Water quality assessment at Jinhae Bay and Gwangyang Bay,South Korea

A new water quality index for evaluating the water quality of Jinhae Bay and Gwangyang Bay was developed. Four water quality parameters were selected as water quality indicators for the water quality index: dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP), chlorophyll-a (Chl-a), and dissolved oxygen (DO). Reference levels of DIN, DIP, and Chl-a were determined as 6.22 μmol L^?1, 0.38 μmol L^?1, and 2.32 μmol L^?1, respectively, on the basis of a long-term dataset that was collected monthly in the Korea Strait over a period of seven years (2006–2012). The water quality index established for Jinhae Bay and Gwangyang Bay is (bottom DO grade × 0.33) + (surface Chl-a grade × 0.33) + (surface DIN grade × 0.17) + (surface DIP grade × 0.17). On the basis of a three-year observation, the water quality of Jinhae Bay was classified as “good” in winter and spring, “poor” in summer, and “fair” in autumn and exhibited large spatial variation, with the lowest-quality water observed in Masan Bay. The water quality of Gwangyang Bay was classified as “good” in winter, “fair” in spring, “poor” in summer, and “fair” in autumn. Unlike Jinhae Bay, the water quality of Gwangyang Bay exhibited minimal spatial variation. In both bays, water quality among the four seasons was worse during summer. It is essential that a survey for water quality evaluation be conducted during summer.     

Spatial and seasonal variations in the water quality of Jinhae Bay,Korea

The chemical and biological characteristics of surface waters in Jinhae Bay were investigated over four seasons to understand water quality in light of the growing industrialisation occurring within this area. Jinhae Bay includes four smaller bays: Masan; Hangam; Jindong; and Gohyun. The water quality in Jinhae Bay varied spatially and seasonally. The water quality of both Hangam Bay and Masan Bay was highly degraded, demonstrating high concentrations of ammonia, nitrate, chlorophyll a and particulate organic carbon. Contamination from sewage was the dominant cause of the water quality deterioration in these bays. Conversely, the water quality in Jindong Bay and Gohyun Bay was not as severely affected as that of the above two bays. Water quality in Jinhae Bay was particularly poor in summer when nutrient loading was highest due to the run-off associated with high precipitation. Principal component analysis indicated that nitrogen contamination was a major factor influencing the water quality of Jinhae Bay. The effective reduction in high-nitrogen discharges is essential to improve water quality in Jinghae Bay.     

Contents and stable isotopic compositions of organic carbon and total nitrogen in the surface sediment of two coastal bays in Korea

Surface sediment from the coastal bays of Gwangyang and Masan in South Korea were analyzed for their contents and isotopic values of organic carbon and total nitrogen. The sources and diagenetic alteration of organic matter were also assessed. Total organic carbon varied from 0.22% to 3.48% (average = 1.40%, n = 75), and C/N ratios varied from 2.4 to 15.2 (average = 8.79, n = 75). δ¹³C_org ranged from −19.92‰ to −25.86‰ (average = −21.21‰, n = 75), and δ¹⁵N_TN ranged from 8.57‰ to 3.93‰ (average = 6.49‰, n = 75). Total organic carbon in both areas was associated with grain-size, with higher contents in finer grained sediment. The high carbon content observed in Masan Bay sediment correlated with its higher C/N ratio. δ¹³C_org and δ¹⁵N_TN varied widely, attributable to various influences such as the input of terrestrial organic matter and diagenetic alteration. The depleted δ¹³C_org and higher δ¹⁵N_TN observed in the sediment of Gwangyang Bay reflected terrestrial supply, implying that biogeochemical processes, i.e. bacterial degradation, were more active in Masan Bay sediment, which showed less depleted δ¹³C_org and higher δ¹⁵N_TN than Gwangyang Bay sediment. δ¹⁵N_TN was the more useful indicator of biogeochemical processes in the highly anoxic sediment. These results indicate that the δ¹³C_org and δ¹⁵N_TN of sedimentary organic matter in coastal bays can indicate the source and degree of diagenetic alteration of sedimentary organic matter.     

