[Objective] The paper was to investigate the spatio-temporal distribution of fishery resources in the northern South China Sea and to provide reference for scientific evaluation and effective protection of fishery res...[Objective] The paper was to investigate the spatio-temporal distribution of fishery resources in the northern South China Sea and to provide reference for scientific evaluation and effective protection of fishery resources in the northern South China Sea. [Methods] Based on monitoring data and satellite remote sensing data [including Sea Surface Temperature(SST), Chlorophyll a concentration(Chl a) and Sea Surface Wind(SSW)] in winter(January to February) and summer(August to September) in the northern South China Sea, the relationship between spatio-temporal distribution of fishery resources and marine environment was investigated by using Generalized Linear Models(GLM), fishing ground gravity and correlation analysis. [Results] The suitable SST and Chl a of light falling-net fishing ground in winter were 17-23°C and 0.2-0.6 mg/m3, respectively. The suitable SST and Chl a in summer were approximately 28°C and 0.2-1.0 mg/m3. Standardized Catch Per Unit Effort(SCPUE) was higher in summer(2-4) and lower in winter(1-3). From winter to summer, the fishing ground gravity migrated to the east about 1 °E. [Conclusion] The spatio-temporal distribution of fishery resources is related to eastern Hainan-western Guangdong upwelling and the coastal flow, caused by the monsoon in the northern South China Sea, and the major catch species of light falling-net.展开更多
This study aims to assess ecological effects of the construction of marine ranching in the eastern Guangdong waters. Variations in sea surface temperature (SST), chlorophyll a concentration (Chl-a), catch per unit eff...This study aims to assess ecological effects of the construction of marine ranching in the eastern Guangdong waters. Variations in sea surface temperature (SST), chlorophyll a concentration (Chl-a), catch per unit effort (CPUE), biodiversity, biomass and density of benthos were compared during the pre- (August in 2011) and post- (August in 2013) marine ranching. These were based on satellite remote sensing and survey data. Results showed that the ratio of Nitrogen (N): Phosphorus (P) was closed to 16, Chl-a increased from 7.5 - 12.3 mg·m-3 to 10.4 - 16.2 mg·m-3, and CPUE increased from 2.1 - 5.5 kg·h-1 to 5.8 - 14.5 kg·h-1. The species number of fish, crustaceans, cephalopods and shellfish increased by 25, 3, 2 and 3 respectively. Shannon-Wiener biodiversity index of fish, crustaceans, cephalopods and shellfish increased by 0.5, 0.4, 0.1 and 1.0 respectively. Both biomass and density of benthos increased also. The construction of marine ranching in the eastern Guangdong had restored the habitat to some extent, and played positive effects in the conservation and proliferation of fishery resources in local area.展开更多
The complete mitogenome of Parachiloglanis hodgarti was sequenced and characterized,which is the first mitogenome of the genus Parachiloglanis within Sisoridae.The mitogenome is 16511-bp long and included 13 protein-c...The complete mitogenome of Parachiloglanis hodgarti was sequenced and characterized,which is the first mitogenome of the genus Parachiloglanis within Sisoridae.The mitogenome is 16511-bp long and included 13 protein-coding genes,22 transfer RNAs,two ribosomal RNAs,and one control region.The genome composition was A+T biased(58.64%)and exhibited a positive AT-skew(0.095)and a negative GC-skew(-0.283).Compared with other Sisoridae fishes,the characteristics of nucleotide skews,codon usage,and amino acid usage of the P.hodgarti mitogenome are more similar to those of non-Glyptosternoid fishes.Furthermore,the phylogenetic trees show that Sisoridae fishes fall into four major clades and P.hodgarti(CladeⅠ)is basal to the Sisoridae family,forming a sister clade to the Glyptosternoids(CladeⅣ).The topological structures constructed in this study raised doubts over the traditional classification system.These results will help better understand the feature s of the P.hodgarti mitogenome and provide a reference for further phylogenetic research on Sisoridae species.展开更多
A prevailing,controversial hypothesis is that fishing pressure has played a greater role than climatic and environmental drivers,in changing fish species succession and biomass fluctuation in the South China Sea(SCS)....A prevailing,controversial hypothesis is that fishing pressure has played a greater role than climatic and environmental drivers,in changing fish species succession and biomass fluctuation in the South China Sea(SCS).Based on otter trawl survey data from 1959 to 2010 in the outer Beibu Gulf(OBG),northern SCS,large seasonal and interannual variation is reported for fish species composition,the proportional abundances of dominant taxa,and fish biomass.Generalized additive models are developed to quantify relationships between fish biomass and the external factors of fishing pressure and climate change.Fishing pressure proved to be the main driver of sharp declines in demersal fish stocks,with high-value species being replaced by low-value ones over time.Abrupt decreases in fish biomass during the years of 1993 and 1998 correspond to El Nino events,with climate change possibly the main driver of proportional representation of pelagic species in fisheries trawl catch.The need to differentiate impacts of fishing and environmental drivers on fish species with different life history strategies is stressed to better understand fish community dynamics.展开更多
