2018 Vol. 40, No. 12
Display Method:
2018, 40(12): 1-10.
doi: 10.3969/j.issn.0253-4193.2018.12.001
Abstract:
The accurate calculation of ocean wave energy power is the basis for the development and utilization of wave energy. In practice, the wave energy converters are generally installed in finite water depths. For irregular waves, the amount of wave power can be calculated only when the detailed wave spectra are known. For a variety of reasons, most of the measured wave data in practice are given in the forms of scatter diagrams or of wave significant heights and statistical wave periods. As a result, the popular choice is to use the formulas for deep-water waves to calculate the wave power in finite depth, which will cause large errors. It will be shown in this study that for irregular wave of JONSWAP theoretical spectrum in the depth of 50 m, the calculation error is up to 14.6%. In order to improve the accuracy of wave power, a method called "first- and second-order approximations based on energy frequency" is proposed, with which the wave power for different depths can be calculated accurately in the cases where the wave spectra are unknown. The examples for two theoretical wave spectra show that the method can reduce the errors of wave power calculation in limited bandwidth to less than 2.8%.
The accurate calculation of ocean wave energy power is the basis for the development and utilization of wave energy. In practice, the wave energy converters are generally installed in finite water depths. For irregular waves, the amount of wave power can be calculated only when the detailed wave spectra are known. For a variety of reasons, most of the measured wave data in practice are given in the forms of scatter diagrams or of wave significant heights and statistical wave periods. As a result, the popular choice is to use the formulas for deep-water waves to calculate the wave power in finite depth, which will cause large errors. It will be shown in this study that for irregular wave of JONSWAP theoretical spectrum in the depth of 50 m, the calculation error is up to 14.6%. In order to improve the accuracy of wave power, a method called "first- and second-order approximations based on energy frequency" is proposed, with which the wave power for different depths can be calculated accurately in the cases where the wave spectra are unknown. The examples for two theoretical wave spectra show that the method can reduce the errors of wave power calculation in limited bandwidth to less than 2.8%.
2018, 40(12): 11-20.
doi: 10.3969/j.issn.0253-4193.2018.12.002
Abstract:
Allelopathy is one of the important factors of green tide, while the studies of structure, category and yield of allelochemicals released by Ulva prolifera are lacking. Based on the procedure of toxicity identification evaluation(TIE), this study was carried to extract and identify the allelochemicals from the disaster-causing algaes on green tides in the yellow sea, so that we can confirm the main components of allelochemicals realeased by U. prolifer. Firstly, U. prolifera was extracted with three different organic solvents, which include petroleum ether, ethyl acetate and methanol. Three different solvents crude extracts were obtained and the ethyl acetate extract has the stongest effect on anti-algal activity, the 96h-EC50 value against S. costatum was 22.25 mg/L. Next, the primary extracts were obtained by isolating ethyl acetate extract, the 96h-EC50 value against S. costatum was 21.12 mg/L. Then, chromatography column was used to purify the above primary extracts and six components were certained, the 96h-EC50 value of the most toxic component against S. costatum was 10.57 mg/L. Finally, the possible allelochemicals of U. prolifera dry tissues were detected using Gas chromatography-mass spectrometry (GC-MS) and infrared spectroscopy (IR) analysis. Eight fatty acids were identified for both species:4,7,10,13,16,19-docosahexaenoic acid, 2-Hexadecenoic acid,Hexadecanoic acid, 5,8,11,14,17-eicosapentaenoate, 9,12-octadecadienoic acid, 9,12,15-octadecatrienoic acid, arachidonic acid, 13-docosenoic acid. The results of the study play a significant role in systematically illustrating the mechanism of the outbreak of green tides.
