浅谈浮游有孔虫群落海水古温度估算

微体化石组合很早就被用来进行海水古温度估算,近年来利用浮游有孔虫组合来估算古温度的方法有IK TF,MAT,RAM,SIMMAX,ANN和ANND等。本文介绍了这六种方法的主要原理和他们适用的纬度和温度范围,并分别利用FP12E、SIMMAX28及ANN等三类方法来估算冲绳海槽255站位、南海17957站位和ODP1143站位的表层海水古温度,比较计算结果的异同,以验证他们的适用性。     

南海南部表层海水古温度估算与次表层海水特征变化

南海南部～2 MaBP以来的表层海水古温度估算表明,表层海水温度变化在更新世冰期旋回中波动比南海北部为小、保持比较温暖,但在长时间尺度上转换函数古水温仍然存在一定的变化趋势。转换函数古温度计算的低温时期并不与冰期相对应,表明南海南部具有独特的表层海洋演化特征,可能与次表层水体性质、上部水体结构等密切相关。过去2 MaBP以来的浮游有孔虫组合演化表明,南海南部海水温跃层呈现由氧同位素MIS79期向～53期相对变浅,自MIS 53期向布容／松山(B／M)古地磁界线附近变深,然后,自布容／松山界线以来又相对变浅的演化过程。     

南海北部表层硝酸盐浓度反演研究

研究首次利用南海北部船基观测数据资料建立硝酸盐和海表温度的关系, 然后通过MODIS-SST资料与现场海表温度比较后进行了订正。利用订正后的数据表明南海北部的表层硝酸盐和海表温度之间存在显著的负相关关系(R²=0.7126)。结合海表硝酸盐和海表温度的关系式, 利用遥感海表温度的8 d平均值和月平均值估测了南海北部的表层硝酸盐浓度, 8 d平均海表硝酸盐浓度值范围为0～3.3167 μM, 月平均值为0～2.0590 μM, 该值与现场监测数据及历史资料均一致。     

Monthly Variation of Pigment Concentrations and Seasonal Winds in China's Marginal Seas

China's marginal seas extend from temperate, subtropical to tropical zones, which encounter different monsoons. This study investigates the monthly variation of phytoplankton pigment concentrations (PC) from 1978 to 1986, and analyzes seasonal winds with sea surface temperatures (SST) among the Bohai Sea, the Yellow Sea, the East China Sea and the northern South China Sea. Nimbus satellite Coastal Zone Color Scanner (CZCS)-derived PC images were averaged into monthly fields for the entire area; we then emphasize the period of one year from November 1979 to October 1980, when CZCS data availability was relatively good. Monthly variability of PC has been compared among three regions (the outlets of the Yellow River, the Yangtze River and the Pearl River). The results revealed well-defined seasonality of PC, wind and SST from north to south in China's marginal seas. In the northern area (Bohai Sea and Yellow Sea), variability in SST (0–28?°C) and PC (0.5–3.5 mg m^?3) was high with two peaks of PC appeared in spring–summer and in fall–winter in each year. In the East China Sea, two peaks of PC (1.2 mg m^?3 in March and 1.3 mg m^?3 in November) were in evidence, where SST variations were ranged 7–28?°C in one year. However, in the southern area (northern South China Sea), variation in SST (15–29?°C) and PC (0.1–0.4 mg m^?3) was relatively low; the monthly variation of PC was not so high compared with north area. OCTS derived ocean color data obtained from April 1997 conformed the spatial pattern of Chl-a and colored dissolved organic matter (CDOM), and showed high CDOM and total suspended material (TSS) in the coast waters in the north part of China's marginal seas. Seasonal variation of PC may be related to the reversed monsoon; and spatial variation of PC may be influenced by river discharge, upwelling and coastal currents. High PC areas match good fishing grounds in terms of season and location in the study waters.     

