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81.
《Polar Science》2014,8(3):298-305
Small copepod species play important roles in the pelagic food webs of the Arctic Ocean, linking primary producers to higher trophic levels. The egg production rates (EPs) and weight-specific egg production rates (SEPs) of two common copepods, Acartia longiremis and Temora longicornis, were studied under experimental conditions in Dalnezelenetskaya Bay (southern Barents Sea) during summer. The average EP and SEP at 5–10 °C were 4.7 ± 0.4 eggs female−1 day−1 and 0.025 ± 0.002 day−1, respectively, for A. longiremis and 13.1 ± 0.9 eggs female−1 day−1 and 0.075 ± 0.006 day−1, respectively, for T. longicornis. EP and SEP were significantly higher at 10°C than at 5°C for both species. The mean egg diameter correlated positively and significantly with female prosome length (PL) in each species. SEP of T. longicornis correlated negatively and significantly with PL. Daily EP and SEP were similar to rates recorded for other Acartia and Temora species in temperate and warm regions. The influence of environmental factors (temperature, salinity, and phytoplankton concentration) on EP of both species is discussed. We conclude that temperature is the main factor determining the reproduction rate and timing in A. longiremis and T. longicornis in the Barents Sea. 相似文献
82.
Caspian Sea amphipods: biodiversity,systematic position and ecological peculiarities of some species
Galina M. Pjatakova Anatolyi G. Tarasov 《International Journal of Salt Lake Research》1996,5(1):63-79
In the Caspian Sea, one group of crustaceans, the Amphipoda, is represented by 72(70?) species, 60(58?) of which are gammarids, arranged in 20 genera. Almost all are endemic to the Ponto-Caspian zoogeographical region. To simplify the taxonomy of the genusGammarus Fabricius s.l., the Caspian gammarids ought to be grouped in 4 genera:Dikerogammarus Stebbing,Pontogammarus Sowinsky,Stenogammarus Martynov, andChaetogammarus Martynov. Taking into account the influence of different ecological factors on the external morphology of gammarids, we consider that all described forms ofDikerogammarus haemobaphes (Eichwald),D. villosus (Sowinsky),D. palmatus Martynov,D. fluviatilus Martynov, and perhapsD. aralensis (Uljanin) are one species —D. haemobaphes. Study of the ecological area and distribution ofIphigenella andrusovi Sars,Pandorites podoceroides (Grimm) andChaetogammarus placidus Sars indicates that these species are endemic to the Caspian Sea. 相似文献
83.
C. R. Aldwell 《Environmental Geology》1996,27(2):82-84
Because of its copious and reliable rainfall, Ireland has an abundance of springs. Many of the larger ones issue from the Carboniferous limestone that occurs in over 40% of the country. The spring water is mainly a calcium bicarbonate type with a temperature of about 10°C. In the 18th century, warm and cold springs were developed as spas in various parts of Ireland. The popularity of these springs was short and most were in major decline by 1850. Today only one cold spa at Lisdoonvarna, Co. Clare is still operating. Springs in Ireland were places of religious significance for the pre-Christian Druidic religion. In the Christian period they became holy wells, under the patronage of various saints. Cures for many different ailments were attributed to water from these wells. 相似文献
84.
The area of north Evia and eastern central Greece is characterized by strong geomorphological contrast and is built up mainly of consolidated rocks. Unconsolidated young sediments of Pleistocene to Holocene age cover the valley and basin flats, forming the most productive aquifers in this area. However, two more types of aquifers can be distinguished within the consolidated rock area. The first one is associated with karstified limestones and the second with strongly tectonized ultramafic rocks. The schist–chert formation, with intercalations of shales and cherts, seals the ultramafic masses underneath. Surface and spring waters associated with ultramafic rocks in north Evia and eastern central Greece were studied. Two types of water can be distinguished: (1) high Mg2+ and SiO2 , bicarbonate as the dominant anion, pH 7·4–9·2, temperature 9·5–16·3 °C, low TDS (total dissolved solutes) (459–1037 mg/l), found both in peridotite and serpentinite areas, classified as Mg–HCO3 type; (2) high Ca2+, low Mg2+ and SiO2 , hydroxyl ion as the major anion, pH 11·2, temperature 28 °C, very low TDS (122 mg/l), found in peridotite areas, classified as Ca–OH type. The studied waters are highly supersaturated with respect to quartz, amorphous silica, brucite and most low temperature magnesium silicates (antigorite, sepiolite, talc, etc.). These waters show relatively narrow SiO2 concentration ranges and a trend parallel to the amorphous silica saturation surface. The silica supersaturated waters have the potential to precipitate silica and consequently could affect the people of the local communities that use it as drinking water, causing health problems (kidney stones). Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
85.
