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1.
《Deep Sea Research Part I: Oceanographic Research Papers》2006,53(5):776-794
A sampling survey was carried out to study the distribution and ecology of leptocephali in several different areas of the western South Pacific between 160 and 175°E during August and September of 1995. The survey included transects of stations across the westward flowing South Equatorial Current (SEC) region to the northwest of Fiji and south to 30°S, a transect to the north of the Tasman Front, and a transect that passed through the Solomon Islands. A total of 2362 leptocephali of at least 94 species of 13 families of eels and other elopomorph fishes were collected. The most abundant leptocephali in the region were of the marine eel families Serrivomeridae, Congridae, Nemichthyidae, and Muraenidae of the order Anguilliformes. The leptocephali of shallow water eels of the Chlopsidae, Moringuidae, Muraenidae, and Ophichthidae were most abundant and present at a wide size range in the low salinity “Fresh Pool”, which is also located closest to the major islands in the SEC region. Anguillid leptocephali were also most abundant in the SEC region and several species appeared to be spawning at that latitude. Cluster analysis and ordination of the catch rates of leptocephali suggested there were four regional assemblages related to the offshore spawning of mesopelagic serrivomerid eels, the presence of anguillid leptocephali in the SEC region and the relationship between the regional ocean current patterns and the geography of islands where shallow water marine eels live and probably spawn nearby. More impoverished assemblages were found in the southern regions where there are fewer islands, colder, higher salinity surface waters, and predominantly eastward flow. These findings support the hypothesis that various taxa of anguillid and marine eels use different spawning and recruitment strategies in the western South Pacific region as has been suggested by studies on leptocephali in the Northern Hemisphere. 相似文献
2.
2009—2011年东海陆架海域网采浮游植物群落的季节变化 总被引：3，自引：0，他引：3
根据2009年7、8月(夏季)、12月到翌年1月(冬季)、2010年11月(秋季)和2011年4、5月(春季)共4个航次在东海陆架区进行的现场多学科综合调查,报道了4个季节在整个东海海域的浮游植物的空间分布及群落结构特征,并探讨了影响其分布格局的环境因子效应。结果表明,东海浮游植物群落主要由硅藻、甲藻组成。共检出浮游植物5门88属299种(含未定种)。调查区夏季细胞丰度达最高,平均为(8 659.572±28 937.27)cell/L,其次是秋、冬季,春季最低,分别为(4 413.726±12 534.573)cell/L、(421.773±647.532)cell/L和(218.479±265.897)cell/L。硅藻细胞丰度在夏、秋、冬3个季节占总平均丰度的95%以上,甲藻细胞丰度在春季最高,占总浮游植物细胞丰度的69%。调查海区浮游植物丰度高值区主要集中在长江口海域,并向外海呈递减趋势。不同群落间存在季节更替和演替现象。物种丰富度自春夏秋冬逐渐升高。香农指数(Shannon-Wiener index)和均匀度指数(Pielou index)分布较为一致,物种丰富度指数(Margalef index)呈现时空分布差异。Pearson相关分析结果表明:不同季节的物种间更迭与海区特定的物理化学参数显著相关。 相似文献
3.
《Journal of Sea Research》2007,57(2-3):198-208
Dover sole (Microstomus pacificus) and rex sole (Glyptocephalus zachirus) are both commercially valuable, long-lived pleuronectids that are distributed widely throughout the North Pacific. While their ecology and life cycle have been described for southern stocks, few investigations have focused on these species at higher latitudes. We synthesized historical research survey data among critical developmental stages to determine the distribution of life cycle stages for both species in the northern Gulf of Alaska (GOA). Bottom trawl survey data from 1953 to 2004 (25 519 trawls) were used to characterize adult distribution during the non-spawning and spawning seasons, ichthyoplankton data from 1972 to 2003 (10 776 tows) were used to determine the spatial and vertical distribution of eggs and larvae, and small-meshed shrimp trawl survey data from 1972 to 2004 (6536 trawls) were used to characterize areas utilized by immature stages. During the non-spawning season, adult Dover sole and rex sole were widely distributed from the inner shelf to outer slope. While both species concentrated on the continental slope to spawn, Dover sole spawning areas were more geographically specific than rex sole. Although spawned in deep water, eggs of both species were found in surface waters near spawning areas. Dover sole larvae did not appear to have an organized migration from offshore spawning grounds toward coastal nursery areas, and our data indicated facultative settling to their juvenile habitat in winter. Rex sole larvae progressively moved cross-shelf toward shore as they grew from April to September, and larvae presumably settled in coastal nursery areas in the autumn. In contrast with studies in the southern end of their range, we found no evidence in the GOA that Dover or rex sole have pelagic larval stages longer than nine months; however, more sampling for large larvae is needed in winter offshore of the continental shelf as well as sampling for newly settled larvae over the shelf to verify an abbreviated pelagic larval stage for both species at the northern end of their range. 相似文献
4.