Threshold value of Benthic Pollution Index (BPI) for a muddy healthy benthic faunal community and its application to Jinhae Bay in the southern coast of Korea

For the determination of benthic community health criteria of a biotic index, Benthic Pollution Index (BPI), the faunal data on macrobenthic community of Deukryang Bay collected in 2012 were used. Each macrobenthic fauna was classified into 4 functional groups according to their feeding and life history strategies and BPI was calculated using the abundance of fauna for these functional groups. Amphipods were the dominant faunal group belonging to Functional Group (FG) II in Deukryang Bay during all seasons. The BPI value fluctuated seasonally from 55 to 61, and the overall mean value of BPI in the reference area was 60, which was estimated as the threshold value for healthy communities. We tried to use BPI as an assessment tool for macrofaunal community health status by categorizing the BPI values into 5 grades. If the BPI value of the community is more than 60, the health status of a macrobenthic community will be assessed as ‘Excellent’ (Grade 1) and as ‘Good’ (Grade 2), if between 40 and 60, as ‘Fair’ (Grade 3), if between 30 and 40, as ‘Poor’ (Grade 4), if between 20 and 30, and finally the health status of a community will be assessed as ‘Very Poor’ (Grade 5), if the BPI value is less than 20. This assessment tool using BPI was applied to macrobenthic communities in Jinhae Bay including the Special Management Area of South Korea. In Jinhae Bay, the FG IV containing a spionid species, Paraprionospio patiens was the most dominant group. The values of BPI in Jinhae Bay were very low and ranged from 11 to 23. The ecological health status of macrobenthic communities in Jinhae Bay was ‘Very Poor’ at more than 50% of sites, especially in summer.     

胶州湾海域浮游植物和赤潮物种的生物多样性研究进展

胶州湾是我国的一个典型近海海湾,也是近海生态系统的缩影。历史上胶州湾海域赤潮频发,因此也是研究赤潮暴发机制(包括赤潮物种组成、时空动态变化及对环境因子响应)的理想实验场所。迄今,几代科学家对胶州湾浮游植物和赤潮物种开展了长期而系统的调查研究,获得了大量的研究成果。为了系统跟踪胶州湾海域浮游植物群落组成,尤其是赤潮物种的组成变化,本文对近84年间(1936—2019年)胶州湾海域涉及浮游植物调研的54个调查数据结果进行了系统的统计和比较分析。文献共报道了549种浮游植物,包括硅藻326种、甲藻164种、绿藻21种、金藻9种、隐藻9种、淡色藻6种、定鞭藻5种、蓝藻3种、黄藻3种、下睫虫2种、裸藻1种和针胞藻1种。其中只有不到一半(40.29%)的浮游植物的全长18S rDNA序列得到解析,表明分子标记数据库需要继续完善,促进宏条形码分析的有效应用。胶州湾海域的优势浮游植物随时间的推移发生了较大变化,但是报道的甲藻与硅藻物种数的比例没有显著的变化。统计表明,研究者在胶州湾共鉴定到153种赤潮物种,包括硅藻79种、甲藻67种、定鞭藻2种、金藻2种、淡色藻1种、黄藻1种和针胞藻1种。胶州湾海域的典型优势浮游植物均为赤潮物种,包括中肋骨条藻、短角弯角藻、旋链角毛藻、加氏星杆藻、日本星杆藻、星脐圆筛藻和尖刺拟菱形藻,其中短角弯角藻和中肋骨条藻是胶州湾海域的"常驻"赤潮物种。本文通过系统综述胶州湾浮游植物和赤潮物种的生物多样性,为利用宏条形码和宏基因组等方法跟踪研究胶州湾和其他海域的浮游植物和赤潮物种的演化奠定了基础。     

Sedimentation,suspension, and resuspension in Tasman Bay and Beatrix Bay,New Zealand,two contrasting coastal environments which thermally stratify in summer

Abstract

The influence of density stratification on sedimentation, suspension, and resuspension in Tasman Bay and Beatrix Bay, New Zealand, two contrasting coastal environments, was studied with specific reference to the implications for modelling aquaculture sustainability. Tasman Bay, an enhanced scallop (Pecten novaezelandiae Reeve) fishery, is a very large coastal indentation gently shelving to c. 20 m deep c. 10 km from shore and open to the Tasman Sea, whereas Beatrix Bay, an area of intense Greenshell? mussel (Perna canaliculus Gmelin) aquaculture, is a small (22 km² × 30–40 m deep) enclosed embayment off the side of the nearby Pelorus Sound. Sediment trap arrays were used to determine the vertical fluxes of suspended solids and the associated chlorophyll component. Benthic chambers were used to investigate sediment nutrient regeneration. In summer, salinity gradients in both bays are minimal or non‐existent because of low inputs of fresh water and density stratification is mainly controlled by water temperature. The data from mid summer exhibited different spatial distribution patterns for detritus and phytoplankton biomass (as indicated by chlorophyll) in these two very different bays, although they had similar turbulent environments. The density discontinuity at the thermocline had a strong influence on settling of phytoplankton. There was evidence of upwards entrainment of suspended paniculate matter into the upper water column from the thermocline in Beatrix Bay. Benthic resuspension was estimated to contribute up to 90% of the suspended solids caught in sediment traps near the sea floor in both bays. The trapping rate of phytoplankton was thought to be dependent on species dominance. Possible mechanisms of resuspension included turbulence in the benthic boundary layer, and high velocities below the thermocline associated with internal seiches. The presence of a mid water column chlorophyll maximum in Beatrix Bay is discussed in terms of nutrient and light regimes at the thermocline, and species composition. In Tasman Bay, the chlorophyll maximum was thought to be caused by resuspension of benthic microphytes and their subsequent confinement in a thin layer (2–4 m thick) of high turbulence between the thermocline and the seabed.     