Sotillo MG Fanjul EA Castanedo S Abascal AJ Menendez J Emelianov M Olivella R García-Ladona E Ruiz-Villarreal M Conde J Gómez M Conde P Gutierrez AD Medina R 《Marine pollution bulletin》2008,56(4):686-703
The ESEOO Project, launched after the Prestige crisis, has boosted operational oceanography capacities in Spain, creating new operational oceanographic services and increasing synergies between these new operational tools and already existing systems. In consequence, the present preparedness to face an oil-spill crisis is enhanced, significantly improving the operational response regarding ocean, meteorological and oil-spill monitoring and forecasting. A key aspect of this progress has been the agreement between the scientific community and the Spanish Search and Rescue Institution (SASEMAR), significantly favoured within the ESEOO framework. Important achievements of this collaboration are: (1) the design of protocols that at the crisis time provide operational state-of-the-art information, derived from both forecasting and observing systems; (2) the establishment, in case of oil-spill crisis, of a new specialized unit, named USyP, to monitor and forecast the marine oceanographic situation, providing the required met-ocean and oil-spill information for the crisis managers. The oil-spill crisis scenario simulated during the international search and rescue Exercise "Gijón-2006", organized by SASEMAR, represented an excellent opportunity to test the capabilities and the effectiveness of this USyP unit, as well as the protocols established to analyze and transfer information. The results presented in this work illustrate the effectiveness of the operational approach, and constitute an encouraging and improved base to face oil-spill crisis. 相似文献
86.
87.
The annual cycle of Synechococcus (cyanobacteria) in the northern Levantine Basin shelf waters (Eastern Mediterranean) 总被引:1,自引:0,他引:1
Abundance of picoplanktonic chroococcoid marine cyanobacteria Synechococcus was monitored weekly over the year 1998 in shallow coastal waters of the northern Levantine Basin. The ambient physical, chemical and biological variables (temperature, salinity, Secchi disk depth, total suspended sediment, nitrate, phosphate, Chl a and phytoplankton) were also measured. Synechococcus was found to be more abundant during summer and early autumn and less during winter and early spring. At the surface and 15 m depth, cell concentrations were in the range 6.4 × 103–1.5 × 105 and 3.2 × 103–1.6 × 105 cells·ml−1, respectively. Based on the Pearson product–moment correlation analysis, a highly significant correlation between Synechococcus abundance and ambient temperature was observed (n = 40, r = 0.558, P < 0.01). As Synechococcus forms blooms that usually do not last more than a week, the short time‐scale survey achieved in this study was appropriate to reveal its abundance dynamics. Several factors such as rapid changes in nutrient concentration (especially nitrate), phytoplankton, light availability, temperature, salinity, freshwater input and vertical mixing played a relevant role on the abundance of Synechococcus over the year in the highly dynamic shallow coastal waters of the Levantine Basin. 相似文献
88.
九龙江-河口表层水体营养盐含量的时空变化及潜在富营养化评价 总被引:1,自引:0,他引:1
分别于2012年9月、2013年1、6月,对九龙江两大支流北溪、西溪及河口区开展了3个航次的营养盐监测.研究结果表明,河口区表层水体溶解无机氮(DIN)、总磷(TP)和活性磷酸盐(PO4-P)质量浓度范围分别为0.13-17.35、0.14-1.00和0.00-0.38 mg/dm3,受上游输入和海水稀释作用,营养盐浓度由淡水端至海水端逐渐降低.北溪表层水体的DIN、TP和活性磷酸盐质量浓度范围分别为1.99-24.92、0.12-1.47和0.04-0.68 mg/dm3,受龙岩地区工农业生产及城市进程影响,由上游至下游逐渐降低.西溪表层水体的DIN、TP和活性磷酸盐质量浓度范围分别为2.74-20.61、0.14-0.92和0.02-0.37 mg/dm3,受上游农业生产和下游漳州地区人类活动影响,上下游的DIN质量浓度较高.此外,九龙江沿岸的人类活动可能影响了该地区水体中的溶解无机氮形态组成:北溪和西溪上游的NH4-N和NO3-N占比分别较高.水期分析表明,2013年1月的DIN浓度显著高于其他水期,而不同区域TP和活性磷酸盐的水期波动不尽相同.营养盐结构分析表明,九龙江总体处于磷限制状态,但在河口及北溪部分站位,CDIN/CPO4-P比值已达到适合浮游生物生长繁殖的水平.潜在富营养化程度评价表明,九龙江河口多数站位均处于N或P限制的富营养化级别,但由于N、P营养盐的绝对浓度较高,具有水华暴发的潜在风险. 相似文献
89.
南海主要珊瑚礁水域软骨鱼类的组成与分布 总被引:1,自引:0,他引:1
利用1998年3~5月和1999年5~6月在西沙和南沙的12座珊瑚礁水域渔业资源专业调查资料以及1998年2月~1999年12月在南沙群岛水域进行的渔业资源监测调查资料,分析讨论了南海珊瑚礁水域软骨鱼类的组成与分布。专业调查结果:捕获软骨鱼类14属16种,渔获量计64尾2 844.1kg,优势种为大眼角鲨、鼬鲨、日本燕、侧条真鲨、灰六鳃鲨;监测调查表明南沙珊瑚礁水域的软骨鱼类在全年均可捕获,产量的变动主要与捕捞努力量相关。综合2种调查知:软骨鱼类在南海珊瑚礁水域总体分布范围较广,单鱼种在各个岛礁表现出一定的地域分布性;南海珊瑚礁区捕获软骨鱼类的主要作业方式为延绳钓和大型流刺网。 相似文献
90.