Climate change influences the distribution of many marine species. To project the biogeographical changes of benthic mollusks in response to climate change in the Yellow Sea and East China Sea, ensemble species distribution models (SDMs) were applied. Ensemble SDMs performed well for ten of the thirteen selected benthic mollusks with environmental variables including temperature, salinity, current velocity, and depth. Six cold water mollusks, including bivalves Acila mirabilis , Ennucula niponica , Ennucula tenuis , Nuculana yokoyamai , Pendaloma otohimeae and Megayoldia japonica , were projected to contract their habitats and move northward in 2050s and 2100s under all of the RCP2.6, 4.5, 6.0 and 8.5 climate scenarios, with temperature being the most important environmental variable. Two warm water mollusks (bivalves Nucula tokyoensis and Leptomya minuta ) were projected to lose their suitable habitats under future climate scenarios (all RCP scenarios), while two (the gastropod Cylichna biplicata and the bivalve Moerella hilaris ) were projected to expand their habitats to the deeper water area. The most important environmental variable varied among warm water species between temperature, salinity and depth. This study will contribute to better understanding the marine species biogeographical changes under climate change, and thus we can better protect their biodiversity.

To detect potential impacts of climate change on the distribution of common echinoderm species in the Yellow Sea (YS) and East China Sea (ECS), species distribution models (SDMs) were applied. Ensemble SDMs were constructed and were in good model performance for six of the eight selected common echinoderm species. Under future climate scenarios, the brittle stars Ophiopholis mirabilis, Amphioplus depressus and the sea cucumber Protankyra bidentata were projected to expand in the southwestern areas of the YS, the ECS, and the coastal areas of the YS and ECS, respectively; the brittle stars Stegophiura sladeni, Amphiura digitula and Amphiura vadicola will likely contract their ranges in the south distribution areas and expand in the north, showing a northward movement trend. Temperature was the most important environmental variable influencing the distribution of the latter three echinoderms. Our findings will improve our understanding of the impacts of climate change on marine species distributions.

Species distribution models (SDMs) are used to detect potential effects of climate change on the habitat suitability of macrobenthos in the Yellow Sea and East China Sea. We obtained the presence/absence data of five dominant and characteristic macrobenthos from 268 sites investigated during 2000-2016 and 13 environmental variables from online datasets. The ensemble SDMs were constructed and were in good model performance for all five species. Model projections showed that the five species displayed different reactions to future climate scenarios: two species (the ophiuroid Ophiura sarsii vadicola and the bivalve Thyasira tokunagai) will likely contract their ranges, two (the crab Xenophthalmus pinnotheroides and the polychaete Sternaspis chinensis) will likely expand their ranges, and one (the ophiuroid Amphioplus japonicus) will likely move northward. Those differences were mainly due to their difference in thermal tolerance. Our findings provide important scientific basis for understanding the influence of climate change on marine benthic ecosystems.

本研究根据2000年10月、2001年3月、2003年6月、2004年1月、2011年4月和8月黄海大型底栖动物调查资料(仅2011年4月和8月航次测定水体和沉积物环境数据)对黄海大型底栖动物功能摄食类群的空间格局及其与环境因子的相互关系进行研究.结果 表明,黄海大型底栖动物功能摄食类群相对丰度较高的为肉食者、食底泥者和滤食者.黄海大型底栖动物食底泥者和肉食者相对丰度高值出现在201 1年8月航次,分别为44.88％和39.04％.黄海大型底栖动物空间分布以黄海冷水团区域为参照,黄海大型底栖动物肉食者主要分布在黄海冷水团边缘靠近海州湾东侧.食底泥者主要分布在黄海近岸及黄海冷水团边缘.滤食者主要分布在黄海冷水团中央区域.运用摄食多样性指数(J'FD)对黄海水域生态质量和底栖群落健康状况进行评价,结果表明,黄海近岸海域生态质量状况较低.对2011年4月和8月航次黄海大型底栖动物功能群与环境因子进行冗余分析,结果表明,底层水温度、盐度、水深和中值粒径是影响黄海大型底栖动物功能摄食类群的主要环境因素.

