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1.
黄河口附近海域营养盐特征及富营养化程度评价 总被引：11，自引：0，他引：11
根据 2005 年 5 月、8 月 2 个航次对黄河口附近海域 33 个站点(38 °02′00 ″ ～ 37 °20′00 ″N, 119 °03′24 ″ ～ 119 °31′00 ″E)的海水化学调查资料,研究了该海域的活性硅酸盐(SiO3-Si)、活性磷酸盐(PO4-P)和无机氮(DIN)等营养要素的特征及富营养化水平.结果表明,营养盐的高浓度区域分布在黄河口南部海域,8 月 SiO3-Si 和 PO4-P 的浓度高于5月,而 DIN 的浓度则相反.表层海水 SiO3-Si 和 DIN 的浓度与表层海水盐度都呈显著负相关性(P<0.01),DIN 与 COD 呈显著正相关性(P<0.01).黄河口附近海域DIN:P值5月为136,8月为 54.3,为磷限制性营养状态.黄河口附近海域富营养化指数(EI)的平均值大于1,黄河口南部海域富营养化现象严重,COD 和 DIN 是造成海域富营养化的主要因子. 相似文献
2.
文章基于2015年1—12月杭州湾海域12个航次的调查资料,对杭州湾海域营养盐溶解无机氮(DIN)和活性磷酸盐(PO_4~(3-))的月度时空分布特征及其影响进行了探讨。结果表明,杭州湾表层海水DIN和PO_4~(3-)含量空间分布月际间变化明显,其变化受湾内、沿岸径流输入和长江冲淡水影响显著。杭州湾海域12个月DIN含量均超第四类海水水质标准,硝酸盐氮(NO_3~-)占DIN的94%及以上。N/P值处于较高水平,内湾(IB)和外湾(OB)的N/P值季节性变化幅度比中湾(CB)大,海湾生态系统对磷的变化敏感。营养盐-盐度对研究区域的水体混合状况有明显的指示作用,杭州湾营养盐的分布主要受物理混合作用所控制,浮游生物活动对营养盐分布的影响相对较小。 相似文献
3.
2007年8月于长江口南支4个站位进行了营养盐和叶绿素a浓度的定点连续观测,结果表明:调查站位的营养盐和叶绿素a浓度垂直变化不大,分层不明显,表中底层平均值的相对标准偏差在0～29.86%之间,且整个潮汛期的变化基本上不具规律性,少数营养盐(如亚硝酸盐和铵盐)呈现出半日周期的变化,即高潮时浓度达到谷值,低潮时浓度出现峰值;位于长江口南支水域南部S2和S4站位的硅酸盐、磷酸盐和硝酸盐在整个潮汛期的平均值都小于北部的S1和S3站位,且S1站位的硅酸盐、磷酸盐和硝酸盐在大小潮之间平均值差异不明显,而S2站位的硅酸盐和硝酸盐大潮时平均值要高于小潮,磷酸盐则相反,此外,S4站位的叶绿素a平均值都大于其他3个站位;4个连续测站的表层叶绿素a浓度与营养盐(NO2--N、PO34--P、SiO23--Si、NO3--N、NH4+-N)相关系数低(-0.6584～0.5494),叶绿素a浓度与营养盐的周日波动相关性不明显;观测区域硅酸盐、磷酸盐、硝酸盐、亚硝酸和铵盐的平均通量分别是238.62、1.36、84.10、1.031、0.55kg.s-1。 相似文献
4.