T. M. Ward J. Staunton-Smith S. Hoyle I. A. Halliday 《Estuarine, Coastal and Shelf Science》2003,56(5-6):1125-1140
The diverse pelagic fish assemblage of sub-tropical southern Queensland includes fishes with predominantly temperate distributions, such as tailor Pomatomus saltatrix, sardine Sardinops sagax, round herring Etrumeus teres, and Australian anchovy Engraulis australis. The peak spawning seasons of P. saltatrix, S. sagax and E. teres occur during late winter and early spring (June–October). Eggs and larvae of these three species are widely distributed in shelf waters and comprise >50% of the ichthyoplankton assemblage during this period. Mean monthly sea surface temperatures (SSTs) during late winter and early spring range from 21 to 23 °C, and are thus similar to those recorded in southern Australia during summer and autumn, which is the spawning season of these three species in those temperate waters. E. australis eggs occur mainly in inshore waters, and comprise >50% of fish eggs collected during summer and autumn when mean monthly SSTs in southern Queensland exceed 27 °C. E. australis also spawns mainly during summer and autumn in temperate Australia. Hence, water temperature may be less important as a determinant of the spawning season of E. australis than it is for the other three species. The suitability of southern Queensland for spawning by predominantly temperate species during late winter and early spring may contribute to the high diversity of the region's pelagic fish assemblage. Adult P. saltatrix, S. sagax and E. teres appear to migrate northwards into southern Queensland during early winter to spawn, and larvae may be transported southwards into temperate waters by the East Australian Current. This dispersal-migration pattern is similar to those observed for several species, including P. saltatrix, in the western boundary current systems off the east coasts of North America and Africa. Hence, pelagic fishes in ecosystems off the east coast of three continents migrate into sub-tropical waters to spawn, and larvae are transported back into temperate nursery areas by the prevailing current. 相似文献
5.
Multi‐specific synchronous spawning has never been documented for East Africa, but coral spawn‐slicks are observed annually around Vamizi Island, Northern Mozambique. We monitored gamete development in Acropora species from July 2012 to October 2013 and from August to September 2014 to describe patterns of reproductive seasonality and synchrony within and amongst species of Acropora. Gamete maturation was highly synchronized within and amongst Acropora species and culminated in multi‐specific spawning events lasting 1–3 nights in each year of the study, in late August or September. In 2013 and 2014, 50% or more of the colonies of over 50% of the species sampled prior to the spawning events had mature gametes. In all years, 91–99% colonies sampled after the spawning events had no visible gametes. The percentage of colonies with mature gametes was up to 100% for some species. In other species, the absence of mature gametes throughout the study period indicates that they might not spawn in certain years. The analysis of a 8‐year record of observations of spawn‐slicks showed that spawning generally occurred once a year for a few consecutive days between September and December, during periods of rising sea surface temperature and low wind speed and rainfall. This study is the first to quantitatively document coral reproduction in Mozambique and multi‐specific synchronous spawning off the coast of Africa. These findings contrast with the asynchronous breeding reported for Kenyan reefs and support the absence of breakdown in coral reproductive synchrony towards low latitudes. 相似文献
6.