Temporal and spatial variability of the oxygen isotopic composition of massive corals from the South China Sea: Influence of the Asian monsoon

Coral colonies of Porites lutea and P. lobata were collected from areas to the east and south offshore of Hainan Island, South China Sea. Oxygen isotope ratios, ¹⁸O/¹⁶O, were analyzed along the major axis of growth at a resolution of 25–28 samples within an annual band from three colonies, giving data series lengths of 15, 20 and 30 years. Coral δ¹⁸O correlates well with sea surface temperature (SST) throughout most years, particularly when the Asian winter monsoon prevails over the region. Due to the same seasonal phases of SST and sea surface salinity (SSS), it is estimated that most of the seasonal features of coral δ¹⁸O are controlled by changes in SST with a significant contribution of SSS. This indicates the importance of temperature, as determined by the Asian winter monsoon, as a control on seasonal coral δ¹⁸O variations in the South China Sea. Given the fact that annual SSS maxima show minor inter-annual changes, the inter-annual change of annual coral δ¹⁸O maximum mainly reflects the SST induced by the winter monsoon. While the coral δ¹⁸O is mainly controlled by SST, deviations of the δ¹⁸O from SST correlate statistically with sea surface salinity, particularly for summer extreme events when SST reaches its annual maximum with minor inter-annual change. Therefore, we suggest that the inter-annual variation of the annual coral δ¹⁸O minima is mainly controlled by seawater composition. Seawater composition analysis indicates that its δ¹⁸O and salinity are simultaneously affected by freshwater inputs primarily from precipitation, which is mainly supplied by the Asian summer monsoon. Thus seasonal alternations of the winter and summer monsoon mainly control the coral δ¹⁸O, thereby allowing reconstruction of these monsoonal variables. The three coral records consistently reveal clear inter-decadal trends in δ¹⁸O — a gradual increase from 1968 to 1987, and a subsequent decrease from 1987 to 2003. These inter-decadal trends are roughly consistent with salinity changes — but not with temperature and precipitation, suggesting that seawater composition controlled by freshwater inputs from distant source areas, rather than from local precipitation, is responsible for the trends in seawater composition and coral δ¹⁸O over the last 30 years. Comparison of the three coral records indicates that spatial variations in coral δ¹⁸O coincide with variations in seawater salinity and local precipitation, but not with temperature. This confirms the dominant role of seawater composition, mainly controlled by monsoonal precipitation, on the spatial variability of coral δ¹⁸O in the South China Sea.     

High-resolution sea surface temperature records derived from foraminiferal Mg/Ca ratios during the last 260 ka in the northern South China Sea

High-resolution sea surface temperatures (SST) derived from Mg/Ca ratios of Globeriginoides sacculifer at ODP Site 1144 were reported to reveal the SST changes during the last 260 ka in the northern South China Sea (SCS). The results indicate an average Holocene SST of about 26.7 °C, about 3.6 °C increase from LGM to the Holocene, and higher temperature during MIS 5.5 than the Holocene. These agree well with other foraminifer Mg/Ca and U^k₃₇ SST records in this region. The Mg/Ca records suggest warmer SSTs during MIS 3 in the northern SCS, compared with those in the eastern Pacific. Strong East Asian summer monsoon during MIS 3 indicated by paleoclimate records from nearby continents may account for it. Step-wise increases during terminations are shown in our SST record, and the beginning of deglacial warming occurs at about 19 ka, which precedes the change of oxygen isotopes, suggesting a tropical driven forcing for the SST change in the northern SCS. This is further supported by a robust semi-precessional cycle centering at  9.1 ka in the spectra of the SST record, which is absent in that of the oxygen isotopes. However, tropical driven forcing seems not to be indicated in another Mg/Ca SST record in the northern SCS [Oppo, D.W. and Sun, Y.B., 2005. Amplitude and timing of sea-surface temperature change in the northern South China Sea: Dynamic link to the East Asian monsoon. Geology, 33 (10): 785–788.]. The discrepancy may be caused by different post-deposition dissolutions of foraminifer tests at these two sites. Details about the modification of foraminifer Mg/Ca ratios after burial, however, are not well known in this region, and further studies are needed.     

Conservation of reef corals in the South China Sea based on species and evolutionary diversity

The South China Sea in the Central Indo-Pacific is a large semi-enclosed marine region that supports an extraordinary diversity of coral reef organisms (including stony corals), which varies spatially across the region. While one-third of the world’s reef corals are known to face heightened extinction risk from global climate and local impacts, prospects for the coral fauna in the South China Sea region amidst these threats remain poorly understood. In this study, we analyse coral species richness, rarity, and phylogenetic diversity among 16 reef areas in the region to estimate changes in species and evolutionary diversity during projected anthropogenic extinctions. Our results show that richness, rarity, and phylogenetic diversity differ considerably among reef areas in the region, and that their outcomes following projected extinctions cannot be predicted by species diversity alone. Although relative rarity and threat levels are high in species-rich areas such as West Malaysia and the Philippines, areas with fewer species such as northern Vietnam and Paracel Islands stand to lose disproportionately large amounts of phylogenetic diversity. Our study quantifies various biodiversity components of each reef area to inform conservation planners and better direct sparse resources to areas where they are needed most. It also provides a critical biological foundation for targeting reefs that should be included in a regional network of marine protected areas in the South China Sea.     