To examine the temporal variation of macrobenthic community zonation over nearly 60 years and the effects of latitude and depth in the southern Yellow Sea and East China Sea, a total of 1386 box-corer samples from four large spatial scale studies during 1958-1959, 2000-2004, 2011-2013 and 2014-2016 period, respectively, were compiled. A total of 26, 14, 13 and 18 communities were identified, respectively during the four periods with the same analytical method. The Yellow Sea Cold Water Mass (YSCWM) community, restricted to the 34°N latitude in the south and 50 m isobaths in the west, varied little in its spatial pattern over nearly 60 years, while other communities did not. The representative species in the YSCWM community changed from the polychaetes to the brittle stars during 1958-2016. However, in other large spatial scale communities except the YSCWM community, the representative species changed from the echinoderms, nemerteans or crustaceans to the polychaetes. For the revisited locations across studies, significant temporal and spatial variations in community structure at both species and family levels were detected. Macrobenthic species with high consecutive contributions to the community similarity were significantly influenced by latitude, depth, temperature and salinity, among which latitude and depth were the first two most significant environmental variables. Species diversity increased from 32 to 37°N during 1958-1959, but decreased during 2014-2016. It seems that the latitude of 32°N is an ecological barrier for macrobenthic community and diversity, but its effects weakened from 1958 to 2016. Species diversity roughly showed a first increasing then decreasing trend with the increase of the water depth in the southern Yellow Sea and East China Sea.

The main environmental variables of bottom seawater and macrobenthic invertebrates were investigated from February 2015 to January 2016 to evaluate the benthic ecological status in adjacent areas of the Yangtze River Estuary, China. Diverse ecological assessment results were given by the AZTI Marine Biotic Index (AMBI), multivariate-AMBI (M-AMBI) and benthic opportunistic polychaetes amphipods (BOPA) index, showing that the M-AMBI was the most suitable in the study area. A clear spatial distribution pattern related to the distance from the estuary and the coasts was found both for the benthic ecological status and the eutrophication-related bottom seawater environmental variables, indicating that the study area was under eutrophication pressure. Two major disturbed regions (one was east of the Yangtze River Estuary, and the other was east of Zhejiang Province) were discovered, which was probably mainly caused by the Changjiang Diluted Water (CDW). No significant seasonal changes were found in the ecological status.

Main environmental variables of the bottom water and the macrozoobenthic community were compared between northern and southern adjacent sea areas of the Yangtze River estuary, China, using data of ten months from 2015 to 2016. The PCA (principal component analysis) results showed significant north-south differences in the environmental variables. Results of PCO (principal coordinates) analysis and cluster analysis revealed an obvious north-south distribution pattern of the macrozoobenthic community, and a phenomenon of patchy distribution of macrozoobenthos was also found in the study area. Relationships of environmental variables and the macrozoobenthic community dissimilarities were analysed by BIOENV analysis and CCA (canonical correspondence analysis). Depth, salinity and turbidity were revealed as major environmental factors related to the north-south differences in the macrozoobenthic community in adjacent sea areas of the Yangtze River estuary, and among them, depth contributed most to the differences. The CDW (Changjiang Diluted Water) was suggested as an important driving factor related to the north-south differences of both environmental variables and the macrozoobenthic community. ABC (abundance/biomass comparison) curves indicated that macrozoobenthos in the north suffered a higher level of disturbance than those in the south, probably due to suffering more interference from the Yangtze River.

In the present study, environmental parameters and macrozoobenthos in the Yangtze River estuary and its adjacent area, China, were investigated in summer and winter of 2015, and significant seasonal differences were found. Biodiversity was found to be lower in summer, which may result from the higher deposition rate. The relationship between the macrozoobenthic community and environmental parameters (especially dissolved oxygen) was revealed. Linear models describing the response of macrozoobenthic biodiversity indexes to mild oxygen deficiency were constructed. Mild seasonal oxygen deficiency was revealed significantly related to seasonal variations of the macrozoobenthic community, but this deficiency could not damage the community. In contrast, when mild oxygen deficiency occurred, natural predators of macrozoobenthos decreased, which may relieve the survival pressure of macrozoobenthos to some extent. Dissolved oxygen alone could not explain many variations of macrozoobenthos, and other environmental parameters, especially water depth, phosphate concentration and turbidity, also greatly contributed to those variations.

