青岛近海物理-生物地球化学过程及其生态响应

近些年来,夏季黄海浒苔大规模暴发,并在青岛近岸海域大面积聚集,引起了广泛的关注。本文基于在夏季和冬季所获得的多学科调查资料,重点研究了青岛近海的水文-生物地球化学过程及其生态影响,阐明了该海域物理-化学-生物等多参数之间的耦合响应。研究显示,夏季黄海冷水团的边界可扩展至青岛近岸海域,并在局部涌升至上层水体,形成沿岸上升流;该上升流可对上层营养盐产生一定的补充,进而促进浮游植物的繁殖,并于底层海域对应形成溶解氧（DO）和pH的低值。夏季青岛近海的上升流可能还有利于随南风漂移至此的浒苔的生长,并在一定程度上引起浒苔的局地旺发;同时,夏季该海域特定的锋面系统对浒苔聚集的影响也不容忽视。冬季黄海暖流在苏北浅滩外侧向山东半岛南部海域延伸,扩展至青岛近海的暖水舌与近岸低温水之间的锋面特征明显,而且在向岸暖水与近岸冷水间还对应形成了明显的营养盐和叶绿素（Chl-a）锋面。该项研究从多学科交叉的视角,增进了对青岛近海物理、化学和生物过程之间耦合关系的认识。     

Biological components of Ross Sea short-term particle fluxes in the austral summer of 1995–1996

The Ross Sea, a region of high seasonal production in the Southern Ocean, is characterized by blooms of the haptophyte Phaeocystis antarctica and of diatoms. The different morphology, structural composition and consumption of these two phytoplankton by grazing zooplankton may result in different carbon cycling dynamics and carbon flux from the euphotic zone. We sampled short-term (2 days) particle flux at 5 sites from 177.6°W to 165°E along a transect at 76.5°S with traps placed below the euphotic zone at 200 m during December 1995–January 1996. We estimated carbon flux of as many eucaryotic organisms and fecal pellets as possible using microscopy for counts and measurements and applying volume:carbon conversions from the literature. Eucaryotic organisms contributed about 20–40% of the total organic carbon flux in both the central Ross Sea polynya and in the western polynya, and groups of organisms differed in contribution to the carbon flux at the different sites. Algal carbon flux ranged from 4.5 to 21.1 mg C m⁻² day⁻¹ and consisted primarily of P. antarctica (cell plus mucus) and diatom carbon at all sites. Different diatom species dominated the diatom flux at different sites. Carbon fluxes of small pennate diatoms may have been enhanced by scavenging, by sinking senescent P. antarctica colonies. Heterotrophic carbon flux ranged from 9.2 to 37.6 mg C m⁻² day⁻¹ and was dominated by athecate heterotrophic dinoflagellate carbon in general and by carbon flux of a particular large athecate dinoflagellate at two sites. Fecal pellet carbon flux ranged from 4.6 to 54.5 mg C m⁻² day⁻¹ and was dominated by carbon from ovoid/angular pellets at most sites. Analysis of fecal pellet contents suggested that large protozoans identified by light microscopy contributed to ovoid/angular fecal pellet fluxes. Carbon flux as a percentage of daily primary production was lowest at sites where P. antarctica predominated in the water column and was highest at sites where fecal pellet flux was highest. This indicates the importance of grazers in carbon export.     

