Aggregation of species with similar ecological properties is one of the effective methods to simplify food web researches.However,species aggregation will affect not only the complexity of modeling process but also th...Aggregation of species with similar ecological properties is one of the effective methods to simplify food web researches.However,species aggregation will affect not only the complexity of modeling process but also the accuracy of models’outputs.Selection of aggregation methods and the number of trophospecies are the keys to study the simplification of food web.In this study,three aggregation methods,including taxonomic aggregation(TA),structural equivalence aggregation(SEA),and self-organizing maps(SOM),were analyzed and compared with the linear inverse model–Markov Chain Monte Carlo(LIM-MCMC)model.Impacts of aggregation methods and trophospecies number on food webs were evaluated based on the robustness and unitless of ecological net-work indices.Results showed that aggregation method of SEA performed better than the other two methods in estimating food web structure and function indices.The effects of aggregation methods were driven by the differences in species aggregation principles,which will alter food web structure and function through the redistribution of energy flow.According to the results of mean absolute percentage error(MAPE)which can be applied to evaluate the accuracy of the model,we found that MAPE in food web indices will increase with the reducing trophospecies number,and MAPE in food web function indices were smaller and more stable than those in food web structure indices.Therefore,trade-off between simplifying food webs and reflecting the status of ecosystem should be con-sidered in food web studies.These findings highlight the importance of aggregation methods and trophospecies number in the analy-sis of food web simplification.This study provided a framework to explore the extent to which food web models are affected by dif-ferent species aggregation,and will provide scientific basis for the construction of food webs.展开更多
The chlorophyll a(Chl a)is an important indicator of marine ecosystems.The spatiotemporal variation of the Chl a greatly aff ects the mariculture and marine ranching in coastal waters of the Shandong Peninsula.In the ...The chlorophyll a(Chl a)is an important indicator of marine ecosystems.The spatiotemporal variation of the Chl a greatly aff ects the mariculture and marine ranching in coastal waters of the Shandong Peninsula.In the current study,the climatology and seasonal variability of surface Chl-a concentration around the Shandong Peninsula are investigated based on 16 years(December 2002-November 2018)of satellite observations.The results indicate that the annual mean Chl-a concentration is greater in the Bohai Sea than in the Yellow Sea and decreases from coastal waters to off shore waters.The highest Chl-a concentrations are found in Laizhou Bay(4.2-8.0 mg/m^(3)),Haizhou Bay(4.2-5.9 mg/m^(3))and the northeast coast of the Shandong Peninsula(4.4-5.0 mg/m^(3)),resulting from the combined eff ects of the intense riverine input and long residence time caused by the concave shape of the coastline.The seasonal Chl-a concentration shows a significant spatial variation.The Chl-a concentrations in these three subregions generally exhibit an annual maximum in August/September,due to the combined eff ects of sea surface temperature,river discharge and sea surface wind.In the southeast coast region,however,the Chl-a concentration is lowest throughout the year and reaches a maximum in February with a minimum in July,forced by the seasonal evolution of the Yellow Sea Cold Water and monsoon winds.The interannual Chl-a concentration trends vary among regions and seasons.There are significant increasing trends over a large area around Haizhou Bay from winter to summer,which are mainly caused by the rising sea surface temperature and eutrophication.In other coastal areas,the Chl-a concentration shows decreasing trends,which are clearest in summer and induced by the weakening land rainfall.This study highlights the differences in the Chl-a dynamics among regions around the Shandong Peninsula and is helpful for further studies of coupled physical-ecological-human interactions at multiple scales.展开更多
We used the Integrated Biological Responses version 2(IBRv2)method to evaluate the biological eff ects of heavy metals in the sediments in Laizhou Bay,China on the benthic goby Acanthogobius ommaturus.In December 2018...We used the Integrated Biological Responses version 2(IBRv2)method to evaluate the biological eff ects of heavy metals in the sediments in Laizhou Bay,China on the benthic goby Acanthogobius ommaturus.In December 2018,gobies and sediments were collected from 15 stations.We measured the activities of defense enzymes and the contents of malondialdehyde(MDA)and metallothionein(MT)in the goby liver as well as the levels of heavy metals in the sediments and goby muscle tissue.Most of the heavy metal concentrations in sediment at each station were below the Class I criteria set by Chinese Standards for Marine Sediment Quality,and the Håkanson ecological risk index suggested low risk for the heavy metals.We found that A.ommaturus could eff ectively accumulate mercury,cadmium,arsenic,and zinc and that the contents of MT and MDA and the activities of glutathione peroxidase and glutathione reductase were suitable biomarkers of heavy metal pollution in this species.The IBRv2 method integrated these four biomarkers and discriminated stations according to heavy metal pollution.Higher IBRv2 values suggested more adverse eff ects in gobies,corroborating more serious heavy metal contamination.The stations with high IBRv2 values and high contents of heavy metals were mainly distributed in the west and northeast parts of the bay.These results show that the IBRv2 approach is a feasible strategy for assessing heavy metal pollution through biological response and biological status and that it can be implemented for environmental monitoring in Laizhou Bay.展开更多
Single-species management ignores the interactions between species,and ecosystem-based fisheries management(EBFM)has become a main method to fisheries management.Understanding food web structures and species interacti...Single-species management ignores the interactions between species,and ecosystem-based fisheries management(EBFM)has become a main method to fisheries management.Understanding food web structures and species interactions is essential for the implementation of EBFM and maintenance of ecosystem functions.Overfishing is one of the main reasons behind the depletion,which could even lead to the depletion of some target species in local areas.So understanding the impacts of species depletion on food web structures is important for the implementation of EBFM.The impacts of species depletion can be transmitted through the food web and cause the local extinction of both target and non-target species.In this study,topological network analysis was applied to examine the impacts of species depletion on the food web structure of Haizhou Bay.Results showed that fine crayfish Leptochela gracilis,squid Loligo sp.,and Japanese snapping shrimp Alpheus japonicus have the highest numbers of outgoing links(48,32 and 31 respectively);thus,these species may be considered key prey species.Whitespotted conger Conger myriaster,fat greenling Hexagrammos otakii,and bluefin gurnard Chelidonichthys kumu were key predators with the highest number of incoming links(37,36 and 35 respectively).The competition graphs derived from the Haizhou Bay food web were highly connected(more than 40%predators sharing over 10 common prey species),and showed close trophic interaction between high trophic level fishes.Simulation analysis showed that the food web structure has small changes to the depletion of species in a highly complex food web.The most-connected target species did not necessarily indicate high structural importance;however,some species with low connectivity may demonstrate stronger trophic interactions and play important ecological roles in the food web.But most species were more sensitive to the depletion of the most-connected target species than other target species(for instance,for zooplankton,closeness centrality 13.876 in D6,but closeness centrality 82.143 in original food web).Therefore,EBFM should focus on the most-connected target species,but also on those species with few but strong links and feeding relationships in the food web.展开更多