The bottom branches of the Kuroshio Current in the East China Sea were recently discovered from physical and chemical oceanographic perspectives. To examine the diversity and distribution of demersal fish community in the East China Sea and to assess the impact of the bottom branches of the Kuroshio Current, we investigated the demersal fish community with an Agassiz trawl in the East China Sea shelf in the summer of 2015. A total of 72 species were collected in 40 sampling sites with Amblychaeturichthys hexanema, Champsodon snyderi, Odontamblyopus rubicundus, Cynoglossus interruptus, and Coelorinchus multispinulosus being the top 5 most abundant species. Three ecological groups of demersal fish—the Coastal group (CG), Transitional group (TG) and Kuroshio group (KG)—were identified through multivariate analyses, and significant differences in species composition among the three ecological groups were detected. The dominant species varied among the groups: gobies in CG; Neobythites sivicola, Cynoglossus interruptus and Aseraggodes kobensis in TG; and Champsodon snyderi, Callionymus beniteguri and Ostorhinchus fasciatus in KG. Most diversity indices, including the number of species (S), Margalef's index (d), Shannon-Wiener's index (H'(log2)), Simpson's index (1-λ'), rarefaction index (ES(100)), Hill's number (N∞), average taxonomic diversity (Δ), total taxonomic distinctness (SΔ+), variation in taxonomic distinctness (Λ+) and total phylogenetic diversity (SΦ+) increased from inshore to offshore, whereas abundance and biomass increased from south to north. K-dominance curves suggested diversity rankings of offshore region > inshore region and southern region > northern region for regional comparisons. A diversity ranking of KG > TG > CG for group comparisons was also detected. The funnel and ellipse plots of taxonomic measures indicated that diversity was approximately equal to the expected range in KG (healthy), whereas it was significantly lower in CG (unhealthy). CCA (canonical correspondence analysis) revealed that turbidity, fine silt sediment, fluorescence, dissolved oxygen and salinity were the most active environmental variables influencing demersal fish community. RDA (redundancy analysis) found turbidity and temperature showed significant associations with the biodiversity matrix.

To detect the large-scale spatial pattern of the benthic macroinvertebrate communities and the relationship with their environment on the East China Sea shelf, forty sites were sampled for benthic macroinvertebrates and environmental variables during August and September 2015. A total of 12529 benthic macroinvertebrate individuals and 274 species were collected, with crustaceans being predominant, followed by mollusks. Four communities were identified by hierarchical agglomerative cluster (HAC) analysis and cross-verified by non-metric multidimensional scaling (NMDS) ordination: an Inshore community (IC); a Transitional community (TC); a Northern offshore community (NOC); and a Southern offshore community (SOC). Significant differences in their community structure were found by permutational multivariate analysis of variance (PERMANOVA). The indicator species varied among the four communities, with Solenocera crassicornis, Sternaspis scutata and Virgularia sp. dominating IC, Solenocera koelbeli, Trachysalambria curvirostris and Nitidotellina valtonis dominating TC, Parapenaeus fissuroides, Onustus exutus and Drachiella morum dominating NOC, and Heikeopsis japonica, Solenocera pectinulata and Actiniaria dominating SOC. Significant differences among communities were detected for species number (S), Margalef's index (d), Pielou's index (J′), Hill's number (N∞), total taxonomic distinctness (SΔ+), average phylogenetic diversity (Φ+), total phylogenetic diversity (SΦ+) and abundance through statistical analyses. The redundancy analysis (RDA) model revealed that turbidity, silicate and depth were significant environmental variables influencing the benthic macroinvertebrates. Variation partitioning (VPA) showed that water characteristics had a greater impact than sediment conditions on the distribution of benthic macroinvertebrates in the East China Sea.