安达曼海泰国水域的立方水母Chiropsoides属分类辨析

采集于泰国西南部安达曼近岸海域的一种立方水母Chiropsoides buitendijki,伞部呈典型的箱式、触手单侧分支,并缺乏幅间沟。触手带型呈1–3–2–3–2–3–2–3–1（1-主带,2-粗副带,3-细副带）。18S核糖体基因序列分析证实了其分类地位。同时,16S线粒体基因序列揭示样品内存在一定的遗传分化,说明该种内可能存在不同的群体,值得进一步研究。     

Recruitment variability in dab (Limanda limanda) in the southeastern North Sea

Data from three annual surveys, covering inshore and offshore waters of the southeastern North Sea, were analysed to study recruitment variability in dab (Limanda limanda) over the period 1978–1997. Geometric mean abundance of 0- to 5-group dab was estimated using general linear models. Juvenile dab (0- and 1-group) were found over the entire area, from inside the estuaries to 50 m depth offshore. Environmental conditions (water temperature, wind stress, turbidity) affected the catch rates. The potential errors in the estimates of year-class strength, caused by differences in catchability, are discussed. The inter-annual pattern of year-class strength appeared to be established between ages 1 and 2, suggesting that factors determining recruitment are not restricted to the pelagic early life phase only, but also operate during the demersal juvenile phase. Recruitment variability at age 2 was in the order of 50–60% and appears to be equal to, or lower than, recruitment variability in plaice and sole. These results contradict expectations based on the concentration hypothesis, which states that the degree of variation in recruitment is inversely related to the degree of concentration during early life phases.     

Dissolved organic carbon variability in a shallow coastal marine system (Gulf of Trieste,northern Adriatic Sea)

The variability of dissolved organic carbon (DOC) over days to a multi-year time span has been investigated in the Gulf of Trieste (northern Adriatic Sea) over a period of 5 years (January 1999 to December 2003). Samples were collected in a grid of 9 to 12 stations on monthly frequency and in one station on weekly (2003) and daily (1-month) frequency. DOC samples were analyzed by the HTCO method. DOC concentration varied over the five years in the range of 50 to 194 μM with annual median values ranging from 88 to 98 μM. Over the years 1999–2002, DOC showed a clear annual periodicity with winter minima and late summer maxima, higher in 1999 and 2000. During 2003 no seasonality was detected. The absence of DOC seasonality and the lower DOC concentrations during 2003 are most likely related to the drought that characterized the whole year. Accumulation was calculated as the difference between averaged winter minima (59 ± 7 μM) and the monthly averaged integrated value. DOC that had accumulated from spring to summer totally disappeared from the water column in winter when DOC concentrations reached the background value. The Gulf of Trieste, as with the rest of the Northern Adriatic each year, seems to be able to bring back DOC concentrations at low levels despite the significant external (mainly Isonzo River inputs) and internal organic matter loads. DOC concentration exhibited quite wide fluctuations weekly and daily, suggesting there might be DOC of different turnover time through production, consumption, migration and accumulation.     

Microbial respiration in the aphotic zone of the Ross Sea (Antarctica)

In January–February 2001, we measured microbial biomass as ATP and community respiration as ETS activity of organisms < 200 μm in the aphotic zone of the Ross Sea. Microbial respiration amounted to 2.14 mmol C m^− 2 day^− 1 in the depth range 200–1000 m. Our daily estimates of carbon export are close to the daily percentage of net community production (NCP), removed as sinking biogenic particles from the upper 100 m in the entire Ross Sea, but lower than those of other oceanic systems. Comparing remineralization determined in this study with that obtained by sediment traps in the Ross Sea, it appeared that about 63% of organic carbon remineralized by respiration derived from POC pool. Such evidence highlighted POC source as the main organic fuel of the biological pump in the Ross Sea.     

Microalgal Communities of the Sea Ice, Ice-Covered and Ice-Free Waters of Wood Bay (Ross Sea, Antarctica) During the Austral Summer 1993 – 94

Abstract. During the austral summer 1993 – 94, microalgal density and biomass were investigated in the sea ice, in the underlying water column, in the melt water and during the formation of the sea ice. Of the 96 taxa identified, 59 were diatoms and 32 were dinoflagellates. Among the remaining five species, Pseudopleurochloris antarctica  was very abundant both in the sea ice and in the ice-free waters. Cell densities and biomass of microalgae were higher in the bottom of the sea ice and during the formation of the ice than in the seawater, and diatoms were the dominant group at higher microalgal biomass. Among these, Entomoneis kufferathii , Chaetoceros dichaeta and Fragilariopsis species were the most common taxa.     