东海鲐鱼资源时空分布特征

利用1998年1月～2006年12月我国东海鲐鱼灯光围网生产统计数据和月平均海水表层温度SST及表温距平均值,利用GLM模型对其单位日产量CPUE进行标准化,然后对其资源时空分布进行了分析.结果表明:其CPUE与年份、月份、纬度、船队、表温及年份与纬度和年份与船队之间的交互效应有关.CPUE的年际变化与SST间有着显著的相关性.秋季是东海鲐鱼资源丰度最高的季节,渔业分布范围进一步拓展,资源的丰度也比夏季更高,且东海西北部的丰度较高:l0月份,东海鲐鱼的分布范围又出现回缩,仅在东海中部水域有渔业分布,但资源的丰度也为四个季节中最高.     

南中国海野生海水鱼类外寄生车轮虫新记录

研究对采自南中国海的7种海水鱼类进行了调查研究, 并分离获得4种隶属于车轮虫属的种类,分别为浦氏车轮虫Trichodina puytoraci Lom, 1962; 日本车轮虫Trichodina japonica Imai, et al., 1991; 直钩车轮虫Trichodina rectuncinata Raabe, 1958 与鲀车轮虫Trichodina fugu Imai, et al., 1997。研究发现鲀车轮虫Trichodina fugu Imai, et al., 1997为寄主鱼虫纹东方鲀Takifugu vermicularis的病原, 且能在野生条件下将其致死。上述4种车轮虫的形态分类学数据均基于干银法标本获得。研究是对我国南中国海车轮虫的首次报道。       

涠洲岛42年来海面温度变化及其对珊瑚礁的影响

涠洲岛位于南海珊瑚礁分布的北缘温度是影响其珊瑚礁生态系统发育的重要因素,对器测温度分析发现,近42年来涠洲岛海面温度(SST)与全球气候变暖呈准同步变化趋势,存在3～4年与7～8年的变化周期,20世纪80年代后期以来,涠洲岛SST上升比较明显。其月平均最高SST的持续上升将使本区珊瑚生长处于一种非常敏感的边缘,加上人类活动(建筑取材、炼油、旅游、捕鱼、养殖等)对涠洲岛珊瑚礁的潜在不利影响,则可能导致珊瑚礁的退化。此外,在系统的野外调查基础上,描述了涠洲岛现代珊瑚礁的分布范围。     

Coastal States in the South China Sea and Submissions on the Outer Limits of the Continental Shelf

The purpose of this article is to examine the outer continental shelf submissions made by the coastal states of the South China Sea and their potential impact on legal and political developments in the South China Sea. In accordance with the United Nations Convention on the Law of the Sea of 1982 and the guidelines of the Commission on the Limits of the Continental Shelf, coastal states are to establish the outer limits of their continental shelf where it extends beyond 200 nautical miles. Meeting this obligation is complicated in enclosed or semienclosed seas where there are maritime disputes such as in the South China Sea.     

Modeled connectivity of <Emphasis Type="Italic">Acropora millepora</Emphasis> populations from reefs of the Spratly Islands and the greater South China Sea

The Spratly Island archipelago is a remote network of coral reefs and islands in the South China Sea that is a likely source of coral larvae to the greater region, but about which little is known. Using a particle-tracking model driven by oceanographic data from the Coral Triangle region, we simulated both spring and fall spawning events of Acropora millepora, a common coral species, over a 46-yr period (1960–2005). Simulated population biology of A. millepora included the acquisition and loss of competency, settlement over appropriate benthic habitat, and mortality based on experimental data. The simulations aimed to provide insights into the connectivity of reefs within the Spratly Islands, the settlement of larvae on reefs of the greater South China Sea, and the potential dispersal range of reef organisms from the Spratly Islands. Results suggest that (1) the Spratly Islands may be a significant source of A. millepora larvae for the Palawan reefs (Philippines) and some of the most isolated reefs of the South China Sea; and (2) the relatively isolated western Spratly Islands have limited source reefs supplying them with larvae and fewer of their larvae successfully settling on other reefs. Examination of particle dispersal without biology (settlement and mortality) suggests that larval connectivity is possible throughout the South China Sea and into the Coral Triangle region. Strong differences in the spring versus fall larval connectivity and dispersal highlight the need for a greater understanding of spawning dynamics of the region. This study confirms that the Spratly Islands are likely an important source of larvae for the South China Sea and Coral Triangle region.     