Allelopathy is one of the important factors of green tide, while the studies of structure, category and yield of allelochemicals released by Ulva prolifera are lacking. Based on the procedure of toxicity identification evaluation(TIE), this study was carried to extract and identify the allelochemicals from the disaster-causing algaes on green tides in the yellow sea, so that we can confirm the main components of allelochemicals realeased by U. prolifer. Firstly, U. prolifera was extracted with three different organic solvents, which include petroleum ether, ethyl acetate and methanol. Three different solvents crude extracts were obtained and the ethyl acetate extract has the stongest effect on anti-algal activity, the 96h-EC50 value against S. costatum was 22.25 mg/L. Next, the primary extracts were obtained by isolating ethyl acetate extract, the 96h-EC50 value against S. costatum was 21.12 mg/L. Then, chromatography column was used to purify the above primary extracts and six components were certained, the 96h-EC50 value of the most toxic component against S. costatum was 10.57 mg/L. Finally, the possible allelochemicals of U. prolifera dry tissues were detected using Gas chromatography-mass spectrometry (GC-MS) and infrared spectroscopy (IR) analysis. Eight fatty acids were identified for both species:4,7,10,13,16,19-docosahexaenoic acid, 2-Hexadecenoic acid,Hexadecanoic acid, 5,8,11,14,17-eicosapentaenoate, 9,12-octadecadienoic acid, 9,12,15-octadecatrienoic acid, arachidonic acid, 13-docosenoic acid. The results of the study play a significant role in systematically illustrating the mechanism of the outbreak of green tides.
2018, 40(12): 21-30.
doi: 10.3969/j.issn.0253-4193.2018.12.003
Abstract:
In previous study, we found that creatine kinase (CK) was one of the proteins which were up-regulated in the skin mucus of roughskin sculpin Trachidermus fasciatus post Vibrio anguillarum injection. To date, the function of this gene has not been well studied in fish. In this study, the cDNA sequence of CK gene was cloned using 3' RACE and 5'RACE techniques from roughskin sculpin, named as TfM-CK. The full-length of TfM-CK cDNA was 1 474 bp, which contained an open reading frame (ORF) of 1 146 bp encoding a polypeptide of 381 amino acids. The sequence BLASTP in NCBI indicated that TfM-CK was highly conserved. Quantitative real-time PCR (qPCR) analysis showed that TfM-CK mRNA expressed in all the detected tissues, with the highest expression in the muscle. After Vibrio anguillarum infection, TfM-CK transcripts were up-regulated significantly in the muscle, spleen, skin and head kidney, with the highest increase of 900 fold in the spleen. The kinase activity of recombinant protein of TfM-CK (rTfM-CK) was relatively high with 22.0 U/mg protein. It displayed high agglutination activity to all 4 tested bacterial including 2 Gram-negative bacteria Escherichia coli, Vibrio Anguillarum and 2 Gram-positive bacteria Staphylococcus aureus and Bacillus megaterium. These data indicate that TfM-CK participate in the fish immune response against pathogen infection. The present results may provide a theoretical basis for further investigation into the functions of fish TfM-CK and its molecular mechanisms of regulating fish immune response to pathogens.
In previous study, we found that creatine kinase (CK) was one of the proteins which were up-regulated in the skin mucus of roughskin sculpin Trachidermus fasciatus post Vibrio anguillarum injection. To date, the function of this gene has not been well studied in fish. In this study, the cDNA sequence of CK gene was cloned using 3' RACE and 5'RACE techniques from roughskin sculpin, named as TfM-CK. The full-length of TfM-CK cDNA was 1 474 bp, which contained an open reading frame (ORF) of 1 146 bp encoding a polypeptide of 381 amino acids. The sequence BLASTP in NCBI indicated that TfM-CK was highly conserved. Quantitative real-time PCR (qPCR) analysis showed that TfM-CK mRNA expressed in all the detected tissues, with the highest expression in the muscle. After Vibrio anguillarum infection, TfM-CK transcripts were up-regulated significantly in the muscle, spleen, skin and head kidney, with the highest increase of 900 fold in the spleen. The kinase activity of recombinant protein of TfM-CK (rTfM-CK) was relatively high with 22.0 U/mg protein. It displayed high agglutination activity to all 4 tested bacterial including 2 Gram-negative bacteria Escherichia coli, Vibrio Anguillarum and 2 Gram-positive bacteria Staphylococcus aureus and Bacillus megaterium. These data indicate that TfM-CK participate in the fish immune response against pathogen infection. The present results may provide a theoretical basis for further investigation into the functions of fish TfM-CK and its molecular mechanisms of regulating fish immune response to pathogens.
