical and geochemical characteristics of hydrothermal metal sulfides recovered from this are. The results show that the mineral assemblage were highly weathered, characterized by a large number of intermediate Fe-hydroxides filling in the vugs or fractures. Marcasite is the main mineral (there are two generations marcasite), followed by the isocubanite, and a small amount of covellite, sphalerite and pyrite were not identified. Four distinctive mineralization stages have been identified:(1) low-temperature stage consisting largely of marcasite; (2) high temperature stage distinguished by isocubanite;(3)low-temperature stage consisting mainly of euhedral marcasite stage; (4) weathering stage characterized by minor Cu-sulfides (covellite), mass Fe-ox hydroxides. For the Fe-sulfide, there only observed marcasite, which could be due to the strong reducing environment resulted from the serpentinization of peridotite. Geochemical analysis indicates that the hydrothermal sulfides relative enrichment of Fe(31.57%-44.59%), a small amount of Cu(0.16%-7.24%), however, the Zn(0.01%-0.11%) content is relatively low. As for trace elements, enrichment of Co(328×10-6-2 400×10-6)and Mn(48.47×10-6-1 730×10-6) content. The high content of Fe and Co is comparable to results from seafloor massive sulfides collected from other ultramafic-hosted sites, significantly higher than that of collected from other mafic-hosted hydrothermal systems. The unique mineral and elements characteristics of hydrothermal sulfide in coincidence with the widely exposed mantle rock and the extensive development of detachment faults at this field.
2018, 40(4): 76-85.
doi: 10.3969/j.issn.0253-4193.2018.04.007
Abstract:
Skipjack is a commercially important species in the ocean, mainly distributed in the western-central Pacific, and its fishing grounds and resource abundance are susceptible to marine environmental factors. Based on the production data of the tuna purse seine fleet in the main fishing area (15°S-10°N,120°E-155°W)during the period 1995 to 2014, the sea surface temperature (SST) and sea surface height (SSH) data, the habitat models based on SST and SSH were established using the arithmetic mean (AM) model in the period of weak, medium and strong. The results show that in the water with Habitat suitability index (HSI) greater than 0.6, the proportion of operation in each stage of La Niña is above 60%. With the data obtained during weak La Niña (December 2005-March 2006), medium La Niña (October 2011 to March 2012) and strong La Niña (June 2010 to April 2011), it is found that the main fishing ground distributed in the waters with HSI greater than 0.6 in the HSI model, and its percentage of fishing times reached 53.9%, 66.5% and 63.6%, respectively. The results show that with the increase of the intensity of La Niña, the abundance is obviously increased, and the distribution of fishing ground spread to the northeast and southeast. The study shows that the habitat model based on SST and SSH in different La Niña modes can predict the skipjack in the western-central Pacific and provide a reference for the analysis of the fishing ground during the La Niña period.
Skipjack is a commercially important species in the ocean, mainly distributed in the western-central Pacific, and its fishing grounds and resource abundance are susceptible to marine environmental factors. Based on the production data of the tuna purse seine fleet in the main fishing area (15°S-10°N,120°E-155°W)during the period 1995 to 2014, the sea surface temperature (SST) and sea surface height (SSH) data, the habitat models based on SST and SSH were established using the arithmetic mean (AM) model in the period of weak, medium and strong. The results show that in the water with Habitat suitability index (HSI) greater than 0.6, the proportion of operation in each stage of La Niña is above 60%. With the data obtained during weak La Niña (December 2005-March 2006), medium La Niña (October 2011 to March 2012) and strong La Niña (June 2010 to April 2011), it is found that the main fishing ground distributed in the waters with HSI greater than 0.6 in the HSI model, and its percentage of fishing times reached 53.9%, 66.5% and 63.6%, respectively. The results show that with the increase of the intensity of La Niña, the abundance is obviously increased, and the distribution of fishing ground spread to the northeast and southeast. The study shows that the habitat model based on SST and SSH in different La Niña modes can predict the skipjack in the western-central Pacific and provide a reference for the analysis of the fishing ground during the La Niña period.