Based on the biological data of purpleback flying squid(Sthenoteuthis oualaniensis)collected by light falling-net in the southern South China Sea(SCS) during September to October 2012 and March to April 2013,growth an...Based on the biological data of purpleback flying squid(Sthenoteuthis oualaniensis)collected by light falling-net in the southern South China Sea(SCS) during September to October 2012 and March to April 2013,growth and mortality of 'Medium' and 'Dwarf' forms of squid are derived using the Powell-Wetherall,ELEFAN methods and length-converted catch curves(FiSAT package).Given a lack of commercial exploitation,we assume total mortality to be due entirely to natural mortality.We estimate these squid have fast growth,with growth coefficients(k) ranging from 1.42 to 2.39,and high natural mortality(M),with estimates ranging from 1.61 to 2.92.To sustainably exploit these squid stocks,yield per recruitment based on growth and natural mortality was determined using the Beverton-Holt dynamic pool model.We demonstrate squid stocks could sustain high fishing mortality and low ages at first capture,with an optimal fishing mortality >3.0,with the optimal age at first capture increased to 0.4-0.6 years when fishing mortality approached optimal levels.On the basis of our analyses and estimates of stock biomass,we believe considerable potential exists to expand the squid fishery into the open SCS,relieving fishing pressure on coastal waters.展开更多
Effective culture and management of adult tri-spine horseshoe crab,Tachypleus tridentatus can ensure that stock enhancement programs and aquaculture systems are maintained.To explore suitable feed for animals during t...Effective culture and management of adult tri-spine horseshoe crab,Tachypleus tridentatus can ensure that stock enhancement programs and aquaculture systems are maintained.To explore suitable feed for animals during the breeding season,Pacific oyster(Ostrea gigas)(oyster group;OG)and frozen sharpbelly fish(Hemiculter leucisculus)(frozen fish group;FG)were selected to feed 20 T.tridentatus male and female pairs,respectively.At the end of the experiment,intestinal samples were obtained to measure digestive enzymes activities.The intestinal flora were determined by 16S r DNA sequencing.No eggs were observed in the FG and one T.tridentatus adult died.No animals died in the OG,and 9.7×10;eggs were obtained.These results show that oysters are more suitable for the development and reproduction of adult T.tridentatus than frozen fish.Additionally,the digestive enzyme activity analysis revealed that animals in the OG exhibited higher protein digestibility than those in the FG,but no significant differences in lipid and carbohydrate uptake were observed between the groups.Furthermore,the intestinal flora analysis showed that operational taxonomic units(OTUs)and the Chao1 index were significantly higher in the OG than in the FG,but no significant difference was observed in the Shannon or Simpson indices between the groups.Our data indicate that the oyster diet improved the intestinal microbial diversity of T.tridentatus.We hypothesize that nutrients,such as oyster-based taurine,proteins,and highly unsaturated fatty acids,improve protease activity in the T.tridentatus digestive tract,alter the intestinal floral structure,and improve the reproductive performance of T.tridentatus.展开更多
Ciliates are very important components in most marine ecosystem. They are trophic link between the microbial food web and grazing food chain. In this study, ciliates were collected from 11 sites in the southern South ...Ciliates are very important components in most marine ecosystem. They are trophic link between the microbial food web and grazing food chain. In this study, ciliates were collected from 11 sites in the southern South China Sea (SCS) during August 25 to September 28, 2011. Their composition and distribution at the surface and 75m deep depth of the ocean were studied. A total of 30 species belonging to 22 genera were identified, and 22 species of 15 genera were Tintinnids. Eutintinnusfraknoii and E. stramentus were the most common species. The other dominants were strombidiids ciliates including Strombidium conicum and S. globosaneum, which were followed by the tide form, Mesodinium pulex. Ciliates abundance ranged from 46 indL-1 to 368 indL-1 in the open sites, 46-368indL-1 at surface and 73-198indL-1 at 75m deep layer. In the Yongshu reef, ciliates abundance ranged from 167indL-1 to 365 ind L-1 in the water colunm, similar to that in Sanya coral reef waters. Ciliates composition showed obvious difference between surface and 75m deep layer at station S2 (P〈0.05), while no similar result was observed at other sites. At 75m deep layer, salinity was negatively related to mixed layer depth (P〈 0.05), but positively to chlorophyll a concentration (P〈 0.05), indicating that the change of vertical mixing in water column influenced vertical distribution of ciliates in the southern SCS.展开更多
Konosirus punctatus is an economically important marine fishery resource and is widely distributed from the Indian to Pacific oceans.It is a good non-model species for genetic studies on salinity and temperature adapt...Konosirus punctatus is an economically important marine fishery resource and is widely distributed from the Indian to Pacific oceans.It is a good non-model species for genetic studies on salinity and temperature adaptation.However,a high-quality reference genome has not yet been reported.展开更多
The stock enhancement programs for black sea bream Acanthopagrus schlegelii have been conducted in China for a fewyears.However,little information has been reported concerning the effectiveness and genetic effect of b...The stock enhancement programs for black sea bream Acanthopagrus schlegelii have been conducted in China for a fewyears.However,little information has been reported concerning the effectiveness and genetic effect of black sea bream stock enhancement.In order to detect the contribution of released individuals in Zhujiang River Estuary(ZRE)and Daya Bay(DB),six microsatellite markers were used to identify the hatchery-released individuals.In addition,this pedigree of hatchery populations(broodfish and hatchery-released offspring)was traced to detect the number of effective parents(N_(e)),the inbreeding coefficient and the decrease of genetic variability in the reproduction.The pedigree reconstruction showed that at least 69(out of 93)broodfish had offspring.The estimated N_(e) was 54.8,consequently the inbreeding coefficient was 0.91%.The genetic diversity of hatchery-released offspring was lower than that in that of broodfish(heterozygosity alleles,0.727-0.774),some alleles(number of alleles,61-69)and genetic variance were lost during reproduction.It was observed that wild samples had higher levels of genetic diversity compared with hatchery populations as well as recaptured samples in releasing area.A total of 128 hatchery-released black sea bream were identified among 487 recaptured samples in ZRE,while a total of 15 samples were identified among 96 samples in DB.In summary,there was a high survival of released fish.N_(e)vertheless,the results provided evidence to consider a loss of genetic variation in hatcheryreleased stock and a negative genetic effect of the stock enhancement.展开更多