Short-term environmental impact of clam dredging in coastal waters (south of Portugal): chemical disturbance and subsequent recovery of seabed

The physical and chemical changes in sediment and near bottom water caused by clam dredging were examined during July and September 1999, at two locations Vilamoura (VL) and Armona (AR), south coast of Portugal. Sediment cores and near bottom water were collected simultaneously before dredging (control samples) and within short time intervals (min-h) after dredging. After dredging operations, microphytobenthos coming from the path were accumulated in the re-worked sediment (ridge). Chlorophyll a in superficial sediment increased from 1.2 microg x g(-1) before dredging to 1.7 microg x g(-1) after dredging and these higher values remained for a few hours. However, the expected increase of chlorophyll a in near bottom water due to re-suspension was not observed. After sediment disturbance an instantaneous sorption of phosphorus onto iron oxides occurred in the upper sediment layers (from 2 to 3 micromol x g(-1) before dredging to 4-5 micromol x g(-1) after dredging). A microcosm experiment showed that after sediment disturbance HPO(4)(2-) dissolved in pore water decreased from 40 to 10 microM being simultaneously sorbed onto iron oxides formed in the top layer of sediment. The ammonium, nitrates, organic nitrogen, phosphate and silicate dissolved in pore water decreased immediately after dredging activity and simultaneously an increase in near bottom water was sporadically observed. Generally, the re-establishment of seabed was reached within a short time (min-h), at both stations (VL and AR).     

Short-term variability of fCO2 in seawater and air–sea CO2 fluxes in a coastal upwelling system (Ría de Vigo, NW Spain)

Coastal upwelling systems are regions with highly variable physical processes and very high rates of primary production and very little is known about the effect of these factors on the short-term variations of CO₂ fugacity in seawater (fCO₂^w). This paper presents the effect of short-term variability (<1 week) of upwelling–downwelling events on CO₂ fugacity in seawater (fCO₂^w), oxygen, temperature and salinity fields in the Ría de Vigo (a coastal upwelling ecosystem). The magnitude of fCO₂^w values is physically and biologically modulated and ranges from 285 μatm in July to 615 μatm in October. There is a sharp gradient in fCO₂^w between the inner and the outer zone of the Ría during almost all the sampling dates, with a landward increase in fCO₂^w.CO₂ fluxes calculated from local wind speed and air–sea fCO₂ differences indicate that the inner zone is a sink for atmospheric CO₂ in December only (−0.30 mmol m⁻² day⁻¹). The middle zone absorbs CO₂ in December and July (−0.05 and −0.27 mmol·m⁻² day⁻¹, respectively). The oceanic zone only emits CO₂ in October (0.36 mmol·m⁻² day⁻¹) and absorbs at the highest rate in December (−1.53 mmol·m⁻² day⁻¹).     

东海原甲藻赤潮的垂向发展过程:生物-物理耦合数值模拟

近年来,东海原甲藻赤潮在我国东海近岸海域频繁发生。本研究利用生物-物理耦合模型对发生于2005年的东海原甲藻赤潮进行后报模拟,并对控制其起始与发展的因素展开研究。该模型由东海原甲藻种群动力学模型与多层嵌套的水动力模型组合。通过对比模拟结果与室内实验结果,证实种群动力学模型能够很好地重现东海原甲藻在不同光照与磷营养限制条件下的生长过程,同时能够再现藻细胞内部磷含量及藻类对外部营养盐浓度的影响。耦合模型能够较好地再现模拟海域水动力（见Sun et al.,2016）与东海原甲藻赤潮的时空分布。模拟的赤潮发展过程与此前研究中的观测结果一致,且模拟结果表明模型能够捕捉到赤潮初期种群的次表层孕育现象。随后模拟结果被用于诊断决定赤潮垂直分布的决定性因素,结果表明磷酸盐是控制这一现象的关键因素。同时,表层风场在决定赤潮的分布中扮演着重要角色。模拟结果强调了营养盐限制在东海原甲藻次表层孕育及消散过程中的作用,本文所建立的耦合模型需要进一步优化并应用于其它条件下东海原甲藻赤潮的研究中。     

