Pseudocycnus appendiculatus Heller, 1868 (copepoda,dichelesthiidae) in New Zealand waters   总被引：1，自引：1，他引：0  

G. C. Hewitt 《新西兰海洋与淡水研究杂志》2013,47(1):169-176

Pseudocycnus appendiculatus Heller is described and recorded, for the first time from New Zealand, on Thunnus alalunga (Bonnaterre, 1788). Pseudocycnus spinosus Pearse, 1951 and P. thynnus Brandes, 1955 are thought to be synonyms of P. appendiculatus. Other species previously placed in the genus are discussed and the action of Yamaguti (1963) in removing them to other genera supported. It is suggested that the family Pseudocycnidae Yamaguti, 1963 cannot be differentiated from the family Dichelesthiidae Bassett‐Smith, 1898.  相似文献   

Preliminary observations of the internal tide over the shelf west of New Zealand   总被引：1，自引：1，他引：0  

B. R. Stanton 《新西兰海洋与淡水研究杂志》2013,47(4):703-712

Abstract

Semidiurnal variations in the depth of the thermocline observed near the shelf edge north‐west of Cape Egmont are probably caused bv an internal tide generated at around 200 m depth over the continental slope. The observations suggest that in this region an internal tide, with amplitude of about 20 m, propagates onto the shelf with a speed of approximately 0.5 m·s^?1 and a wavelength of about 22 km.  相似文献   

Urban stormwater quality I. Hillcrest,Hamilton, New Zealand     

R. B. Williamson 《新西兰海洋与淡水研究杂志》2013,47(3):413-427

Water quality parameters associated with siltation (non‐volatile and volatile suspended solids), oxygen depletion (chemical and biochemical oxygen demand), nutrient enrichment (N, P), toxicity (Pb, Zn, Cu, Cr, Ni, Cd), and human pathogenic micro‐organisms (coliforms, faecal coliforms, faecal streptococci) were measured in baseflow and stormflow from a residential catchment in Hamilton, New Zealand, from November 1979 to December 1981. A macro‐invertebrate survey was conducted. All parameters, except nitrogen, were predominantly associated with particulate material, and closely followed suspended solids behaviour during storm runoff. The concentrations of these particulate parameters are linearly related to suspended solid concentrations, which implies a reasonable consistency in the particulate source material, probably attributable to the uniform stable land use. The runoff was enriched with nitrate (from septic tank seepage) and the particles by Zn, Pb, and Cu. There was little or no enrichment of the particulates with phosphorus, nitrogen, organic matter, Cr, or Ni relative to catchment soils. Ni, Cr, and Cd were generally below detection limits. Dissolved reactive phosphorus and NH₄ ⁺‐N levels were low and unimportant in total P or N leaving the catchment. Most organic matter was particulate and only slowly degraded, and consequently the biological oxygen demand was only a small fraction (c. 13%) of chemical oxygen demand. Interpretation of the water quality data allows some tentative predictions to be made of potential receiving water impacts. It is doubtful that urban runoff will cause significant oxygen depletion, although the high level of organic‐rich particulate material could lead to a deterioration of receiving water sediments and affect benthic invertebrates. Urban runoff may be an important source of nutrients, but (apart from nitrate) its importance depends on the amount of suspended material in the runoff rather than increased input of nutrients from urban‐related activities. Bacterial counts indicate a poor water quality. The impact of metals will depend largely on the bioavailability of the particulate‐bound fraction. The key to the understanding of transport, treatment, and impact of most potential pollutants in urban runoff is probably their association with particulate materials.  相似文献   

Estimation of Arsenic Toxicity by Analysis of Certain Marker Enzymes of the Air‐Breathing Catfish Clarias batrachus (Linn.)          下载免费PDF全文

Randhir Kumar  Tarun Kumar Banerjee 《洁净——土壤、空气、水》2014,42(5):690-695

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不同种类纳米零价铁的毒性比较研究   总被引：1，自引：1，他引：0  