Acoustic characters and distribution pattern of modern fine-grained deposits in a tide-dominated coastal bay: Jinhae Bay,Southeast Korea

Jinhae Bay, a semi-enclosed, tide-dominated coastal embayment on the southeastern coast of Korea, receives large amounts of sediment derived from the Nakdong River. The irregular surface of the acoustic basement is overlain by a modern sedimentary sequence up to 25 m thick, characterized by an acoustically semitransparent subbottom. Sediments, consisting mainly of terrigenous and bioturbated mud, accumulate at a rate of 2–5 mm/yr. About 21% of the suspended sediments discharged from the Nakdong River, that is approximately 1.0 × 10⁶ tons per year, accumulate in Jinhae Bay. Modern sedimentation began probably at about 5000 yr BP, when sea level approached its present level.     

Characteristics of algal blooms in the southern coastal waters of Korea

We have investigated the characteristics of algal blooms in relation to the marine environment since their first known occurrence in the southern coastal waters of Korea. The algal blooms occurred most frequently in Masan and Jinahe bays, suggesting that they were related to the development of anoxic water masses. Skeletonema costatum, Heterosigma akashiwo and Prorocentrum sp. commonly occurred as the dominant organisms causing the blooms in all regions, although the conditions of their appearance differed from place to place. Algal blooms in all regions were more likely to occur when precipitation ten days prior to the bloom was greater than the long-term mean values. However, the factors that relate to the development of the algal blooms in Gamak Bay differed depending upon the causative species while they were largely identical in Jinhae Bay, regardless of the species.     

Numerical experiments of HAB inducement in Qingdao adjacent coastal area

A three-dimension ecological dynamic model was established to numerically study the relationship of HAB and environmental conditions.The numerical experiments showed that the growth of diatom,the dominant HAB specie,was mainly restricted by phosphate and silicate.If the concentrations of phosphate and silicate reach 17-25 μg/L and 300-375 μg/L respectively,the water is in a state of eutrophication.When phosphate and silicate up to 26-32 μg/L and 350-500 μg/L respectively,HAB could be induced.The major regions of HAB occurrence are Jiaozhou Bay mouth,coastal bays,and coastal area from Maidao to Shilaoren.To avoid HAB occurrence,concentration of phosphate and silicate should not exceed 17-20 μg/L and 300 μg/L as a whole.Reasonable control of pollutant discharge is a key point to prevent water eutrophication and HAB occurrence.     

东海原甲藻抗体的制备及酶联免疫检测方法的建立

通过制备针对东海原甲藻细胞破碎物的多克隆和单克隆抗体,建立了基于双抗体酶联免疫分析定量检测东海原甲藻(Prorocentrum donghaiense)的检测方法。利用该方法对单一藻种、混合藻种和现场样品中的东海原甲藻进行检测的结果与镜检结果相一致,最低检测限度为1×103 cells/m L。该方法的建立对中国近海赤潮暴发的实时监控具有重要意义。     

