长心卡帕藻(Kappaphycus alvarezii)是主要生长于热带海域的大型经济红藻,在营养物生物提取方面具有重要的经济和生态价值,作为提取K-卡拉胶的重要原料,广泛应用于食品和医学等多种行业.由于人类活动导致大气中CO2浓度持续升高,引发海洋表层海水逐渐酸化和升温,对大型海藻产生耦合效应.因此,本文设置了两种CO2浓度梯度(450×10-6和1 200×10-6)和三种温度梯度(26 ℃、29 ℃和32 ℃),从光合作用、细胞代谢产物、碳氮积累和酶活性方面探讨长心卡帕藻响应海洋酸化和海水升温的环境适应性变化.结果表明,CO2浓度与温度变化对长心卡帕藻的Fv/Fm影响显著(P＜0.05),在两种CO2浓度条件下,Fv/Fm均随温度升高而增加;酸化条件与非酸化条件下可溶性糖浓度变化趋势相反,海水升温对游离氨基酸浓度影响极显著(P＜0.01),在两种CO2水平下,升温均会降低藻体游离氨基酸浓度.综合分析可知,升高温度对长心卡帕藻的光合作用有一定程度的积极影响,藻体对于酸化和高温的同时发生具有适应性.在当前CO2浓度下,长心卡帕藻在26 ℃～29 ℃温度范围内表现出了更高的可溶性内含物积累(C、N).高CO2浓度造成的海洋酸化对长心卡帕藻产生了一定程度的负面影响,但在海水酸化的条件下,长心卡帕藻在29 ℃～32 ℃表现出更好的碳氮积累.
Light is a complex environmental factor that significantly affects the survival,feeding,growth,and vis-ual perception of fish.To investigate the effects of Light Emitting Diode(LED)spectra on the retinal structure and the number and thickness of the cells in each retinal layer of Sebastods schlegelii,1,000 S.schlegelii juveniles(body mass 38.80±0.43 g,body length 10.20±0.17 cm)were cultured in five spectral treatment groups:blue light(λ450 nm),green light(λ525 nm),yellow light(λ590 nm),white light(λ460 nm),red light(λ630 nm),green light(λ525 nm),yellow light(λ590 nm),white light(λ460 nm),and red light(λ630 nm).The white light group was the control group,and the other four groups were the treatment groups.After 60 days of treatment,samples were taken from the retinas of each group for observation.The results showed that the different LED spectra did not affect the retinal structure of S.schlegelii,but the number of retinal cells noted after treatment under each spectrum was slightly different.Under the five different spectral conditions,the number of cells in the inner retinal layer in the blue light group(24.33±2.08)was significantly lower per unit area(100 µm×100 µm)than that in the white light group(P＜0.05);the number of cells in the outer nuclear layer was significantly lower in the red light group(33.33±3.51)than that in all of the other groups except the white light group(P＜0.05).The number of cells in the outer nuclear layer of the red light group(33.33±3.51)was significantly lower than that in all of the other groups except the white light group(P＜0.05).A comparison of the number of cells in each retinal layer of each spectrum showed that the blue light group had the lowest number along with the red light group,and the differences between the other layers were not significant.In summary,the retinal thickness and cell number of S.schlegelii juveniles maintained in different spectral treatment groups underwent adaptive changes in response to changes in the external light environment.This study provides a theoretical basis for revealing the adaptive changes of S.schlegelii to a lighted environment and provides a theoretical reference for setting the lighting conditions for culturing S.schlegelii juveniles.
Low carbon is crucial in realizing the circular economy of the ocean,and achieving carbon balance in marine fisheries is a critical development method for transforming the traditional economy of the ocean.This study analyzes the carbon balance in China in general and nine coastal provinces(districts)in particular on the basis of the carbon emissions and sinks in marine fishing from 2013 to 2022.The results show that except for Shandong Province,which has a carbon balance status of surplus in 2020-2022,all others have a carbon deficit status.As for the factors affecting the carbon balance status,in general,the factors that have a greater correlation with the nine coastal provinces(districts)in the country are marine capture production,the number of fishing personnel and the area of mariculture.Finally,we propose countermeasures to accelerate the upgrade and renovation of fishing vessels,adjust the operation mode of fishing,and increase the scale of mariculture shellfish and algae farming.Furthermore,we provide recommendations for hastening the establishment of professional fishery cooperative organizations and accelerating the promotion of fishery carbon trading to achieve carbon balance in marine fisheries as soon as possible.