中国沿海海鞘的物种多样性

至今,中国海已经记录了66种海鞘。其中,渤海有5种,黄海21种,东海24种,南海53种。种类分布从北往南逐渐递增,柄瘤海鞘在黄海、渤海数量很大(8100个/m²),但往南分布,未发现超过罗源湾。皱瘤海鞘在南海数量很大(2225个/m²),往北也未发现超过罗源湾。玻璃海鞘和乳突皮海鞘在全国沿海都有分布。     

环境因子对东海区帆式张网主要渔获物渔获量影响

帆式张网渔业是东海区重要的渔业捕捞方式之一．利用广义加性模型(GAMs)定量研究了海表水温、渔场水深、渔场位置和潮汐(农历日期)等环境因子对东海区帆式张网主要渔获物渔获量变动的影响．结果表明,海表水温和渔场水深是影响带鱼、小黄鱼和鲳鱼单位努力渔获量(CPUE)的主要因子,且各因子的影响程度不尽相同,多呈非线性相关关系．从模型的拟合结果来看,海表水温对带鱼的影响最大,其次是水深,渔场位置和潮汐的影响很小．渔场水深对小黄鱼的影响最大,海表水温、渔场位置和潮汐的影响比较接近．渔场水深和海表水温是影响鲳鱼单位努力渔获量的主要环境因子,影响程度比较接近．     

POPULATION GENETIC STRUCTURE OF FINLESS PORPOISES, NEOPHOCAENA PHOCAENOIDES, IN CHINESE WATERS, INFERRED FROM MITOCHONDRIAL CONTROL REGION SEQUENCES

Seven hundred and twenty base pairs (bp) of the mitochondrial control region from 73 finless porpoises, Neophocaena phocaenoides , in Chinese waters were sequenced. Thirteen variable sites were determined and 17 haplotypes were defined. Of these, 5 and 7 were found only in the Yellow Sea population and the South China Sea population, respectively, whereas no specific haplo-type was found in the Yangtze River population. Phylogenetic analyses using NJ and ML algorithm did not divide the haplotypes into monophyletic clades representing recognized geographic populations of finless porpoises in Chinese waters, suggesting the existence of migration and gene flow among populations. Analysis of molecular variance showed the obvious population genetic structure (φ_st= 0.41, P < 0.05); however, the structure was mainly between either the Yangtze River population or the Yellow Sea population and the South China Sea population. The genetic diversity (nucleotide diversity and haplotypic diversity) of the Yellow Sea population was significantly higher than those of the Yangtze River population and the South China Sea population, suggesting the relatively later divergence of the latter two populations and supporting the Yellow Sea population as the original center of Neophocaena .     

鲷无胄虫的描述及无胄虫科的分类地位

对寄生于大亚湾黑鲷(Acanthopagrus schlegeli)体表的鲷无胄虫(Anoplodiscus spari)进行了形态描述, 并扩增了该虫的28S rDNA C1-D2区部分序列, 构建了相关类群的分子系统树, 探讨了无胄虫科的分类地位。结果显示: 所获标本与Ogawa等的描述基本一致, 但交接管基部及末端位置略有不同: 本研究标本的交接管基部始于支持器的下方、末端于支持器三分叉的中支略伸出, 而Ogawa等的标本交接管基部靠近支持器三叉处、末端从三叉处延伸并略弯曲; 无胄虫属(Anoplodiscus)为单系起源, 隶属于指环虫目、四钩虫亚目、无胄虫科(Anoplodiscidae), 无胄虫科是一独立的科, 在分类地位上与四钩虫科(Tetraonchidae)互为姐妹群, 与Udonellidae科和微沟科(Microbothriidae)的关系较远。     

Paleoenvironmental change in the middle Okinawa Trough since the last deglaciation: Evidence from the sedimentation rate and planktonic foraminiferal record