桑沟湾养殖海域营养盐和沉积物-水界面扩散通量研究

利用2006年4,7,11月和2007年1月4个航次对桑沟湾养殖海域的观测资料,分析了该海域营养盐分布、结构特征、主要控制过程以及沉积物-水界面扩散通量,结果表明,该海域的营养盐分布具有明显的季节变化,海水中NO3-,NO2-,PO43-,DOP,TDP和SiO32-浓度皆是秋季最高,而NH4+,DON,TDN浓度则为夏季最高;各种营养盐的最低值除DON外都出现在春季。春季湾内外海水交换不畅,再加上大型藻类海带等生长旺盛期的消耗,使营养盐浓度处于较低水平,在夏秋两季丰水期沿岸河流注入对该海域营养盐的影响较大,冬季无机营养盐浓度分布主要受沿岸流的影响。磷的结构变化较大,其中DOP百分含量在夏季最高,达到81%。从春季到秋季海水中TDN的结构变化从以DON为主转变成以DIN为主。硅和氮的原子比值全年变化不大,硅和氮和氮和磷原子比值春夏两季的高于秋冬季的。分析营养盐化学计量限制标准和浮游植物生长的最低阈值结果表明,磷是春夏两季桑沟湾浮游植物生长的限制性因素;春季硅浓度低于浮游植物生长的最低阀值,也是一个潜在的限制因素。计算结果显示桑沟湾沉积物释放的NH4+,SiO32-和PO43-对初级生产力的贡献较小,与其他浅海环境相比,桑沟湾沉积物-水界面的营养盐通量处于较低或中等水平。     

2021年秦皇岛近岸典型海域浮游植物群落结构的时空变化特征

为了解秦皇岛近岸典型海域浮游植物的群落特征及其影响因素,基于2021年4~10月在秦皇岛金梦海湾、东山浴场两个典型海域7个航次的逐月调查结果,对该海域网采浮游植物种类组成、优势种、丰度、多样性等特征及其与环境因子的关系进行了研究,并对两个典型海域海水水质和浮游植物群落之间的差异进行了比较。结果表明:研究海域共检出浮游植物3门45属92种(包含变种和变型),其中硅藻门(Bacillariophyta)32属67种,甲藻门(Pyrrophyta) 12属24种,金藻门(Chrysophyta)1属1种,硅藻门占绝对优势。全年优势种共26种,其中硅藻20种,甲藻6种,且多出现在4~7月,未出现7个月份共有的优势种。浮游植物丰度在8月达到全年最高值,为1.01×10⁸ cells/m³,其余月份浮游植物丰度均在10⁶ cells/m³量级。聚类分析表明,研究海域浮游植物群落有明显的季节更替现象。生物与环境(BIOENV)相关分析表明,水温和盐度是影响研究海域浮游植物群落结构的主要环境因子。两个典型海域浮游植物种类组成差别不大,但金梦海湾海域的营养盐环境和水动力条件更适合甲藻生长。     

Seasonal Variation in the Phytoplanktonic Community,Seston and Environmental Variables During a 2-Year Period and Oyster Growth at Two Mariculture Sites,Southern Chile

Phytoplankton and its relationships with physical and chemical variables were analysed over a 2-year period in Hueihue and Linao Bays (southern Chile). Samples were collected on a monthly basis from May 1991 to May 1993. The growth rate of a single stock of hatchery-produced oysters (Ostrea chilensis) distributed between these two bays was also monitored monthly. The growth rate of oysters maintained at Linao Bay (site associated with a fish farm) was significantly higher, at every depth, compared with the oysters maintained at Hueihue Bay. Temperature and salinity values and their annual fluctuations were similar at both locations, presenting higher variations at the surface (1 m) due to the influence of air temperature and local precipitation than at depth. However, significant differences in phytoplankton abundance and composition were found between the two locations. The phytoplankton community was characterized by high biomass values during spring and summer, the dominance of diatoms and an inverse relationship between temperature and species diversity. However, phytoplankton cell abundance, biovolume and chlorophyll a concentration were significantly higher at Linao at every depth sampled. Cell abundance ranged between 4.49 × 10⁴ and 7.45 × 10⁶ cells · l^?1 in Hueihue and between 6.48 × 10⁴ and 8.71 × 10⁶ cells ·1^?1 in Linao. The influence of temperature on chlorophyll a concentration was significant except at 8 m at both locations. The instantaneous oyster growth rate was found to be positively correlated with temperature, chlorophyll a concentration and particulate organic matter at both locations. A significant negative relationship between oyster growth and amount of particulate inorganic matter was found; this confirms the important role played by seston composition in oyster growth. The demonstration of variation in oyster growth rate associated with differences in food availability between the two locations provides insight into the ecological role played by fish farms in southern Chile. The results suggest a strong link between food availability and oyster growth.     