We aimed to study the effect of microplastics on oyster immunity by injecting oysters(average shell length:6.6 cm)with different concentrations of polystyrene microplastics(0.05,0.5,and 5 mg·L-1,with sterilized saline water as diluent)via intrashell injection(without damaging the soft tissue of oyster).The gills were sampled at 24,48,and 72 h,respectively,and the activities of six immune-related indices,including alkaline phosphatase(AKP),superoxide dismutase(SOD),malondialdehyde(MDA),catalase(CAT),nitric oxide synthase(NOS),and acetylcholinesterase(AChE),were determined.After 24 h of treatment,the concentration of microplastics had a significant effect on gill AKP activity in the oysters(P＜0.05).AKP,SOD,and structural NOS initially increased and subsequently decreased.After 48 h of treatment,increasing the microplastic concentration led to a significant decrease in AChE activity(P＜0.05),and CAT,SOD,and AKP initially increased and subsequently decreased.After 72 h of microplastic expo-sure,the activities of AKP and AChE initially decreased and then increased with an increase in microplastic concen-tration,whereas the activities of SOD,CAT,and inducible NOS initially increased and subsequently decreased.The MDA content increased with time and concentration of microplastics.These results show that microplastics induce an immune stress response in oysters,and longer stress time causes a more intense immune stress response.
In recent decades,a noticeable decline in the health of the world's oceans and seas has become increas-ingly apparent.To prevent,reduce,and reverse future deterioration of the health and functions of the oceans,the United Nations General Assembly proclaimed the United Nations Decade of Ocean Science for Sustainable Devel-opment(2021-2030)(Ocean Decade)to integrate global resources and the efforts of ocean-related communities,mobilize financial support,and develop priority areas of marine science and technology,aiming to fill gaps in ocean-related knowledge and sustainably protect and utilize the oceans.The Ocean Decade provides a broad plat-form for ocean-related scientists,policymakers,private sectors,NGOs,and local communities to efficiently and sustainably protect and exploit marine resources,presenting opportunities and challenges for China to implement its maritime power strategy and develop marine science and technology.In this study,we analyzed the development and implementation of the UN Ocean Decade in an in-depth manner.Further,we outlined and discussed the hot-spots of research on the Ocean Decade by reviewing the development process,endorsed actions,and activities of the Ocean Decade,as well as concurrent literature analysis.Since the Ocean Decade was officially announced in September 2020,409 actions from 60 countries have been approved.These actions include 47 programs,277 pro-jects,and 85 contributions.The priority study areas of Ocean Decade research include marine policymaking and management,ecosystem health,and biodiversity.Based on this analysis,the study provides recommendations on promoting China's participation in the Ocean Decade to expedite marine technology innovation and expand inter-national cooperation through the perspectives of strengthening the implementation and coordination of Ocean Dec-ade actions,capacity building,financial support,talent development,communication,and advocacy.
The swept area method is currently widely used in biomass assessment of fisheries because of its sim-plicity.However,this method assumes a uniform distribution of resources,and to improve the accuracy of biomass assessment,many stations must be sampled,which increases financial costs.In this study,we simulated and ana-lyzed the biomass assessment process;further,we explored the use of machine learning methods to assess the bio-mass of economically important crab species Portunus trituberculatus,Charybdis bimaculata,Charybdis japonica,and Ovalipes punctatus in the Zhoushan fishing ground based on data obtained from bottom trawl surveys of fishery resources conducted in August 2006 and January,May,and November 2007.The results showed that with the re-duction of the number of survey stations,the performance of the Extreme Gradient Boost method was better than that of the swept area method in autumn and winter when crabs were dispersed,and the estimated error decreased by 7.49%-21.34%.In spring and summer,when crabs were more evenly dispersed,there was no significant differ-ence between the estimated biomass obtained using the swept area method and machine learning methods(P＜0.05).We conclude that the machine learning methods improve the accuracy of assessment and save the cost of resource surveys,suggesting that they can be used in the biomass assessment of other fishery resource species.