2018, 40(4): 86-95.
doi: 10.3969/j.issn.0253-4193.2018.04.008
Abstract:
Based on the data collected from the bottom trawl surveys in 2013-2014, the spatial and temporal changes of taxonomic diversity of fish assemblages in the Yellow River Estuary were examined using taxonomic diversity indices. In the survey of 2013-2014, in total 52 species belonging to 9 orders, 26 families, 44 genera were caught in the Yellow River estuary, and the species in Perciformes, Clupeiformes and Scorpaeniformes accounted for the majority of fish species composition. The monthly ranges were 39.98-65.48 and 59.15-75.54 for taxonomic diversity △ and taxonomic distinctness △*, respectively. Both two indices were highest in summer months, followed by spring and autumn months, the lowest in winter in 2013-2014 surveys. Except the spring months, the average taxonomic distinctness △+of fish community in other months was significantly lower than that of fish master list in the Yellow River estuary. There was a certain spatial variation for the average taxonomic distinctness △+ in each month in 2013-2014. The average taxonomic distinctness values were in the 95% confidence intervals for most sampling stations in summer and autumn months, and were significantly lower than the expected △+ in part sampling stations in spring and winter months, which was probably due to concentration of the most fish species in the Perciformes in these stations.
Based on the data collected from the bottom trawl surveys in 2013-2014, the spatial and temporal changes of taxonomic diversity of fish assemblages in the Yellow River Estuary were examined using taxonomic diversity indices. In the survey of 2013-2014, in total 52 species belonging to 9 orders, 26 families, 44 genera were caught in the Yellow River estuary, and the species in Perciformes, Clupeiformes and Scorpaeniformes accounted for the majority of fish species composition. The monthly ranges were 39.98-65.48 and 59.15-75.54 for taxonomic diversity △ and taxonomic distinctness △*, respectively. Both two indices were highest in summer months, followed by spring and autumn months, the lowest in winter in 2013-2014 surveys. Except the spring months, the average taxonomic distinctness △+of fish community in other months was significantly lower than that of fish master list in the Yellow River estuary. There was a certain spatial variation for the average taxonomic distinctness △+ in each month in 2013-2014. The average taxonomic distinctness values were in the 95% confidence intervals for most sampling stations in summer and autumn months, and were significantly lower than the expected △+ in part sampling stations in spring and winter months, which was probably due to concentration of the most fish species in the Perciformes in these stations.
2018, 40(4): 96-105.
doi: 10.3969/j.issn.0253-4193.2018.04.009
Abstract:
To evaluate the effect of fermentation Enteromorpha prolifera on growth performance, digestive enzyme activities and serum non-specific immunity, 6 diets adding 0%, 1%, 2%, 3%, 4%, 5% fermentation E. prolifera were respectively fed to pearl gentian grouper(Epinephelus lanceolatus♂×Epinephelus fuscoguttatus♀) (19.16±0.25) g for 28 d. The results showed that with the increasing of fermentation E. prolifera level,the weight gain ratio(WGR) and the specific growth ratio(SGR) in each group showed a trend of first rising then falling,while the feed conversion ratio(FCR)was on the contrary. The WGR,SGR and FCR showed significantly better than the control group at the content of 2%(P<0.05). Adding fermentation E. prolifera enhanced the activities of serum total Superoxide dismutase (T-SOD), Alkaline phosphatase (AKP) and acid phosphatase (ACP) significantly (P<0.05), but no significant differences were found in the activities of Lysozyme (LZM) and Polyphenol Oxidase (PO) between trials (P>0.05). With the addition of fermentation E. prolifera, the activity of amylase, lipase and trypsin were significantly increased (P<0.05), and the best level is 2%-3%. In conclusion, fermentation E. prolifera can obviously promote the growth performance, improved the activity of non-specific immunity enzyme in the serum and digestion enzyme in the gut, it is recommended the amount adding is about 2%.
To evaluate the effect of fermentation Enteromorpha prolifera on growth performance, digestive enzyme activities and serum non-specific immunity, 6 diets adding 0%, 1%, 2%, 3%, 4%, 5% fermentation E. prolifera were respectively fed to pearl gentian grouper(Epinephelus lanceolatus♂×Epinephelus fuscoguttatus♀) (19.16±0.25) g for 28 d. The results showed that with the increasing of fermentation E. prolifera level,the weight gain ratio(WGR) and the specific growth ratio(SGR) in each group showed a trend of first rising then falling,while the feed conversion ratio(FCR)was on the contrary. The WGR,SGR and FCR showed significantly better than the control group at the content of 2%(P<0.05). Adding fermentation E. prolifera enhanced the activities of serum total Superoxide dismutase (T-SOD), Alkaline phosphatase (AKP) and acid phosphatase (ACP) significantly (P<0.05), but no significant differences were found in the activities of Lysozyme (LZM) and Polyphenol Oxidase (PO) between trials (P>0.05). With the addition of fermentation E. prolifera, the activity of amylase, lipase and trypsin were significantly increased (P<0.05), and the best level is 2%-3%. In conclusion, fermentation E. prolifera can obviously promote the growth performance, improved the activity of non-specific immunity enzyme in the serum and digestion enzyme in the gut, it is recommended the amount adding is about 2%.