2010年胶州湾网采浮游植物种类组成与数量的周年变化

为了研究胶州湾网采浮游植物的种类组成与数量变化,作者根据2010年的胶州湾调查资料,对调查区浮游植物丰度、优势种类和季节变化进行分析研究。结果表明,胶州湾浮游植物主要由硅藻和甲藻两大类组成,硅藻占据绝对优势地位。除了7月以外,甲藻/硅藻比均0.2。生态类型主要以近岸广布种和暖温带种为主,在不同季节也出现了少数暖水种和外洋种。浮游植物丰度表现为明显的"双周期",冬、春两季较高,夏、秋两季较低。2月为全年最高峰,数量为1108×104个/m3,10月为夏、秋两季的高峰,数量为458.7×104个/m3。浮游植物群落的多样性指数平均为1.9。     

Seasonal variations in dissolved organic carbon concentrations and characteristics in a shallow coastal bay

Dissolved organic matter (DOM) composition and dynamics in temperate shallow coastal bays are not well described although these bays may be important as local sources of organic carbon to ocean waters and are often sites of economically-important fisheries and aquaculture. In this study surface water samples were collected on a monthly to bi-monthly basis over two years from a mid-Atlantic coastal bay (Chincoteague Bay, Virginia and Maryland, USA). Dissolved organic carbon (DOC) concentrations and light absorbance characteristics were measured on sterile-filtered water, and high-molecular weight (> 1 kDa) dissolved OM (DOM) was isolated to determine stable isotope composition and molecular-level characteristics. Our time series encompassed both a drought year (2002) and a year of above-average rainfall (2003). During the dry year, one of our sites developed a very intense bloom of the brown tide organism Aureococcus anophagefferens while during the wet year there were brown tide bloom events at both of our sampling sites. During early spring of the wet year, there were higher concentrations of > 1 kDa DOC; this fraction represented a larger proportion of overall DOC and appeared considerably more allochthonous. Based upon colored dissolved organic matter (CDOM) and high-molecular weight DOM analyses, the development of extensive phytoplankton blooms during our sampling period significantly altered the quality of the DOM. Throughout both years Chincoteague Bay had high DOC concentrations relative to values reported for the coastal ocean. This observation, in conjunction with the observed effects of phytoplankton blooms on DOM composition, indicates that Chincoteague Bay may be a significant local source of “recently-fixed” organic carbon to shelf waters. Estimating inputs of DOC from Chincoteague Bay to the Mid-Atlantic Bight suggests that shallow productive bays should be considered in studies of organic carbon on continental shelves.     

胶州湾海域浮游植物和赤潮物种的生物多样性研究

胶州湾是我国一个典型的近海海湾,也是近海生态系统的缩影。历史上胶州湾海域赤潮频发,因此也是研究赤潮暴发机制(包括赤潮物种组成、时空动态变化及对环境因子响应)的理想实验场所。迄今,几代科学家对胶州湾浮游植物和赤潮物种开展了长期而系统的调查研究,获得了大量的研究成果。为了系统跟踪胶州湾海域浮游植物群落组成,尤其是赤潮物种的组成变化,解读基于分子标记的宏条形码分析结果,本文对近84年间(1936年-2019年)胶州湾海域涉及浮游植物调研的54个调查数据进行了系统的统计和比较分析。文献共报道了549种浮游植物,包括硅藻326种、甲藻164种、绿藻21种、金藻9种、隐藻9种、淡色藻6种、定鞭藻5种、蓝藻3种、黄藻3种、下睫虫2种、裸藻1种和针胞藻1种。其中只有不到一半(40.29%)的浮游植物的全长18S rDNA序列得到解析,表明分子标记数据库需要继续完善,促进宏条形码分析的有效应用。胶州湾海域的优势浮游植物随时间发生了较大变化,但是甲藻与硅藻数目的比例没有显著的变化。统计表明,胶州湾共鉴定到153种赤潮物种,包括硅藻79种、甲藻67种、定鞭藻2种、金藻2种、淡色藻1种、黄藻1种和针胞藻1种。胶州湾海域典型的优势赤潮物种包括中肋骨条藻、短角弯角藻、旋链角毛藻、加氏星杆藻、日本星杆藻、星脐圆筛藻和尖刺拟菱形藻。本文通过系统综述胶州湾浮游植物和赤潮物种的生物多样性,为利用宏条形码和宏基因组等方法跟踪研究胶州湾和其他海域的浮游植物和赤潮物种的演化奠定了基础。     