2018, 40(12): 31-39.
doi: 10.3969/j.issn.0253-4193.2018.12.004
Abstract:
Hormone sensitive lipase (HSL) and acetyl-CoA carboxylase (ACC) are key enzymes in lipid metabolism. Muscle and liver tissues are major main places. To study the role of the two enzymes during fasting, we detected the mRNA expression and activity changes of HSL and ACC in large yellow croaker muscle and liver tissues during 35 d fasting by real-time fluorescent quantitative PCR (qPCR) and Elisa, respectively. The results showed that fasting significantly decreased fat content and ACC mRNA level (P< 0.05), and increased HSL mRNA expression in both muscle and liver tissues (P<0.05). Moreover, fasting had a significant influence on the activities of HSL and ACC in both muscle and liver tissues of large yellow croaker (P<0.05). Muscle and liver HSL activities were moderately correlated with the corresponding mRNA expression level, as well as ACC in muscle. But liver ACC activity was negatively correlated with the mRNA level. These results suggested that the expression of HSL and ACC were regulated in both pre-translational and post-translational levels during fasting in the large yellow croaker. The results of the present study provide insights into the molecular mechanisms underlying the lipid metabolic response of the large yellow croaker to fasting.
Hormone sensitive lipase (HSL) and acetyl-CoA carboxylase (ACC) are key enzymes in lipid metabolism. Muscle and liver tissues are major main places. To study the role of the two enzymes during fasting, we detected the mRNA expression and activity changes of HSL and ACC in large yellow croaker muscle and liver tissues during 35 d fasting by real-time fluorescent quantitative PCR (qPCR) and Elisa, respectively. The results showed that fasting significantly decreased fat content and ACC mRNA level (P< 0.05), and increased HSL mRNA expression in both muscle and liver tissues (P<0.05). Moreover, fasting had a significant influence on the activities of HSL and ACC in both muscle and liver tissues of large yellow croaker (P<0.05). Muscle and liver HSL activities were moderately correlated with the corresponding mRNA expression level, as well as ACC in muscle. But liver ACC activity was negatively correlated with the mRNA level. These results suggested that the expression of HSL and ACC were regulated in both pre-translational and post-translational levels during fasting in the large yellow croaker. The results of the present study provide insights into the molecular mechanisms underlying the lipid metabolic response of the large yellow croaker to fasting.
2018, 40(12): 40-48.
doi: 10.3969/j.issn.0253-4193.2018.12.005
Abstract:
This report aimed to investigate the effects of basal diets by adding different dosages(0.5%, 1%, 2%, 3%, 4%, 5%) of multi-vitamins on the growth performance, non-specific immunity indices and digestive enzymatic activity of Lateolabrax japonicus. The fishes with initial body mass of (38.54±0.05)g were fed 28 days in indoor close-recirculating culture systems, and divided into six groups, each group contained 30 individuals and set in triplicate. The results showed that the dosage of multi-vitamins had no significant influence to the body composition, survival rate, hepatosmatic index and feed conversion ratio (P>0.05) of L. japonicus; the weight gain rate (WGR) and specific growth rate (SGR) reached highest at 2% diet; with the increase of multi-vitamin dosages, WGR and SGR decreased significantly (P<0.05) compared to 2% diet. The 5% diet improved the intestinal protease activity, while the intestine amylase (AMS) activity of the control group was significantly higher than any other groups (P<0.05), but there was no significant influences on intestinal LPS activity (P>0.05). Intestinal total protein (TP) content reached maximum at 3% diet with significant difference (P<0.05). The 5% diet improved the activity of total superoxide dismutase (T-SOD), alkaline phosphatase (AKP) and TP content in serum significantly (P<0.05), while serum LSZ activity had no significant change (P<0.05). In conclusion, the feed by adding 5% multi-vitamins significantly improved the non-specific immunity indices of L. japonicus and the intestinal protease activity, while the feed supplemented with 2% multi-vitamins obviously promoted the growth of L. japonicus.