通过3个航次的调查,分析了2008年枯水季、丰水季和平水季广西铁山港附近海域无机氮、活性磷酸盐和活性硅酸盐的分布特征及营养盐结构特征,探讨该海域营养盐季节变化及其影响因素。结果表明,铁山港附近海域无机氮的浓度范围为1.03~44.99μmol/L,活性磷酸盐浓度为0.03~1.57μmol/L,活性硅酸盐的浓度为7.86~102.14μmol/L。高浓度的营养盐主要分布在铁山港湾内及靠岸站点,营养盐的浓度均从铁山港湾口向北海南部海域呈递减的趋势。无机氮、活性磷酸盐和活性硅酸盐显现了相近的季节变化特征,即枯水期到丰水期浓度增加之后从丰水期到平水期浓度降低。该海区无机氮主要以硝酸盐氮和氨氮占最主要比重,枯水期和丰水期以硝酸盐氮为主而平水期以氨氮为主。海区N/P和Si/P较高,表明该海区N限制减弱而P限制加重。铁山港营养盐的季节变化主要受到径流等输入的影响,浮游植物的消耗也可能是其季节变化的原因之一。 相似文献
5.
浙江近岸典型港湾的营养盐行为特征 总被引：4，自引：0，他引：4
利用象山港（2010年4 月）、三门湾（2010年3月）及乐清湾（2009 年4 月）平水期的调查资料,分析讨论了不同
类型的港湾水体营养盐的分布和行为特征。发现象山港具有3个港湾中最高浓度的PO43-和NO2-,分别为1.87和1.22 滋mol/dm3,
三门湾则具有最高的NO3-浓度（61.0 滋mol/dm3）。三门湾的NO3-/PO43-比值高达43.0,其次是乐清湾（32.4） 和象山港
（27.5）,水体富营养化特征明显。3个养殖港湾SiO32-浓度均与盐度之间呈显著的负相关,表明在混合过程中均呈保守行为,
这与硅酸盐的天然来源和港内较弱的生物吸收有关。乐清湾NO3-与盐度之间存在一定的相关关系,而象山港和三门湾NO3-在
混合稀释过程则表现为不保守,此外三门湾和乐清湾PO43-均表现为不保守行为,这主要由于NO3- 和PO43-多样的人为来源和
复杂的转移机制。另外,NO3-/SiO32-比值随盐度的变化表明象山港和三门湾在咸水端则均有较明显的硝酸盐输入,显然来源
于海水养殖自身污染,水产养殖对海域氮和磷的负荷具有较显著的贡献。 相似文献
6.
长江口水域营养盐时空分布及其迁移过程 总被引：1，自引：1，他引：0
根据2014年长江口水域4个季节航次水体中五项营养盐(硝酸盐_-N、亚硝酸盐NO_2-N、铵盐NH4-N、磷酸盐PO_4-P和硅酸盐SiO_3-Si)的调查数据,解析长江口水域营养盐的时空分布特征,结合盐度(S)、溶解氧(DO)、温度(T)、悬浮体(SPM)和叶绿素a等环境参数,探究其迁移过程的分布行为。结果表明:NO_3-N、SiO_3-Si和PO_4-P在长江口水域的时空分布主要受长江陆源输入的影响,随长江冲淡水扩展范围的季节变化而变化,除冬季外,在122°20′E以东,主要受到温盐跃层的影响,其在31°N断面出现明显的分层现象,冬季水体垂直混合均匀,其垂直分布较为均匀。春季长江陆源输入较高浓度的NO_3-N,40μmol/L的NO_3-N随长江冲淡水向东北方向最远扩展到123°E,垂直方向上扩展至水深10 m,而秋季长江陆源输入较高浓度的SiO_3-Si和PO_4-P,其浓度分别为40μmol/L和0.6μmol/L的等值线分别向东最远扩展到123°E、123°20′E和水深20 m、50 m。受到生物吸收,硝化作用等因素影响,NO_2-N和NH_4-N的时空分布比较复杂,季节分布规律不明显,而冬季自口门向外海浓度逐渐降低,且垂直分布也相较均匀。通过盐度这一保守性指标引入理论稀释线来研究营养盐的迁移过程,结合叶绿素a和SPM的数据表明:春、夏季营养盐浓度低于理论稀释浓度可能是由于生物吸收所致,而PO_4-P在春、夏和秋季均有散点高于理论稀释浓度可能与悬浮颗粒物释放有关。 相似文献
7.