王菁姣  陈家玮 《现代地质》2012,26(5):926-931

纳米零价铁是一种高效的环境修复材料,可以处理多种污染物;然而,纳米粒子的尺寸效应可能导致其在自然界中存在潜在毒性风险。选择几种常用包覆型、负载型和裸露的纳米铁,通过大肠杆菌的耐受性实验,比较3种纳米铁的毒性。研究表明,负载型纳米铁的分散性最好,而裸露纳米铁最差。3种纳米铁虽然对大肠杆菌都表现出毒性,但是负载型纳米铁的毒性最小。通过毒性减缓的机理分析,说明纳米铁改性后阻止了纳米颗粒与细菌的直接接触,这是空间位阻效应的作用。研究结果进一步证实了在使用纳米材料前应充分评估潜在毒性和环境效应的重要性。  相似文献   

Differential developmental toxicity of naphthoic acid isomers in medaka (Oryzias latipes) embryos   总被引：1，自引：0，他引：1  

Michael W. Carney  Kyle Erwin  Ron Hardman  Bonny Yuen  David C. Volz  David E. Hinton  Seth W. Kullman   《Marine pollution bulletin》2008,57(6-12):255

Polycyclic aromatic hydrocarbons (PAHs) are widespread persistent pollutants that readily undergo biotic and abiotic conversion to numerous transformation products in rivers, lakes and estuarine sediments. Here we characterize the developmental toxicity of four PAH transformation products each structural isomers of hydroxynaphthoic acid: 1H2NA, 2H1NA, 2H3NA, and 6H2NA. Medaka fish (Oryzias latipes) embryos and eleutheroembryos were used to determine toxicity. A 96-well micro-plate format was used to establish a robust, statistically significant platform for assessment of early life stages. Individual naphthoic acid isomers demonstrated a rank order of toxicity with 1H2NA > 2H1NA > 2H3NA > 6H2NA being more toxic. Abnormalities of circulatory system were most pronounced including pericardial edema and tube heart. To determine if HNA isomers were AhR ligands, spatial-temporal expression and activity of CYP1A was measured via in vivo EROD assessments. qPCR measurement of CYP1A induction proved different between isomers dosed at respective concentrations affecting 50% of exposed individuals (EC50s). In vitro, all ANH isomers transactivated mouse AhR using a medaka CYP1A promoter specific reporter assay. Circulatory abnormalities followed P450 induction and response was consistent with PAH toxicity. A 96-well micro-plates proved suitable as exposure chambers and provided statistically sound evaluations as well as efficient toxicity screens. Our results demonstrate the use of medaka embryos for toxicity analysis thereby achieving REACH objectives for the reduction of adult animal testing in toxicity evaluations.  相似文献   

Study of physical and chemical properties of vitrinites. Inferences on depositional and coalification controls     

A. Jimnez  M. J. Iglesias  F. Laggoun-Dfarge  I. Surez-Ruiz 《Chemical Geology》1998,150(3-4):197-221

A detailed study of petrological, geochemical, textural and coking properties was carried out on vitrains from the Puertollano, Blanzy–Montçeau, Asturias and Teruel. The objective was to determine in depth the physical and chemical properties of a series of natural and pure vitrinites of different rank, and the influence that the sedimentary and post-sedimentary conditions had on them. It is demonstrated that although vitrains are almost entirely made up of the huminite/vitrinite maceral group they have a different composition, thermal behaviour and physical properties. Thus, geochemical and textural properties of Blanzy–Montçeau vitrains can be considered to be representative of the telinite, the major component in both samples (75% vol.) at the beginning of the bituminization stage (subbituminous/high volatile C bituminous coals). The characteristics of the Puertollano vitrains described here can also be attributed to the telocollinite (>80% vol.) for the high volatile C bituminous coal. Variations in physico-chemical properties between Puertollano and Blanzy–Montçeau vitrains are due to the differences in the initial composition of organic matter. Slight differences (i.e., bed moisture content or porosity) between vitrains from the two coal seams in the same basin can be attributed to their stratigraphic position. Several parameters such as S₂, HI, oil and extraction yield and fluorescent properties suggest that the Puertollano and Blanzy–Montçeau vitrains have a lower hydrocarbon potential. The relationships between geochemical and textural properties make it possible to distinguish between ‘normal' and perhydrous vitrains. The two different hydrogen-enrichment processes that occur in vitrains from the Teruel and Asturias basins can be distinguished from the extraction yield data.  相似文献   