Distrubution of Dissolved and Particulate Iron, copper and Manganese in the Shelf waters of the Ross sea (Antarctica)

Abstract. During the austral summer 1997–98, within the framework of the activities of the Climatic Long-term Interaction for the Massbalance in Antarctica (CLIMA) Project of the Italian National Program for Antarctic Research (PNRA) in the Ross Sea, measurements were conducted to focus on the role of dissolved iron, copper and manganese as micronutrients, and on their distribution in suspended particulate matter in different water masses. Sampling was carried out in two selected shelf areas, both important for formation and mixing processes of the water bodies.
Metal data were evaluated together with physical measurements and classical chemical parameters such as oxygen and nutrients.
In both the studied areas, the distribution of dissolved metals along the waste column confirmed their micronutrient behaviour, showing depletion where phytoplanktonic activities occurred.
The trend of particulate metals underlined the scavenging phenomena along the water column and presented an interesting correlation at intermediate depths with the amount and origin of suspended matter.     

First observation of Karlodinium veneficum from the East China Sea and the coastal waters of Germany

Harmful algal blooms often occurred in the East China Sea (ECS) and the German coastal waters of the North Sea but Karlodinium veneficum had not been taxonomically reported. Two strains of Karlodinium (LAMB090611 and LAMB010601) were isolated from the two areas in 2009. The morphological characteristics and molecular phylogeny of two strains are compared on the basis of observation of a light microscope, a scanning electron microscope (SEM), a laser scanning micro-scope (LSM) and an internal transcribed spacer (ITS) sequence data. The mean cell length of strain LAMB090611 is (14.2 ± 1.8) μm (range 11.1-18.7 μm) and mean width is (10.8 ± 1.5) μm (range 8.2- 14.7 μm). The mean cell length of strain LAMB010601 is (15.1 ± 1.2) μm (range 12.7-17.9 μm) and the mean width is (11.4 ± 1.1) μm (range 9.1-14.7 μm), respectively. The two strains are similar in morphological characteristics, including a straight apical groove, distinct ventral pore, sulcal extension, cingulum displacement, two or four irregular shaped chloroplasts within the cell and almost equal sized epicone and hypocone. The large and round nucleus is located at the center or at the hypocone of the cell. The sequence length of the ECS strain LAMB090611 and the German strain LAMB010601 is 640 and 646 bp, respectively. The GC content is 49%. The nucleotide similarity of the two strains is 98.1%. The sequence divergence is 0.003. Both strains are confirmed as Karlo-dinium veneficum (D. Ballantine) J. Larsen and this is the first taxonomic report from China and Germany coastal waters. The population dynamics of this toxic species in the ECS and German coastal waters needs to be investigated in the near future.     

Oceanic distribution and life cycle of Calanus species in the Norwegian Sea and adjacent waters