8.
渤海硝酸盐氮和亚硝酸盐氮季节循环分析 总被引：10，自引：1，他引：10
根据1985－1987年期间19个月份的断面调查资料分析，莱州湾、渤海湾是硝酸盐氮浓度较高的海域，辽东湾、渤海湾是亚硝酸盐氮浓度较高的海域。硝酸盐氮浓度冬季最高，夏季最低；亚硝酸盐氮浓度秋季最高，春季最低。硝酸盐氮浓度的季节在莱州湾、渤海湾海域最大；亚硝酸盐氮浓度的季节变化在辽东湾最大。在分析海域，秋季硝酸盐氮浓度表、底层差异最大；夏季平均亚硝酸盐氮浓度表、底层差异最大。海洋生物化学过程是引起渤海硝酸盐氮和亚硝酸盐氮浓度季节变化的主要原因。渤海硝酸盐氮和亚硝酸盐氮基本维持着准平衡态季节循环，底层硝酸盐氮和亚硝酸盐氮准平衡态季节循环比较稳定，表层的季节循环容易受到其他因素的影响发生变异。 相似文献
9.
2013年夏季渤海环境因子与叶绿素a的空间分布特征及相关性分析 总被引：2，自引：0，他引：2
通过对2013 年7 月渤海海域26 个站点温度、盐度、营养盐及叶绿素a（Chla） 浓度的空间分布特征及其相关性进行了分析,发现：受渤海水深和夏季陆源河流输入影响,近岸水域表现出明显的高温、低盐与高营养盐特征,且垂直变化特征不显著;在水深较深的辽东湾湾口和渤海海峡,海水呈现明显的层化现象,表层水温高于中底层,而表层盐度与营养盐浓度则低于中底层。营养盐结构分析表明,渤海夏季磷酸盐浓度存在显著的绝对与相对限制,而受河流输入影响,硅酸盐的相对限制得到显著缓解。表层Chl a浓度的高值区位于滦河及复州河河口附近海区,中层与底层的高值区则出现在滦河与黄河口附近。Chla浓度与环境因子的相关性分析表明,盐度、磷酸盐与硅酸盐的浓度、氮磷比、氮硅比是影响Chl a浓度空间分布的重要因素,且温度还影响到Chl a浓度的垂直分布。 相似文献
10.
利用2006年夏季长江口调查数据分析了长江口海域硝酸盐(NO3-)、亚硝酸盐(NO2-)、铵盐(NH4+)大面分布,NO3-浓度呈近岸高、外海低的特征,NO2-和NH4+浓度在上海市排污口位置有高值区并向外扩散。NO3-,NH4+浓度总体上符合咸淡水混合之稀释效应,与盐度的相关系数(r2)分别为0.815,0.255,呈保守行为,而NO2-浓度与盐度的相关性系数为0.074,呈非保守行为。在确定了淡水端元和咸水端元的基础上,做出理论稀释曲线TDL(theoretical dilution line),由于上海市污染物的输入,淡水端元NO3-,NO2-,NH4+浓度不同程度地正偏于TDL,在外海深层水范围内有机颗粒矿化再生亦呈加入态势。对应高溶解氧的盐度羽状峰处,由于真光层初级生产较强,表层NO3-浓度负偏于TDL约1~19μmol/dm3,NO2-,NH4+浓度也存在不同程度的减小。在长江口最大浑浊带附近,由于高浓度悬浮物吸附NH4+而呈现明显的迁出机制。外海表层海水三氮营养盐浓度数据点偏离TDL程度较小,但在底层由于来自上层的有机颗粒耗氧分解而再生出营养盐,使NO3-,NO2-,NH4+浓度数据一般在TDL之上。 相似文献
11.
Fishing, selection, and phenotypic evolution 总被引：10，自引：9，他引：10
12.