This report aimed to investigate the effects of basal diets by adding different dosages(0.5%, 1%, 2%, 3%, 4%, 5%) of multi-vitamins on the growth performance, non-specific immunity indices and digestive enzymatic activity of Lateolabrax japonicus. The fishes with initial body mass of (38.54±0.05)g were fed 28 days in indoor close-recirculating culture systems, and divided into six groups, each group contained 30 individuals and set in triplicate. The results showed that the dosage of multi-vitamins had no significant influence to the body composition, survival rate, hepatosmatic index and feed conversion ratio (P>0.05) of L. japonicus; the weight gain rate (WGR) and specific growth rate (SGR) reached highest at 2% diet; with the increase of multi-vitamin dosages, WGR and SGR decreased significantly (P<0.05) compared to 2% diet. The 5% diet improved the intestinal protease activity, while the intestine amylase (AMS) activity of the control group was significantly higher than any other groups (P<0.05), but there was no significant influences on intestinal LPS activity (P>0.05). Intestinal total protein (TP) content reached maximum at 3% diet with significant difference (P<0.05). The 5% diet improved the activity of total superoxide dismutase (T-SOD), alkaline phosphatase (AKP) and TP content in serum significantly (P<0.05), while serum LSZ activity had no significant change (P<0.05). In conclusion, the feed by adding 5% multi-vitamins significantly improved the non-specific immunity indices of L. japonicus and the intestinal protease activity, while the feed supplemented with 2% multi-vitamins obviously promoted the growth of L. japonicus.
2018, 40(12): 49-57.
doi: 10.3969/j.issn.0253-4193.2018.12.006
Abstract:
Chinese herbal medicine contains various active substances, with no residual fuel resistant characteristics, is widely used in China and abroad. To evaluate the effect of compound Chinese herbal medicine which consists of Astragalus, Codonopsis, Thubarb and other 9 kinds of Chinese herb medicine on growth performance, serum non-specific immunity and digestive enzyme activities of Pearl gentian grouper, 6 diets adding 0%, 0.4%, 0.8%, 1.2%, 1.6%, 2.0% compound Chinese herbal medicine were respectively fed to Pearl gentian grouper (19.16±0.25) g for 28 days. The results showed that with in the amount of 1.6%, Pearl gentian grouper feed conversion ratio significantly reduced (P<0.05), while the weight gain ratio and the specific growth ratio in each group showed no significant with the control group (P>0.05). The compound Chinese herbal medicine can enhance the content of total protein and the activities of Alkaline phosphatase (AKP), acid phosphatase (ACP) and total Superoxide dismutase (T-SOD)in serum significantly (P<0.05). Based on the effect of the results in the serum non specific immune enzyme activity, it proves that during an amount of addition 0.8% and 1.2% can well improve the immunity of Pearl gentian grouper. The activity of amylase, lipase, total protein content and trypsin were significantly influenced (P<0.05), but no apparent effect on the activity of amylase (P>0.05). Seen from the effect of compound Chinese herbal medicine on digestion enzyme in the gut, it suggests that the best adding level is 1.2%. Comprehensive grouper growth, digestion and non specific immunity results showed that this kind of compound Chinese herbal medicine best amount adding is about 1.2%.
Chinese herbal medicine contains various active substances, with no residual fuel resistant characteristics, is widely used in China and abroad. To evaluate the effect of compound Chinese herbal medicine which consists of Astragalus, Codonopsis, Thubarb and other 9 kinds of Chinese herb medicine on growth performance, serum non-specific immunity and digestive enzyme activities of Pearl gentian grouper, 6 diets adding 0%, 0.4%, 0.8%, 1.2%, 1.6%, 2.0% compound Chinese herbal medicine were respectively fed to Pearl gentian grouper (19.16±0.25) g for 28 days. The results showed that with in the amount of 1.6%, Pearl gentian grouper feed conversion ratio significantly reduced (P<0.05), while the weight gain ratio and the specific growth ratio in each group showed no significant with the control group (P>0.05). The compound Chinese herbal medicine can enhance the content of total protein and the activities of Alkaline phosphatase (AKP), acid phosphatase (ACP) and total Superoxide dismutase (T-SOD)in serum significantly (P<0.05). Based on the effect of the results in the serum non specific immune enzyme activity, it proves that during an amount of addition 0.8% and 1.2% can well improve the immunity of Pearl gentian grouper. The activity of amylase, lipase, total protein content and trypsin were significantly influenced (P<0.05), but no apparent effect on the activity of amylase (P>0.05). Seen from the effect of compound Chinese herbal medicine on digestion enzyme in the gut, it suggests that the best adding level is 1.2%. Comprehensive grouper growth, digestion and non specific immunity results showed that this kind of compound Chinese herbal medicine best amount adding is about 1.2%.