The distribution of hexachlorocyclohexanes(HCHs) and dichlorodiphenyltrichloroethanes(DDTs) in the surface seawater and sediment of Jincheng Bay mariculture area were investigated in the present study. The concentrati...The distribution of hexachlorocyclohexanes(HCHs) and dichlorodiphenyltrichloroethanes(DDTs) in the surface seawater and sediment of Jincheng Bay mariculture area were investigated in the present study. The concentration of total HCHs and DDTs ranged from 2.98 to 14.87 ng L-1 and were < 0.032 ng L-1, respectively, in surface seawater, and ranged from 5.52 to 9.43 and from 4.11 to 6.72 ng g-1, respectively, in surface sediment. It was deduced from the composition profile of HCH isomers and DDT congeners that HCH residues derived from a mixture of technical-grade HCH and lindane whereas the DDT residues derived from technical-grade DDT and dicofol. Moreover, both HCH and DDT residues may mainly originate from historical inputs. The hazard quotient of α-HCH, β-HCH, γ-HCH and δ-HCH to marine species was 0.030, 0.157, 3.008 and 0.008, respectively. It was estimated that the overall probability of adverse biological effect from HCHs was less than 5%, indicating that its risk to seawater column species was low. The threshold effect concentration exceeding frequency of γ-HCH, p,p'-DDD, p,p'-DDE and p,p'-DDT in sediment ranged from 8.3% to 100%, and the relative concentration of the HCH and DDT mixture exceeded their probable effect level in sediment. These findings indicated that the risk to marine benthos was high and potentially detrimental to the safety of aquatic products, e.g., sea cucumber and benthic shellfish.展开更多
Study on morphological changes of a bay can help to identify the effects of anthropogenic activities on coastal environ-ment and guide the exploration of marine resources.In this paper,morphological data including coa...Study on morphological changes of a bay can help to identify the effects of anthropogenic activities on coastal environ-ment and guide the exploration of marine resources.In this paper,morphological data including coastline and water areas in five discrete years between 1968 and 2015 were selected and extracted from the remote sensing images and historical marine charts to study the morphological changes in Laizhou Bay(LZB),one of the bays in the southwest of the Bohai Sea.A systematic analysis on spatial variations of the coastline and the surface areas of different types of waters in LZB was conducted.The results showed that the surface area of LZB was decreased by 1253.2km^(2)in the last half century,which is 17.4%of the total in the 1970s.The areas of the natural wetland and the intertidal zone were decreased by 17.2%and 56.1%,respectively,and the average water depth varied from 9.05 m to 8.16m at low tide level from 1968 to 2015.The coastline and shape variations of the bay turned to be complex after the 1980s,and the shape index of LZB showed an increasing trend in more recent years.The centroid of the bay generally migrated to the northeast direction,i.e.,the direction of the center of the Bohai Sea,and the shrinking direction of the bay was consistent with the migration direction of the coastline.The reclamation area during 1968-2015 in LZB was 1201.7km^(2),and 94.1%was in the inter-tidal zone.The overall morphological change of the bay during the last half century was mainly controlled by the coastal reclamation activities,and the Yellow River runoff including the river course change and sediment load variation was also an important control-ling factor.展开更多
The community characteristics of macrobenthos in the Huanghe(Yellow River) Estuary is influenced by a combination of natural and anthropogenic factors. Here, we investigated short-term changes(1-month) in macrobenthic...The community characteristics of macrobenthos in the Huanghe(Yellow River) Estuary is influenced by a combination of natural and anthropogenic factors. Here, we investigated short-term changes(1-month) in macrobenthic community structure in response to water and sediment discharge regulation(WSDR) in 2011.Specifically, we sampled the macrobenthos at 18 sampling stations situated at four distances(5, 10, 20, and 40 km)from the mouth of the Huanghe Estuary before(mid-June), during(early-July), and after(mid-July) WSDR. The results showed that a total of 73, 72, and 85 species were collected before, during, and after WSDR, respectively.Then, 13, 1, and 16 dominant species were detected at this three periods. Four phyla were primarily detected at all three periods(Annelida, Mollusca, Arthropoda, and Echinodermata). However, while Mollusca and Annelida were the most important phyla in our study, Echinodermata and Annelida were the most important phyla in 1982,demonstrating major changes to community structure over a 3-decadal period. All stations were of high quality BOPA index before WSDR, whereas two and three stations were of reduced quality BOPA index during and after WSDR, respectively. The results of ABC curves showed that had incurred disturbed conditions after human activities WSDR. Most important of all, multivariate analyses and RDA analysis indicated that the structure of the macrobenthic community was closely linked to environment factors, including that organic content factor caused the distribution of macrobenthic community mostly during WSDR, while water depth after WSDR affected the macro benthos community structure seriously, and during WSDR, the environment factor influencing it was not single, including organic content, sulfide content, Hg and As. These differences may have been due to changes in water transparency negatively impacting the growth and development of macrobenthos, due to specific lifehistory requirements. Our results demonstrate that anthropogenic activity is having both long-term(3 decadal)and short term(1-month) impacts on the structure of the macrobenthic community of the Huanghe Estuary. In conclusion, human activities WSDR influence the habitat environment of macro benthos, including the water temperature, nutrients, bioturbation, and so on. Therefore, we suggest the necessity to strengthen regulations of land-derived organic pollutant input to maintain the ecological balance of the Huanghe Estuary.展开更多
Semicarbazide has become an important pollutant in the environment,but there was no comprehensive literature on its advances.In this review,the source,biotoxicity and detection methods are summarized.Among the sources...Semicarbazide has become an important pollutant in the environment,but there was no comprehensive literature on its advances.In this review,the source,biotoxicity and detection methods are summarized.Among the sources is the material of chemical reaction,a metabolite of nitrofurazone,food processing(production by azobisformamide and hypochlorite treatment),endogenous substances,etc.Semicarbazide is demonstrated to be accumulative and reproductive toxicity,mutagenicity and genotoxicity,endocrine disruptors,and neurotoxicity.There are still many controversies on the effect of genotoxicity and no clear result on the carcinogenic mechanism.HPLC-MS/MS is the mainstream of the detection methods.Other methods,including HPLC,immunoassay method,biosensor method,electrochemical detection,capillary electrophoresis technique,and spectral techniques mainly,have become less and less in recent years.On all these counts,to reduce the content of semicarbazide in the environment,the key is to control the use of nitrofurazone as the banned drug effectively.Meanwhile the toxicity data should be supplemented to reveal its toxic mechanism.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