甲基汞在褐牙鲆幼鱼体内蓄积的组织特异性及其对免疫功能和生长的毒性作用     

任中华  曹亮  刘金虎  崔雯婷  窦硕增 《海洋科学》2019,43(5):71-80

甲基汞(MeHg)对鱼类多种生命过程存在极强的毒性作用,但有关其对海水鱼类免疫功能的毒性作用研究较少。本文利用实验毒理学方法研究了MeHg(暴露浓度0.0, 0.1, 1.0, 10.0, 20.0μg/L;暴露时间30天)在褐牙鲆(Paralichthys olivaceus)幼鱼组织(鳃、肝脏和脾脏)中的蓄积特征及其对幼鱼的四种免疫功能生物指示物(溶菌酶LZM、酸性磷酸酶ACP、碱性磷酸酶AKP和免疫球蛋白MIgM)和生长的毒性作用。结果表明,幼鱼体内MeHg蓄积量具有显著的浓度依赖性和组织特异性,各组织对MeHg的蓄积能力总体上呈现肝脏鳃脾脏的趋势;四种免疫功能生物指示物(活性或含量)对不同MeHg浓度暴露的响应方式各异,且具有显著的组织特异性; MeHg达到一定暴露浓度后显著抑制幼鱼的生长。总体而言,MeHg在褐牙鲆幼鱼体内蓄积,对其产生免疫毒性,并抑制幼鱼的生长。此外,ACP、AKP和LZM等免疫性指标能较好的反映对MeHg暴露的浓度依赖关系和组织特异性,可作为海水环境中MeHg污染风险评估和生物毒性分析的潜在生物指示物。  相似文献   

Aspects of Assaying Sediment Toxicity in Irish Estuarine Ecosystems     

Pamela A. Byrne  John O&#x; Halloran 《Marine pollution bulletin》1999,39(1-12):97-105

The toxicity of surface sediments collected from eight estuarine sites around the Irish coast was assessed in March 1997 using a whole sediment bioassay. Two molluscan species, Tapes semidecussatus (1 + age class) and Scrobicularia plana (unknown age) were exposed to test sediments for 21 days. Survival, morphometric, behavioural and histochemical measurements were taken during the 21 day bioassay. 100% mortality occurred in both species in sediments from one site in Dublin Bay within 18 days of initial exposure. 100% survival of T. semidecussatus was observed in all but four of the test sediments to which it was exposed during this study. The animal condition and wet tissue weight of T. semidecussatus decreased for all sediments during the bioassay. 95% survival of S. plana was observed after 21 days exposure to Youghal (reference) sediment. Condition and wet tissue weight of S. plana increased in all test sediments during the bioassay, however, there was significant variation in wet tissue weight of this species on day 25 of the bioassay in all test sediments. There was significant variation in the burrowing behaviour of S. plana during the bioassay. Lipofuscin accumulation was observed in the digestive diverticula of T. semidecussatus exposed to all test sediments with the exception of Youghal (reference). The potential for both species as bioassay organisms is discussed.  相似文献   

污泥/煤流化床混烧底灰中的重金属毒性研究     

赵晓莉  朱伟  徐德福  邱林倩  张超  杨创 《南京气象学院学报》2013,5(3):244-250

研究了污泥与煤按不同质量比例混烧后,底灰中的重金属形态分布与浸出毒性.结果表明:30:70的泥煤比使底灰中重金属硫化物及有机态和残渣态所占比例最大,即生物无效部分比例最大;在浸出毒性实验中,30:70的泥煤比使底灰重金属浸出量最小.由此推出,对环境毒害程度最小的泥煤质量比为30:70,即该实验条件下最优泥煤质量比为30:70.  相似文献