The distribution and demography of Calanus finmarchicus, C. glacialis and C. hyperboreus were studied throughout their growth season on a basin scale in the Norwegian Sea using ordination techniques and generalized additive models. The distribution and demographic data were related to the seasonal development of the phytoplankton bloom and physical characteristics of water masses. The resulting quantified relationships were related to knowledge on life cycle and adaptations of Calanus species. C. finmarchicus was the numerically dominant Calanus species in Coastal, Atlantic and Arctic waters, showing strong association with both Atlantic and Arctic waters. C. hyperboreus and C. glacialis were associated with Arctic water; however, C. glacialis was occasionally observed in the Norwegian Sea and is probably an expatriate advected into the area from various origins. Demography indicated one generation per year of C. finmarchicus, a two-year life cycle of C. hyperboreus, and both one- and two-year life cycles for C. glacialis in the water masses where they were most abundant. For the examined Calanus species, young copepodites of the new generation seemed to be tuned to the phytoplankton bloom in their main water mass. The development of C. finmarchicus was delayed in Arctic water, and mis-match between feeding stages and the phytoplankton bloom may reduce survival and reproductive success of C. finmarchicus in Arctic water. Based on low abundances of C. hyperboreus CI–III in Atlantic water and main recruitment to CI prior to the phytoplankton bloom, we suggest that reproduction of C. hyperboreus in Atlantic water is not successful.     

基于线粒体控制区部分序列的南海大斑石鲈遗传多样性分析

为了研究南海大斑石鲈(Pomadasys maculatus)不同地理群体的遗传多样性情况,作者测定了东兴、乌石、潭门、闸坡4个群体共计61尾大斑石鲈控制区的993 bp序列。检测出变异位点35个,单倍型47种,平均单倍型多样性指数为0.9884,核苷酸多样性指数为0.0076,总体表现出高单倍型多样性和低核苷酸多样性的特点,其中潭门群体核苷酸多样性相对较高(0.00879)。中性检验结果显示Fu’s Fs值均为显著负值–5.34(P=0.03),核苷酸不配对分布没有显著偏离群体扩张模型呈现出单峰(SSD值和Rg指数较小),表明大斑石鲈在历史上经历过种群扩张,推测扩张时间约4.74万~1.18万年间。群体间(0.0065~0.0089)与群体内遗传距离(0.0066~0.0089)处于同一水平,总遗传分化指数Fst为–0.0057(P0.05),群体间基因流Nm=33.76。不同组群划分方式的分子方差分析均表明群体内遗传差异显著大于群体间,遗传变异主要来源于群体内部。南海海域大斑石鲈群体遗传多样性匮乏,群体间不存在显著的遗传分化,可划归一个管理保护单元,潭门群体建议优先给予保护。     

Deep-sea bacterial communities in sediments and guts of deposit-feeding holothurians in Portuguese canyons (NE Atlantic)

Deposit-feeding holothurians often dominate the megafauna in bathyal deep-sea settings, in terms of both abundance and biomass. Molpadia musculus is particularly abundant at about 3400 m depth in the Nazaré Canyon on the NE Atlantic Continental Margin. However, these high abundances are unusual for burrowing species at this depth. The objective of this research was to understand the reasons of the massive occurrence of these molpadiid holothurians in the Nazaré Canyon. To address this question we investigated possible trophic interactions with bacteria at sites where the organic content of the sediment was different (Setúbal and Cascais Canyons, NE Atlantic Continental Margin). The molecular fingerprinting technique of Denaturing Gradient Gel Electrophoresis (DGGE) with band sequencing, combined with non-metric multi-dimensional scaling and statistical analyses, was used to compare the bacterial community diversity in canyon sediments and holothurian gut contents. Our results suggest that M. musculus does not need to develop a specialised gut bacterial community to aid digestion where the sediment is rich in organic matter (Nazaré Canyon); in contrast, such a community may be developed where the sediment is poorer in organic matter (Cascais Canyon).     