2015年11月(秋季)、2016年2月(冬季)、2016年6月(春季)、2016年9月(夏季)大潮期间对山东长岛列岛中南长山岛和北长山岛的3个不同底质类型的潮间带采样点进行了系统的大型底栖动物调查,研究了其数量特征和季节变化,包括群落种类组成、密度和生物量、优势种、物种多样性等,结果表明:本次调查共鉴定出大型底栖动物隶属7个门,共81种.其中环节动物门多毛类动物25种,软体动物门25种,节肢动物门22种,棘皮动物门6种,其他类群共3种(包括纽虫、腔肠动物和鱼类各1种).潮间带大型底栖动物平均密度为118.97 ind./m2,软体动物和甲壳动物占据了研究区域底栖群落的密度主要成分,两者分别占比为39.58％和36.68％.各采样点平均密度为北长山岛(BCS)(141.17 ind./m2)>避险角(NCS1)(122.33 ind./m2)>明珠广场东(NCS2)(93.42 ind./m2);各采样点平均生物量为128.03 g/m2,软体动物和甲壳动物占据了研究区域底栖群落的生物量主要成分,两者分别占比为58.56％和35.32％.平均生物量北长山岛(BCS)(234.95 g/m2)>避险角(NCS1)(99.99 g/m2)>明珠广场东(NCS2)(49.13 g/m2).从季节来看,各站点的物种数、平均密度和生物量季节变化的规律性不明显,总体为秋、春季较多,夏、冬季较少.3个站点物种多样性指数(H′)、丰富度指数(D)和均匀度指数(J′)平均值分别为2.30、1.99和0.79,各潮区中,均为中潮带>低潮带>高潮带,各季节变化不明显.优势种受底质类型和季节变化的影响明显,没有在各站点和季节均为优势种的种类,主要的优势种有平背蜞(Gaetice depressus)、绒螯近方蟹(Hemigrapsus penicillatus)、短滨螺(Littorina brevicula)等.与以往历史资料相比,长岛潮间带生物出现了一定变化,种类和数量减少,与烟台近岸潮间带大型底栖动物种类组成差别很大.

Decadal variations (2000–2013) in the macrobenthic community of the southern Yellow Sea were investigated based on the analysis of the community at two stations located basically along the 70 m depth contour. Significant decadal variations in community structure were found through cluster analysis, nMDS ordination and one-way ANOSIM. SIMPER analysis showed that the decadal community variations could be roughly attributed to the decrease of two species of Mollusks (Thyasira tokunagai and Nucula tenuis) and the increase of one echinoderm (Ophiura sarsii vadicola), one polychaete (Notomastus latericeus) and one bivalve (Portlandia japonica) at both stations. Redundancy analysis showed that the Pacific Decadal Oscillation and the Southern Oscillation Index were significant climate indices influencing the macrobenthic community structure in the southern Yellow Sea. Most of the species collected in 2000s showed a positive correlation with Pacific Decadal Oscillation at both stations, especially for cold water species Thyasira tokunagai, while most species in 2010s were positively correlated to Southern Oscillation Index, e.g. Portlandia japonica and Notomastus latericeus at station 1 and Sigambra bassi and Aricidea fragilis at station 2.

The Kuroshio Current intrudes in the bottom layer of the East China Sea continental shelf from the northeast of Taiwan via two bottom branches named the Nearshore Kuroshio Branch Current (NKBC, along the 60 m isobath) and the Offshore Kuroshio Branch Current (OKBC, along the 100 m isobath). However, knowledge on the macrofaunal responses to these bottom branches is limited. This study examined the variations in the benthic macrofaunal community in a section of the East China Sea under the influence of the NKBC. Seven sites corresponding to three regions (the west, middle and east region) were sampled using an Agassiz trawl net at a monthly rate from February to November 2015 (except in August). A total of 270 macrofaunal species were collected in this study. Cluster analysis and nMDS ordination revealed three communities: the inshore, Kuroshio and offshore communities, roughly corresponding to the west, middle and east of NKBC route. Significant differences in the species composition (one-way PERMANOVA) and diversity indices (one-way ANOVA) among the regions and communities were observed, while no statistically significant difference among the months was detected. The indicator species also varied among the communities, with Sternaspis scutata and Odontamblyopus rubicundus dominating the inshore community, Camatopsis rubida, Schizaster lacunosus and Craspidaster hesperus dominating the Kuroshio community, and Portunus argentatus, Champsodon snyderi and Coelorinchus multispinulosus dominating the offshore community. Some rare species (e.g., Neobythites sivicola) may indicate the passage of the NKBC better than the indicator species. A redundancy analysis was used to describe the relationship between the macrofaunal species and environmental variables in this study. Water depth and turbidity played important roles in the distribution of the macrofauna. S. scutata and O. rubicundus were associated with high turbidity and shallow depth, while Plesionika izumiae and P. argentatus were associated with low turbidity and deep depth. This study outlines the impact of the NKBC on the distribution patterns of the macrofaunal community of the East China Sea. More studies are needed to understand the detailed interactions between macrofauna and the NKBC in the future.

