The phytoplankton bloom response to wind events and upwelled nutrients during the CoOP WEST study

In the coastal waters off northern California, seasonal wind-driven upwelling supplies abundant nutrients to be processed by phytoplankton productivity. As part of the Coastal Ocean Processes: Wind Events and Shelf Transport (CoOP WEST) study, nutrients, CO₂, size-fractionated chlorophyll, and phytoplankton community structure were measured in the upwelling region off Bodega Bay, CA, during May–June 2000, 2001 and 2002. The ability of this ecosystem to assimilate nitrate (NO₃) and silicic acid/silicate (Si(OH)₄) and accumulate particulate material (i.e. phytoplankton) was realized in all 3 years, following short events of upwelling-favorable winds, followed by periods of relaxed winds. This was observed as phytoplankton blooms, dominated by chlorophyll in cells greater than 5 μm in diameter, that reduced the ambient nutrients to zero. These communities were located over the near-shore shelf (<100 m depth) and were dominated by diatoms. An optimal window of 3–7 days of relaxed winds, following an upwelling pulse, was required for chlorophyll accumulation. The large-celled phytoplankton that result are likely important players in coastal new production and carbon cycling.     

A regional analysis of new production on the northwest European shelf using oxygen fluxes and a ship-of-opportunity

Seasonal new production (g C m⁻²) estimates obtained from dissolved oxygen and nitrate concentrations in surface waters (5 m depth) along a track between the UK (Portsmouth) and northern Spain (Bilbao) are compared. An oxygen flux method, in combination with a ship of opportunity (SOO), was tested on the northwest European shelf for its value in distinguishing high production in frontal regions. Dissolved oxygen, nitrate and chlorophyll a samples were collected monthly from February to July 2004, alongside continuous autonomous measurements of salinity, temperature and chlorophyll fluorescence. Depth integrated new production estimates for all the individually analysed hydrographic regions of the route were produced.Results from three widely used gas-exchange parameterizations gave seasonal (February–July) new production estimates of 54–68 g C m⁻² for the Ushant region of the western English Channel and 31–40 g C m⁻² for the shelf slope, averaging 24–31 g C m⁻² for the route. This is double the route average obtained using the nitrate assimilation method (17 g C m⁻²) and within the ranges of previous estimates in the same region. The oxygen flux method gave a fivefold enhancement compared to the nitrate method in the Ushant frontal region and a threefold enhancement in the English Channel and shelf break regions. Determining oxygen fluxes to estimate new production may be more reliable than nitrate assimilation in active tidal or frontal regions of shelves where nitrate may be added to the system post-winter through advection or entrainment.     

浙江乐清湾现代沉积与悬沙质量浓度分布特征及意义

通过对乐清湾野外考察、表层沉积物的粒度分析和水样的悬沙质量浓度分析，探讨了乐清湾现代沉积和悬沙质量浓度分布特征。研究结果表明，乐清湾现代沉积主要以细颗粒沉降为主，粉沙和粘土总含量占90％以上；悬沙质量浓度具有从湾口向湾内递减的变化趋势，湾口悬沙质量浓度为0．2～0．25kg／m^3，而湾内质量浓度小于0．01kg／m^3。半封闭性海湾和以外海来沙为主的物质来源共同决定沉积物的特征及悬沙质量浓度的空间变化规律，而泥沙来源及沉积过程的研究将为港湾治理工程提供重要的依据参数。     

胶州湾浮游植物群落结构及其变化的初步研究

利用2003年胶州湾调查资料，分析了浮游植物群落结构及其与温度和营养盐的相关性。结果表明，胶州湾浮游植物群落主要由硅藻和甲藻组成，生态类型为近岸广布种、温带种和暖温带种以及少数暖水种。浮游植物数量一年中出现2次高峰期，主高峰出现在9月，次高峰出现在2月，低值期在7月和10月至翌年1月期间。浮游植物数量较近几年继续降低，尤其是峰值。浮游植物在春季以角毛藻、丹麦细柱藻、中肋骨条藻和冰河拟星杆藻为优势种群，夏季至秋初暖水性近岸种中华齿状藻、泰晤式旋鞘藻和广温性种星脐圆筛藻占优势地位，而秋季至冬初羽纹硅藻和派格棍形藻逐渐占优势地位，并一直持续整个冬季。溶解无机氮、硅酸盐和磷酸盐与硅藻丰度无明显相关性（R^2〈0．1）。中心硅藻丰度与溶解态无机氮呈线性负相关（R^2=0．4399），而与硅酸盐和磷酸盐无明显相关性（R^2〈0．1）。群落多样性指数与中心硅藻丰度和硅酸盐呈线性相关（R^2=0．3198和0．4443）。     

Biogeochemistry of Dimethylsulfoniopropionate (DMSP) in the Surface Microlayer and Subsurface Seawater of Funka Bay,Japan

