西藏狮泉河鱼道设计初探

狮泉河水电站是西藏狮泉河流域梯级开发的第一座水电站,对水域生境和鱼类资源的影响巨大。为了缓解水利工程对鱼类资源带来的不利影响,通过对狮泉河水电站参数、水电站阻隔鱼类资源的初步分析,提出了狮泉河应修建鱼道来保护鱼类的方案。作者就狮泉河鱼道的过鱼对象、类型、主要结构设计特点等作了简要介绍。     

鱼道进口布置方案研究

鱼道进口的布置除受其自身布置原则的限制之外,还受到枢纽布置及河势、地形、地质、下游水位等其他边界条件的限制。为同时满足以上双重要求,对某工程鱼道进口的布置进行深入研究,提出一种能满足边界条件及绝大部分布置原则的初步布置方案。对该初步布置方案中不能满足布置原则的采取相应的工程措施加以优化。水工模型验证表明,优化后的鱼道进口布置方案对河道中的洄游鱼类具有较大的吸引能力,在流量、流态、水深及流速等方面,均能较好地满足设计要求。     

异侧布置竖缝式鱼道紊流结构试验研究

鱼道是辅助鱼类克服障碍物,实现产卵洄游、索饵洄游和越冬洄游的通道。全球目前已建鱼道中,鱼类能够溯游通过的鱼道尚不足50%,大多数鱼道的水力设计仅考虑平均流速,忽略了鱼道内的紊流结构,探究鱼道的水力特性尤其是紊流结构,对改进其设计具有重要的指导意义。通过在大比尺水槽模型中试验研究异侧布置竖缝式鱼道的紊流结构,利用声学多普勒测速仪(ADV)实测竖缝式水池内每一点的三维瞬时流速,剖析流场的三维时均流速分布、流动特征、旋涡特性、纵向和横向紊动强度分布、不同水平面的雷诺应力分布等,考虑了两种典型流量(Q1=20.62 L/s,Q2=30.75 L/s)和3个特征水平面(h/3,h/2和2h/3),提出了三维流速分布的半理论半经验公式、流场矢量图及各点的旋度,并与自由壁面射流进行比较。结果表明,异侧布置竖缝式鱼道前半池内纵向流速具有壁面射流的特征,后半池由于受下游隔板的阻挡则偏离壁面射流规律;水池内存在顺时针方向的水平旋涡,其旋度随流量的增大而增强;前半池壁面射流区的紊动强度存在峰值区,后半池的紊动强度峰值区由水槽左侧移至右侧;壁面射流区的雷诺应力变幅较大,而在旋涡区则较小,有利于洄游鱼类在鱼道上溯和歇息。     

一种鱼道进口诱鱼结构装置的试验研究

常规鱼道的研究和设计大多侧重于其内部结构和水流条件等方面,对鱼道进口位置布置及结构优化的研究相对较少,往往存在鱼类发现并进入鱼道较为困难的情况。通过建立鱼道进口设计的生态水力学指标,提出了某项目集诱鱼进口所需要满足的流速范围为0.47～1.30 m/s,将鱼类游泳能力与鱼道进口流态指标相结合,用标准三维κ-ε模型数值模拟的方式,对以往鱼道进口位置的选择原则进行了验证,提出了一种可控流量、流速的新型诱鱼补水装置,对鱼道进口结构进行优化。该诱鱼补水装置利用局部水流落差,上游发电下泄水流进行诱鱼补水,避免采用自库区压力管道引水而产生的消能问题,降低了鱼道运行的成本;同时降低机组满发或发电流量较高时河段内的流速,可达到灵活调控诱鱼水流进而诱导鱼类进入鱼道完成洄游的效果,最终完成鱼道进口的优化,提高过鱼效果。     