2018, 40(12): 58-67.
doi: 10.3969/j.issn.0253-4193.2018.12.007
Abstract:
The chub mackerel Scomber japonicas is a pelagic species with high economic values. S. japonicas stock is significantly affected by climatic and environmental variability. In this study, an integrated habitat suitability index (HSI) mode was developed based on the fishing effort to evaluate the impacts of different intensity of El Niño and La Niña events on habitat suitability of S. japonicas by using the fishery data from July to September during 2006-2015 obtained from the data centers of Chinese distance water fishery combined with two key environmental variables including sea surface temperature (SST) and sea surface height (SSH). The results suggested that the HSI model based on the arithmetic mean method could accurately predict the habitat suitability on the fishing ground of S. japonicas based on the calculation and cross-validation. Spatial correlation analysis suggested that significant positive relationship was found between SSTA and the HSI of S. japonicas in space. While significant negative relationship was found between the SSH anomaly (SSHA) and the HSI on the fishing ground of S. japonicas in space. Different intensity of El Niño and La Niña events has different impacts on S. japonicas stock:comparing to the moderate El Niño events (or moderate La Niña events), the very strong El Niño event (or strong La Niña event) would yield decreased SSTA (or increased SSTA) and elevated SSHA (or reduced SSHA). The suitable habitat of S. japonicas would significantly decreased (or increased), leading to low CPUE (or high CPUE). Our findings indicated that the El Niño and La Niña events have closely relationship with the habitat suitability of S. japonicas in the coastal waters of China, however, the impacts on S. japonicas stock varied with the intensity of each anomalous climatic event.
The chub mackerel Scomber japonicas is a pelagic species with high economic values. S. japonicas stock is significantly affected by climatic and environmental variability. In this study, an integrated habitat suitability index (HSI) mode was developed based on the fishing effort to evaluate the impacts of different intensity of El Niño and La Niña events on habitat suitability of S. japonicas by using the fishery data from July to September during 2006-2015 obtained from the data centers of Chinese distance water fishery combined with two key environmental variables including sea surface temperature (SST) and sea surface height (SSH). The results suggested that the HSI model based on the arithmetic mean method could accurately predict the habitat suitability on the fishing ground of S. japonicas based on the calculation and cross-validation. Spatial correlation analysis suggested that significant positive relationship was found between SSTA and the HSI of S. japonicas in space. While significant negative relationship was found between the SSH anomaly (SSHA) and the HSI on the fishing ground of S. japonicas in space. Different intensity of El Niño and La Niña events has different impacts on S. japonicas stock:comparing to the moderate El Niño events (or moderate La Niña events), the very strong El Niño event (or strong La Niña event) would yield decreased SSTA (or increased SSTA) and elevated SSHA (or reduced SSHA). The suitable habitat of S. japonicas would significantly decreased (or increased), leading to low CPUE (or high CPUE). Our findings indicated that the El Niño and La Niña events have closely relationship with the habitat suitability of S. japonicas in the coastal waters of China, however, the impacts on S. japonicas stock varied with the intensity of each anomalous climatic event.
2018, 40(12): 68-80.
doi: 10.3969/j.issn.0253-4193.2018.12.008
Abstract:
As one of the important offshore fisheries in China, the tuna longline fishery in the Indian Ocean is indispensable to explore the spatial and temporal changes in fisheries and their relationship with different environmental factors. Based on the Indian Ocean tuna fishery production data collected from January to June of 2016, combined with the data of environmental factors obtained by satellite remote sensing, ArcGIS and GAM models were used to analyze the temporal and spatial changes of Thunnus obesus and Thunnus albacares fishing grounds in the Indian Ocean and their relationship with different environmental factors. The results showed that:CPUE values of T. obesus and T. albacares were first decreased and then increased from January to June, reaching the highest values in April, with 2.45 ind/thousand hooks and 3.56 ind/thousand hooks respectively. There was significant difference in each month's CPUE (P <0.001); the temporal and spatial changes of T. obesus and T. albacares fishing grounds tended to be the same. They were the first to the northeast, the latter to the northwest, and finally to the northeast; GAM model analysis showed that the interpretation rate of CPUE and model factors was 32.1% for T. obesus, and latitude and 250 m water depth temperature had the most significant effect. The interpretation rate of CPUE and model factors for T. albacares was 37.2%, and the temperature at 200 m depth was the most significant; according to the collaborative analysis, from January to June, the tuna longline fishing center in the Indian Ocean distributed in 1°S~9.5°N, 47°~64°E, and the sea surface temperature was in the sea area 29.3~30.8℃.