东海陆架表层水温年际变化时空特征分析 总被引：2，自引：2，他引：0
结合东海沿岸嵊山(北)和厦门(南)站1960—2001年海表温度(SST)监测数据与东中国海1982—2011年AVHRR水温资料,讨论了台站监测的空间代表范围,分析了东海陆架SST年际变化的时空特征。结果表明,嵊山和厦门站SST变化分别代表内陆架和台湾海峡。东海陆架52年来SST总体呈升温趋势,冬季最为显著;内陆架的升幅远大于台湾海峡。内陆架水温冬季分别在1977年和1995年发生两次跃升,共升温2.34℃;春、夏、秋季均在1994年发生冷暖转折,分别升高1.19℃、1.43℃和1.16℃。台湾海峡水温冬季在1989年跃升0.91℃,夏季在1987年跃升0.38℃,春、秋季则在1996—1997年间分别升温0.80℃和0.58℃。全年水温变化最大处在长江口附近内陆架海区,可能的主导因素是低盐水与外海水混合:随季风、降水、径流变化的沿岸流、长江冲淡水和台湾暖流给该区域带来不同水团,使得热量向下层输运减少,从而导致东海内陆架升温快于其它海区。 相似文献
7.
Larvae (leptocephali) of Gnathophis habenatus (Richardson, 1848) and G. incognitas Castle, 1963 occur off Castlepoint throughout most of the year (not sampled December‐February), In general they are smallest in late summer (March) and ilargest in mid‐spring (October‐November), with metamorphosis to the juvenile in early summer of the year of spawning. The two species therefore have a larval life of approximately 10 months. The early life of these two species in Australian waters, and of G. capensis (Kaup) off southern Africa, agrees well with these observations. Eel eggs collected in the East Cape region of New Zealand and tentatively identified as those of Gnathophis confirm the spawning times (March—April) suggested by the sizes of leptocephali. 相似文献
8.
James A. Yoder 《Estuarine, Coastal and Shelf Science》1983,17(6):637-650
Data collected in 1953 and 1954 by the U.S. Fish and Wildlife Service were statistically analyzed to ascertain where and when fish eggs and larvae are most abundant on the southeastern U.S. continental shelf. The results are related to some oceanographic processes that might affect the survival of larval fish. Along-shelf differences in numbers of eggs and larvae are minimal compared with differences that occur across the shelf. Highest numbers of fish larvae are found on the outer shelf during fall, winter and spring, but larvae are evenly distributed across the shelf in summer.Upwelling strongly influences the dynamics of plankton production on the outer shelf, and thus during most seasons of the year upwelling may be the most important process controlling the amount of food available to larval fish. During winter and spring, mean winds do not favor shoreward transport of larval fish from the outer shelf if the larvae are located in near-surface waters. Thus, during these seasons variability of winds on the ‘event’ time scale may be more important to onshore and offshore transport of larval fish than the mean strength and direction of monthly or seasonally averaged winds. 相似文献
9.
The commercially important sergestid shrimp,Sergia lucens (Hansen), has long been considered an endemic species of Japan because it had been found only in Suruga Bay and neighbouring waters. Recently, however, a considerable amount of a similar shrimp was caught by trawl nets off Tung-kang, southwestern Taiwan. This shrimp is distributed at depths of 100–300 m on the continental slope, around a deep submarine canyon adjacent to the mouth of the Kao-ping River. A morphological comparison with specimens from Suruga Bay reveals that the shrimp is identical toS. lucens. However, a slight difference in the patterns of water-soluble proteins was observed in a thin layer isoelectrophoretic examination. A difference was also observed in the spawning season of the two populations, indicating sexual and geographic isolation. Considering the distribution and phylogeny of the family Sergestidae, based on a possible evolutionary development from a benthic neritic organism to a pelagic oceanic one along the generaSicyonella-Sergestes-Sergia, it is assumed thatS. lucens entered a lower epipelagic habitat in the coastal waters from the warm oceanic mesopelagic habitat of the original stock. A hypothesis is proposed that speciation ofS. lucens from the original stock occurred when it was trapped in a semi-enclosed inlet (the paleo-East China Sea Gulf) that existed at the present Okinawa Trough during the late Pliocene to early Pleistocene. The inlet was deep, but had a neritic environment due to drainage from ancient large river systems, including the paleo-Yangtze River. The species expanded its distribution to the neighbouring waters during the warm interglacial period. However, a rapid rise in sea level after 14,000 years significantly changed the environmental conditions in the distributional area and the species could not expand into a neritic environment, which was too shallow for survival. Accordingly,S. lucens populations remained only in Suruga Bay and Tung-kang waters, where the environment has remained stable for the last 17,000 years or more. The two areas have the following common characteristics:
- A large amount of fresh water is discharged into the deep submarine canyon adjacent to the river mouth.