Marine macrobenthic mollusk is an important group of marine macrobenthos. This study investigated macrobenthos in summer 2011 – 2013 in 5 sections and 29 stations of southern Yellow Sea (33°-37°N, 120.5°-124°E) using 0.1 m2 Gray-O’Hara box corer, which were processed through a 0.5 mm mesh sieve. The specimens obtained were preserved in 75% ethanol, then stained, identified to the lowest taxonomic level, counted and weighted to form this dataset.

To compare the macrobenthic community composition,community structure,and inter-annual variation inside / outside the Yellow Sea Cold Water Mass Core (YSCWMC) in summer,we analyzed the data collected in three marine surveys in July 1959,June 2004,and August 2012 in 18 stations.Three stations within and beyond the YSCWM were selected in each survey.Biodiversity indices including Shannon-Wiener index (H′),Pielou index (J′),Margalef index (d),and average taxonomic distinctness index (△+) were applied.Variation in taxonomic distinctness index (A +) and abundance-biomass comparison (ABC) curves were used to determine the status of the community.In the three surveys,altogether 33/87 species were found in/out of the cold-water mass.Two-way ANOVA analysis shows no significant differences in H′,J′,and d,as well as in abundance and biomass,in spatial and temporal realms in or out of the YSCWMC.The variation in community component was slightly greater in the inside than the outside,which is also true as shown in ABC curve.Mollusks were obviously more abundant inside than outside in biomass with very little change in species composition.Polychaeta and Echinodermata were major contributor to biomass but very few in variety inside the core,while in the outside,they dominated in both biomass and variety.Mollusks occupied 38％ of the total biomass inside but only 3％ outside.Thyasira tokunagai,Raetellops pulchella,Bivalvia,Nuculanida,and Portlandia japonica were main and common species inside the water mass.Therefore,YSCWMC could provide a favorable condition for mollusk growth and propagation,also maintain the its community structure.

Based on the investigation data of macrobenthic samples collected from coastal waters off Ningjin,Shandong,in the Yellow Sea,in four seasonal cruises in November 2009 (autumn),February 2010 (winter),May 2010 (spring),and August 2010 (summer).To understand the ecological characteristics and seasonal variation of the macrobenthic community,several indices and analytical methods were adopted,including dominance index,diversity index,cluster analysis,and MDS (non-metric multi-dimensional scaling) ordination analysis.The results show that there were 159 macrobenthic species identified,of which 73 belonged to Polychaeta,39 to Crustacea,25 to Mollusca,9 to Echinodermata,and the rest 13 species were other benthic groups.Paralacydonia paradoxa,Heteromastus filiforms,Lumbrineris sp.,and Ampelisca cyclops were the most dominant species.The average values of biomass and abundance were 9.144g/m2 and 233.90ind./m2,respectively.The average values of diversity index,richness index,evenness index were 2.924,2.436,and 0.800,respectively.The average values of secondary production was 1.903g(AFDW)/(m2·a).The macrobenthic community of the waters off Ningjin included both coastal and off-shore communities;however,the boundaries between them were indistinct.

Using data from four periods from 1959 to 2015, we report the long-term variation of the macrobenthic community in the Yangtze River estuary and its adjacent area. In total, 624 species were collected, and Polychaeta was the dominant group. Significant differences between the four periods were found. The CCA (canonical correspondence analysis) and RDA (redundancy analysis) results revealed that temperature, salinity, and depth significantly influenced the macrobenthic communities (89.6% of the species-environment relationship variance was explained by the first two axes of CCA and 94.3% was explained by RDA). The results of K-dominance curves (the elevation increased over time), ABC (abundance/biomass comparison) curves (the W value changed from 0.311 to 0.167 during 1959 to 2014-2015) and the Shannon-Wiener index (log base=2; 2.29-5.03 in 1959, 2.86-4.55 in 2000-2001, 2.28-4.56 in 2011-2012, and 1.79-4.43 in 2014-2015) showed that the ecological status of the benthic study area was deteriorating.

