南麂列岛海洋自然保护区潮间带贝类资源时空分布

为了解南麂列岛海洋自然保护区潮间带贝类十多年来的动态变化,在1992年研究基础上,于2003年度再赴南麂列岛对岩、沙相贝类进行了研究.本次调查鉴定出贝类105种,其中岩相93种、沙相12种,6种为南麂列岛新记录种,对岩相、沙相贝类组合的生态特征进行了分析,岩相多样性和均匀度指数(1.25~2.20和0.54~0.70)高于沙相的(0.23~0.95和0.17~0.94).岩相贝类数量为3025.70g/m2和2660个/m2,生物量垂直分布为低潮区最高(6471.99g/m2),中潮区居中(3772.09g/m2),高潮区最小(78.35g/m2),栖息密度为中潮区最大(4245个/m2),低潮区居中(2973个/m2),高潮区最小(439个/m2).沙相贝类数量为16.81g/m2和11个/m2,低潮区(29.43g/m2和11个/m2)大于中潮区(14.01g/m2和10个/m2).通过与以往资料比对发现,岩礁贝类数量有所增加,沙滩贝类数量则明显下降,监控区贝类数量明显多于其他区域,对贝类资源变化产生影响的相关因子作了分析探讨.     

中国南极长城湾及附近海区1993/1994年夏季表层水样无机氮、磷酸盐的浓度及其分布状况

1993／1994年南极夏季对中国南极长城湾及附近海区表层海水四种营养盐浓度及其分布状况作了调查。结果表明，NH4－N、NO3－N、NO2－N及PO4－P的大致浓度分别是2．13、7．07、0．74和1．12μg·dm-3。一般来说，湾内高于湾外氮盐于12月份常出现高值。四种形态的无机盐类之最高、最低浓度出现的时间和站位不尽一致。∑N／P递减次序大致是12月，2月，1月。水温变化与NH4－N、PO4－P浓度和∑N／P的变化常较一致，而与NO2－N则常不一，一些站位上营养盐浓度偏低可能与浮游植物摄取有关。结果显示了调研海区的浅水内湾特征。浮游植物所需营养充分。该湾仍维持正常状态。     

Vertical Sound Velocity Transition in the Coral Reef Core and Its Significance of Indicating Facies

On the basis of the sound velocity measurements of the coral reef core from Nanyong No.1 well of Yongshu Reef in the Nansha Islands,the paper studies the relations between the vertical sound velocity transition features in the coral reef core and the corresponding stratigraphic depositional facies change as well as stratigraphic gap of erosion,analyses the cause of the sound velocity transition,expounds the concrete process of the sea level change resulting in the stratigraphic gap of erosion and facies change in the coral reef and explains the relations between the vertical sound velocity transition in the coral reef core and the corresponding stratigraphic paleoclimate and the sea level change.This study is of important practical value and theoretical significance to the island and reef engineering construction and the acoustic logging for oil exploration in the reef limestone area as well as the paleoceanographic study of the marginal sea in the westerm Pacific Ocean.     

厦门地区软相潮间带多毛类的生态

根据厦门地区１９９０年２月至１９９２年１月调查软相潮间带所获资料，研究了该区多毛类的种类组成，数量与分布，结果表明，该区多毛类种类丰富，共鉴定出１１８种，隶属于３７科８３属。其中，高潮区４０种，中潮区９０种，低潮区８３种。多毛类平均栖息密度８７个／ｍ＾３，平均生物量３．３３ｇ／ｍ＾２。     

厦门港岩相潮间带多毛类的生态

本文根据１９８７年２、５、８、１１月调查资料，研究了厦门港岩相潮间带多毛类的种类组成、种类与数量的垂直分布、季节变化，并与大亚湾多毛类生态进行比较。结果表明，调查区域有多毛类４７种。平均栖息密度６０个／ｍ＾２，平均生物量１．７８ｇ／ｍ＾２，潮汐作用影响多毛类的种数、密度、生物量的垂直分布。多毛类数量的季节变化不甚明显，但冬季的栖息密度和春季的生物量较高。     

黄海北部降水中氟的浓度变化

1988～1992年连续采集了黄海西北部的大气降水,分析样品中的氟而得到的80多个数据显示出大气降水中氟的平均浓度低于中国北方主要河流的氟平均浓度。在冬季,氟的浓度较其他季节高,这可能和降雨量减少以及人为因素等密切相关。目前还难以估算出人为因素对氟在降水中化学行为的影响程度,但数据显示出人口密集地区降水中氟的浓度明显高于人口稀疏的自然地带。     