The present trial was conducted with starry fl ounder Platichthys stellatus broodstock to evaluate the effects of dietary vitamin A,ascorbic acid,and α-tocopherol on the gonadal development and reproductive performan...The present trial was conducted with starry fl ounder Platichthys stellatus broodstock to evaluate the effects of dietary vitamin A,ascorbic acid,and α-tocopherol on the gonadal development and reproductive performance.8 000 IU/kg diet vitamin A(VA group),500 mg/kg diet ascorbic acid(Vcpp group),or 250 mg/kg diet α-tocopherol(α-TA group)was added into basal diet to create 3 vitamin experimental diets,respectively.Each diet was fed to 450 starry fl ounder broodstock for 104 days.Samples were collected weekly.The gonadosomatic index(GSI)of 3 vitamin experimental groups fi rst decreased and then increased.Maximum GSI of Vcpp group was higher than that of α-TA group but lower than that of VA group.The spawning periods of 3 vitamin experimental groups lasted 49,56,and 45 days,respectively.No mature eggs were observed in the control group during the trial.The absolute fecundity(AF)and relative fecundity(RF)of α-TA group was higher than that of Vcpp group but lower than that of VA group.The results suggest that different vitamins play different roles in the fi sh reproductive process.Vitamin A stimulated the maturation of the ovary,ascorbic acid prolonged the spawning period,and α-tocopherol affected the development of the eggs.展开更多
Ontogenetic changes in digestive enzyme activities and the amino acid(AA) profile of starry flounder,Platichthys stellatus,were investigated and limiting amino acids were estimated compared with the essential AA profi...Ontogenetic changes in digestive enzyme activities and the amino acid(AA) profile of starry flounder,Platichthys stellatus,were investigated and limiting amino acids were estimated compared with the essential AA profile between larvae and live food to clarify starry flounder larval nutritional requirements.Larvae were collected at the egg stage and 0,2,4,7,12,17,24 days after hatching(DAH)for analysis.Larvae grew from 1.91 mm at hatching to 12.13 mm at 24 DAH.Trypsin and chymotrypsin activities changed slightly by 4 DAH and then increased significantly 4 DAH.Pepsin activity increased sharply beginning 17 DAH.Lipase activity increased significantly 4 DAH and increased progressively with larval growth.Amylase activity was also detected in newly hatched larvae and increased 7 DAH followed by a gradual decrease.High free amino acid(FAA) content was detected in starry flounder eggs(110.72mg/g dry weight).Total FAA content dropped to 43.29 mg/g in 4-DAH larvae and then decreased gradually to 13.74 mg/g in 24-DAH larvae.Most FAAs(except lysine and methionine) decreased >50%in 4-DAH larvae compared with those in eggs and then decreased to the lowest values in 24-DAH larvae.Changes in the protein amino acid(PAA) profile were much milder than those observed for FAAs.Most PAAs increased gradually during larval development,except lysine and phenylalanine.The percentages of free threonine,valine,isoleucine,and leucine decreased until the end of the trial,whereas the protein forms of these four AAs followed the opposite trend.A comparison of the essential AA composition of live food(rotifers,Artemia nauplii,and Artemia metanauplii) and larvae suggested that methionine was potentially the first limiting AA.These results may help develop starry flounder larviculture methods by solving the AA imbalance in live food.Moreover,the increased digestive enzyme activities indicate the possibility of introducing artificial compound feed.展开更多
Haliotis discus hannai is an important marine economic species in China.Its egg color was found to be associated with economic traits,which provides a new idea for breeding.However,the molecular mechanism of the egg-c...Haliotis discus hannai is an important marine economic species in China.Its egg color was found to be associated with economic traits,which provides a new idea for breeding.However,the molecular mechanism of the egg-color formation has not been reported.Thus,the pigment composition and comparative transcriptome analyses of H.discus hannai with green and gray egg color were conducted using high-performance liquid chromatography(HPLC)and RNA-Seq methods.Results show that individuals with green and gray eggs both possess the fucoxanthin.Lutein existed in gray-egged individuals,but not in green-egged individuals.In transcriptome analysis,272310 unigenes were received from 461162 transcripts with a mean length of 985 bp and N50 of 1524 bp,respectively.A total of 185 unigenes were identifi ed as diff erentially expressed genes(DEGs).The DEGs involved in“fl avin-containing compound metabolic process”,“melanosome”,“glutathione metabolism”,and“cytochrome b6f complex”were likely related to the formation of the egg color.Our results provide foundational information for the functional analysis of egg-color related genes and are benefi cial to the selective breeding of H.discus hannai.展开更多
With the deterioration of the environment,it is imperative to protect coastal wetlands.Using multi-source remote sensing data and object-based hierarchical classification to classify coastal wetlands is an effective m...With the deterioration of the environment,it is imperative to protect coastal wetlands.Using multi-source remote sensing data and object-based hierarchical classification to classify coastal wetlands is an effective method.The object-based hierarchical classification using remote sensing indices(OBH-RSI)for coastal wetland is proposed to achieve fine classification of coastal wetland.First,the original categories are divided into four groups according to the category characteristics.Second,the training and test maps of each group are extracted according to the remote sensing indices.Third,four groups are passed through the classifier in order.Finally,the results of the four groups are combined to get the final classification result map.The experimental results demonstrate that the overall accuracy,average accuracy and kappa coefficient of the proposed strategy are over 94%using the Yellow River Delta dataset.展开更多
Spartina alterniflora as an alien invasive plant,poses a serious threat to the ecological functions of the coastal wetland of the Jiaozhou Bay.As of 2019,the distribution area of S.alterniflora in the Jiaozhou Bay has...Spartina alterniflora as an alien invasive plant,poses a serious threat to the ecological functions of the coastal wetland of the Jiaozhou Bay.As of 2019,the distribution area of S.alterniflora in the Jiaozhou Bay has reached more than 500 hm^(2).For this reason,combined with field surveys,remote sensing monitoring of the invasion S.alterniflora in the Jiaozhou Bay has been carried out.To accurately identify S.alterniflora within the Jiaozhou Bay coastal wetland,we used a new method which is an implement of deep convolutional neural network,and by which we got a higher accuracy than the traditional method.Based on distribution of S.alterniflora extracted by the proposed method,the temporal and spatial distribution characteristics of S.alterniflora were analyzed.And then combined with environmental factors,the invasion mechanism of S.alterniflora in the Jiaozhou Bay was analyzed in detail.From the monitoring results,it can be seen that S.alterniflora in Jiaozhou Bay is mainly distributed in the beaches near the Yanghe River Estuary and its southern side,the Dagu River Estuary and the Nügukou.Spartina alterniflora first broke out near the Yanghe River Estuary and gradually spread to the tidal flats near the Nügukou.The Dagu River Estuary is dominated by S.anglica,whose area has not changed much over the years,and a small amount of S.alterniflora has invaded later.展开更多
The Japanese common squid Todarodes pacificus is widely distributed in the Sea of Japan,the East China Sea and the Northwest Pacific Ocean,and is largely exploited by the Asia-Pacific countries.In this study,the impac...The Japanese common squid Todarodes pacificus is widely distributed in the Sea of Japan,the East China Sea and the Northwest Pacific Ocean,and is largely exploited by the Asia-Pacific countries.In this study,the impacts of regime shift of the Pacific Decadal Oscillation(PDO)during 1977-2015 on the autumn cohort of T.pacificus were assessed by examining the variations in vertical water temperatures at depths of 0 m(Temp_0 m),50 m(Temp_50 m)and 100 m(Temp_100 m)and the distribution pattern of preferred spawning ground(SSG).Spatial and temporal correlation analysis revealed that the PDO index exhibited a significantly negative relationship with vertical water temperatures at different depths and was negatively related to catch-per-unit-effort(CPUE)and stock biomass of T.pacificus.In addition,water temperatures in the specific three water layers were positively associated with CPUE.The PDO regime shift strongly affected the thermal condition and spawning ground of T.pacificus.Comparing to the negative PDO,the waters from the surface to the deep became cool in the positive PDO phase;correspondingly,the area of SSG largely contracted at different depths.Consequently,the CPUE and stock biomass of T.pacificus profoundly decreased.From the results it can be concluded that the PDO regime shift-driven changes in vertical thermal condition and SSG ranges can yield substantial impacts on T.pacificus abundance.展开更多