[Objective] The paper was to quantitatively evaluate the maintenance effect of summer fishing moratorium (SFM) in Daya Bay. [Method]Based on satellite remote sensing and trawl surveys, the changes in sea surface tem...[Objective] The paper was to quantitatively evaluate the maintenance effect of summer fishing moratorium (SFM) in Daya Bay. [Method]Based on satellite remote sensing and trawl surveys, the changes in sea surface temperature (SST) , chlorophyll a (Chla) concentration, catchper unit effort (CPUE), biodiversity, species composition, body length and weight of total catch in Daya Bay before SFM (May 2015) and after SFM(August 2015) were comparatively analyzed. [Result] The CPUE of total catch mainly distributed from 0-10 kg/h before SFM to 0-40 kg/h afterSFM. The average body length and weight of catches increased, indicating that the growth rate of catches was accelerated. The indices of ShannonWiener diversity index (H忆) and Pielou evenness index(J忆) increased by 0.36 and 0.14, respectively, indicating that the community structure wasimproved. The biomass spectra of fishery resources community suggested that the slopes of normalized biomass spectra after SFM was greater than-1, and the biomass of fishery resources increased with the increase of individual body weight after SFM. SFM reduced offshore fishing intensity,recovered and conserved the fishery resources in Daya Bay. [Conclusion] In order to improve the SFM system and promote the sustainable development of coastal fishery resources, it is suggested to prolong the time of SFM appropriately, reduce the number of coastal fishing boats, and strengthen the conservation of fish resources.展开更多
Daya Bay is a semi-enclosed bay in the South China Sea which is a coastal ecosystem with significant ecological and economic value that is subjected to a variety of anthropogenic disturbances.However,long-term variati...Daya Bay is a semi-enclosed bay in the South China Sea which is a coastal ecosystem with significant ecological and economic value that is subjected to a variety of anthropogenic disturbances.However,long-term variation in fish community structure in this Bay remains uncertain.In this study,we aimed to explore the changing characteristics of fish species composition and community structure in Daya Bay during the past 30 years using data from 1989 to 2021 from bottom trawl surveys and historical literature data.As of now,a total of 544 species of fish have been identified in the Bay,belonging to 24 orders and 125 families.The structure of the fish community in the bay has changed over time.Firstly,there has been a clear decrease in the number of species and biomass of large fish.Secondly,the number of fish constituent orders and families has decreased.Moreover,both the average taxonomic distinctness and variation in taxonomic distinctness decreased from 1989 to 2021.Thirdly,there is low similarity among fishes at different time phases and distinct changes in the composition of dominant species.Present results indicate that the fish community structure in Daya Bay has tended to reflect a decline in diversity,shifts in composition,and shrinking of fish body size in the past 30 years.This study improves our understanding of fish species composition and its drivers over time in Daya Bay,providing important knowledge to support the protection and restoration of this ecosystem and the important ecosystem services it provides.展开更多
A list of coral reef fish species of Huaguang Reef was compiled in 2023 using hand fishing,diving fishing,underwater video,and eDNA detection,combined with historical data from 1979 and archival records from the South...A list of coral reef fish species of Huaguang Reef was compiled in 2023 using hand fishing,diving fishing,underwater video,and eDNA detection,combined with historical data from 1979 and archival records from the South China Sea Fisheries Research Institute of the Chinese Academy of Fisheries Sciences for the years of 1998,1999,2003,and 2005.Successional characteristics of coral reef fishes through time were also explored.The findings revealed:(1)A total of 299 coral reef fish species were identified in Huaguang Reef,categorized into 2 classes,16 orders,and 56 families,with Perciformes exhibiting the highest species count(234),constituting 78.26%of all species.(2)In comparison to the period of 1979–2005,there was a reduction in the number of species at the order and family levels in 2023 at Huaguang Reef.Both the average taxonomic distinctness(Δt)and the variation in taxonomic distinctness(Λt)exhibited a declining trend,indicating disturbances in the fish ecosystem.(3)The proportion of herbivorous fish at Huaguang Reef remained relatively stable in 2023 compared to the 1979–2005 period.Notably,the similarity coefficient of herbivorous fish was the highest among different feeding types,signifying a degraded state of the Huaguang Reef habitat.(4)In contrast to the 1979–2005 period,a significant decline was observed in large-sized and carnivorous fish species at Huaguang Reef in 2023.The low similarity coefficients for both categories,with undiscovered fish species accounting for 58.49%and 45.76%of their respective taxa in the total list,respectively,suggested a notable impact of overfishing on coral reef fishes.The succession patterns revealed in this study provide a theoretical foundation for advancing the sustainable development of coral reef fish resources in the Xisha Islands and offer valuable insights for the protection and management of coral reef fishes.展开更多