The structure and composition of plagioclase in volcanic rocks provide important information regarding magmatic evolution.In this study,we systematically analyzed the mineralogy of plagioclase phenocrysts in lavas from the East Rift(ER),Manus Basin.Results show that the plagioclase phenocrysts in basaltic andesites have normal zoning,the An values for the core-mantle(An=80-87)of plagioclase belong to high-An plagioclase,and the An values decrease sharply for the rim.In dacites,the composition of plagioclase phenocrysts slightly changes from the core to the rim,most plagioclases have normal zoning with the An value decreasing gradually,and few plagio-clases have oscillatory zoning.The calculation results of crystallizing temperature and pressure for phenocrysts show that the magma evolution process in ER involved the following phenomena:1)Magma originated via partial melting of the mantle at～1300℃;2)In the early age,magma had a high ascend rate owing to the large magma sup-ply.3)After a small degree of fractional crystallization,magma eventually ejected at a high velocity and tempera-ture and formed basalt-basaltic andesites.In the late stage of the ER lavas,the magma underwent strong fractional crystallization owing to the low supply rate of magma and long stay of magma in the chamber(3-10 km;960℃-1020℃)and finally formed acidic lavas.Moreover,we argue that magma mixing did not play an important role in the magmatic evolution process.
In the marine environment,trace elements play an important role in the material cycle,significantly regulate life metabolism,and inhibit and poison planktonic and benthic organisms.Therefore,they are considered a"double-edged sword"with significant biogeochemical consequences for the marine system.Since the Industrial Revolution,the oceans have undergone continuous atmospheric CO2 absorption,resulting in a continuous decline in seawater pH,carbonate concentration,and global ocean acidification.As a new environmental stress factor,ocean acidification has disrupted the original balance of trace elements in sediment-interstitial water-overlying water systems,making the biogeochemical behavior of marine trace elements more complex and uncertain.In this review,the occurrence form and exchange process of trace elements in the sediment-seawater system are first discussed,followed by the diffusion,migration,and rebalance behavior of trace elements under ocean acidification conditions.Further,the subsequent toxic and bioavailability effects are analyzed.Finally,research on the ecological effects of trace elements caused by the combined action of ocean acidification and various environmental conditions and pol-lutants is prospected.
The oviduct gland is an important reproductive organ unique to cartilaginous fishes,which develops from the anterior part of the oviduct.The oviduct gland participates in crucial life processes,such as the synthesis of the egg capsule,secretion of the egg jelly,and the storage of sperm.Secretions from the oviduct gland contain a highly crosslinked collagenous composite marine biological material that is extremely tough and possesses antibacterial,antifouling,and degradable properties.However,studies on the oviduct glands of cartilaginous fishes are relatively limited in China.Herein,we review several areas of interest concerning the oviduct glands of cartilaginous fishes,such as reproductive strategies,the structure of the oviduct gland,and the secretion processes.Further,we summa-rize the current challenges in oviduct gland research,such as sperm storage and oviduct gland secretion,that high-light areas for future investigation.We also hope this review provides a reference for future studies on cartilaginous fishes.
Ocean mesoscale eddy visualization can reflect the motion law of ocean mesoscale eddies in graphical images and other intuitive ways,which is a powerful tool for studying marine mesoscale eddies.However,existing visualization methods suffer from shortcomings.For example,the streamlines in the spatiotemporal continuous visualization framework cannot represent the continuous motion process of the entire spatiotemporal region,feature values applied to the extraction of ocean vortexes are severely affected by the threshold,and interactive transfer function relies on user experience.Therefore,to address these issues,this paper proposes a full spatiotemporal con-tinuous framework and a standard morphological model of the transfer function for the first time.The region-based vortex extraction technology(Ω criteria)is employed for the visualization of marine mesoscale eddies.Further,this paper proposes a two-and three-dimensional graphics processing unit(GPU)implementation scheme of the whole-spatiotemporal continuous visualization framework.Experimental results show that the proposed scheme achieves the visualization of real-time interaction,which is of great significance for the interactive visualization of marine mesoscale eddies.