东黄海星康吉鳗渔业生物学特性研究

Whitespotted conger Conger myriaster is a commercially important species in the seas around China, Korea and Japan. The coastal waters of China serve as an important feeding ground for congers, but the spatio-temporal variations in the fishery and biological characteristics of the population have been rarely evaluated and less well understood in this area. We studied the growth, spawning and feeding characteristics of C. myriaster on the basis of samples collected from October 2016 to April 2017 in the Yellow Sea and East China Sea. A total of 529 specimens were collected, with ages ranging from 1 to 6 years and total length ranging from 132 mm to 834 mm.The parameters of von Bertalanffy growth equation L_∞ and k were 1 026 mm and 0.226 a~(–1), respectively; the sex ratio was 88:0(female: male) in the East China Sea and 2.67:1 in the South Yellow Sea; the development stage of ovary ranged from peri-nucleolus stage to secondary yolk globule stage, and the testis of two males was at midmeiotic stage; Crustacean was the major prey for conger of small length, and food source shift to fish with somatic growth. The results showed substantial differences from previous studies in Japan and Korean waters, as well as from China seas in the 1980 s, suggesting potential spatiotemporal changes in the biological characteristics of C.myriaster. This study may improve current understanding of the fishery biology of C. myriaster in the Yellow Sea and East China Sea.     

中国东海颈栉虫属(多毛纲:双栉虫科)一新记录种

本文报道和描述了中国东海双栉虫科颈栉虫属一新记录种,沃氏颈栉虫。本文标本与沃氏颈栉虫的原始描述非常吻合,包括具有两对鳃,胸齿片刚节具有两对加长的腹疣足和具有12个腹部齿片刚节。本文的标本具有长的须状的鳃,可延伸到胸部第9刚节,这在原始描述中没有提及。本文首次在中国海域记录本种。     

Spatial variability of epifaunal communities from artificial habitat: Shipwrecks in the Southern Bight of the North Sea

We investigated the cover, community structure and abiotic environment of nine shipwrecks lying at increasing distance from the Belgian coast. Results indicated that all shipwrecks were strongly dominated by cnidarians in terms of biomass and by amphipods in terms of abundances. Based on their epifaunal composition, three groups of shipwrecks could be determined. Metridium senile dominated a species poor community of the coastal sites. On the same sites, a Tubularia larynx community with a more species-rich assemblage was also developing. The T. larynx community had a lower biomass value (102 g AFDW m⁻²) and significantly lower species richness compared to the other sites. The coastal sites were characterized by periodic salinity decreases, large seasonal temperature fluctuation, high total suspended matter load and reduced current velocity. Channel water masses influence the offshore sites causing a more stable temperature and salinity environment, less turbid waters and high current speed. Tubularia indivisa dominated this community, with an average biomass of 229 g AFDW m⁻². Intermediate sites were also dominated by T. indivisa, but a higher biomass (424 g AFDW m⁻²) was observed. They showed intermediate results for the abiotic parameters and fast current velocities. Hypotheses for the observed variation in community structures are discussed in the light of the abiotic characterization of the shipwrecks.     

Nursery areas of red mullet (Mullus barbatus), hake (Merluccius merluccius) and deep-water rose shrimp (Parapenaeus longirostris) in the Eastern-Central Mediterranean Sea

The spatial pattern of the nursery areas of red mullet (Mullus barbatus), hake (Merluccius merluccius) (Linnaeus, 1758) and deep-water rose shrimp (Parapenaeus longirostris) (Lucas, 1846) was studied in the South Adriatic and North Ionian Seas (Eastern-Central Mediterranean) applying geostatistical techniques and data from time series trawl surveys conducted in the area. The analysed variables were: R (number of recruits/km²) and R/Tot (fraction of recruits on the total sampled population). The structural analysis showed a spatial pattern of both variables characterized by continuity on a small scale. Predictions of nursery area localization with probability of finding recruits at different threshold values were obtained through median indicator kriging. For the red mullet the nurseries were mainly identified in the South Adriatic Sea off the Gargano peninsula and between Molfetta and Monopoli within 50 m in depth. The main concentration of hake juveniles was found to be between 100 and 200 m in depth along the Gargano peninsula and between Otranto and Santa Maria di Leuca, where a nursery of deep-water rose shrimp was also detected. An overlapping depth, between 100 and 200 m, was identified for hake and deep-water rose shrimp nurseries. Protection of these areas through limitations of fishing pressure is discussed.