2018, 40(4): 106-118.
doi: 10.3969/j.issn.0253-4193.2018.04.010
Abstract:
Based on the dataset obtained from 41 stations of a cruise in August of 2016, Shannon-Wiener index (H'), AZTI's Marine Biotic Index (AMBI) and M-AMBI (Multivariate-AMBI) were employed to investigate the potential benthic environmental impacts of offshore mariculture activities in Sansha Bay, a typical aquaculture bay in the East China Sea. The three indices of macrobenthic organisms from four typical waters (finfish, seaweed, abalone farms and non-farm area) were compared and the correlations between these indices and the typical environmental parameters (δ15N, δ13C, C/N ratio, total organic carbon, total nitrogen, total phosphorus, acid volatile sulfide, water content and silt-clay fraction) were analyzed. A total of 74 species of macrobenthic organisms were identified in this study, with H' of 0-3.51, AMBI of 0-4.13 and M-AMBI of 0.30-0.77. Most species were assigned to environment-sensitive type, i.e. the EGI and EGⅡ ecological groups in the AMBI method. The distribution of the three biotic indices indicated that the overall environmental quality of the Sansha Bay was good except for occasional noticeable disturbances occurred in partial areas. Kruskal-Wallis test showed that only H' differed among three typical waters (P<0.05), and supplementary Pairwise comparison showed that H' in cage farm area of Pseudosciaena crocea was statistically higher than that in seaweed farm area (P<0.01). Spearman correlation coefficient showed that significant correlation between indices and environmental parameters were occasionally present, only for H' and M-AMBI were significantly correlated with total phosphorus (P<0.05). Furthermore, cluster analysis revealed that sampling stations were randomly distributed, which did not correspond to differences of the farm categories. In conclusion, analysis of the three biotic indices indicated that the typical mariculture activities in Sansha Bay had no significant impacts on the quality of regional benthic habitats.
Based on the dataset obtained from 41 stations of a cruise in August of 2016, Shannon-Wiener index (H'), AZTI's Marine Biotic Index (AMBI) and M-AMBI (Multivariate-AMBI) were employed to investigate the potential benthic environmental impacts of offshore mariculture activities in Sansha Bay, a typical aquaculture bay in the East China Sea. The three indices of macrobenthic organisms from four typical waters (finfish, seaweed, abalone farms and non-farm area) were compared and the correlations between these indices and the typical environmental parameters (δ15N, δ13C, C/N ratio, total organic carbon, total nitrogen, total phosphorus, acid volatile sulfide, water content and silt-clay fraction) were analyzed. A total of 74 species of macrobenthic organisms were identified in this study, with H' of 0-3.51, AMBI of 0-4.13 and M-AMBI of 0.30-0.77. Most species were assigned to environment-sensitive type, i.e. the EGI and EGⅡ ecological groups in the AMBI method. The distribution of the three biotic indices indicated that the overall environmental quality of the Sansha Bay was good except for occasional noticeable disturbances occurred in partial areas. Kruskal-Wallis test showed that only H' differed among three typical waters (P<0.05), and supplementary Pairwise comparison showed that H' in cage farm area of Pseudosciaena crocea was statistically higher than that in seaweed farm area (P<0.01). Spearman correlation coefficient showed that significant correlation between indices and environmental parameters were occasionally present, only for H' and M-AMBI were significantly correlated with total phosphorus (P<0.05). Furthermore, cluster analysis revealed that sampling stations were randomly distributed, which did not correspond to differences of the farm categories. In conclusion, analysis of the three biotic indices indicated that the typical mariculture activities in Sansha Bay had no significant impacts on the quality of regional benthic habitats.