Nearly 20%–50% of the annual terrestrial dissolved organic carbon(DOC)from the Huanghe(Yellow)River was transported to the estuary during the 5-14d of water and sediment regulation.The concentration of DOC increased ...Nearly 20%–50% of the annual terrestrial dissolved organic carbon(DOC)from the Huanghe(Yellow)River was transported to the estuary during the 5-14d of water and sediment regulation.The concentration of DOC increased sharply during the period of water and sediment regulation,which may promote the terrestrial DOC consumption by heterotrophic bacterioplankton.Water and sediment regulation provides an ideal condition for the study of terrestrial DOC consumption by heterotrophic bacterioplankton when terrestrial DOC increases sharply in rainy season,which may help to seek the fates of terrestrial DOC in the estuaries and coasts.In this study,the concentration and stable isotope of DOC,the biomass,growth,and respiration of heterotrophic bacterioplankton were determined.By the study,we found both average percent contribution of terrestrial DOC to the DOC pool and Contribution of terrestrial DOC to the carbon composition of heterotrophic bacterioplankton decreased as distance from the river mouth increased off shore,which was deceased from(39.2±4.0)%,(37.5±4.3)%to(30.3±3.9)%,(28.2±3.9)%respectively.255-484μg C/(L·d)terrestrial DOC was consumed by heterotrophic bacterioplankton.And 29%-45%terrestrial DOC consumed by heterotrophic bacterioplankton releasing as CO2 by respiration.Comparing with tropical estuary,terrestrial DOC consumed by heterotrophic bacterioplankton was lower in temperate estuary(this study).Temperature may limit the consumption of terrestrial DOC by heterotrophic bacterioplankton.展开更多
Lipid oxidation in salt-dried yellow croaker(Pseudosciaena polyactis) was evaluated during processing with commonly used analytical indices, such as the peroxide value(POV), the thiobarbituric acid reactive substances...Lipid oxidation in salt-dried yellow croaker(Pseudosciaena polyactis) was evaluated during processing with commonly used analytical indices, such as the peroxide value(POV), the thiobarbituric acid reactive substances(TBARS) value, and oxidative-relative lipoxygenase(LOX) activity. Additionally, fatty acids were analyzed using gas chromatography-mass spectrometry. Both POV and TBARS increased significantly(P < 0.05) at the rinsing stage. POV reached its peak value of 3.63 meq O_2 per kg sample at the drying stage, whereas TBARS constantly increased from 0.05 to 0.20 mg MDA per kg sample. Processing of salt-dried yellow croaker had an extremely significant(P < 0.01) effect on LOX activity. Twenty-six fatty acids were identified. Combined eicosapentaenoic acid(EPA; C20:5n3) and docosahexaenoic acid(DHA; C22:6n3) content varied between(19.20 ±0.37) mg g^(-1) and(23.45 ± 1.05) mg g^(-1). The polyunsaturated fatty acid/saturated fatty acid(PUFA/SFA) ratio in yellow croaker was 0.73–1.10, and the n-6/n-3 PUFA ratio was approximately 0.13–0.20. The contents of most fatty acids varied significantly(P <0.05) during the different processing stages, and these differences were caused by lipid oxidation. C18:0, C16:1n7, C19:0, and C22:6n3 showed clear changes in principle component one of a principle components analysis. These fatty acids are potential markers for evaluating lipid oxidation in fish muscle because there was a significant correlation between these markers and TBARS and LOX activity(P < 0.05) with Pearson's coefficients > 0.931.展开更多
Pelagic cephalopods have evolved a series of fascinating traits,such as excellent visual acuity,high-speed agility,and photophores for adaptation to open pelagic oceans.However,the genetic mechanisms underpinning thes...Pelagic cephalopods have evolved a series of fascinating traits,such as excellent visual acuity,high-speed agility,and photophores for adaptation to open pelagic oceans.However,the genetic mechanisms underpinning these traits are not well understood.Thus,in this study,we obtained high-quality genomes of two purpleback flying squid species(Sthenoteuthis oualaniensis and Sthenoteuthis sp.),with sizes of 5450 Mb and 5651 Mb,respectively.Comparative genomic analyses revealed that the S-crystallin subfamily SL20-1 associated with visual acuity in the purpleback flying squid lineage was significantly expanded,and the evolution of high-speed agility for the species was accompanied by significant positive selection pressure on genes related to energy metabolism.These molecular signals might have contributed to the evolution of their adaptative predatory and anti-predatory traits.In addition,the transcriptomic analysis provided clear indications of the evolution of the photophores of purpleback flying squids,especially the recruitment of new genes and energy metabolism-related genes which may have played key functional roles in the process.展开更多
基金Supported by Central Public-interest Scientific Institution Basal Research Fund,CAFS(2018HY-ZD0104)National Key R&D Program of China(2018YFD0900901)+1 种基金Natural Science Foundation of Guangdong Province,China(2018A030313120)State Key Laboratory of Tropical Oceanography,South China Sea Institute of Oceanology,Chinese Academy of Sciences(LTO1806)
文摘[Objective] The paper was to investigate the spatio-temporal distribution of fishery resources in the northern South China Sea and to provide reference for scientific evaluation and effective protection of fishery resources in the northern South China Sea. [Methods] Based on monitoring data and satellite remote sensing data [including Sea Surface Temperature(SST), Chlorophyll a concentration(Chl a) and Sea Surface Wind(SSW)] in winter(January to February) and summer(August to September) in the northern South China Sea, the relationship between spatio-temporal distribution of fishery resources and marine environment was investigated by using Generalized Linear Models(GLM), fishing ground gravity and correlation analysis. [Results] The suitable SST and Chl a of light falling-net fishing ground in winter were 17-23°C and 0.2-0.6 mg/m3, respectively. The suitable SST and Chl a in summer were approximately 28°C and 0.2-1.0 mg/m3. Standardized Catch Per Unit Effort(SCPUE) was higher in summer(2-4) and lower in winter(1-3). From winter to summer, the fishing ground gravity migrated to the east about 1 °E. [Conclusion] The spatio-temporal distribution of fishery resources is related to eastern Hainan-western Guangdong upwelling and the coastal flow, caused by the monsoon in the northern South China Sea, and the major catch species of light falling-net.