Well-dated, high-resolution records of planktonic foraminifera and oxygen isotopes from two sediment cores, A7 and E017, in the middle Okinawa Trough reveal strong and rapid millennial-scale climate changes since ∼ 18 to 17 thousand years before present (kyr B.P.). Sedimentation rate shows a sudden drop at ∼ 11.2 cal. kyr B.P. due to a rapid rise of sea level after the Younger Dryas (YD) and consequently submergence of the large continental shelf on the East China Sea (ECS) and the retreat of the estuary providing sediment to the basin. During the last deglaciation, the relative abundance of warm and cold species of planktonic foraminifera fluctuates strongly, consistent with the timing of sea surface temperature (SST) variations determined from Mg/Ca measurements of planktonic foraminifera from one of the two cores. These fluctuations are coeval with climate variation recorded in the Greenland ice cores and North Atlantic sediments, namely Heinrich event 1 (H1), Bølling–Allerød (B/A) and YD events. At about 9.4 kyr B.P., a sudden change in the relative abundance of shallow to deep planktonic species probably indicates a sudden strengthening of the Kuroshio Current in the Okinawa Trough, which was synchronous with a rapid sea-level rise at 9.5–9.2 kyr B.P. in the ECS, Yellow Sea (YS) and South China Sea (SCS). The abundance of planktonic foraminiferal species, together with Mg/Ca based SST, exhibits millennial-scale oscillations during the Holocene, with 7 cold events (at about 1.7, 2.3–4.6, 6.2, 7.3, 8.2, 9.6, 10.6 cal. kyr BP) superimposed on a Holocene warming trend. This Holocene trend, together with centennial-scale SST variations superimposed on the last deglacial trend, suggests that both high and low latitude influences affected the climatology of the Okinawa Trough.     

从细胞色素b基因序列探讨笛鲷属的分子系统发生关系

测定了9种中国南海的笛鲷属鱼类的细胞色素b基因的部分序列,结合来自GenBank中1种分布于菲律宾和9种分布于美国大西洋的笛鲷属鱼类的相应同源序列,用邻接法和最大简约法构建分子系统树。结果显示:红鳍笛鲷(Lutjanuserythropterus)与红笛鲷(L.sanguineus)之间的同源序列碱基差异百分率只有0.32%,支持二者是同种异名的观点;中国南海的笛鲷属鱼类间的平均碱基差异要高于美国大西洋笛鲷属鱼类。在MP和NJ树中,美国大西洋笛鲷表现为亲缘关系较近,来源于中国南海的笛鲷鱼类相对集中在树的基部,分歧较大。这与所研究的笛鲷地理分布和地理隔离基本相一致,同时也说明中国南海笛鲷分化较早并且分歧较大。     

Mitochondrial control region variability of baiji and the Yangtze finless porpoises,two sympatric small cetaceans in the Yangtze river

BaijiLipotes vexillifer (Miller, 1918) and the Yangtze finless porpoiseNeophocaena phocaenoides asiaeorientalis (Pilleri and Gihr, 1972) are two sympatric small cetaceans inhabiting the middle and lower reaches of the Yangtze River. In this study, a fragment (420–428 bp) of the mitochondrial control region was sequenced to provide the first comparative survey of genetic variability and population structure in these two endangered species, with samples of finless porpoises from the Yellow/Bohai Sea, East China Sea, and South China Sea also included. Low values of haplotype diversity and nucleotide diversity were found for both species, especially for the baiji and the Yangtze River and South China Sea populations of finless porpoises. The analysis of molecular variance (AMOVA) supported a high level of overall genetic structure among three porpoise populations in Chinese waters, with greatest differences found between either the Yangtze River population or the Yellow Sea population and the South China Sea population. The differentiation between the Yangtze and Yellow Sea populations was not significant, and the males have higher genetic differentiation than the females, suggesting a significant female-biased dispersal between these two populations. This study showed that the Yangtze finless porpoise, unlike the sympatric baiji, was not a genetically isolated population. The Yangtze and Yellow Sea porpoises should be included in the same management unit, but further studies using more samples and especially based on more molecular markers are urgently needed to confirm this.     

Global climate drives southern right whale (Eubalaena australis) population dynamics

Sea surface temperature (SST) time-series from the southwest Atlantic and the El Ni?o 4 region in the western Pacific were compared to an index of annual calving success of the southern right whale (Eubalaena australis) breeding in Argentina. There was a strong relationship between right whale calving output and SST anomalies at South Georgia in the autumn of the previous year and also with mean El Ni?o 4 SST anomalies delayed by 6 years. These results extend similar observations from other krill predators and show clear linkages between global climate signals and the biological processes affecting whale population dynamics.