L. I. Lobkovsky A. B. Rabinovich E. A. Kulikov A. I. Ivashchenko I. V. Fine R. E. Thomson T. N. Ivelskaya G. S. Bogdanov 《Oceanology》2009,49(2):166-181
Major earthquakes occurred in the region of the Central Kuril Islands on November 15, 2006 (M w = 8.3) and January 13, 2007 (M w = 8.1). These earthquakes generated strong tsunamis recorded throughout the entire Pacific Ocean. The first was the strongest trans-Pacific tsunami of the past 42 years (since the Alaska tsunami in 1964). The high probability of a strong earthquake (M w ≥ 8.5) and associated destructive tsunami occurring in this region was predicted earlier. The most probable earthquake source region was investigated and possible scenarios for the tsunami generation were modeled. Investigations of the events that occurred on November 15, 2006, and January 13, 2007, enabled us to estimate the validity of the forecast and compare the parameters of the forecasted and observed earthquakes and tsunamis. In this paper, we discuss the concept of “seismic gaps,” which formed the basis for the forecast of these events, and put forward further assumptions about the expected seismic activity in the region. We investigate the efficiency of the tsunami warning services and estimate the statistical parameters for the observed tsunami waves that struck the Far Eastern coast of Russia and Northern Japan. The propagation and transformation of the 2006 and 2007 tsunamis are studied using numerical hydrodynamic modeling. The spatial characteristics of the two events are compared. 相似文献
13.
Linjie Zheng Tomoharu Minami Shotaro Takano Hideki Minami Yoshiki Sohrin 《Journal of Oceanography》2017,73(5):669-685
A central theme of the ongoing GEOTRACES program is to improve the understanding of processes occurring at ocean interfaces with continents, sediments, and ocean crust. In this context, we studied the distributions of Al, Mn, Fe, Co, Ni, Cu, Zn, Cd, and Pb around the Juan de Fuca Ridge (JdFR) in total dissolvable (td), dissolved (d), and labile particulate (lp) fractions, which represent a fraction in unfiltered samples, filtered samples through an AcroPak capsule filter, and the difference between td and d, respectively. Al and Fe were dominated by lp-species, while Ni, Zn, and Cd were dominated by d-species with undetectable amounts of lp-species. Major findings in this study are as follows: (1) The continental margin (CM) provided large sources of Al, Mn, Fe, and Co from the surface to ~2000 m in depth. The supply from CM caused high surface concentrations of dMn and dCo, a subsurface (100–300 m depth) maximum of dCo, and intermediate (500–2000 m depth) maxima of lpAl and lpFe. The supply of dFe from CM was ~10 times that from the high-temperature hydrothermal activity at station BD21, which is located at ~3 km from the Middle Valley venting site and ~ 200 km from Vancouver Island. (2) DPb was maximum at the top layer of North Pacific Intermediate Water, probably owing to isopycnal transport of anthropogenic Pb via advection of subducted surface waters. Although dCo and dPb had different sources in the upper water, they showed a strong linearity below 300 m (r 2 = 0.95, n = 38), indicating concurrent scavenging. (3) A high-temperature hydrothermal plume occurred at a depth of 2300 m at BD21, accounting for maxima of dAl, dMn, dFe, lpCu, and lpPb and a minimum of dCu. (4) Strong bottom maxima of lpAl, lpMn, lpFe, lpCo, and lpPb occurred above the abyssal plain at the western foot of the JdFR, indicating resuspension of sediments. However, bottom maxima of d-species were apparent only for dAl and dCu. 相似文献
14.