文摘This study aims to assess ecological effects of the construction of marine ranching in the eastern Guangdong waters. Variations in sea surface temperature (SST), chlorophyll a concentration (Chl-a), catch per unit effort (CPUE), biodiversity, biomass and density of benthos were compared during the pre- (August in 2011) and post- (August in 2013) marine ranching. These were based on satellite remote sensing and survey data. Results showed that the ratio of Nitrogen (N): Phosphorus (P) was closed to 16, Chl-a increased from 7.5 - 12.3 mg·m-3 to 10.4 - 16.2 mg·m-3, and CPUE increased from 2.1 - 5.5 kg·h-1 to 5.8 - 14.5 kg·h-1. The species number of fish, crustaceans, cephalopods and shellfish increased by 25, 3, 2 and 3 respectively. Shannon-Wiener biodiversity index of fish, crustaceans, cephalopods and shellfish increased by 0.5, 0.4, 0.1 and 1.0 respectively. Both biomass and density of benthos increased also. The construction of marine ranching in the eastern Guangdong had restored the habitat to some extent, and played positive effects in the conservation and proliferation of fishery resources in local area.
基金Supported by the National Natural Science Foundation of China(Nos.41806156,31702321)the Zhejiang Provincial Natural Science Foundation of China(Nos.LY22D060001,LY20C190008)+4 种基金the Fund of Guangdong Provincial Key Laboratory of Fishery Ecology and Environment(No.FEEL-2021-8)the Open Foundation from Key Laboratory of Tropical Marine Bio-resources and Ecology,Chinese Academy of Sciences(No.LMB20201005)the Science and Technology Project of Zhoushan(No.2020C21016)the Fundamental Research Funds for Zhejiang Provincial Universities and Research Institutes(No.2021J008)the Open Foundation from Marine Sciences in the First-Class Subjects of Zhejiang(Nos.20200201,20200202)。
文摘The complete mitogenome of Parachiloglanis hodgarti was sequenced and characterized,which is the first mitogenome of the genus Parachiloglanis within Sisoridae.The mitogenome is 16511-bp long and included 13 protein-coding genes,22 transfer RNAs,two ribosomal RNAs,and one control region.The genome composition was A+T biased(58.64%)and exhibited a positive AT-skew(0.095)and a negative GC-skew(-0.283).Compared with other Sisoridae fishes,the characteristics of nucleotide skews,codon usage,and amino acid usage of the P.hodgarti mitogenome are more similar to those of non-Glyptosternoid fishes.Furthermore,the phylogenetic trees show that Sisoridae fishes fall into four major clades and P.hodgarti(CladeⅠ)is basal to the Sisoridae family,forming a sister clade to the Glyptosternoids(CladeⅣ).The topological structures constructed in this study raised doubts over the traditional classification system.These results will help better understand the feature s of the P.hodgarti mitogenome and provide a reference for further phylogenetic research on Sisoridae species.
基金The Science and Technology Basic Resources Investigation Program of China under contract No.2017FY201405the Open Research Fund Program of Guangxi Key Lab of Mangrove Conservation and Utilization under contract No.GKLMC-201403+2 种基金the National Natural Science Foundation of China under contract No.41666008the Fund of Key Laboratory of Open-Sea Fishery Development,Ministry of Agriculture of China under contract No.LOF 2018-01the Natural Science Foundation of Guangxi under contract No.2016GXNSFDA380035
文摘A prevailing,controversial hypothesis is that fishing pressure has played a greater role than climatic and environmental drivers,in changing fish species succession and biomass fluctuation in the South China Sea(SCS).Based on otter trawl survey data from 1959 to 2010 in the outer Beibu Gulf(OBG),northern SCS,large seasonal and interannual variation is reported for fish species composition,the proportional abundances of dominant taxa,and fish biomass.Generalized additive models are developed to quantify relationships between fish biomass and the external factors of fishing pressure and climate change.Fishing pressure proved to be the main driver of sharp declines in demersal fish stocks,with high-value species being replaced by low-value ones over time.Abrupt decreases in fish biomass during the years of 1993 and 1998 correspond to El Nino events,with climate change possibly the main driver of proportional representation of pelagic species in fisheries trawl catch.The need to differentiate impacts of fishing and environmental drivers on fish species with different life history strategies is stressed to better understand fish community dynamics.
基金Supported by the National Key Technology R&D Program(No.2013BAD13B06)the Guangdong Provincial Program of Science and Technology(No.2014A020217011)+1 种基金funded by the State Oceanic Administration(No.GASI-02-SCS-YSW)supported by a Special Fund for Youth Training from the South China Sea Fisheries Research Institute
文摘Based on the biological data of purpleback flying squid(Sthenoteuthis oualaniensis)collected by light falling-net in the southern South China Sea(SCS) during September to October 2012 and March to April 2013,growth and mortality of 'Medium' and 'Dwarf' forms of squid are derived using the Powell-Wetherall,ELEFAN methods and length-converted catch curves(FiSAT package).Given a lack of commercial exploitation,we assume total mortality to be due entirely to natural mortality.We estimate these squid have fast growth,with growth coefficients(k) ranging from 1.42 to 2.39,and high natural mortality(M),with estimates ranging from 1.61 to 2.92.To sustainably exploit these squid stocks,yield per recruitment based on growth and natural mortality was determined using the Beverton-Holt dynamic pool model.We demonstrate squid stocks could sustain high fishing mortality and low ages at first capture,with an optimal fishing mortality >3.0,with the optimal age at first capture increased to 0.4-0.6 years when fishing mortality approached optimal levels.On the basis of our analyses and estimates of stock biomass,we believe considerable potential exists to expand the squid fishery into the open SCS,relieving fishing pressure on coastal waters.