As one of the important offshore fisheries in China, the tuna longline fishery in the Indian Ocean is indispensable to explore the spatial and temporal changes in fisheries and their relationship with different environmental factors. Based on the Indian Ocean tuna fishery production data collected from January to June of 2016, combined with the data of environmental factors obtained by satellite remote sensing, ArcGIS and GAM models were used to analyze the temporal and spatial changes of Thunnus obesus and Thunnus albacares fishing grounds in the Indian Ocean and their relationship with different environmental factors. The results showed that:CPUE values of T. obesus and T. albacares were first decreased and then increased from January to June, reaching the highest values in April, with 2.45 ind/thousand hooks and 3.56 ind/thousand hooks respectively. There was significant difference in each month's CPUE (P <0.001); the temporal and spatial changes of T. obesus and T. albacares fishing grounds tended to be the same. They were the first to the northeast, the latter to the northwest, and finally to the northeast; GAM model analysis showed that the interpretation rate of CPUE and model factors was 32.1% for T. obesus, and latitude and 250 m water depth temperature had the most significant effect. The interpretation rate of CPUE and model factors for T. albacares was 37.2%, and the temperature at 200 m depth was the most significant; according to the collaborative analysis, from January to June, the tuna longline fishing center in the Indian Ocean distributed in 1°S~9.5°N, 47°~64°E, and the sea surface temperature was in the sea area 29.3~30.8℃.
2018, 40(12): 81-93.
doi: 10.3969/j.issn.0253-4193.2018.12.009
Abstract:
An annual panel test on marine fouling was carried out from March 2016 to February 2017 in the Beiguan Port,China. 59 species of fouling organisms belonging to 53 genera, 44 families and 9 phyla were identified. The fouling organisms were mainly composed of coastal and warm water affinities and reflected distinct characteristics of subtropical embayments.Sessile suspension feeders constituted the main core of settlement for the fouling community. Amphibalanus reticulatus was the most dominant and representative species in the fouling community,and other major species included Caprella equilibra, Ectopleura crocea, Anthopleura nigrescens, Jassa falcate, Stenothoe valida and so on. The settlement of fouling organisms occurred throughout the year, and the area colonized by them reached 100% from June to October,moreover, from June to August, it is the peak time for marine fouling. The average density and biomass on the monthly, seasonal, semiannual and annual test panels were (21 371±8 722)ind/m2 and (1 667.5±506.0)g/m2,(31 605±17 671)ind/m2 and (5 879.1±2 576.5)g/m2,(31 188±10 834)ind/m2 and (13 989.6±4 755.4)g/m2,(18 425±5 757)ind/m2 and (6 581.9±2 175.9)g/m2, respectively, and the adhesive strength of the fouling organisms was highest in summer. The individuals in the fouling community showed a mutual dependence or constraint relationship due to competition for settlement space and food, and they exhibited a particular spatiotemporal distribution in accordance with adaptation to environment. Analysis shows that temperature was the most important environmental factor determining the geographic distribution of fouling organisms. natural environmental conditions(such as salinity, water transparency and light) are all important factors affecting the settlement of fouling organisms.
An annual panel test on marine fouling was carried out from March 2016 to February 2017 in the Beiguan Port,China. 59 species of fouling organisms belonging to 53 genera, 44 families and 9 phyla were identified. The fouling organisms were mainly composed of coastal and warm water affinities and reflected distinct characteristics of subtropical embayments.Sessile suspension feeders constituted the main core of settlement for the fouling community. Amphibalanus reticulatus was the most dominant and representative species in the fouling community,and other major species included Caprella equilibra, Ectopleura crocea, Anthopleura nigrescens, Jassa falcate, Stenothoe valida and so on. The settlement of fouling organisms occurred throughout the year, and the area colonized by them reached 100% from June to October,moreover, from June to August, it is the peak time for marine fouling. The average density and biomass on the monthly, seasonal, semiannual and annual test panels were (21 371±8 722)ind/m2 and (1 667.5±506.0)g/m2,(31 605±17 671)ind/m2 and (5 879.1±2 576.5)g/m2,(31 188±10 834)ind/m2 and (13 989.6±4 755.4)g/m2,(18 425±5 757)ind/m2 and (6 581.9±2 175.9)g/m2, respectively, and the adhesive strength of the fouling organisms was highest in summer. The individuals in the fouling community showed a mutual dependence or constraint relationship due to competition for settlement space and food, and they exhibited a particular spatiotemporal distribution in accordance with adaptation to environment. Analysis shows that temperature was the most important environmental factor determining the geographic distribution of fouling organisms. natural environmental conditions(such as salinity, water transparency and light) are all important factors affecting the settlement of fouling organisms.