Jerry Siok 《Marine Georesources & Geotechnology》2013,31(2-3)
Exploration for oil at Northstar has been long and costly. Northstar leases were first acquired in 1979 at a joint state and federal sale by Shell Oil, Amerada Hess, and Texas Eastern. The Northstar Unit is 6 mi offshore and about 4 mi northeast of the Point McIntyre Field. Oil was first discovered in Shell's Seal Island 1 in 1983. Five additional appraisal wells were drilled (1983-1986) from two man-made gravel islands in 40 ft of water. Early engineering estimates put the cost of development at $ 1.6 billion. In February 1995, BP Exploration (Alaska) acquired a 98 % interest in the Northstar Unit from Amerada Hess and Shell Oil. When developed by BP, Northstar will be the first oil produced from federal leases in Alaska. To date, the oil industry has invested in excess of $ 140 million in exploration and appraisal operations. An additional $ 90 million was spent on lease bonus bids. The giant Prudhoe Bay and Kuparuk Fields lie along the Barrow Arch. This arch is bounded to the north by a rift margin that deepens into the present-day offshore region. Northstar is located among a series of down-stepping faults off this northern rift margin of the Prudhoe Kuparuk high. The structure is a gently south-dipping northwest-trending faulted anticline. The crest of the structure is located near 10,850 ft subsea. The primary reservoir is the Ivishak Formation (325 ft thick) of the Sadlerochit Group. This is the same primary reservoir at Prudhoe Bay, approximately 12 mi to the south. At Northstar the Ivishak is a high-energy, coarse-grained conglomeratic facies of the Ivishak Formation. The primary lithology is a pebbly chert to quartz conglomerate with occasional sandstone. This very high net to gross reservoir appears to contain no regionally continuous permeability barriers. Cementation has reduced primary porosity to less than 15 %. Accurate porosity estimates are difficult to make due to the coarse-grained nature of the lithology and the presence of kaolinite and microporous chert. Permeability is highly variable, but averages 10 to 100 mDarcies. Oil is a very light and volatile 42 API crude with approximately 2,100 ft3 of gas per stock tank barrel of oil. This oil is very different from the heavier oils (26) found to the south in Prudhoe Bay. Estimated recoverable oil reserves range from 100 to 160 million barrels. A free-standing drilling rig is required at Northstar because the reserves are beyond extended-reach drilling techniques from shore-based facilities. The current development plan is to expand the existing Seal Island to about 5 acres. This is significantly less than Endicott's 40-acre island. The proposed drilling and produc tion island will be accessed by summer barges and winter ice roads. Oil, gas, and water will be processed at a stand-alone facility and then sent to shore via a subsurface pipeline. Northstar will have the first Arctic subsea pipeline in Alaska to transport oil to shore facilities (TAPS). Preliminary tests in Spring 1996 were very successful in demonstrating the technology to successfully bury a subsea pipeline safely in the Arctic. 相似文献
15.
The radiometers on board the satellites ERS-1, TOPEX/Poseidon, ERS-2, GFO, Jason-1, and Envisat measure brightness temperatures at two or three different frequencies to determine the total columnal water vapor content and wet tropospheric path delay, a major correction to the altimeter range measurements. In order to asses the long-term stability of the path delay, the radiometers are calibrated against vicarious cold and hot references, against each other, and against several atmospheric models. Four of these radiometers exhibit significant drifts in at least one of the channels, resulting in yet unmodeled errors in path delay of up to 1 mm/year, thus limiting the accuracy at which global sea level rise can be inferred from the altimeter range measurements. 相似文献
16.
Cross-Calibration and Long-Term Monitoring of the Microwave Radiometers of ERS,TOPEX, GFO,Jason, and Envisat 总被引：1，自引：1，他引：0
The radiometers on board the satellites ERS-1, TOPEX/Poseidon, ERS-2, GFO, Jason-1, and Envisat measure brightness temperatures at two or three different frequencies to determine the total columnal water vapor content and wet tropospheric path delay, a major correction to the altimeter range measurements. In order to asses the long-term stability of the path delay, the radiometers are calibrated against vicarious cold and hot references, against each other, and against several atmospheric models. Four of these radiometers exhibit significant drifts in at least one of the channels, resulting in yet unmodeled errors in path delay of up to 1 mm/year, thus limiting the accuracy at which global sea level rise can be inferred from the altimeter range measurements. 相似文献
17.