基金the fund of the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(No.GML2019ZD0605)the Guangdong Provincial Key Laboratory of Fishery Ecology and Environment(No.FEEL-2020-2)+2 种基金the Science and Technology Planning Project of Guangdong Province(No.2019B121201001)the Special Fund for Basic Scientific Research of Central Public Research Institutes of South China Sea Fisheries Research Institute,the Chinese Academy of Fishery(No.2019TS21)the National Natural Science Foundation of China(No.42067038)。
文摘Effective culture and management of adult tri-spine horseshoe crab,Tachypleus tridentatus can ensure that stock enhancement programs and aquaculture systems are maintained.To explore suitable feed for animals during the breeding season,Pacific oyster(Ostrea gigas)(oyster group;OG)and frozen sharpbelly fish(Hemiculter leucisculus)(frozen fish group;FG)were selected to feed 20 T.tridentatus male and female pairs,respectively.At the end of the experiment,intestinal samples were obtained to measure digestive enzymes activities.The intestinal flora were determined by 16S r DNA sequencing.No eggs were observed in the FG and one T.tridentatus adult died.No animals died in the OG,and 9.7×10;eggs were obtained.These results show that oysters are more suitable for the development and reproduction of adult T.tridentatus than frozen fish.Additionally,the digestive enzyme activity analysis revealed that animals in the OG exhibited higher protein digestibility than those in the FG,but no significant differences in lipid and carbohydrate uptake were observed between the groups.Furthermore,the intestinal flora analysis showed that operational taxonomic units(OTUs)and the Chao1 index were significantly higher in the OG than in the FG,but no significant difference was observed in the Shannon or Simpson indices between the groups.Our data indicate that the oyster diet improved the intestinal microbial diversity of T.tridentatus.We hypothesize that nutrients,such as oyster-based taurine,proteins,and highly unsaturated fatty acids,improve protease activity in the T.tridentatus digestive tract,alter the intestinal floral structure,and improve the reproductive performance of T.tridentatus.
基金supported by the National Basic Research Program of China (2014CB441500)Special Fund for Agro-scientific Research in the Public Interest (201403008)Major Project of Ministry of Agriculture (NFZX2013)
文摘Ciliates are very important components in most marine ecosystem. They are trophic link between the microbial food web and grazing food chain. In this study, ciliates were collected from 11 sites in the southern South China Sea (SCS) during August 25 to September 28, 2011. Their composition and distribution at the surface and 75m deep depth of the ocean were studied. A total of 30 species belonging to 22 genera were identified, and 22 species of 15 genera were Tintinnids. Eutintinnusfraknoii and E. stramentus were the most common species. The other dominants were strombidiids ciliates including Strombidium conicum and S. globosaneum, which were followed by the tide form, Mesodinium pulex. Ciliates abundance ranged from 46 indL-1 to 368 indL-1 in the open sites, 46-368indL-1 at surface and 73-198indL-1 at 75m deep layer. In the Yongshu reef, ciliates abundance ranged from 167indL-1 to 365 ind L-1 in the water colunm, similar to that in Sanya coral reef waters. Ciliates composition showed obvious difference between surface and 75m deep layer at station S2 (P〈0.05), while no similar result was observed at other sites. At 75m deep layer, salinity was negatively related to mixed layer depth (P〈 0.05), but positively to chlorophyll a concentration (P〈 0.05), indicating that the change of vertical mixing in water column influenced vertical distribution of ciliates in the southern SCS.
基金supported by the National Natural Science Foundation of China(41806156)Zhejiang Provincial Natural Science Foundation of China(LY20C190008,LY22D060001,Y22D064798)+3 种基金Science and Technology Project of Zhoushan(2020C21016)Fund of Guangdong Provincial Key Laboratory of Fishery Ecology and Environment(FEEL-2021-8)Open Foundation from Key Laboratory of Tropical Marine Bio-Resources and Ecology,Chinese Academy of Sciences(LMB20201005)Open Foundation from Marine Sciences in the First-Class Subjects of Zhejiang(20200201,20200202)。
文摘Konosirus punctatus is an economically important marine fishery resource and is widely distributed from the Indian to Pacific oceans.It is a good non-model species for genetic studies on salinity and temperature adaptation.However,a high-quality reference genome has not yet been reported.
基金The Science and Technology Project of Guangdong Province under contract No.2019B121201001the National Key R&D Program of China under contract No.2019YFD0901301+3 种基金the Fund of China-Vietnam Joint Survey on Fish Stocks in the Common Fishing Zone of the Beibu Gulfthe Central Public-interest Scientific Institution Basal Research Fund,South China Sea Fisheries Research Institute,Chinese Academy of Fishery Science under contract No.2021SD14the China-ASEAN Maritime Cooperation Fund(China-Vietnam Fishery Stock Enhancement and Conservation in Beibu Gulf)the Hainan Provincial Natural Science Foundation of China under contract No.320QN358.
文摘The stock enhancement programs for black sea bream Acanthopagrus schlegelii have been conducted in China for a fewyears.However,little information has been reported concerning the effectiveness and genetic effect of black sea bream stock enhancement.In order to detect the contribution of released individuals in Zhujiang River Estuary(ZRE)and Daya Bay(DB),six microsatellite markers were used to identify the hatchery-released individuals.In addition,this pedigree of hatchery populations(broodfish and hatchery-released offspring)was traced to detect the number of effective parents(N_(e)),the inbreeding coefficient and the decrease of genetic variability in the reproduction.The pedigree reconstruction showed that at least 69(out of 93)broodfish had offspring.The estimated N_(e) was 54.8,consequently the inbreeding coefficient was 0.91%.The genetic diversity of hatchery-released offspring was lower than that in that of broodfish(heterozygosity alleles,0.727-0.774),some alleles(number of alleles,61-69)and genetic variance were lost during reproduction.It was observed that wild samples had higher levels of genetic diversity compared with hatchery populations as well as recaptured samples in releasing area.A total of 128 hatchery-released black sea bream were identified among 487 recaptured samples in ZRE,while a total of 15 samples were identified among 96 samples in DB.In summary,there was a high survival of released fish.N_(e)vertheless,the results provided evidence to consider a loss of genetic variation in hatcheryreleased stock and a negative genetic effect of the stock enhancement.