2018, 40(12): 94-111.
doi: 10.3969/j.issn.0253-4193.2018.12.010
Abstract:
Zooplankton community was seasonally carried out in the macroalgae beds of Naozhou Island of Guangdong, China, from April 2014 to January 2015. The species composition, dominant species, community structure, abundance and biomass of zooplankton and factors were analyzed.Totally, 91 species and 36 pelagic larvae groups, belonging to 17 large groups, were found in this sea area. The annual average density and biomass were 186.5 ind/m3 and 431.0 mg/m3 respectively, with the maximum in summer and the minimum in winter. The dominant species included 19 species. Zooplankton exhibited high in evenness (0.74) and high diversity indices (3.14). By hierarchical cluster analysis and non-metric multidimensional scaling (MDS) assisted analyzing, zooplankton in the area could be formed into four assemblages joining at a distance of 38%. The community exhibited bimodal annual variation trend. Within-group similarity or between-group dissimilarity of groups were all greater than 50% and 37 types were major contributors. The biota-environment matching (BIOENV) analysis showed that the water temperature, salinity, phytoplankton density and Chl a concentration accounted for important temporal variation in the zooplankton community.
Zooplankton community was seasonally carried out in the macroalgae beds of Naozhou Island of Guangdong, China, from April 2014 to January 2015. The species composition, dominant species, community structure, abundance and biomass of zooplankton and factors were analyzed.Totally, 91 species and 36 pelagic larvae groups, belonging to 17 large groups, were found in this sea area. The annual average density and biomass were 186.5 ind/m3 and 431.0 mg/m3 respectively, with the maximum in summer and the minimum in winter. The dominant species included 19 species. Zooplankton exhibited high in evenness (0.74) and high diversity indices (3.14). By hierarchical cluster analysis and non-metric multidimensional scaling (MDS) assisted analyzing, zooplankton in the area could be formed into four assemblages joining at a distance of 38%. The community exhibited bimodal annual variation trend. Within-group similarity or between-group dissimilarity of groups were all greater than 50% and 37 types were major contributors. The biota-environment matching (BIOENV) analysis showed that the water temperature, salinity, phytoplankton density and Chl a concentration accounted for important temporal variation in the zooplankton community.
2018, 40(12): 112-119.
doi: 10.3969/j.issn.0253-4193.2018.12.011
Abstract:
Microplastics could serve as carriers for heavy metals, organic pollutants and pathogens in the coastal and marine environment due to their small sizes and large specific surface area. It has been reported that the microbial colonizers attaching on the surface of microplasti cs mainly assemblaged in the form of biofilms. In this study, two types of soft microplastics, expanded polystyrene (EPS) and polyethylene films (PE), were selected as tested microplastics that were commonly found in the coastal environment in Shandong province. Two DNA extraction kits (MP FastDNA® and MOBIO PowerSoil®) were used to compare their DNA extraction efficiency from different microplastic biofilms. Moreover, impacts from different particle sizes and quantities on DNA extraction efficiency of microplastic-associated biofilms were also evaluated. The results showed that concentrations of biofilm DNA extracted by FastDNA® kit were significantly higher than by MOBIO PowerSoil®kit (1.0-12.5 times). DNA concentrations from PE biofilm were about 1.3-4.4 times higher than that from EPS extracted by FastDNA®. When the quantities of microplastics were no more than 20, DNA concentrations from small sizes (1-3 mm) EPS were significantly lower than that from large sizes (3-5 mm), while it was totally in opposition for PE. With the increasing of microplastics quantities, DNA concentrations were significantly increased in both two sizes of EPS. But for small sizes (1-3 mm) of PE, DNA concentration showed an increasing initially and decreasing afterward trend with the increasing of PE quantities. However, for large sizes (3-5 mm) of PE, DNA concentrations were decreasing with the increasing of PE quantities. Different impacts of microplastic sizes and quantities on DNA concentrations could be attributed to the types and physicochemical properties of microplastics. Results from this study will be helpful for providing methodological support for the research of microbial community composition and diversity of microplastic-associated biofilms in the coastal and marine environment.
