福建近海主要经济渔业生物营养级和有机碳含量研究

本文研究了福建近海52种鱼类、6种虾类、4种蟹类、1种虾蛄和4种头足类的食性和营养级及其有机碳含量。结果表明：营养级以鱼类最高，为2．1～3．7级，平均2．65级；头足类为2．04～2．88级，平均2．60级；蟹类2．38～2．73级，平均2．58级；虾类最低，为1．64～2．21级，平均1．96级．干样有机碳含量百分率也以鱼类最高，为33．0％～76．2％(m／m)，平均46．25％(m／m)；头足类为27．80％～46．16％(m／m),平均40．24％(m／m)；虾类为30．60％～38．40％(m／m),平均34．90％(m/m)；蟹类最低,为25．00％～30．78％(m/m)，平均28．24％(m／m),鲜样有机碳含量百分率还是以鱼类最高,为4．80％～29．55％(m／m),平均13．75％(m／m)；蟹类为8．90％～12．68％(m／m),平均10．74％(m/m)；虾类为6．97％～11．53％(m/m)，平均9．55％(m/m)；头足类最低仅为7．38％～8．52％(m／m),平均7．95％(m/m),干样有机碳含量百分率和鲜样有机碳含量百分率与营养级均成正相关，但前者的相关性高于后者。     

Particulate and dissolved amino acids in the lower Mississippi and Pearl Rivers (USA)

In this study, we present seasonal changes (monthly samples from September 2001 to August 2003) in the abundance and composition of dissolved and particulate amino acids, at one station in the lower Mississippi and Pearl Rivers (LA, MS: USA). Spatial changes over a 4-day transmit from river km 390 to river mouth (Head of Passes, LA) in the Mississippi River, and a two-day downstream sampling from Jackson (MS) to Stennis Space Center (MS) were also determined. Temporal data in the lower Mississippi River showed significantly lower concentrations of dissolved combined amino acids (DCAA, 0.8 to 2.2 μM) and dissolved amino acids in high molecular weight fraction (HMW DAA, 0.2–0.4 μM) than in the Pearl River (DCAA, 1.4–4.3 μM; HMW DAA, 0.4–1.4 μM). Dissolved free amino acids (DFAA) were significantly lower than DCAA in both rivers, and displayed minimal seasonal variability. DCAA, HMW DAA, and particulate amino acids (PAA) were generally higher during high-flow periods, which may have suggested dominance in terrestrial sources. Carbon-normalized yield of PAA (%C-PAA) was generally higher during low-flow conditions and positively correlated with chlorophyll-a (chl-a), reflective of in situ sources. Downstream variability in the lower Mississippi River showed stable DCAA concentrations, a decline in PAA (from 1.06 to 0.43 μM), and a gradual increase in mole percent of non-protein amino acids (%NPAA). This likely reflected bacterial degradation of phytoplankton biomass during falling discharge. Nitrogen-normalized yield of PAA (%N-PAA) was inversely correlated with PAA (R = − 0.7, n = 48), indicative of short-term sedimentation and resuspension events. Conversely, downstream decreases in DCAA and middle-reach peaks of PAA and %N-PAA in the Pearl River, likely resulted from photochemical degradation of DOM as well as algal production during base-flow conditions. The comparisons in abundance and composition of DAA and PAA in these different river systems provides important information on in situ nitrogen and carbon cycling as related to riverine inputs of organic matter to coastal ocean.     

人工神经网络方法反演东中国海悬移质浓度

海中悬移质是决定海洋光学性质、海洋水质,河口海岸带演变动力过程的重要环境参数。本文利用模拟遥感反射比数据集建立人工神经网络反演悬移质浓度,并利用东中国海现场同步数据对该算法进行验证。     

Summer distribution and geochemical composition of suspended-particulate matter in the east china sea

The distribution and geochemical composition of suspended-particulate matter (SPM) in the East China Sea (ECS) were investigated during the summer period of high continental runoff to elucidate SPM sources, distribution and cross-shelf transport. The spatial variability of SPM distribution (0.3–6.5 mg l⁻¹) and geochemical composition (POC, Al, Si, Fe, Mn, Ca, Mg and K) in the ECS was pronounced during summer when the continental fluxes of freshwater and terrestrial materials were highest during the year. Under the influences of Changjiang runoff, Kuroshio intrusion, surface production and bottom resuspension, the distribution generally showed strong gradients decreasing seaward for both biogenic and lithogenic materials. Particulate organic carbon was enriched in surface water (mean ∼18%) due to the influence of biological productivity, and was diluted by resuspended and/or laterally-transported materials in bottom water (mean 9.4%). The abundance of lithogenic elements (Al, Si, Fe, Mn) increased toward the bottom, and the distribution correlations were highly significant. Particulate CaCO₃ distribution provided evidence that the SPM of the bottom water in the northern part of the study area was likely mixed with sediments originally derived from Huanghe. A distinct benthic nepheloid layer (BNL) was present in all seaward transects of the ECS shelf. Sediment resuspension may be caused by tidal fluctuation and other forcing and be regarded as the principal agent in the formation of BNL. This BNL was likely responsible for the transport of biogenic and lithogenic particles across or along the ECS shelf. Total inventories of SPM, POC and PN are 46, 2.8 and 0.4 Tg, respectively, measured over the total area of 0.45 × 10⁶ km² of the ECS shelf. Their mean residence times are about 27, 13 and 11 days, respectively. The inventory of SPM in the water column was higher in the northernmost and southernmost transects and lower in the middle transects, reflecting the influences of terrestrial inputs from Changjiang and/or resuspended materials from Huanghe deposits in the north and perhaps from Minjiang and/or Taiwan’s rivers in the south. The distribution and transport patterns of SPM and geochemical elements strongly indicate that continental sources and cross-shelf transport modulate ECS particulate matter in summer.     