Based on macrobenthos collected in October 2000,March 2001 and 2003,June,January 2004,April and August 2011 in the Yellow Sea,species were studied,of which nine were dominant macrobenthos in the past 10 years in dominant value ＞0.02).In addition,five polychaete species (Nephtys oligobranchia,Notomastus latericeus,Ninōe palmate,Ophelina acuminate and Onuphis geophiliformis),two mollusk species (Thyasira tokunagai and Nucula tenuis),and two Echinodermata species (Ophiura sarsii vadicola and Ophiopholis mirabilis).T.tokunagai was a dominant species in four cruises,O.acuminate,O.sarsii vadicola,and N.palmate were dominant species in two cruises.The dominant values of N.latericeus (0.0859) is the greatest in six cruises.We assessed indicator potential of different taxa independent of environmental elements by Indicator Species Analysis (ISA).To delineate water layers in different depths for two cruises of April and August 2011,we analyzed indicator species based on bottom water temperature and salinity.The results show that in the Yellow Sea,Goniada japonica,Glycinde gurjanovae,Callianassa sp,and Ampelisca sp were the indicator species to 30-m-deep layer (P＜0.05),while N.latericeus,Acila mirabilis,N.palmate,and O.sarsii vadicola to ＞30-m layer.In addition,the compositions of indicator species are consistent with those of dominant species.Therefore,depth,bottom water temperature,and salinity were key environmental factors on the distribution of dominant macrobenthos species in April and August 2011.In the past 10 years,in the coastal water of the Yellow Sea,dominancy of the macrobenthos species has been changed generally from larger bivalves into smaller polychaetes,whereas that of the cold water mass areas remains unchanged.

本文根据2014年6月长江口邻近海域大型底栖生物的调查资料,采用优势度指数、物种多样性指数、丰富度指数、均匀度指数、Bray-Curtis相似性聚类和非参数多维标度排序(nMDS)标序方法,分析了长江口邻近海域夏季大型底栖生物的群落特征.本次调查共采集大型底栖生物135种,其中多毛类动物66种、甲壳动物33种、棘皮动物14种、软体动物13种、其他类群动物9种.调查海域的大型底栖生物平均丰度为122.2ind./m2,平均生物量为7.8g/m2.丰度、生物量和多样性指数在不同海区间的空间差异均不显著.大型底栖生物在20％的相似性水平上可以划分为8个群组,各站位间相似性水平较低.ABC曲线表明,伴随海岸带开发及人类活动的持续影响,长江口邻近海域底栖生境的稳定性受到轻微扰动,建议继续开展长期连续监测,为研究长江口海域环境变化和大型底栖生物群落演替提供基础资料.

胶州湾位于山东半岛南岸,是黄海深入内陆的半封闭天然海湾,底栖动物种类丰富。本文根据2014年2、5、8和11月4个航次（冬、春、夏、秋）的调查资料,采用优势度指数,物种多样性指数、丰富度指数、均匀度指数,Bray-Curtis相似性聚类和非参数多维标度排序（NMDS）方法,分析了胶州湾大型底栖动物群落的季节变化特点。各航次共采集大型底栖动物199种,其中多毛类79种,甲壳动物47种,软体动物40种,棘皮动物17种,其他类群16种。各季度优势种有变化亦有重叠,以多毛类为主。2014年度胶州湾大型底栖动物的年平均丰度为209.85 ind./m~2,最高丰度出现在秋季,最低出现在春季;年平均生物量为79.22 g/m~2,最高生物量出现在夏季,最低出现在春季。物种多样性指数（H’）变化范围为2.16–2.86,物种丰富度指数（D）变化范围为2.79–3.72,物种均匀度指数（J）变化范围为0.58–0.82。聚类分析结果显示,4个航次的群落相似性系数均较低,分布格局存在季节性变化。近年来,伴随海岸带开发及人类活动的持续影响,胶州湾底栖生境的稳定性受到一定的威胁,建议继续开展长期连续的监测,探索有效的综合治理措施,使胶州湾海洋生态系统能够持续健康的发展。