基金Supported by Natural Science Foundation of Guangdong Province(2018A030313120)Basal Research Fund of Central Public-interest Scientific Institutions in Chinese Academy of Aquatic Sciences(2018HY-ZD0104)+1 种基金State Key Laboratory of Tropical Oceanography,South China Sea Institute of Oceanology,Chinese Academy of Sciences(LTO1806)National Key Technology R&D Program(2012BAD18B01)
文摘[Objective] The paper was to quantitatively evaluate the maintenance effect of summer fishing moratorium (SFM) in Daya Bay. [Method]Based on satellite remote sensing and trawl surveys, the changes in sea surface temperature (SST) , chlorophyll a (Chla) concentration, catchper unit effort (CPUE), biodiversity, species composition, body length and weight of total catch in Daya Bay before SFM (May 2015) and after SFM(August 2015) were comparatively analyzed. [Result] The CPUE of total catch mainly distributed from 0-10 kg/h before SFM to 0-40 kg/h afterSFM. The average body length and weight of catches increased, indicating that the growth rate of catches was accelerated. The indices of ShannonWiener diversity index (H忆) and Pielou evenness index(J忆) increased by 0.36 and 0.14, respectively, indicating that the community structure wasimproved. The biomass spectra of fishery resources community suggested that the slopes of normalized biomass spectra after SFM was greater than-1, and the biomass of fishery resources increased with the increase of individual body weight after SFM. SFM reduced offshore fishing intensity,recovered and conserved the fishery resources in Daya Bay. [Conclusion] In order to improve the SFM system and promote the sustainable development of coastal fishery resources, it is suggested to prolong the time of SFM appropriately, reduce the number of coastal fishing boats, and strengthen the conservation of fish resources.
基金funded by Fundamental and Applied Fundamental Research Major Program of Guangdong Province(2019B030302004-05)Science and Technology Planning Project of Guangdong Province(2019B121201001)+2 种基金Central Public-interest Scientific Institution Basal Research Fund,CAFS(2023TD16)Central Public-interest Scientific Institution Basal Research Fund,South China Sea Fisheries Research Institute,CAFS(2021SD04 and 2019TS28)Financial Fund of the Ministry of Agriculture and Rural Affairs,P.R.of China(NFZX2021).
文摘Daya Bay is a semi-enclosed bay in the South China Sea which is a coastal ecosystem with significant ecological and economic value that is subjected to a variety of anthropogenic disturbances.However,long-term variation in fish community structure in this Bay remains uncertain.In this study,we aimed to explore the changing characteristics of fish species composition and community structure in Daya Bay during the past 30 years using data from 1989 to 2021 from bottom trawl surveys and historical literature data.As of now,a total of 544 species of fish have been identified in the Bay,belonging to 24 orders and 125 families.The structure of the fish community in the bay has changed over time.Firstly,there has been a clear decrease in the number of species and biomass of large fish.Secondly,the number of fish constituent orders and families has decreased.Moreover,both the average taxonomic distinctness and variation in taxonomic distinctness decreased from 1989 to 2021.Thirdly,there is low similarity among fishes at different time phases and distinct changes in the composition of dominant species.Present results indicate that the fish community structure in Daya Bay has tended to reflect a decline in diversity,shifts in composition,and shrinking of fish body size in the past 30 years.This study improves our understanding of fish species composition and its drivers over time in Daya Bay,providing important knowledge to support the protection and restoration of this ecosystem and the important ecosystem services it provides.
基金supported by Natural Science Foundation of Hainan Province(323MS124,322CXTD530)Financial Fund of the Ministry of Agriculture and Rural Affairs,P.R.of China(NHZX2024)+3 种基金The Nan-Fan Aquaculture Joint Open Fund Project,Hainan Tropical Ocean University(2023SCNFKF06)Fundamental and Applied Fundamental Research Major Program of Guangdong Province(2019B030302004-05)Central Public-interest Scientific Institution Basal Research Fund,CAFS(2023TD16)Central Public-interest Scientific Institution Basal Research Fund,South China Sea Fisheries Research Institute,CAFS(2021SD04 and 2019TS28).
文摘A list of coral reef fish species of Huaguang Reef was compiled in 2023 using hand fishing,diving fishing,underwater video,and eDNA detection,combined with historical data from 1979 and archival records from the South China Sea Fisheries Research Institute of the Chinese Academy of Fisheries Sciences for the years of 1998,1999,2003,and 2005.Successional characteristics of coral reef fishes through time were also explored.The findings revealed:(1)A total of 299 coral reef fish species were identified in Huaguang Reef,categorized into 2 classes,16 orders,and 56 families,with Perciformes exhibiting the highest species count(234),constituting 78.26%of all species.(2)In comparison to the period of 1979–2005,there was a reduction in the number of species at the order and family levels in 2023 at Huaguang Reef.Both the average taxonomic distinctness(Δt)and the variation in taxonomic distinctness(Λt)exhibited a declining trend,indicating disturbances in the fish ecosystem.(3)The proportion of herbivorous fish at Huaguang Reef remained relatively stable in 2023 compared to the 1979–2005 period.Notably,the similarity coefficient of herbivorous fish was the highest among different feeding types,signifying a degraded state of the Huaguang Reef habitat.(4)In contrast to the 1979–2005 period,a significant decline was observed in large-sized and carnivorous fish species at Huaguang Reef in 2023.The low similarity coefficients for both categories,with undiscovered fish species accounting for 58.49%and 45.76%of their respective taxa in the total list,respectively,suggested a notable impact of overfishing on coral reef fishes.The succession patterns revealed in this study provide a theoretical foundation for advancing the sustainable development of coral reef fish resources in the Xisha Islands and offer valuable insights for the protection and management of coral reef fishes.