渤海湾盆地沙河街组钙质超微化石古生态及沉积环境

渤海湾盆地沙河街组中钙质超微化石的发现,表明这一时期渤海湾盆地与海水有过联系。对钙质超微化石古生态及沉积环境研究表明,化石主要产出时代为始新世晚期至渐新世早中期,属“间冰期”亚热带气候型。这一问题的深入研究,对于渤海湾盆地的石油勘探有重要意义。     

胶州湾海水中颗粒有机碳含量的分布与变化

本文报道了胶州湾表层海水及C_3和D_3站中层和底层水中的颗粒有机碳(POC)的分布与变化规律。结果表明,胶州湾POC年平均浓度为155～410μg/L;平面分布有明显的规律性,近岸和河口一带的含量较高,湾中部较低,湾口诸站为最低;垂直分布有个别数值偏高或偏低现象,但没有明显的规律;季节变化较明显,初春较高,秋季较低。     

Geochemical cycling in the Hooghly estuary, India

U–Th decay series isotopes, δ¹⁸O and Si measurements in the river estuarine waters and sediments of the polluted Hooghly estuary as well as the surface waters of the Bay of Bengal, its high salinity end member, are reported. Dissolved Si indicates that there are probably two mixing regimes, dissolved U behaviour is nonconservative and δ¹⁸O behaves conservatively in the overall estuarine region. Isotopes of reactive elements, viz. ²³⁴Th and ²¹⁰Po, are removed from the estuarine waters in <2 days and <1 month, respectively, which is due to high suspended matter (30–301 mg l⁻¹). ²²⁸Ra and ²²⁶Ra are profusely released into the estuarine waters in the low to mid-salinity regions.As expected, the opposite trend is observed in the case of estuarine sediments and suspended matter. Reactive isotopes of Th, ²¹⁰Pb and ²¹⁰Po are enriched, whereas Ra isotopes are depleted with respect to their parent nuclides in the estuarine sediments and suspended matter. ²³²Th/Al ratio appears well suited to study the distribution and mixing of the bed load sediments of the Ganga–Brahmaputra (G–B) and the Hooghly rivers with those from other rivers on the Bay of Bengal floor.     

珠江口水域化学耗氧量、溶解氧、无机磷与有机磷的三维水质数学模拟

珠江沿岸城市排污量大,对污染源治理能力十分有限,大量污染物通过河流或直接排放到珠江口,河口区半封闭的地形及潮水顶托使得污染物不易输送出外海,致使珠江口水质恶化,原有海洋生态环境遭到破坏,反过来制约了经济的发展.     

A depocenter of organic matter at 7800 m depth in the SE Pacific Ocean

The Atacama trench, the deepest ecosystem of the southern Pacific Ocean (ca. 8000 m depth) was investigated during the Atacama Trench International Expedition. Sediments, collected at three bathyal stations (1040–1355 m depth) and at a hadal site (7800 m) were analyzed for organic matter quantity and biochemical composition (in terms of phytopigments, proteins, carbohydrates and lipids), bacterial abundance, biomass and carbon production and extracellular enzymatic activities. Functional chlorophyll-a (18.0±0.10 mg m⁻²), phytodetritus (322.2 mg m⁻²) and labile organic carbon (16.9±4.3 g C m⁻²) deposited on surface sediments at hadal depth (7800 m) reached concentrations similar to those encountered in highly productive shallow coastal areas. High values of bacterial C production and aminopeptidase activity were also measured (at in situ temperature and 1 atm). The chemical analyses of the Atacama hadal sediments indicate that this trench behaves as a deep oceanic trap for organic material. We hypothesize that, despite the extreme physical conditions, benthic microbial processes might be accelerated as a result of the organic enrichment.     

台风“灿鸿”对长江口外海域悬浮体分布的影响

台风作为事件性的强动力因素,其对河口海域沉积环境的影响目前研究较少,开展典型台风事件对长江口外海域悬浮体分布的影响研究对于深入理解长江径流挟带陆源物质向东海陆架扩散机制等具有重要意义。利用2015年09号台风"灿鸿"过境前后长江口外海域现场调查数据,分析台风前后长江口外水体结构和悬浮体粒度分布变化,结合同期环境观测数据与开源数据,阐明台风对河口外海域悬浮体分布的影响机制。结果表明:长江口外海域悬浮体中细颗粒组分(≤ 128μm)主要为无机矿物颗粒,而粗颗粒组分(>128μm)主要是生源有机颗粒。生源有机粗颗粒主要分布于中上层水体,而无机细颗粒主要分布于底层水体,使得长江口外海域悬浮体平均粒径分布呈双层结构。台风前后悬浮体粒度分布变化反映了台风对长江口外海域物理和生物过程的双重影响,其中物理过程主要影响无机细颗粒分布变化,生物过程主要影响有机粗颗粒。台风期间强烈的偏北风使得长江冲淡水在口门外海域由东北输运转为往东输运,与长江冲淡水输运方向一致的表层无机细颗粒在台风后输运方向同样往东。另外,台风作用在河口区产生的下降流将12250-4站位底部再悬浮的泥质沉积物向东搬运至12300-4站,导致12300-4站底层悬浮体浓度增加、粒度变细。台风过境还造成长江口外海域初级生产力提高,而浮游植物生长对悬浮体中有机粗颗粒的形成有促进作用,使得口门外海域上层水体中有机粗颗粒体积浓度升高。长江口外海域由于台风过境导致悬浮体中无机细颗粒和生源有机颗粒含量均增加,使得其平均粒径整体变化不大。