Twenty-eight sea surface microlayer samples, along with subsurface bulk water samples were collected in Funka Bay, Japan during October 2000–March 2001 and analyzed for dimethylsulfoniopropionate, dissolved (DMSP_d) and particulate (DMSP_p), and chlorophyll a. The aim of the study was to examine the extent of enrichment of DMSP in the microlayer and its relationship to chlorophyll a, as well as the production rate of dimethylsulfide (DMS) from DMSP and the factors that influence this. The enrichment factor (EF) of DMSP_d in the surface microlayer ranged from 0.81 to 4.6 with a mean of 1.85. In contrast, EF of DMSP_p in the microlayer varied widely from 0.85–10.5 with an average of 3.21. Chlorophyll a also appeared to be enriched in the microlayer relative to the subsurface water. This may be seen as an important cause of the observed enrichment of DMSP in the microlayer. The concentrations of DMSP_p in the surface microlayer showed a strong temporal variation, basically following the change in chlorophyll a levels. Moreover, the microlayer concentrations of DMSP_p were, on average, 3-fold higher than the microlayer concentrations of DMSP_d and there was a significant correlation between them. Additionally, there was a great variability in the ratios of DMSP_p to chlorophyll a over the study period, reflecting seasonal variation in the proportion of DMSP producers in the total phytoplankton assemblage. It is interesting that the production rate of DMS was enhanced in the microlayer and this rate was closely correlated with the microlayer DMSP_d concentration. Microlayer enrichment of chlorophyll a and higher DMS production rate in the microlayer provide favorable evidence supporting the view that the sea surface microlayer has a greater biological activity than the underlying water.     

台湾南湾区秋末冬初海樽类的种类组成和数量分布

根据2001年11月2--3日和12月8--10日在台湾南湾12个测站分别用2种圆锥形浮游生物网(长180cm，网口直径45cm，网目333μm或200μm)采集表层和底层的浮游动物样品，分析了南湾浮游海樽类的种类组成和数量分布，其鉴定海樽类16利，其中7种为台湾周围海域新记录。东方双尾纽鳃樽和小齿海樽为优势种。南湾海樽类的种类数及个体数量均以12月多于11月。讨论了水文条件与海樽类时空分布的关系，认为外海高盐水团足南湾冬季海樽类生态特征的主要制约因子。典型的高温高盐种大西洋火体虫、长吻纽鳃樽、安纽鳃樽、多手纽鳃樽、书氏纽鳃樽、羽环纽鳃樽和斑点纽鳃樽等可以作为外海高温高盐水入侵南湾的指标种。与邻近海域比较，秋冬季南湾与台湾岛以东海域海樽类的区系特征比与台湾海峡和南海北部更加相似。     

乐清湾泥蚶血细胞周期和DNA含量

用流式细胞仪测定乐清湾泥蚶血细胞DNA含量，得出组方图中只有一个峰（G0/G1），表明了乐清湾泥蚶血液不存在合成期（S）、合成后期（G2）和分裂期（M）细胞，血细胞已失去分裂功能，不存在周期现象，以小鸡血细胞做标准对照物（DNA含量以2.3pg/N)，测得乐清湾泥蚶血细胞DNA含量为3.08pg/N。     

莱州湾围隔浮游生态系统氮、磷营养盐迁移-转化模型研究

通过对目前生态动力学模型的总结和综合，以生态系统中氮、磷营养盐循环为主线，建立了适用于海洋围隔浮游生态系统的多变量的营养盐迁移-转化动力学模型。该模型包括浮游植物、浮游动物、溶解无机态营养盐、溶解有机态营养盐和生物碎屑5个模块，涉及溶解无机氮、磷酸盐、溶解有机氮、溶解有机磷、浮游植物、浮游动物和生物碎屑7个状态变量。利用2002年8月末莱州湾围隔生态实验数据进行了模型的验证工作，成功地模拟了富加营养盐条件下围隔浮游生态系统中氮、磷营养盐生物化学迁移-转化过程，并通过灵敏度分析探讨了模型主要状态变量对参数改变的灵敏程度。     

胶州湾近岸海域水质状况调查与评价

根据2005年5月、8月和10月对胶州湾近岸海域的水质调查结果,应用单因子污染指数和富营养化指数进行了该海域的水质评价和分析.结果表明:PO43--P在局部海域有超标现象,DIN则超标严重;E值在0.24~64.92范围,该海域水体呈富营养化。与往年相比,湾内部分水域COD、DIN及PO43--P含量有所提高,应根据海域纳污能力,实施陆源污染物排海总量控制。     

大亚湾海域沉积物中的硝化与反硝化作用

2004年1、4、8、10月在大亚湾海域的4个站点采用自行设计和制作的无扰动沉积物采样器采集沉积物样品,通过使用AIT技术(乙炔同时抑制硝化与反硝化作用),进行实验室同步恒温受控模拟培养实验,并同时测定沉积物上覆水的温度、盐度、DO和pH值,沉积物的Eh值和有机质含量,间隙水的NO3-、NO2-和NH4 浓度,研究沉积物中的硝化与反硝化速率及其影响因素。结果显示大亚湾沉积物的硝化速率范围为[(0.00—4.68)±0.87]μmol/(m2·h);反硝化速率范围[(0.00—2.88)±0.41]μmol/(m2·h);硝化与反硝化作用之间存在耦合,比例范围为0%—100%。沉积物的硝化、反硝化速率和耦合比例与上覆水的温度、DO含量,及沉积物中的有机质含量和Eh值密切相关,人类活动对沉积物的硝化与反硝化作用有明显的影响。