The C1q domain-containing proteins(C1qDCs)have been demonstrated to play crucial roles in the im-mune responses of invertebrates,with very few reports in the ark shells.In the present study,a C1qDC gene with a typical C1q domain(designated as SsC1qDC)was identified from the ark shell Scapharca subcrenata and its possi-ble immune responses against pathogen infection was also characterized.The full-length cDNA sequence of SsC1qDC was 711 bp,encoding a peptide of 199 amino acids with an N-terminal signal peptide.SsC1qDC was clustered with the C1qDCs from bivalves in the phylogenetic tree.SsC1qDC was widely expressed in the tissues,with the high expression level in hepatopancreas and adductor muscles.The expression of SsC1qDC was increased significantly from eggs to eye-point larvae stage and induced remarkably by Vibro parahaemolyticus infection.Moreover,compared to the controls,knockdown of SsC1qDC resulted in a remarkable increase of mortality and apoptotic levels of ark shells after V.parahaemolyticus challenge,and thus a significant reduction of total number and phagocytosis of hemocytes.Meanwhile,knockdown of SsC1qDC could significantly inhibit the expression of maternally derived immune-related genes(Vg,LSZ,Dscam,TEP and SsC1qDC-3),while the expression of C3,PAF3,SsC1qDC-1 and SsC1qDC-2 was up-regulated remarkably.Taken together,these results suggested that SsC1qDC performs crucial roles in immune defense against pathogen infection in ark shells,which is of great guiding significance to the immunology of shellfish and the breeding of new disease-resistant strains.
In recent years,there have been frequent incidents related to cold source safety at nuclear power plants caused by marine organisms,indicating that cold source safety is an important factor that affects nuclear power safety and reliability.In this paper,the main incidents at a national and international level are analyzed to summa-rize the classification and characteristics of organisms that cause cooling-water system disasters,discuss the screening and grading of the early warning standards of these organisms,and analyze relevant detection technolo-gies.Finally,the key scientific and technical problems needing urgent resolution are proposed to provide a refer-ence and theoretical basis for better dealing with the safety problems of coastal nuclear power cold sources.
Fluoroquinolones(FQs)from a class of widely used synthetic antibiotics and exist in various environ-mental media,such as water and sediments.FQs are gradually enriched in aquatic organisms,posing a negative effect on human health and the sustainable development of the global ecosystem.Determining the FQ residues in the environment is the foundation for understanding their environmental biogeochemical behavior and potential ecological risks.This article systematically summarizes the results related to the features,as well as the sample pretreatment and determination of the FQ residues in seawater,sediments,and biological samples obtained in recent years.Accordingly,the development trend of sample pretreatment and determination methods for FQ analysis in marine environments is discussed.The physical and chemical properties,along with the complexity of sample compositions,must be considered during the sample pretreatment and determination of FQs.Sediment and biologi-cal samples should be prepared to remove more water,select the appropriate extraction solvent,and employ ultra-sonic-assisted extraction,considering the matrix effect and pH.Solid-phase extraction(SPE),QuEChERS extrac-tion,and magnetic solid-phase extraction are common methods for the separation and enrichment of FQs.The se-lection and optimization of the eluting solution are key factors for improving sample recovery.The determination of FQs is mostly carried out through liquid chromatography-tandem mass spectrometry or liquid chromatography combined with a fluorescence detector,wherein selecting the chromatographic column,adding an ion-pairing agent,and adjusting pH are the key factors.In future research,more attention should be paid to the development of online automatic SPE technology and new extraction adsorbents.