2018, 40(4): 119-126.
doi: 10.3969/j.issn.0253-4193.2018.04.011
Abstract:
To investigate allelopathic effects of extracts from the filtrate of Phaeodactylum triconutum on growth and physiology of bloom-forming Prorocentrum donghaiense and Dunaliella salina, the cell density, cell size, membrane integrity and esterase activity were determined by the flow cytometry during a 6 d exposure test in laboratory. The results suggested that the growth of P. donghaiense was significantly inhibited by ethyl acetate extracts from the filtrate of P. triconutum. With the ethyl acetate extracts treatments, the cell size increased and the part of the algae membrane integrity was damaged, at the same time esterase activity significantly increased within a short time and was inhibited subsequently. However, the growth of D. salina was not inhibited by extracts from the filtrate of P. triconutum significantly. Both the cell size and membrane integrity was not inhibited, compared with the control cultures, the extracts induced negative effects on the esterase activity after 6 days exposure. These results confirmed that P. donghaiense was more sensitive to the allelochemical contained in the ethyl acetate of P. triconutum. Many P. donghaiense cells rapidly died and disappeared which be caused by the special internal structure of cells that the allelochemicals could easily enter the P. donghaiense cells. Esterase activity was the most sensitive parameter to evaluate the influence of the P. triconutum allelochemical on P. donghaiense, a kind of emergency mode of biological self-protection under environmental pressure.
To investigate allelopathic effects of extracts from the filtrate of Phaeodactylum triconutum on growth and physiology of bloom-forming Prorocentrum donghaiense and Dunaliella salina, the cell density, cell size, membrane integrity and esterase activity were determined by the flow cytometry during a 6 d exposure test in laboratory. The results suggested that the growth of P. donghaiense was significantly inhibited by ethyl acetate extracts from the filtrate of P. triconutum. With the ethyl acetate extracts treatments, the cell size increased and the part of the algae membrane integrity was damaged, at the same time esterase activity significantly increased within a short time and was inhibited subsequently. However, the growth of D. salina was not inhibited by extracts from the filtrate of P. triconutum significantly. Both the cell size and membrane integrity was not inhibited, compared with the control cultures, the extracts induced negative effects on the esterase activity after 6 days exposure. These results confirmed that P. donghaiense was more sensitive to the allelochemical contained in the ethyl acetate of P. triconutum. Many P. donghaiense cells rapidly died and disappeared which be caused by the special internal structure of cells that the allelochemicals could easily enter the P. donghaiense cells. Esterase activity was the most sensitive parameter to evaluate the influence of the P. triconutum allelochemical on P. donghaiense, a kind of emergency mode of biological self-protection under environmental pressure.
2018, 40(4): 127-133.
doi: 10.3969/j.issn.0253-4193.2018.04.012
Abstract:
Seagrass is the only one epigeal angiosperm completely growing under the seawater. Over 70 species of seagrasses belonging to 6 families and 13 genera are recorded in the world, while there are 22 species belonging to 4 families and 10 genera in China. The domestic experts of seagrass research in China have reach a consensus on unifying the Chinese scientific name of seagrass as "grass" instead of "algae", on the occasion of "The 11th International Seagrass Biology Workshop" held in Sanya in November 2014. However, it is difficult to give the exact Chinese name in domestic articles when quoting non-Chinese seagrass species. For example, several Chinese names were observed for the same seagrass species; different species belong to the same genera have been considered as the same Chinese name; several species were expressed as Chinese general names with latin without providing the exact name. Meanwhile, "algae" names were found for their Chinese scientific name causing confusion. Thus, it is necessary to standardize the Chinese nomenclature of the other seagrasses species in the world on the basis of the nomenclature of the "algae" name of seagrasses in China. This will be conducive to the seagrass research in China.
Seagrass is the only one epigeal angiosperm completely growing under the seawater. Over 70 species of seagrasses belonging to 6 families and 13 genera are recorded in the world, while there are 22 species belonging to 4 families and 10 genera in China. The domestic experts of seagrass research in China have reach a consensus on unifying the Chinese scientific name of seagrass as "grass" instead of "algae", on the occasion of "The 11th International Seagrass Biology Workshop" held in Sanya in November 2014. However, it is difficult to give the exact Chinese name in domestic articles when quoting non-Chinese seagrass species. For example, several Chinese names were observed for the same seagrass species; different species belong to the same genera have been considered as the same Chinese name; several species were expressed as Chinese general names with latin without providing the exact name. Meanwhile, "algae" names were found for their Chinese scientific name causing confusion. Thus, it is necessary to standardize the Chinese nomenclature of the other seagrasses species in the world on the basis of the nomenclature of the "algae" name of seagrasses in China. This will be conducive to the seagrass research in China.
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