Microplastics could serve as carriers for heavy metals, organic pollutants and pathogens in the coastal and marine environment due to their small sizes and large specific surface area. It has been reported that the microbial colonizers attaching on the surface of microplasti cs mainly assemblaged in the form of biofilms. In this study, two types of soft microplastics, expanded polystyrene (EPS) and polyethylene films (PE), were selected as tested microplastics that were commonly found in the coastal environment in Shandong province. Two DNA extraction kits (MP FastDNA® and MOBIO PowerSoil®) were used to compare their DNA extraction efficiency from different microplastic biofilms. Moreover, impacts from different particle sizes and quantities on DNA extraction efficiency of microplastic-associated biofilms were also evaluated. The results showed that concentrations of biofilm DNA extracted by FastDNA® kit were significantly higher than by MOBIO PowerSoil®kit (1.0-12.5 times). DNA concentrations from PE biofilm were about 1.3-4.4 times higher than that from EPS extracted by FastDNA®. When the quantities of microplastics were no more than 20, DNA concentrations from small sizes (1-3 mm) EPS were significantly lower than that from large sizes (3-5 mm), while it was totally in opposition for PE. With the increasing of microplastics quantities, DNA concentrations were significantly increased in both two sizes of EPS. But for small sizes (1-3 mm) of PE, DNA concentration showed an increasing initially and decreasing afterward trend with the increasing of PE quantities. However, for large sizes (3-5 mm) of PE, DNA concentrations were decreasing with the increasing of PE quantities. Different impacts of microplastic sizes and quantities on DNA concentrations could be attributed to the types and physicochemical properties of microplastics. Results from this study will be helpful for providing methodological support for the research of microbial community composition and diversity of microplastic-associated biofilms in the coastal and marine environment.
2018, 40(12): 120-128.
doi: 10.3969/j.issn.0253-4193.2018.12.012
Abstract:
The diatom genus Pseudo-nitzschia Peragallo is a kind of harmful bloom microalgae. But the relative studies are still insufficient in China, and low species diversity and few toxic species have been recorded. To explore the diversity and verify the toxicity, 8 monoclonal strains were established from southeastern China waters. Morphology was observed under light and transmission electron microscopy, and the sequences of ribosomal transcribed spacer region were analyzed to build phylogenetic relationships. Combined morphology and molecular data, two Pseudo-nitzschia taxa were identified, i.e., Ps. circumpora C. H. Lim, C. P. Leaw & P. T. Lim and Ps. multiseries (Hasle) Hasle, with the former as a new record for China. Using liquid chromatography tandem mass spectrometry (LC-MS/MS), domoic acid (DA) was detected from 5 Ps. multiseries strains, with DA concentrations around 1.01-96.11 fg/cell. Meanwhile, a toxic Ps. multiseries strain (MC4177) was selected and induced by mix-culture with Artemia salina L. and Paracalanus crassirostris Dahl, respectively. The result showed that DA concentration increased greatly, about 26-55 times after induction.
The diatom genus Pseudo-nitzschia Peragallo is a kind of harmful bloom microalgae. But the relative studies are still insufficient in China, and low species diversity and few toxic species have been recorded. To explore the diversity and verify the toxicity, 8 monoclonal strains were established from southeastern China waters. Morphology was observed under light and transmission electron microscopy, and the sequences of ribosomal transcribed spacer region were analyzed to build phylogenetic relationships. Combined morphology and molecular data, two Pseudo-nitzschia taxa were identified, i.e., Ps. circumpora C. H. Lim, C. P. Leaw & P. T. Lim and Ps. multiseries (Hasle) Hasle, with the former as a new record for China. Using liquid chromatography tandem mass spectrometry (LC-MS/MS), domoic acid (DA) was detected from 5 Ps. multiseries strains, with DA concentrations around 1.01-96.11 fg/cell. Meanwhile, a toxic Ps. multiseries strain (MC4177) was selected and induced by mix-culture with Artemia salina L. and Paracalanus crassirostris Dahl, respectively. The result showed that DA concentration increased greatly, about 26-55 times after induction.
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