- The northeastern part is surrounded by land so that a direct inflow of boreal water into the environment is blocked.
- Warm Kuroshio extension water intrudes and mixes with water from the rivers, and for Suruga Bay there is a current system that keeps distribution of the eggs and larvae restricted to the local habitats.
10.
基于1993—2017年卫星高度计海面高度异常中尺度涡旋追踪数据集,对东海陆架区及从西北太平洋入侵东海的涡旋进行路径分类、季节变化及特征参量统计分析,并结合再分析流场资料,进行背景流场、涡度场分析。研究结果显示,近25 a,在东海追踪到318个气旋涡和276个反气旋涡。根据涡旋运动路径将其分为:东海陆架浅海生成往深海传播型(148个)、深海生成向东海陆架浅海传播型(35个)、沿等深线运动型(180个)、徘徊型(121个)、外来入侵到达东海陆架型(25个)及外来入侵到达东海深海型(85个)。6类涡旋的数量存在明显的季节分布,各个类型气旋与反气旋涡数量的季节分布也各不相同。其中,沿等深线运动型涡在春、夏季的数量高于秋、冬季。陆架浅海区生成往深海运动型涡的季节分布较为平均,气旋式涡在夏季数量最少,在春季和冬季数量较多。黑潮与涡旋数量的季节分布有关。徘徊型涡的平均生命周期最长,约为44 d;陆架浅海生成往深海运动型及外来入侵到达东海陆架的中尺度涡具有最大的平均振幅,为13.2 cm;外来入侵到达东海陆架型涡具有最大的直径,为122 km;外来入侵到达东海深海型涡在进入东海后的生命周期、振幅、直径在数值上均为最小。 相似文献
11.
Pelagic chaetognaths in Sagami Bay and Suruga Bay, Central Japan, were studied. Their community structure was very similar in both of these bays. Four genera and 26 species were identified. In Sagami Bay the habitat segregation by depths was clearly obtained. The population and species number of epipelagic (0–200 m) chaetognaths were larger in summer than in winter. The populations of meso- (200–500 m) and bathypelagic (500–1,000 m) species were smaller than that of epipelagic ones and fairly stable seasonally. 相似文献
12.
Twice monthly sampling over two 16 month periods at a shallow site on Newfoundland's east coast showed the fish assemblage to be dominated by four taxa (Gasterosteus aculeatus, G. wheatlandi, Osmerus mordax, Gadus spp.) that accounted for 96% of the individuals collected. Of the 16 479 fish measured, 65% were adults based on the estimated size of first spawning. The fish assemblage was dominated (86%) by species with demersal eggs, several of which spawn at the same shallow sites used by juveniles as nursery sites. Coastal spawning and demersal eggs maintain offspring in coastal nursery areas where survival is thought to be increased. Number of species and number of fish were both correlated with water temperature being highest from mid-summer to early autumn and lowest in winter. Temperature, time of spawning, and movements of juveniles and adults facilitated grouping species into five assemblages based on seasonal abundance: seasonal periodic species (summer and winter), regular species, regular species collected in all seasons except winter, and occasional (rare) species. At the diel scale, two consistent species groupings were observed: species that showed no significant difference between day and night and species caught primarily at night. Number of night species exceeded day species by a factor of two. No seine-caught species in shallow water exhibited significantly higher catches during the day. Observations by SCUBA divers indicated some species were more abundant during day time at slightly deeper depths. This observation in conjunction with day and night seining in shallower water, suggests these species aggregate in deeper water during day and move to shallow waters at night. 相似文献
13.