Meiofauna is an important component of the mangrove ecosystem.Thus,it is important to elucidate the community characteristics of mangrove meiofauna to gain knowledge on the biodiversity,monitoring,and evalua-tion of the mangrove ecosystem's health.The meiofauna on leaf litter and the sediment from five typical mangrove forests were investigated in Hainan,Dongzhai Harbor National Nature Reserve,China,in November 2020 to study the community characteristics and factors affecting meiofauna.A total of 12 meiofaunal groups were identified,and the relative abundances of nematodes and copepods were 67.67%and 29.31%,respectively.The average abundance of epiphytic meiofauna was(5.27±3.35)ind·g-1,and the average biomass was(4.94±2.35)µg dwt·g-1.The abun-dance and biomass of epiphytic meiofauna were significantly different among the five mangrove forests.The abundance and biomass of meiofauna in Avicennia marina and Rhizophora stylosa were higher than those of other mangrove forests,whereas the abundance and biomass of meiofauna in the mixed forest were the lowest.The abundance and biomass of meiofauna were negatively correlated with the content of soluble condensed tannins and the sorting coefficient,whereas they were positively correlated with the skewness coefficient.A combination of environmental factors,including the contents of chlorophyll a and cellulose condensed tannins,as well as the sort-ing and skewness coefficients,clearly explained the community structure of meiofauna.These results not only pro-vide basic data for an overall understanding of the mangrove ecosystem but also new perspectives for future studies on the structure and function of mangrove ecosystems.
为了查清南黄海自由生活海洋线虫(Nematoda)种类组成和物种多样性,作者开展了南黄海沿岸潮间带自由生活海洋线虫的分类和多样性研究.通过形态学分类方法鉴定出海洋线虫247种或分类实体,其中最优势属为吞咽线虫属(Daptonema),属内个体占线虫总数的19.6％,次之为近色矛线虫属(Chromadorina)、折咽线虫属(Ptycholaimellus)和棘刺线虫属(Theristus).最优势种为暹罗海单宫线虫(Thalassomonhystera siamensis Kito & Aryuthaka,1998),数量上占线虫总数的 12.6％,其次为拟短毛吞咽线虫(Daptonema parabreviseta Huang & Sun,2018)和眼点折咽线虫(Ptycholaimellus ocellus Huang &Wang,2011)等.描述并图示了中国4个海洋线虫新纪录种,即居中嘴咽线虫(Enoplolaimus medius Pavljuk,1984)、暹罗海单宫线虫(Thalassomonhystera siamensis Kito&Aryuthaka,1998)、韦伯斯特绒毛线虫(Pomponema websteri Sharma & Vincx,1982)和条纹隆唇线虫(Xyala striata Cobb,1920),进一步了解了这4个物种的地理分布区.隆唇线虫属(Xyala)是中国海域的首次报道,为中国线虫多样性增加了新属的纪录,同时丰富了中国海洋线虫的物种多样性信息.南黄海沿岸潮间带8个采样站位海洋线虫香农-威纳多样性指数(H')为1.859～3.022,小于南黄海潮下带的多样性指数2.56～3.79,因此南黄海潮间带线虫的多样性低于潮下带线虫多样性.
针对利用传统瞬时水边线提取方法处理高分辨率遥感影像存在提取结果不连续、效率不高和无法同时提取多片水域等问题,提出了一种顾及轮廓信息和距离正则化水平集演化(distance regularized level set evolution,DRLSE)模型的遥感影像瞬时水边线快速提取方法,并将其应用于福建泉州附近海域瞬时水边线提取.首先,使用DRLSE模型提取地物轮廓信息,以解决经典阈值方法水边线提取结果不连续问题;其次,利用DRLSE模型的初始矩形轮廓中心位置和周长信息,对噪声点等轮廓进行自动剔除,并提取多片水域,以提高瞬时水边线提取后处理效率.研究结果表明:相较于泛洪算法、Canny算子和CV(Chan-Vese)模型,应用本方法进行大陆海岸线瞬时水边线提取更高效,且提取结果连续、精度更高.
为提高遥感影像融合质量,提升资源一号(ZY-1 02D)高光谱遥感影像滨海湿地植被分类精度,提出将ZY-1 02D高光谱影像与空间分辨率为10 m的哨兵2号(Sentinel-2)影像进行Brovey融合,并通过搭建AlexNet卷积神经网络对ZY-1 02D高光谱影像和Brovey融合影像的滨海湿地植被进行分类,与支持向量机、随机森林和BP神经网络分类算法进行精度对比.研究结果表明:经Brovey融合后,AlexNet、支持向量机、随机森林和BP神经网络算法的植被分类总体精度分别提高15.60％、7.00％、14.80％和 10.00％,Kappa 系数提高了21.35％、9.93％、18.97％、12.85％;基于 Brovey 影像融合与 AlexNet算法的植被分类精度最高,总体精度为92.40％,Kappa系数为89.42％.空谱融合配合AlexNet卷积神经网络有效解决了高光谱遥感影像在滨海湿地植被分类应用中精度较低的问题,为滨海湿地植被资源动态监测提供技术和方法支撑.