我国过鱼设施现状分析及鱼道适宜性管理的关键问题

水电开发对于洄游性鱼类产生的负面影响最为直接,阻碍了其繁殖、索饵以及越冬等生命行为。在调查的25个水电项目中,有17个采取了鱼类保护措施,其中采取增殖放流措施的占82.4%,仅有1个项目修建了鱼道。介绍了“莱茵河-2000计划”和哥伦比亚河鱼道建设及运行效果。鱼道不单纯是洄游性鱼类的通道,更是实现大坝上下游物质与能量循环的生态廊道。国内开展鱼道适应性管理的关键问题是：建立鱼道长效运行与保障机制,对鱼道过鱼进行长效监测以及研究鱼道过鱼效果评价方法。     

我国又一座鱼道建成

<正> 洋塘鱼道,是一座低水头水电站枢纽型鱼道,它位于湖南省湘江中游的主要支流洙水下游衡东县境的杨梓洲。电站下距湘江河口8.7公里。洙水全长327公里,宽400多米。它是湘江中下游鱼类索饵洄游产卵和越冬的主要场所。由于修建河坝,切断了鱼类上溯洄     

洋塘鱼道过鱼的昼夜、季节变化的初步研究

前言鱼道是保持鱼类洄游路线畅通的水工建筑物之一。它对解决江湖阻隔,保持和增殖天然鱼类资源,保持水域必要的生态环境具有一定的作用。洋塘鱼道是一座具有厂房集鱼系统的河川水电站枢纽型鱼道,位于洋塘水轮泵水电站枢纽工程的左侧,该工程座落在湖南省衡东县境内洣水下游之杨梓洲头,下距湘江河口8.7公里。 1981—1982年期间,我们对洋塘鱼道的运行进行了145天,2814 1/3小时的原体观察,总计过鱼1279645尾,隶属于5目13科或亚科,33属,45种。     

连江西牛鱼道运行效果的初步研究

鱼道建设被认为是有效缓解水坝阻隔鱼类洄游的重要方法之一,而鱼道效果监测是评价其功能的重要环节。连江西牛鱼道是广东省第一座建立在水坝主体上的过鱼通道,为了解其运行效果,采用张网法和截堵法,２０１２年３－８月共６次对西牛鱼道的过鱼效果进行监测。研究表明,西牛鱼道共监测到鱼类３目、８科、３０属、３８种,以银鮈（Squalidus argentatus）、乐山小鳔鮈（Microphysogobio kiatingensis）、子陵吻鰕虎（Rhinogobit giurinus）等小型鱼类为优势类群。进入鱼道的鱼类呈现昼夜差异,上午集鱼效果要显著优于其他时间段;不同季节集鱼的种类和数量呈现较大差别,３－８月集鱼数量逐渐减少,集鱼种类数以５月最多。与国内外其他鱼道的过鱼效果比较,西牛鱼道能较好地发挥其功能。     

卡尔加林水利枢纽区段闪光鲟洄游行为的研究

<正> 捷列克河上的卡尔加林水利枢纽位于达吉斯坦境内。卡尔加林枢纽于1956年建成梯式鱼道,八十年代拟改建鱼道,主要过鱼鲟科鱼类和鲑鳟鱼类。1986年和在4月和7月对该枢纽坝区河段闪光鲟的洄游行为作了生物遥测研究,为枢纽设计建造新的过鱼设施提供科学资料。遥测观察的区段是大坝上、下河段各2公里。用作标记的发射装置直径1.5厘米,长     

不同位置和朝向的鱼道进口诱鱼效果

为了探明不同进口朝向的布置方式和进口位置对诱鱼效果的影响,本研究通过建立鱼道进口概化模型,设计3种环境流速工况,以马口鱼为实验对象,针对不同朝向和不同位置鱼道进口分别进行放鱼实验。结果显示,在同一鱼道进口位置时,垂直于河道水流方向上的鱼道进口其诱鱼效果明显优于顺河道水流方向的鱼道进口;当开启与电站不同相对位置不同的进口时,其诱鱼效果受河道水流速度和进口位置的影响较为显著;在所设计实验工况中,环境流速为0.3 m/s时,鱼道进口诱鱼效果最好。研究结果将对水利工程中鱼道进口布置具有重要的参考意义并指导工程实践。     

Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean

The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna.     