基金Supported by the Guangdong Provincial Key Laboratory of Fishery Ecology and Environment(No.LFE-2015-7)the China Agriculture Research System(No.CARS-47-Z14)the Scientific and Technological Innovation Project of Shandong Marine and Fishery(No.2017HY10)
文摘Nearly 20%–50% of the annual terrestrial dissolved organic carbon(DOC)from the Huanghe(Yellow)River was transported to the estuary during the 5-14d of water and sediment regulation.The concentration of DOC increased sharply during the period of water and sediment regulation,which may promote the terrestrial DOC consumption by heterotrophic bacterioplankton.Water and sediment regulation provides an ideal condition for the study of terrestrial DOC consumption by heterotrophic bacterioplankton when terrestrial DOC increases sharply in rainy season,which may help to seek the fates of terrestrial DOC in the estuaries and coasts.In this study,the concentration and stable isotope of DOC,the biomass,growth,and respiration of heterotrophic bacterioplankton were determined.By the study,we found both average percent contribution of terrestrial DOC to the DOC pool and Contribution of terrestrial DOC to the carbon composition of heterotrophic bacterioplankton decreased as distance from the river mouth increased off shore,which was deceased from(39.2±4.0)%,(37.5±4.3)%to(30.3±3.9)%,(28.2±3.9)%respectively.255-484μg C/(L·d)terrestrial DOC was consumed by heterotrophic bacterioplankton.And 29%-45%terrestrial DOC consumed by heterotrophic bacterioplankton releasing as CO2 by respiration.Comparing with tropical estuary,terrestrial DOC consumed by heterotrophic bacterioplankton was lower in temperate estuary(this study).Temperature may limit the consumption of terrestrial DOC by heterotrophic bacterioplankton.
基金the National Natural Science Foundation of China (Nos. 31371800 and 31571869)Earmarked Fund for Modern Agro-Industry Technology Research System (No. CARS-49-G27)Special Promotion of Guangdong Marine Fishery Science and Technology (Nos. A201301C01 and A201503)
文摘Lipid oxidation in salt-dried yellow croaker(Pseudosciaena polyactis) was evaluated during processing with commonly used analytical indices, such as the peroxide value(POV), the thiobarbituric acid reactive substances(TBARS) value, and oxidative-relative lipoxygenase(LOX) activity. Additionally, fatty acids were analyzed using gas chromatography-mass spectrometry. Both POV and TBARS increased significantly(P < 0.05) at the rinsing stage. POV reached its peak value of 3.63 meq O_2 per kg sample at the drying stage, whereas TBARS constantly increased from 0.05 to 0.20 mg MDA per kg sample. Processing of salt-dried yellow croaker had an extremely significant(P < 0.01) effect on LOX activity. Twenty-six fatty acids were identified. Combined eicosapentaenoic acid(EPA; C20:5n3) and docosahexaenoic acid(DHA; C22:6n3) content varied between(19.20 ±0.37) mg g^(-1) and(23.45 ± 1.05) mg g^(-1). The polyunsaturated fatty acid/saturated fatty acid(PUFA/SFA) ratio in yellow croaker was 0.73–1.10, and the n-6/n-3 PUFA ratio was approximately 0.13–0.20. The contents of most fatty acids varied significantly(P <0.05) during the different processing stages, and these differences were caused by lipid oxidation. C18:0, C16:1n7, C19:0, and C22:6n3 showed clear changes in principle component one of a principle components analysis. These fatty acids are potential markers for evaluating lipid oxidation in fish muscle because there was a significant correlation between these markers and TBARS and LOX activity(P < 0.05) with Pearson's coefficients > 0.931.
基金supported by grants from the Guangdong Major Project of Basic and Applied Basic Research, China (Grant No. 2019B030302004)the National Key R&D Program of China (Grant No. 2018YFC1406502)+6 种基金the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou),China(Grant No. GML2019ZD0605)the Financial Fund of the Ministry of Agriculture and Rural Affairs of China (Grant No. NFZX2018)the Central Public-interest Scientific Basal Research Fund, Chinese Academy of Fishery Sciences (Grant Nos. 2019HY-XKQ03, 2020TD05, and 2021SD18)the China Postdoctoral Science Foundation (Grant No. 2021M693342)the Hubei Postdoctoral Innovation Post Project, Chinathe 1000 Talent Project of Shaanxi Province, Chinathe Research Funds for Interdisciplinary subject of Northwestern Polytechnical University, China (Grant No. 19SH030408)
文摘Pelagic cephalopods have evolved a series of fascinating traits,such as excellent visual acuity,high-speed agility,and photophores for adaptation to open pelagic oceans.However,the genetic mechanisms underpinning these traits are not well understood.Thus,in this study,we obtained high-quality genomes of two purpleback flying squid species(Sthenoteuthis oualaniensis and Sthenoteuthis sp.),with sizes of 5450 Mb and 5651 Mb,respectively.Comparative genomic analyses revealed that the S-crystallin subfamily SL20-1 associated with visual acuity in the purpleback flying squid lineage was significantly expanded,and the evolution of high-speed agility for the species was accompanied by significant positive selection pressure on genes related to energy metabolism.These molecular signals might have contributed to the evolution of their adaptative predatory and anti-predatory traits.In addition,the transcriptomic analysis provided clear indications of the evolution of the photophores of purpleback flying squids,especially the recruitment of new genes and energy metabolism-related genes which may have played key functional roles in the process.