海带(Saccharina japonica)是一种重要的经济养殖海藻.中国海带与褐藻胶的产量分别占世界总产量的60％和90％.与高等农作物相似,在海带育苗及养殖过程中常常会暴发病害,严重时可造成20％～50％的减产.分离、鉴定致病菌及其致病因子是预防和控制病害发生的前提条件.由于海藻的致病菌大多是条件致病菌,迄今为止,海带致病菌的分离和鉴定仍是一个瓶颈问题.本研究运用传统微生物分离培养方法从脱苗病海带幼苗藻体分离出一株致病菌LJ2-4,经过复染实验及科赫法则验证,证实该菌株在实验室条件下可使健康海带雌、雄配子体产生白化的病症.LJ2-4菌落圆形、边缘完整,呈浅橙色.扫描电镜和透射电镜观察表明:LJ2-4菌体呈球形/杆状,长0.5～1.2 μm,宽0.4～0.7 μm无鞭毛.经 16S rDNA 分子鉴定,其与 Planococcus okeanokoites IFO 12536T 的相似性为 99.45％.结合 LJ 2-4 的生理生化特性,将该菌株命名为Planomicrobium okeanokoites LJ2-4.P.okeanokoites LJ2-4是在实验室条件下可引起健康海带配子体产生白化病的条件致病菌.本研究为海带致病菌致病机理的研究奠定了前期工作基础,同时也可为预防与控制海带苗期脱苗病的暴发提供理论依据.
台风强度预报误差较大,相关物理机制有待深入研究.针对台风"海马"个例,利用台风最佳路径数据集和欧洲中心再分析资料设定台风特征参数,使用基于海-气相互作用理论的简单台风模型对台风"海马"进行数值模拟,并针对焓交换系数与拖曳系数比值开展敏感性试验.控制试验结果表明,在台风的成熟期,台风的切向动能主要存在于眼壁外侧的云下层和对流层中下层,而径向动能主要集中在对流层上部和眼壁外侧的云下层,这些结果描述了台风成熟期的基本特征.敏感性试验表明,当海洋表面焓交换系数与拖曳系数的比值增大时,台风的主级环流与次级环流明显增强,台风边界层的平均径向风速度分布更趋向中心,且风速明显增加,同时,垂直上升速度增加,台风切向动能明显增加,台风强度增强.研究结果有助于理解海气交换对台风强度的影响.
根据2022年8月大潮期间庙岛群岛岛屿的潮间带和潮下带大型底栖动物的调查结果,对其种类组成、数量分布、优势种、多样性以及群落结构特点进行了研究.结果表明:本次潮间带定量调查共鉴定大型底栖动物52种,其中甲壳动物最多(17种);定性调查共鉴定42种,软体动物最多(30种).潮下带定量调查共鉴定大型底栖动物39种,低于潮间带定量调查,其中软体动物最多(26种).潮间带大型底栖动物平均丰度为234个/m2,平均生物量为82.82 g/m2.潮下带平均丰度为180.2个/m2,平均生物量为708.02 g/m2.潮间带大型底栖动物多样性指数(H')、丰富度指数(D)和均匀度指数(J')平均值分别为1.187、1.723和0.540;潮下带H'、D和J'平均值均高于潮间带,分别为1.301、2.204和0.669.在本次潮间带定量调查中,大型底栖动物优势种为施氏玻璃钩虾(Hyale schmidti).平背蜞(Gaetice de-pressus)、潮间海钩虾(Pontogeneia littorea)等.潮下带优势种与潮间带不同,为紫贻贝(Mytilus gallo-provincialis).东方缝栖蛤(Hiatella orientalis)、锈凹螺(Chlorostoma rustica)等.聚类分析和 nMDS 分析表明,在20％的相似性水平上,庙岛群岛潮间带和潮下带大型底栖动物分别可划分为4个和3个群落.与周边海域潮间带历史资料相比,调查区域的大型底栖动物在物种数量、平均丰度和平均生物量方面处于中等水平.