Growth performance,digestive enzyme activity and immune response of Japanese sea bass,Lateolabrax japonicus fed with fructooligosaccharide

In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg.     

Protein and amino acid composition from the mantle of juvenile O ctopus vulgaris exposed to prolonged starvation

Protein and amino acid composition of the mantle of juvenile O ctopus vulgaris (Cuvier, 1797) during fasting for 27 days were determined. Average protein content of octopus mantle was of 711.19 ± 46.80 g kg^?1 DW, and it decreased with increasing fasting days. The non‐essential amino acids content was higher (486.18 ± 11.08 g kg^?1 protein) than essential amino acids (425.82 ± 9.15 g kg^?1 protein) at the start of the experiment (unstarved animals). The results suggest that the amino acid profile of the mantle where the most abundant amino acids are Arg, His, Lys, Gly, Leu and Pro could indicate a prolonged fasting condition (>20 days) or poor nutrition of O . vulgaris. This study supports the idea of using mantle for metabolic needs of starved O . vulgaris suggesting that the degradation pathway of amino acids to pyruvate and tricarboxylic acid cycle intermediates was favoured contrary to the degradation pathway of ketogenic amino acids. Special considerations should be taken concerning Thr, Ile, Ser, Ala, Asx (Asp, Asn), Glx (Glu, Gln) (because of their fast intake) and Lys and His (due to their stable contents) during a prolonged period of fasting.     

Involvement of gonadal steroids in final oocyte maturation of white perch (Morone americana) and white bass (M. chrysops): in vivo and in vitro studies

Plasma estradiol-17 (E₂), testosterone (T), 17,20-dihydroxy-4-pregnen-3-one (DHP) and 17,20,21-tri-hydroxy-4-pregnen-3-one (20-S) levels were measured by radioimmunoassay (RIA) in white perch (Morone americana) and white bass (M. chrysops) that were induced to undergo final oocyte maturation (FOM) with human chorionic gonadotropin (hCG). Plasma DHP levels increased in females of both species in association with oocyte germinal vesicle migration (GVM) and germinal vesicle breakdown (GVBD) and decreased thereafter. Plasma 20-S levels also increased with oocyte GVM in white bass, but were several-fold lower than DHP levels. Circulating E₂ and T levels were greatest during GVM and GVBD in both species and decreased to low levels during oocyte hydration and ovulation. Follicles from white perch and white bass which received a priming injection of hCG in vivo, produced both DHP and 20-S in vitro after exposure to hCG and their oocytes underwent GVBD. Ovarian incubates from unprimed fish of either species produced only E₂ and T and their oocytes did not complete GVBD. Oocytes from unprimed bass, but not perch, matured when follicles were exposed to hCG in vitro. Both trilostane and cycloheximide blocked in vitro production of DHP and 20-S and oocyte GVBD by white perch follices. DHP and 20-S were equipotent inducers of FOM in the GVBD bioassay. None of several other structurally-related steroids tested were effective within a physiological range of concentrations. These results indicate a role for DHP and 20-S in the control of FOM in white perch and white bass.     

Cardiac,ventilatory and metabolic responses of two ecologically dissimilar species of fish to waterborne cyanide