Sinonovacula constricta is one of the important economic aquaculture species in China. In this study, we constructed genetic linkage maps of S. constricta based on 300 microsatellite markers derived from RAD-seq using...Sinonovacula constricta is one of the important economic aquaculture species in China. In this study, we constructed genetic linkage maps of S. constricta based on 300 microsatellite markers derived from RAD-seq using an F1 full-sib family. The female map contained 204 microsatellites assigned to 22 linkage groups, which covered 1529.5 cM with an average interval of 10.3 cM. The male consisted of 187 microsatellites in 19 linkage groups corresponding to the haploid chromosome number(n(28)19), which spanned 1429.3 cM with an average interval of 8.7 cM. The genome coverage was approximately 83.5% and 81.4%, respectively. An integrated map was constructed according to the common markers in parental linkage groups, which had a total length of 1683.8 cM with an average interval of 7.3 cM. The genome coverage of the integrated map was approximately 86.3%. The genetic linkage map would form the foundation for further studies on the quantitative trait loci(QTL), as well as accelerating the breeding process of this species.展开更多
As an important part of the Bohai economic rim,the Laizhou Bay has been stressed by serious eco-environmental problems in recent years.In this study,the Shannon-Wiener index(H′),AZTI’s marine biotic index(AMBI)and t...As an important part of the Bohai economic rim,the Laizhou Bay has been stressed by serious eco-environmental problems in recent years.In this study,the Shannon-Wiener index(H′),AZTI’s marine biotic index(AMBI)and the multivariate AMBI(M-AMBI)were used to assess the ecological quality status(EQS)of the Laizhou Bay according to macrobenthos data collected annually in August 2011–2014.The results showed that the overall benthic habitat quality in the Laizhou Bay was assessed as“Good”.However,25%of the samples were classified as“Moderate”,“Bad”or“Poor”status under degraded conditions.Ecological group III(EGIII)species which had a certain tolerance to environmental disturbances had a higher proportion in each station,and most of them had appeared the pollution indicator species Capitella capitata.This indicated that the benthic habitat in the Laizhou Bay had been disturbed and polluted to some extent.The comparison of the three indices evaluation result and the RDA analysis showed that the H′and M-AMBI were more suitable when the relative abundance of the single species was high and the macrobenthic community was significantly imbalanced;when the relative abundance of opportunistic species(EGIV and EGV)was high,the AMBI and M-AMBI could reflected the EQS objectively;in an undisturbed and polluted environment,all the three indices could indicate the benthic habitats quality.In summary,the better correlation between the three indices and environmental factors showed that they were well responsive to the tendency of the benthic habitats quality in the Laizhou Bay.展开更多
To determine if water-sediment regulation has affected macrobenthic community structure in the Huanghe River Estuary,China,macrobenthic samples were collected following regulation events from 2012 to 2016.We identify ...To determine if water-sediment regulation has affected macrobenthic community structure in the Huanghe River Estuary,China,macrobenthic samples were collected following regulation events from 2012 to 2016.We identify seven phyla and 138 macrobenthic species from within samples throughout the survey area,over time.Species richness and abundance in 2012 were significantly higher than in 2016.Biomass did not differ significantly during 2012–2016.Dominant species were mostly small polychaetes,with mollusks,arthropods,and echinoderms all being relatively rare.In 2016,dominant species were small polychaetes.MDS reveals macrobenthic communities at all surveyed distances from the estuary to have become the same community structure over time.Shannon-Wiener diversity and Margalef richness indexes trended down over time.CCA reveals the most dominant sediment-dwelling species to prefer lower dissolved oxygen,sulfides,and pH,and sediments with high D50 and low clay content.We speculate that water-sediment regulation has affected seabed communities,particularly Region A in our survey area.展开更多
Polycyclic aromatic hydrocarbons(PAHs),as persistent toxic substances(PTS),have been widely monitored in coastal environment,including seawater and sediment.However,scientific monitoring methods,like ecological risk a...Polycyclic aromatic hydrocarbons(PAHs),as persistent toxic substances(PTS),have been widely monitored in coastal environment,including seawater and sediment.However,scientific monitoring methods,like ecological risk assessment and integrated biomarker response,still need massive researches to verify their availabilities.This study was performed in March,May,August and October of 2018 at eight sites,Yellow River estuary(S1),Guangli Port(S2),Xiaying(S3),Laizhou(S4),Inner Bay(S5),Outer Bay(S6),Hongdao(S7)and Hongshiya(S8)of Shandong Peninsula,China.The contents of 16 priority PAHs in local seawater and sediment were determined,by which ecological risk assessment risk quotient(RQ)for seawater and sediment quality guidelines(SQGs)were calculated to characterize the PAHs pollution.Meanwhile,multiple biomarkers in the digestive gland of clam Ruditapes philippinarum were measured to represent different biological endpoints,including ethoxyresorufin-O-deethylase(EROD),glutathione S-transferase(GST),sulfotransferase(SULT),superoxide dismutase(SOD)and lipid peroxidation(LPO),by which integrated biomarker response(IBR)was calculated to provide a comprehensive assessment of environmental quality.Taken together,these results revealed the heaviest pollution at S2 as both PAHs concentrations and biomarkers responses reflected,and supported the integrated biomarker response as a useful tool for marine environmental monitoring,through its integration with SQGs.展开更多
Abundance and distribution of jumbo flying squid(Dosidicus gigas)are evidently influenced by the changes of marine environment.In this study,the maximum entropy(MaxEnt)model was applied to examine the impacts of marin...Abundance and distribution of jumbo flying squid(Dosidicus gigas)are evidently influenced by the changes of marine environment.In this study,the maximum entropy(MaxEnt)model was applied to examine the impacts of marine environmental variables on its potential distribution,and identified habitat hotspots of D.gigas in summer and autumn along the coast of Chile.The MaxEnt model was constructed by using the fisheries data of D.gigas from summer to autumn during 2011–2017 combined with critical environmental factors including mixed layer depth(MLD),sea surface salinity(SSS),sea surface height(SSH)and water temperature at depths of 0 m,25 m,50 m,100 m,150 m,200 m,300 m,400 m and 500 m.Results showed that the actual fishing efforts of D.gigas in summer and autumn were mostly distributed in the suitable habitat,indicating that the MaxEnt model can well predict the habitat hotspots of D.gigas off Chile.The key environmental factors and their suitable ranges for D.gigas showed significant intermonthly changes from December to May.The critical environmental factors of D.gigas off Chile were MLD,SSH,water temperature at different depths in summer(Temp_25 m in December,Temp_300 m in January and Temp_400 m in February)and SSH,SSS,Temp_400 m in autumn.Our findings suggest that selecting the key environmental factors is vital to study the potential distribution of D.gigas off Chile in each month to explore its habitat hotspots.展开更多
基金supported by the National Key R&D Program of China(Nos.2019YFD0901204,2019YFD 0901205).