南海头足类资源丰富 ,文献报道的种类有 89种。在水深 40m以浅海域分布数量较多的种类为杜氏枪乌贼Loligoduvaucelii(Orbigny) ,在水深 40m以深海域分布数量较多的种类为中国枪乌贼L .chinensis(Gray)。渔汛期为夏、秋季。统计历年生产资料表明 ,头足类的年产量和占渔获物比例有逐年上升的趋势。随着底拖网捕捞技术的提高 ,头足类的密度指数有所增加 ,但并不说明头足类的资源就很丰富。若不注意合理开发利用 ,将导致头足类资源的衰退。限制和废除损害头足类资源的渔具十分重要。 相似文献
14.
长江口及邻近海域细颗粒沉积物中重金属的空间分布及沉积通量 总被引：4，自引：0，他引：4
长江每年输送大量的泥沙进入东海,其中细颗粒沉积物具有搬运距离远、扩散范围大的特点,成为示踪河口及近海沉积物源汇过程的良好载体。本文基于采自长江口及邻近海域的44个表层沉积物样品,分析了细颗粒组分中重金属的空间分布和沉积通量,探讨了重金属来源和搬运沉积过程。研究表明:长江口及邻近海域细颗粒沉积物中Cu、Cr、Ni、V和Zn含量、沉积通量的空间分布具有高度的相似性,总体表现为长江口及浙闽沿岸高,向外急剧降低;该区细颗粒沉积物中的重金属主要来自长江,入海后向两个方向扩散,其一为向西南方向扩散,沉积于内陆架泥质区;其二是向东的跨陆架输送,沉积于长江冲淡水影响的海域。从长江口向西南方向的输送和沉积是长江入海重金属最重要的汇。 相似文献
15.
Water mass properties along cross-sections of the Kuroshio in the East China Sea (ECS) are investigated in detail. We used temperature, salinity and dissolved oxygen data from 2000 and 2002, together with historical temperature and salinity data from 1987 to 2004. Water properties were divided into two groups: high and low salinities or oxygen at temperatures warmer than 15 and 12 °C, respectively. We found the existence of outer shelf water W2, as defined by clear modes in frequency distributions of salinity and oxygen within various temperature segments. The outer shelf water was different from both Kuroshio Tropical Water (KTW) and coastal water. We mapped horizontal and vertical distributions of W2, along with W1 and KTW. The outer shelf water was distributed with density σ t = 22.5–25.5 over a relatively broad area, from the outer continental shelf to the continental slope, particularly in autumn. Vertical distribution of the water suggests that W2 spread from the outer shelf to just the shelf side of the Kuroshio Current velocity maximum. Seasonal variations are examined with historical data along PN section over 17 years, and suggest that the appearance of W2 is distinct in summer and autumn. By comparing temperature–salinity (T–S) diagrams from Taiwan Strait and east of Taiwan, the outer shelf water (W2) originates from South China Sea Tropical Water (SCSTW), as suggested by Chen, J Geophys Res 110:C05012 (2005). The present study of the ECS clearly shows that SCSTW is transported along the east coast of Taiwan or through the Taiwan Strait into the ECS. It then spreads over a relatively wide area from the outer shelf to just the shelf side of the Kuroshio axis, and there is some horizontal mixing between SCSTW and KTW around the shelf break. 相似文献
16.
17.
为更好地了解象山港海湾浮游动物群落的现状,保护海洋生态环境,分别于2015年1、4、7、10月在象山港海域进行了25个站位的4个航次生态综合调查,结果表明:4个航次共鉴定出98种浮游动物和20类浮游幼体,优势种共21种,无4季共有优势种。浮游动物群落具有明显的季节变化,平均丰度(ind/m3):夏季(186.2±96.4)春季(152.6±112.1)秋季(56.8±30.2)冬季(15.4±22.2);平均生物量(mg/m3):春季(90±75)夏季(52±24)秋季(26±19)冬季(14±11);平均多样性指数:秋季(2.305±0.370)夏季(1.908±0.449)春季(1.622±0.578)冬季(1.348±0.474)。聚类和多维尺度分析表明,春、夏和秋季3个季节浮游动物群落结构具有明显区域性差异,港口部和口外部海域的群落聚类明显,与其他群落之间相似度最低。分析象山港近35年的浮游动物历史数据表明,浮游动物丰度和生物量的下降可能与陆源排污、水产养殖污染和滨海电厂建设等人类活动有关。 相似文献
18.