莱州湾近岸海域浮游纤毛虫群落组成和季节变化

浮游纤毛虫是真核微型生物的重要类群,在浮游生态系统中发挥着重要作用。利用传统形态学与高通量测序技术相结合的方法,于2020年9月至2021年8月对莱州湾三山岛近岸浮游纤毛虫进行每月两次的调查。对环境DNA的18S rRNA基因的V4区进行高通量测序,结果显示无壳寡毛类(占纤毛虫序列丰度的40.14%)和砂壳纤毛虫(10.67%)是优势类群,并且具有明显的季节变化。无壳寡毛类在冬季序列相对丰度最高,主要由急游虫属(Strombidium)和急游虫科未定类群(Strombidiidae_X)组成;砂壳类在春夏季序列相对丰度最高,主要由砂壳目未定类群(Tintinnida_XX)和拟铃虫属(Tintinnopsis)组成。浮游纤毛虫群落的β多样性呈现显著的季节变化,而α和β多样性在站点间差异均不显著。与环境因子的RDA分析显示,总有机碳和溶解氧含量是影响纤毛虫群落结构的主要环境驱动因子。形态学方法共检获鉴定17种纤毛虫,分别隶属于7个属,其中砂壳类在多样性和检获频率上均为最优势类群。研究填补了莱州湾三山岛海域浮游纤毛虫的多样性、群落结构和季节动态研究的空白,同时为深入研究温带海湾近岸浮游纤毛虫群落的长期变化规律以及对环境因子的响应机制提供本底资料。     

2006年冬季北黄海网采浮游植物群落结构

根据2006年12月30日—至2007年1月17日北黄海的调查资料,对该海域浮游植物的种类组成、优势种、丰度及其分布和多样性等基本状况进行了分析。本次调查共鉴定浮游植物4门68属131种,主要以温带近岸和广布性种为主,其中硅藻有53属113种,占总种数的86.3%,甲藻有11属16种,占总种数的12.2%。浮游植物丰度平均值为88.89×104个/m3,硅藻丰度平均值为86.58×104个/m3,甲藻丰度平均值为2.28×104个/m3,硅藻丰度分布趋势决定了浮游植物丰度的分布趋势。辽宁南岸是浮游植物密集区,山东半岛北岸其次,而北黄海中部是浮游植物的稀疏区。优势种为:短角弯角藻(Eucampia zodiacus)、具槽帕拉藻(Paralia sulcata)、尖刺拟菱形藻(Pseu-do-nitzschia pungens)、密连角毛藻(Chaetoceros densus)、柔弱角毛藻(Chaetoceros debilis)、刚毛根管藻(Rhizosolenia setigera)。浮游植物群落Shannon-Weiner物种多样性指数平均值为1.80,Peilou均匀度指数平均值为0.42。与1959年1月相比,2007年1月北黄海浮游植物丰度由150.00×104个/m3降为88.89×104个/m3,下降了近41%,硅藻丰度由148.00×104个/m3降为86.58×104个/m3,而甲藻丰度由1.25×104个/m3上升为2.28×104个/m3,占浮游植物丰度的比例由0.8%上升为2.5%。主要优势种及优势属也发生了一定程度的变化,但浮游植物群落结构仍以硅藻为主、甲藻其次,浮游植物丰度总的分布格局变化不明显。     

A potential source of recruitment of Acartia pacifica nauplii: viable benthic resting eggs

Many estuarine and coastal planktonic copepods depend on the hatching of benthic resting eggs for recruitment of nauplii to the water column population. The distribution and abundance of viable resting eggs of Acartia pacifica in the Xiamen Bay were determined by the presence of nauplii in the laboratory. The number of viable eggs varied temporally and spatially. The maximum number (9.2×10⁴m^-2) of viable eggs was in summer. In spring the average abundance of viable eggs was 5.6×10⁴ m^-2. The abundances of viable eggs in fall and winter were similar, respectively 2.7×10⁴ and 3.3×10⁴ m^-2, which were the lowest in the year. The numbers of viable eggs inside the stations of the Xiamen Bay were higher than those outside the stations. The viable eggs were found at all depths (0～10 cm),although not in every station. The maximin number did not necessarily occur in the uppermost centimeter of the sediments but often occurred several centimeters below the water-sediment interface. The accumulation of viable eggs in the seabed of a subtropical bay constitutes a potential source of recruitment of nauplii into the pelagic population.     

烟台四十里湾浮游植物群落的季节变化及其对环境的指示意义

2009年8,10,12月及2010年3月分别对烟台四十里湾的12个站位开展了四个航次的季节调查.研究发现浮游植物3门45属73种,其中硅藻46种,甲藻24种,褐胞藻3种.硅藻是构成调查区域浮游植物群落的主要类群.浮游植物种类与数量呈现出明显的季节变化特征.夏季(8月)物种数最多(57种),秋季(10月)次之(40种)...