文摘Aggregation of species with similar ecological properties is one of the effective methods to simplify food web researches.However,species aggregation will affect not only the complexity of modeling process but also the accuracy of models’outputs.Selection of aggregation methods and the number of trophospecies are the keys to study the simplification of food web.In this study,three aggregation methods,including taxonomic aggregation(TA),structural equivalence aggregation(SEA),and self-organizing maps(SOM),were analyzed and compared with the linear inverse model–Markov Chain Monte Carlo(LIM-MCMC)model.Impacts of aggregation methods and trophospecies number on food webs were evaluated based on the robustness and unitless of ecological net-work indices.Results showed that aggregation method of SEA performed better than the other two methods in estimating food web structure and function indices.The effects of aggregation methods were driven by the differences in species aggregation principles,which will alter food web structure and function through the redistribution of energy flow.According to the results of mean absolute percentage error(MAPE)which can be applied to evaluate the accuracy of the model,we found that MAPE in food web indices will increase with the reducing trophospecies number,and MAPE in food web function indices were smaller and more stable than those in food web structure indices.Therefore,trade-off between simplifying food webs and reflecting the status of ecosystem should be con-sidered in food web studies.These findings highlight the importance of aggregation methods and trophospecies number in the analy-sis of food web simplification.This study provided a framework to explore the extent to which food web models are affected by dif-ferent species aggregation,and will provide scientific basis for the construction of food webs.
基金Supported by the National Natural Science Foundation of China(Nos.41776012,41606107,41576082)the National Key Research and Development Program of China(Nos.2019YFD0901305,2018YFC1407605)+4 种基金the Science and Technology Development Plan Project of Shandong Province(No.2016ZDJS09A02)the Key Research and Development Project of Zhejiang Province(No.2020C03012)the Key Research and Development Project of Guangdong Province(No.2020B1111030002)the Major Science and Technology Project of Sanya YZBSTC(No.YZ2019ZD0X)the Shandong Provincial Natural Science Foundation(No.ZR201911060280)。
文摘The chlorophyll a(Chl a)is an important indicator of marine ecosystems.The spatiotemporal variation of the Chl a greatly aff ects the mariculture and marine ranching in coastal waters of the Shandong Peninsula.In the current study,the climatology and seasonal variability of surface Chl-a concentration around the Shandong Peninsula are investigated based on 16 years(December 2002-November 2018)of satellite observations.The results indicate that the annual mean Chl-a concentration is greater in the Bohai Sea than in the Yellow Sea and decreases from coastal waters to off shore waters.The highest Chl-a concentrations are found in Laizhou Bay(4.2-8.0 mg/m^(3)),Haizhou Bay(4.2-5.9 mg/m^(3))and the northeast coast of the Shandong Peninsula(4.4-5.0 mg/m^(3)),resulting from the combined eff ects of the intense riverine input and long residence time caused by the concave shape of the coastline.The seasonal Chl-a concentration shows a significant spatial variation.The Chl-a concentrations in these three subregions generally exhibit an annual maximum in August/September,due to the combined eff ects of sea surface temperature,river discharge and sea surface wind.In the southeast coast region,however,the Chl-a concentration is lowest throughout the year and reaches a maximum in February with a minimum in July,forced by the seasonal evolution of the Yellow Sea Cold Water and monsoon winds.The interannual Chl-a concentration trends vary among regions and seasons.There are significant increasing trends over a large area around Haizhou Bay from winter to summer,which are mainly caused by the rising sea surface temperature and eutrophication.In other coastal areas,the Chl-a concentration shows decreasing trends,which are clearest in summer and induced by the weakening land rainfall.This study highlights the differences in the Chl-a dynamics among regions around the Shandong Peninsula and is helpful for further studies of coupled physical-ecological-human interactions at multiple scales.
基金Supported by the National Key Research and Development Program of China(No.2019YFD0900704)the Yantai Key Research and Development Program(No.2019XDHZ097)+2 种基金the National Natural Science Foundation of China(No.42076137)the Natural Science Foundation of Shandong Province(No.ZR2020QD003)the Shandong Key Laboratory of Coastal Environmental Processes,YICCAS(No.2019SDHADKFJJ16)。
文摘We used the Integrated Biological Responses version 2(IBRv2)method to evaluate the biological eff ects of heavy metals in the sediments in Laizhou Bay,China on the benthic goby Acanthogobius ommaturus.In December 2018,gobies and sediments were collected from 15 stations.We measured the activities of defense enzymes and the contents of malondialdehyde(MDA)and metallothionein(MT)in the goby liver as well as the levels of heavy metals in the sediments and goby muscle tissue.Most of the heavy metal concentrations in sediment at each station were below the Class I criteria set by Chinese Standards for Marine Sediment Quality,and the Håkanson ecological risk index suggested low risk for the heavy metals.We found that A.ommaturus could eff ectively accumulate mercury,cadmium,arsenic,and zinc and that the contents of MT and MDA and the activities of glutathione peroxidase and glutathione reductase were suitable biomarkers of heavy metal pollution in this species.The IBRv2 method integrated these four biomarkers and discriminated stations according to heavy metal pollution.Higher IBRv2 values suggested more adverse eff ects in gobies,corroborating more serious heavy metal contamination.The stations with high IBRv2 values and high contents of heavy metals were mainly distributed in the west and northeast parts of the bay.These results show that the IBRv2 approach is a feasible strategy for assessing heavy metal pollution through biological response and biological status and that it can be implemented for environmental monitoring in Laizhou Bay.
基金The National Key R&D Program of China under contract No.2018YFD0900904the National Natural Science Foundation of China under contract Nos 31772852 and 31802301。
文摘Single-species management ignores the interactions between species,and ecosystem-based fisheries management(EBFM)has become a main method to fisheries management.Understanding food web structures and species interactions is essential for the implementation of EBFM and maintenance of ecosystem functions.Overfishing is one of the main reasons behind the depletion,which could even lead to the depletion of some target species in local areas.So understanding the impacts of species depletion on food web structures is important for the implementation of EBFM.The impacts of species depletion can be transmitted through the food web and cause the local extinction of both target and non-target species.In this study,topological network analysis was applied to examine the impacts of species depletion on the food web structure of Haizhou Bay.Results showed that fine crayfish Leptochela gracilis,squid Loligo sp.,and Japanese snapping shrimp Alpheus japonicus have the highest numbers of outgoing links(48,32 and 31 respectively);thus,these species may be considered key prey species.Whitespotted conger Conger myriaster,fat greenling Hexagrammos otakii,and bluefin gurnard Chelidonichthys kumu were key predators with the highest number of incoming links(37,36 and 35 respectively).The competition graphs derived from the Haizhou Bay food web were highly connected(more than 40%predators sharing over 10 common prey species),and showed close trophic interaction between high trophic level fishes.Simulation analysis showed that the food web structure has small changes to the depletion of species in a highly complex food web.The most-connected target species did not necessarily indicate high structural importance;however,some species with low connectivity may demonstrate stronger trophic interactions and play important ecological roles in the food web.But most species were more sensitive to the depletion of the most-connected target species than other target species(for instance,for zooplankton,closeness centrality 13.876 in D6,but closeness centrality 82.143 in original food web).Therefore,EBFM should focus on the most-connected target species,but also on those species with few but strong links and feeding relationships in the food web.