Taku Yoshimura Kenji Morinaga Seiji Oshimo Yoshinobu Konishi Tsuneo Goto 《新西兰海洋与淡水研究杂志》2013,47(2):591-604
The annual distribution and dispersal of early‐stage phyllosoma of the Japanese spiny lobster Panulirus japonicus were examined in the East China Sea and the Sea of Japan off western Japan. Early‐stage larvae were sampled mainly in summer and relatively near the coast off western Kyusyu Island. Few larvae were found in the other three seasons in the East China Sea and the Sea of Japan. This finding suggests that P. japonicus larvae are retained in coastal areas for a few months after hatching until stage V and are transported offshore until autumn, before they grow to stage VI. Examination of archival drifter data off western Kyusyu Island during the spawning season of P. japonicus supported the relatively rapid dispersal of the larvae from the East China Sea near Japan to the Pacific Ocean or the Sea of Japan. Larval transport from the East China Sea to the Pacific Ocean, which is considered to be a main distribution area of middle‐ and late‐stage larvae, would occur in the south at approximately 32–33°N in the East China Sea near western Kyusyu Island. 相似文献
19.
东海、黄海鱼类群落结构的季节变化研究 总被引：21，自引：3，他引：21
根据2000年春(4月)、夏(6月)、秋(9月)、冬(12月)四季东海、黄海底拖网鱼类资源调查资料,分析了该海域的鱼类群落结构的四季变化特征.四季全部调查海域中出现的优势鱼种有8种:带鱼、小黄鱼、黄鲫、发光鲷、细条天竺鲷、鳀、鳄齿鱼和刺鲳,其中带鱼和小黄鱼是常年优势种.鱼种季节迁移变化以黄海南部波动最大,东海中部相对较为稳定,东海北部稳定性介于两者之间.生物多样性指数中丰富度指数(D)和Shannon-Wiener多样度指数(H')变化趋势一致,在春、夏两季3个区域相差不大,而在秋、冬两季黄海南部与东海北部和中部有明显分异;种类均匀度指数(J')在四季节3个区域之间相差不大.在暖季(夏、秋)南部鱼类呈向北迁移,而在冷季(冬、春)北部的鱼类有向南迁移的趋势. 相似文献
20.
基于ROMS(Regional Ocean Modeling System)模式,对西北太平洋海域进行了水平分辨率高达4km的水动力环境数值模拟,该分辨率可以很好地分辨我国东海陆架环流以及中尺度涡旋等过程,此外模式考虑了8个分潮,模式结果很好地再现了黄、东海陆架环流等。基于模式结果,对"桑吉"号泄漏物质可能的扩散和迁移轨迹进行了数值模拟分析。在"桑吉"号沉船位置的表、底Ekman层内,释放拉格朗日粒子和示踪物来示踪"桑吉"号泄漏物质的可能影响范围。拉格朗日粒子和示踪物模拟结果表明:在未来3个月,"桑吉"号泄漏物质对我国黄海的影响较小,其主要随着对马暖流进入日本海和随着黑潮进入日本九州以南的太平洋海域。随着冬、春的季节转换,三个月后,北风会减弱,减弱风场的试验表明,风场减弱会减少泄漏物质向黄海的输送。5月份后黄海冷水团逐渐形成,由于斜压效应,在黄海深层水中会逐渐建立起气旋式环流,从而进一步阻碍了"桑吉"号泄漏物质向黄海的输送,该气旋式环流有利于"桑吉"号泄漏物质通过对马海峡向日本海的输送,而会抑制底层泄漏物质向我国黄海西侧的输送。 相似文献