Tautog, Tautoga onitis, is an abundant species of fish in estuaries of the northeastern United States. Planktonic tautog larvae are abundant in summer in these estuaries, but there is little information on rates of growth of tautog larvae feeding on natural assemblages of food in the plankton. We examined abundance and growth of larval tautog and environmental factors during weekly sampling at three sites along a nearshore‐to‐offshore transect in Buzzards Bay, Massachusetts, USA during summer 1994. This is the first study of a robust sample size (336 larvae) to estimate growth rates of field‐caught planktonic tautog larvae feeding on natural diets, using the otolith daily‐growth‐increment method. The study was over the entire summer period when tautog larvae were in the plankton. The sampling sites contrasted in several environmental variables including temperature, dissolved oxygen (DO), and chlorophyll a concentration. There was a temporal progression in the abundance of tautog larvae over the summer, in relation to location and temperature. Tautog larvae were first present nearshore, with a pronounced peak in abundance occurring at the nearshore sites during the last 2 weeks in June. Larvae were absent at this time further offshore. From late June through August, larval abundance progressively decreased nearshore, but increased offshore although never approaching the abundance levels observed at the nearshore sites. The distribution and abundance of tautog larvae appeared to be related to a nearshore‐to‐offshore seasonal warming trend and a nearshore decrease in DO. Otoliths from 336 larvae ranging from 2.3 to 7.7 mm standard length had otolith increment counts ranging from 0 to 19 increments. Growth of larval tautog was estimated at 0.23 mm·day?1, and length of larvae prior to first increment formation was estimated at 2.8 mm indicating that first increment formation occurs 3–4 days after hatching at 2.2 mm. Despite spatial and temporal differences in environmental factors, there were no significant differences in growth rates at any of three given sites over time, or between sites. Because larval presence only occurred at a narrow range of temperature (17–23.5 °C) and DO (6.5–9.3 mg·l?1), in situ differences in growth did not appear to be because of differences in larval distribution and abundance patterns relative to these parameters. 相似文献
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Abstract Concentrations of cadmium (Cd), lead (Pb), copper (Cu), and zinc (Zn) were measured in adult barnacles (Elminius modestus Darwin) from Waitemata and Manukau Harbours in the Auckland area, New Zealand. As in studies on sediments reported in the literature, it was possible to identify areas of likely anthropogenic influence, e.g., around the Auckland Harbour Bridge for Pb, Cu, and Zn. Groups of individuals with highest concentrations for these metals showed 19.8–23.8 mg Pb kg?1, 198–266 mg Cu kg?1, and 4460–6530 mg Zn kg?1 (95% confidence limits, dry weight basis). Cd concentrations found for all barnacles from the Auckland area ranged from 0.8 to 3.1 mg kg?1. Two samples from Omaha Beach, 60 km north of Auckland, were used as a reference. Accordingly, groups of individuals with lowest concentrations for Pb, Cu, and Zn could be allocated to this site using the Student‐Newman‐Keuls Multiple Range Test (0.5–1.3 mg Pb kg?1, 8–10 mg Cu kg?1, and 144–214 mg Zn kg?1 ; 95% confidence limits). Only Cd concentrations were highest at Omaha Beach (8.6–12.1 mg Cd kg?1 ). This result may have arisen from “naturally” increased bio‐availabilities of certain metals in mangrove systems which are reported in the literature. Generally, metal concentrations in barnacles from the Auckland Harbour area and from Omaha Beach were within the wider range for E. modestus as well as other barnacle species reported in the international literature. 相似文献
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Park Sojung Choi Mansik Jang Dongjun Joe Dongjin Park Kyunggue 《Ocean Science Journal》2020,55(1):49-67
Ocean Science Journal - In this study, we investigated the spatial and temporal distribution and sources of dissolved and particulate heavy metals in Masan Bay, an area that for a long time has... 相似文献