基金supported by the Marine Special Scientific Fund for the Non-profit Public Industry of China (200805031)Fund of Key Laboratory of Fishery Ecology and Environment, Guangdong Province (LFE-20144)Scientific Research Foundation for the Third Institute of Oceanography, State Oceanic Administration (No. 2013031)
文摘The distribution of hexachlorocyclohexanes(HCHs) and dichlorodiphenyltrichloroethanes(DDTs) in the surface seawater and sediment of Jincheng Bay mariculture area were investigated in the present study. The concentration of total HCHs and DDTs ranged from 2.98 to 14.87 ng L-1 and were < 0.032 ng L-1, respectively, in surface seawater, and ranged from 5.52 to 9.43 and from 4.11 to 6.72 ng g-1, respectively, in surface sediment. It was deduced from the composition profile of HCH isomers and DDT congeners that HCH residues derived from a mixture of technical-grade HCH and lindane whereas the DDT residues derived from technical-grade DDT and dicofol. Moreover, both HCH and DDT residues may mainly originate from historical inputs. The hazard quotient of α-HCH, β-HCH, γ-HCH and δ-HCH to marine species was 0.030, 0.157, 3.008 and 0.008, respectively. It was estimated that the overall probability of adverse biological effect from HCHs was less than 5%, indicating that its risk to seawater column species was low. The threshold effect concentration exceeding frequency of γ-HCH, p,p'-DDD, p,p'-DDE and p,p'-DDT in sediment ranged from 8.3% to 100%, and the relative concentration of the HCH and DDT mixture exceeded their probable effect level in sediment. These findings indicated that the risk to marine benthos was high and potentially detrimental to the safety of aquatic products, e.g., sea cucumber and benthic shellfish.
基金This study was financially supported by the National Science Foundation of China(NSFC)-Shandong Joint Funds(Nos.U1606404,U1906215)the Ocean Spe-cial Funds for Scientific Research on Public Causes(No.201205001).
文摘Study on morphological changes of a bay can help to identify the effects of anthropogenic activities on coastal environ-ment and guide the exploration of marine resources.In this paper,morphological data including coastline and water areas in five discrete years between 1968 and 2015 were selected and extracted from the remote sensing images and historical marine charts to study the morphological changes in Laizhou Bay(LZB),one of the bays in the southwest of the Bohai Sea.A systematic analysis on spatial variations of the coastline and the surface areas of different types of waters in LZB was conducted.The results showed that the surface area of LZB was decreased by 1253.2km^(2)in the last half century,which is 17.4%of the total in the 1970s.The areas of the natural wetland and the intertidal zone were decreased by 17.2%and 56.1%,respectively,and the average water depth varied from 9.05 m to 8.16m at low tide level from 1968 to 2015.The coastline and shape variations of the bay turned to be complex after the 1980s,and the shape index of LZB showed an increasing trend in more recent years.The centroid of the bay generally migrated to the northeast direction,i.e.,the direction of the center of the Bohai Sea,and the shrinking direction of the bay was consistent with the migration direction of the coastline.The reclamation area during 1968-2015 in LZB was 1201.7km^(2),and 94.1%was in the inter-tidal zone.The overall morphological change of the bay during the last half century was mainly controlled by the coastal reclamation activities,and the Yellow River runoff including the river course change and sediment load variation was also an important control-ling factor.
基金The Public Science and Technology Research Funds Projects of Ocean under contract No.200905019the Taishan Scholars Station of Aquatic Animal Nutrition and Feed under contract No.HYK201004
文摘The community characteristics of macrobenthos in the Huanghe(Yellow River) Estuary is influenced by a combination of natural and anthropogenic factors. Here, we investigated short-term changes(1-month) in macrobenthic community structure in response to water and sediment discharge regulation(WSDR) in 2011.Specifically, we sampled the macrobenthos at 18 sampling stations situated at four distances(5, 10, 20, and 40 km)from the mouth of the Huanghe Estuary before(mid-June), during(early-July), and after(mid-July) WSDR. The results showed that a total of 73, 72, and 85 species were collected before, during, and after WSDR, respectively.Then, 13, 1, and 16 dominant species were detected at this three periods. Four phyla were primarily detected at all three periods(Annelida, Mollusca, Arthropoda, and Echinodermata). However, while Mollusca and Annelida were the most important phyla in our study, Echinodermata and Annelida were the most important phyla in 1982,demonstrating major changes to community structure over a 3-decadal period. All stations were of high quality BOPA index before WSDR, whereas two and three stations were of reduced quality BOPA index during and after WSDR, respectively. The results of ABC curves showed that had incurred disturbed conditions after human activities WSDR. Most important of all, multivariate analyses and RDA analysis indicated that the structure of the macrobenthic community was closely linked to environment factors, including that organic content factor caused the distribution of macrobenthic community mostly during WSDR, while water depth after WSDR affected the macro benthos community structure seriously, and during WSDR, the environment factor influencing it was not single, including organic content, sulfide content, Hg and As. These differences may have been due to changes in water transparency negatively impacting the growth and development of macrobenthos, due to specific lifehistory requirements. Our results demonstrate that anthropogenic activity is having both long-term(3 decadal)and short term(1-month) impacts on the structure of the macrobenthic community of the Huanghe Estuary. In conclusion, human activities WSDR influence the habitat environment of macro benthos, including the water temperature, nutrients, bioturbation, and so on. Therefore, we suggest the necessity to strengthen regulations of land-derived organic pollutant input to maintain the ecological balance of the Huanghe Estuary.
基金The work was supported by the National Key R&D Program of China(No.2017YFC1600702)the Key Lab of Marine Bioactive Substance and Modern Analytical Technique,SOA(No.MBSMAT-2019-04)+1 种基金the Modern Agro-Industry Technology Research System in Shandong Pro-vince(No.SDAIT-26-05)the National Natural Science Foundation of China(No.31901787).
文摘Semicarbazide has become an important pollutant in the environment,but there was no comprehensive literature on its advances.In this review,the source,biotoxicity and detection methods are summarized.Among the sources is the material of chemical reaction,a metabolite of nitrofurazone,food processing(production by azobisformamide and hypochlorite treatment),endogenous substances,etc.Semicarbazide is demonstrated to be accumulative and reproductive toxicity,mutagenicity and genotoxicity,endocrine disruptors,and neurotoxicity.There are still many controversies on the effect of genotoxicity and no clear result on the carcinogenic mechanism.HPLC-MS/MS is the mainstream of the detection methods.Other methods,including HPLC,immunoassay method,biosensor method,electrochemical detection,capillary electrophoresis technique,and spectral techniques mainly,have become less and less in recent years.On all these counts,to reduce the content of semicarbazide in the environment,the key is to control the use of nitrofurazone as the banned drug effectively.Meanwhile the toxicity data should be supplemented to reveal its toxic mechanism.
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Supported by the Public Science and Technology Research Funds Projects of Ocean(No.201205025)the Platform of Aquatic Nutrition and Feed(No.201304001)the Taishan Scholar Fellowship of Shandong Province
文摘The present trial was conducted with starry fl ounder Platichthys stellatus broodstock to evaluate the effects of dietary vitamin A,ascorbic acid,and α-tocopherol on the gonadal development and reproductive performance.8 000 IU/kg diet vitamin A(VA group),500 mg/kg diet ascorbic acid(Vcpp group),or 250 mg/kg diet α-tocopherol(α-TA group)was added into basal diet to create 3 vitamin experimental diets,respectively.Each diet was fed to 450 starry fl ounder broodstock for 104 days.Samples were collected weekly.The gonadosomatic index(GSI)of 3 vitamin experimental groups fi rst decreased and then increased.Maximum GSI of Vcpp group was higher than that of α-TA group but lower than that of VA group.The spawning periods of 3 vitamin experimental groups lasted 49,56,and 45 days,respectively.No mature eggs were observed in the control group during the trial.The absolute fecundity(AF)and relative fecundity(RF)of α-TA group was higher than that of Vcpp group but lower than that of VA group.The results suggest that different vitamins play different roles in the fi sh reproductive process.Vitamin A stimulated the maturation of the ovary,ascorbic acid prolonged the spawning period,and α-tocopherol affected the development of the eggs.