锌对虾夷扇贝和刺参幼体的毒性效应

以虾夷扇贝和刺参幼体为材料,采用急性毒性试验和亚急性毒性试验的方法,研究了锌对虾夷扇贝稚贝及幼贝和刺参幼虫的毒性效应。结果显示,锌对虾夷扇贝稚贝的２４ｈＬＣ５０ ６．４０ｍｇ／Ｌ,４８ｈＬＣ５０为３．３１ｍｇ／Ｌ,７２ｈＬＣ５０为１．３９ｍｇ／Ｌ,９６ｈＬＣ５０为０．６１ｍｇ／Ｌ;而对幼贝的２４ｈＬＣ５０为３．３２ｍｇ／Ｌ,４８ｈＬＣ５０为２．６４ｍｇ／Ｌ。７２ｈＬＣ５０为１．７６ｍｇ／Ｌ,９６ｈ     

Stratigraphic framework of gas accumulations in the Ría de Pontevedra (NW Spain)

Knowledge of marine geological environments in which shallow gas is accumulating is becoming increasingly important in global studies of climate change because a measurable proportion of the total methane source comes from continental margins. Previous studies have revealed that coastal environments represent important geological environments where microbial methane is being generated, is accumulating, and is being released. In the Ría de Pontevedra, at least 4.5 km² of seafloor in the innermost part of the ría is underlain by sediments containing natural gas. Seismic interpretation contributes new findings for the definition of periods and geological environments in which the gas could have been generated, and is accumulating and released in the Ría de Pontevedra. Groundtruthing the seismic data (facies, environments) makes it possible to identify favourable geological environments for gas generation in the sedimentary infill of the Ría de Pontevedra. Sequence stratigraphy based on high-resolution seismic profiles and post-Last Glacial Maximum sea-level records makes it possible to establish the stratigraphic architecture of the ría and to define the periods in which gas could have been generated. The results of this study show that the sedimentary infill is composed of a fifth-order sequence developed since the Last Glacial Maximum. Within this sequence, gas appears to have accumulated in the Holocene deposits associated with the latest transgressive and highstand system tracts. Seismic analysis shows that gas could have been generated in different geological environments in the Ría de Pontevedra. If coastal environments at times of lower sea level were similar to those of the present, organic-rich mud deposits (deposited mainly in lakes, estuaries and floodplains) could have survived transgression and remained buried as potential gas sources in the inner part of the ría.     

Spatially resolved spectroscopic observations of Jupiter during the 1987 opposition

Spectroscopic observations in the spectral region 6000–6600 » of major belts and zones of Jupiter have been carried out at Calar Alto Observatory (Spain) during the 1987 opposition, in support to the International Jupiter Watch Program. More than a hundred long-slit, medium resolution spectra have been taken at the coudé focus of the 1.52 m telescope. The longitudinal and latitudinal distribution of the equivalent widths of the methane and ammonia absorption bands at 6190 » and 6450 » have been investigated. Unlike the CH₄-6190 » band, the longitudinal distribution in the NH₃-6450 » band shows asymmetries in some of the Jovian regions analyzed, being the absorption greater at West than at East limbs. These results are interpreted in terms of inhomogeneous scattering models by the simultaneous variation of the NH₃ cloud optical thickness and its altitude level. The north-south scans show little latitudinal dependence on absorption in both methane and ammonia bands, although some relationship could be established between the absorption and relative continuum reflectivity variation.

---

Resumen Se presentan los resultados obtenidos de las observaciones espectroscópicas de las principales zonas y cinturones de Júpiter realizadas durante la oposición de 1987 como una contribución al International Jupiter Watch Program. Las observaciones fueron llevadas a cabo haciendo uso del foco coudé del telescopio de 1.52 m del observatorio hispanoalemán de Calar Alto (España), habiéndose obtenido algo más de cien espectros, de resolución media, en la región espectral de 6000–6600 ». Se exponen los resultados de las anchuras equivalentes de las bandas de absorción del metano en 6190 » y del amoniaco en 6450 », estudiándose, al mismo tiempo, la distribución tanto longitudinal como latitudinal de las mismas. Mientras que los resultados para la banda del metano presentan un comportamiento simétrico en todas las regiones analizadas, las anchuras equivalentes para la banda NH₃-6450 » presentan un comportamiento asimétrico en algunas regiones del planeta, con una mayor absorción hacia el limbo del oeste que hacia el del este. Los resultados son interpretados en base a un modelo de scattering no homogéneo, variando, simultáneamente, el espesor óptico y la altitud de la nube de amoniaco. Los espectros tomados en la dirección norte-sur, aunque presentan una dependencia latitudinal pequeña en la absorción de las bandas mencionadas, sugieren una relación entre la absorción y las variaciones de reflectividad en el continuo.

---

---

Also at Departamento de Física Aplicada, Facultad de Ciencias, Universidad de Granada, Campus Universitario Fuentenueva, Granada, Spain.