基金Supported by the Scientific and Technological Development Plan Project of Yantai City(No.2013ZH348)the Aquatic Animal Nutrition and Feed Research and Innovation Demonstration Platform(No.201301001)the National Special Research Fund for Non-Profit Marine Sector(No.1205025)
文摘Ontogenetic changes in digestive enzyme activities and the amino acid(AA) profile of starry flounder,Platichthys stellatus,were investigated and limiting amino acids were estimated compared with the essential AA profile between larvae and live food to clarify starry flounder larval nutritional requirements.Larvae were collected at the egg stage and 0,2,4,7,12,17,24 days after hatching(DAH)for analysis.Larvae grew from 1.91 mm at hatching to 12.13 mm at 24 DAH.Trypsin and chymotrypsin activities changed slightly by 4 DAH and then increased significantly 4 DAH.Pepsin activity increased sharply beginning 17 DAH.Lipase activity increased significantly 4 DAH and increased progressively with larval growth.Amylase activity was also detected in newly hatched larvae and increased 7 DAH followed by a gradual decrease.High free amino acid(FAA) content was detected in starry flounder eggs(110.72mg/g dry weight).Total FAA content dropped to 43.29 mg/g in 4-DAH larvae and then decreased gradually to 13.74 mg/g in 24-DAH larvae.Most FAAs(except lysine and methionine) decreased >50%in 4-DAH larvae compared with those in eggs and then decreased to the lowest values in 24-DAH larvae.Changes in the protein amino acid(PAA) profile were much milder than those observed for FAAs.Most PAAs increased gradually during larval development,except lysine and phenylalanine.The percentages of free threonine,valine,isoleucine,and leucine decreased until the end of the trial,whereas the protein forms of these four AAs followed the opposite trend.A comparison of the essential AA composition of live food(rotifers,Artemia nauplii,and Artemia metanauplii) and larvae suggested that methionine was potentially the first limiting AA.These results may help develop starry flounder larviculture methods by solving the AA imbalance in live food.Moreover,the increased digestive enzyme activities indicate the possibility of introducing artificial compound feed.
基金Supported by the Seed Improvement Project of Shandong Province of China(No.2017LZGC009)the Major Scientifi c and Technological Innovation Project of Shandong Provincial Key Research and Development Program(No.2019JZZY020706)。
文摘Haliotis discus hannai is an important marine economic species in China.Its egg color was found to be associated with economic traits,which provides a new idea for breeding.However,the molecular mechanism of the egg-color formation has not been reported.Thus,the pigment composition and comparative transcriptome analyses of H.discus hannai with green and gray egg color were conducted using high-performance liquid chromatography(HPLC)and RNA-Seq methods.Results show that individuals with green and gray eggs both possess the fucoxanthin.Lutein existed in gray-egged individuals,but not in green-egged individuals.In transcriptome analysis,272310 unigenes were received from 461162 transcripts with a mean length of 985 bp and N50 of 1524 bp,respectively.A total of 185 unigenes were identifi ed as diff erentially expressed genes(DEGs).The DEGs involved in“fl avin-containing compound metabolic process”,“melanosome”,“glutathione metabolism”,and“cytochrome b6f complex”were likely related to the formation of the egg color.Our results provide foundational information for the functional analysis of egg-color related genes and are benefi cial to the selective breeding of H.discus hannai.
基金supported by the Beijing Natural Science Foundation(No.JQ20021)the National Natural Science Foundation of China(Nos.61922013,61421001 and U1833203)the Remote Sensing Monitoring Project of Geographical Elements in Shandong Yellow River Delta National Nature Reserve。
文摘With the deterioration of the environment,it is imperative to protect coastal wetlands.Using multi-source remote sensing data and object-based hierarchical classification to classify coastal wetlands is an effective method.The object-based hierarchical classification using remote sensing indices(OBH-RSI)for coastal wetland is proposed to achieve fine classification of coastal wetland.First,the original categories are divided into four groups according to the category characteristics.Second,the training and test maps of each group are extracted according to the remote sensing indices.Third,four groups are passed through the classifier in order.Finally,the results of the four groups are combined to get the final classification result map.The experimental results demonstrate that the overall accuracy,average accuracy and kappa coefficient of the proposed strategy are over 94%using the Yellow River Delta dataset.
基金The National Natural Science Foundation of China under contract Nos 42076189,41206172 and 61601133the Natural Science Foundation of Beijing under contract No.JQ20021the Remote Sensing Monitoring Project of Geographical Elements in Shandong Yellow River Delta National Nature Reserve—the Remote Sensing Monitoring Technology Project of Spartina alterniflora in Shandong Province in 2020。
文摘Spartina alterniflora as an alien invasive plant,poses a serious threat to the ecological functions of the coastal wetland of the Jiaozhou Bay.As of 2019,the distribution area of S.alterniflora in the Jiaozhou Bay has reached more than 500 hm^(2).For this reason,combined with field surveys,remote sensing monitoring of the invasion S.alterniflora in the Jiaozhou Bay has been carried out.To accurately identify S.alterniflora within the Jiaozhou Bay coastal wetland,we used a new method which is an implement of deep convolutional neural network,and by which we got a higher accuracy than the traditional method.Based on distribution of S.alterniflora extracted by the proposed method,the temporal and spatial distribution characteristics of S.alterniflora were analyzed.And then combined with environmental factors,the invasion mechanism of S.alterniflora in the Jiaozhou Bay was analyzed in detail.From the monitoring results,it can be seen that S.alterniflora in Jiaozhou Bay is mainly distributed in the beaches near the Yanghe River Estuary and its southern side,the Dagu River Estuary and the Nügukou.Spartina alterniflora first broke out near the Yanghe River Estuary and gradually spread to the tidal flats near the Nügukou.The Dagu River Estuary is dominated by S.anglica,whose area has not changed much over the years,and a small amount of S.alterniflora has invaded later.
基金This study was financially supported by the Shanghai Talent Development Funding for the Project(No.2021078)the National Natural Science Foundation of China(No.41906073)the Construction and Application Demonstration of Natural Resources Satellite Remote Sensing Technology System(No.202101003).
文摘The Japanese common squid Todarodes pacificus is widely distributed in the Sea of Japan,the East China Sea and the Northwest Pacific Ocean,and is largely exploited by the Asia-Pacific countries.In this study,the impacts of regime shift of the Pacific Decadal Oscillation(PDO)during 1977-2015 on the autumn cohort of T.pacificus were assessed by examining the variations in vertical water temperatures at depths of 0 m(Temp_0 m),50 m(Temp_50 m)and 100 m(Temp_100 m)and the distribution pattern of preferred spawning ground(SSG).Spatial and temporal correlation analysis revealed that the PDO index exhibited a significantly negative relationship with vertical water temperatures at different depths and was negatively related to catch-per-unit-effort(CPUE)and stock biomass of T.pacificus.In addition,water temperatures in the specific three water layers were positively associated with CPUE.The PDO regime shift strongly affected the thermal condition and spawning ground of T.pacificus.Comparing to the negative PDO,the waters from the surface to the deep became cool in the positive PDO phase;correspondingly,the area of SSG largely contracted at different depths.Consequently,the CPUE and stock biomass of T.pacificus profoundly decreased.From the results it can be concluded that the PDO regime shift-driven changes in vertical thermal condition and SSG ranges can yield substantial impacts on T.pacificus abundance.
基金supported by the grants from the Natural Science Foundation of Shandong Province(No.ZR2012 CM037)the Shandong Provincial Agriculture Thorough-bred Projectthe Innovation Project of Guangxi Graduate Education(No.YCBZ2015007)
文摘Sinonovacula constricta is one of the important economic aquaculture species in China. In this study, we constructed genetic linkage maps of S. constricta based on 300 microsatellite markers derived from RAD-seq using an F1 full-sib family. The female map contained 204 microsatellites assigned to 22 linkage groups, which covered 1529.5 cM with an average interval of 10.3 cM. The male consisted of 187 microsatellites in 19 linkage groups corresponding to the haploid chromosome number(n(28)19), which spanned 1429.3 cM with an average interval of 8.7 cM. The genome coverage was approximately 83.5% and 81.4%, respectively. An integrated map was constructed according to the common markers in parental linkage groups, which had a total length of 1683.8 cM with an average interval of 7.3 cM. The genome coverage of the integrated map was approximately 86.3%. The genetic linkage map would form the foundation for further studies on the quantitative trait loci(QTL), as well as accelerating the breeding process of this species.
基金The National Natural Science Foundation of China-Shandong Joint Fund for Marine Science Research Centers under contract No.U1606404the National Basic Research Program(973 Program)of China under contract No.2015CB453301the National Marine Public Welfare Research Project of China under contract No.201405007
文摘As an important part of the Bohai economic rim,the Laizhou Bay has been stressed by serious eco-environmental problems in recent years.In this study,the Shannon-Wiener index(H′),AZTI’s marine biotic index(AMBI)and the multivariate AMBI(M-AMBI)were used to assess the ecological quality status(EQS)of the Laizhou Bay according to macrobenthos data collected annually in August 2011–2014.The results showed that the overall benthic habitat quality in the Laizhou Bay was assessed as“Good”.However,25%of the samples were classified as“Moderate”,“Bad”or“Poor”status under degraded conditions.Ecological group III(EGIII)species which had a certain tolerance to environmental disturbances had a higher proportion in each station,and most of them had appeared the pollution indicator species Capitella capitata.This indicated that the benthic habitat in the Laizhou Bay had been disturbed and polluted to some extent.The comparison of the three indices evaluation result and the RDA analysis showed that the H′and M-AMBI were more suitable when the relative abundance of the single species was high and the macrobenthic community was significantly imbalanced;when the relative abundance of opportunistic species(EGIV and EGV)was high,the AMBI and M-AMBI could reflected the EQS objectively;in an undisturbed and polluted environment,all the three indices could indicate the benthic habitats quality.In summary,the better correlation between the three indices and environmental factors showed that they were well responsive to the tendency of the benthic habitats quality in the Laizhou Bay.
基金Foundation item:The Shandong Provincial Natural Science Foundation under contract No.ZR2018PD011the Science and Technology Innovation Development Program of Yantai under contract No.2020MSGY061the National Key Research and Development Program of China under contract No.2018YFC1407605.
文摘To determine if water-sediment regulation has affected macrobenthic community structure in the Huanghe River Estuary,China,macrobenthic samples were collected following regulation events from 2012 to 2016.We identify seven phyla and 138 macrobenthic species from within samples throughout the survey area,over time.Species richness and abundance in 2012 were significantly higher than in 2016.Biomass did not differ significantly during 2012–2016.Dominant species were mostly small polychaetes,with mollusks,arthropods,and echinoderms all being relatively rare.In 2016,dominant species were small polychaetes.MDS reveals macrobenthic communities at all surveyed distances from the estuary to have become the same community structure over time.Shannon-Wiener diversity and Margalef richness indexes trended down over time.CCA reveals the most dominant sediment-dwelling species to prefer lower dissolved oxygen,sulfides,and pH,and sediments with high D50 and low clay content.We speculate that water-sediment regulation has affected seabed communities,particularly Region A in our survey area.
基金supported by Shandong Provincial Department of Agriculture and Rural Affairs(No.20180163)the National Natural Science Foundation of China-Shandong Joint Fund for Marine Science Research Centers(No.20180165)。
文摘Polycyclic aromatic hydrocarbons(PAHs),as persistent toxic substances(PTS),have been widely monitored in coastal environment,including seawater and sediment.However,scientific monitoring methods,like ecological risk assessment and integrated biomarker response,still need massive researches to verify their availabilities.This study was performed in March,May,August and October of 2018 at eight sites,Yellow River estuary(S1),Guangli Port(S2),Xiaying(S3),Laizhou(S4),Inner Bay(S5),Outer Bay(S6),Hongdao(S7)and Hongshiya(S8)of Shandong Peninsula,China.The contents of 16 priority PAHs in local seawater and sediment were determined,by which ecological risk assessment risk quotient(RQ)for seawater and sediment quality guidelines(SQGs)were calculated to characterize the PAHs pollution.Meanwhile,multiple biomarkers in the digestive gland of clam Ruditapes philippinarum were measured to represent different biological endpoints,including ethoxyresorufin-O-deethylase(EROD),glutathione S-transferase(GST),sulfotransferase(SULT),superoxide dismutase(SOD)and lipid peroxidation(LPO),by which integrated biomarker response(IBR)was calculated to provide a comprehensive assessment of environmental quality.Taken together,these results revealed the heaviest pollution at S2 as both PAHs concentrations and biomarkers responses reflected,and supported the integrated biomarker response as a useful tool for marine environmental monitoring,through its integration with SQGs.
基金supported by the National Key R&D Program of China(No.2019YFD0901405)the National Natural Science Foundation of China(Nos.41906073,31900333)the Natural Science Foundation of Shanghai(No.19ZR1423000).
文摘Abundance and distribution of jumbo flying squid(Dosidicus gigas)are evidently influenced by the changes of marine environment.In this study,the maximum entropy(MaxEnt)model was applied to examine the impacts of marine environmental variables on its potential distribution,and identified habitat hotspots of D.gigas in summer and autumn along the coast of Chile.The MaxEnt model was constructed by using the fisheries data of D.gigas from summer to autumn during 2011–2017 combined with critical environmental factors including mixed layer depth(MLD),sea surface salinity(SSS),sea surface height(SSH)and water temperature at depths of 0 m,25 m,50 m,100 m,150 m,200 m,300 m,400 m and 500 m.Results showed that the actual fishing efforts of D.gigas in summer and autumn were mostly distributed in the suitable habitat,indicating that the MaxEnt model can well predict the habitat hotspots of D.gigas off Chile.The key environmental factors and their suitable ranges for D.gigas showed significant intermonthly changes from December to May.The critical environmental factors of D.gigas off Chile were MLD,SSH,water temperature at different depths in summer(Temp_25 m in December,Temp_300 m in January and Temp_400 m in February)and SSH,SSS,Temp_400 m in autumn.Our findings suggest that selecting the key environmental factors is vital to study the potential distribution of D.gigas off Chile in each month to explore its habitat hotspots.