Changes in heart rate, ventilatory activity and oxygen consumption were determined in trout (Salmo gairdneri) and brown bullhead catfish (Ictalurus nebulosus) during exposure to a steadily increasing concentration of waterborne cyanide selected to produce death in 8–9 hours for each species. The lethal cyanide concentration for the bullheads was an order of magnitude higher than for trout. Trout developed an immediate and gradually increasing bradycardia throughout the exposure period. Cyanide produced tachycardia in the bullhead followed by a gradual onset of bradycardia as the concentration of cyanide was raised. Pericardial injection of atropine (a muscarinic cholinergic antagonist) indicated that bradycardia in the trout was due initially to increased vagal tone but later due to the direct effect of cyanide on the heart. Hyperventilation in the trout persisted throughout the exposure period, although the rate and amplitude fluctuated and was variable between individual fish. During the last hour of exposure (highest cyanide concentration), ventilation was characterized by rapid, shallow breaths followed by a sudden respiratory arrest. The bullheads exhibited hyperventilation during the first 3 hours of exposure followed by a gradual, linear drop in ventilation rate and amplitude until death occurred. Cardiac and ventilatory responses in both species were attributed to stimulation of central and peripheral chemoreceptors by cyanide. Evidence is presented which suggests the initial response in the bullheads was due, at least in part, to gustatory stimulation by the cyanide. Oxygen consumption of the trout remained above pre-exposure levels for the majority of the test period. Oxygen consumption in the bullhead paralleled the changes in heart and ventilatory rates. Whole-body lactate levels of fingerlings of both species during cyanide exposure were measured to estimate the extent of anaerobiosis. Whole-body lactate levels were much greater in the bullheads than the trout, indicating a higher capacity for anaerobiosis, possibly due to a greater fuel supply. Overall, the trout responded to cyanide in a manner similar to that produced by environmental hypoxia whereas the bullheads experienced a gustatory stimulus which masked the hypoxia-like response.     

An overview of stress physiology of fish transport: changes in water quality as a function of transport duration

This study brings an integrated analysis about the relationship between water deterioration and its physiological consequences in live fish transport. The analysis was focused on the transport water and its deterioration, and physiological challenges imposed on the fish. Usual commercial handling procedures employed to mitigate fish stress during transport were discussed. Future topics of research for the establishment of safer fish transport protocols were proposed. Transport was classified into short (≤8 h) or long transport (>8 h). The main issue in short transports should be the prevention of water pH reduction, while in long transports it is the increase in ammonia. Plasma cortisol is the most employed marker for stress and is acutely elevated upon short episodes of transport, but remains elevated even in long‐transport events. Plasma glucose is perhaps a better marker for handling stress. Plasma lactate, pH, osmolality CO₂ and ions should be more often evaluated. Plasma Na⁺ and Cl^‐ are very useful markers of acidosis, due to their respective exchange for H⁺ and , for acid–base regulation. The establishment of species‐specific transport protocols should be preceded by such combined analyses of water and physiological parameters.     

Are hatchery‐reared abalone naïve of predators? Comparing the behaviours of wild and hatchery‐reared northern abalone,Haliotis kamtschatkana (Jonas, 1845)

Abalone populations have declined worldwide, generating interest in enhancement using hatchery‐reared individuals. In many cases, such restoration efforts have met with limited success due to high predator‐induced mortality rates. Furthermore, the mortality rates of outplanted hatchery abalone are often considerably higher than for wild individuals. This study uses northern abalone (Haliotis kamtschatkana) as a case study to determine whether hatchery‐reared abalone behave differently than their wild counterparts. In the field, outplanted hatchery‐reared abalone were significantly less responsive than wild abalone, in terms of number of abalone responding and intensity of response, to nearby movement and to physical contact with an inert probe. Also, when encountering a cue to which all abalone responded (a seastar predator), hatchery‐reared individuals remained subdued. Anti‐predator behavioural deficits in hatchery‐reared abalone were more pronounced in 4‐year‐old individuals than in 1‐year‐old individuals, suggesting an influence of either age or amount of time spent in the hatchery environment. These behavioural differences are expected to increase the vulnerability of hatchery‐reared abalone to predators, and are likely a major cause of their elevated predator‐induced mortality when outplanted.     

Effects of cadmium on the kinetics of calcium uptake in developing tilapia larvae, Oreochromis mossambicus

The toxic effects of Cd²⁺ on Ca²⁺ influx kinetics in developing tilapia (Oreochromis mossambicus) larvae were evaluated. Addition of 20 µg l^-1 of Cd²⁺ to the environment of 0 and 3 day-old larvae competitively inhibited the Ca²⁺ uptake within 4h resulting in a great increase in K_m values for Ca²⁺ influx (19.3 and 17.4 fold, respectively) as compared with their respective controls. Consequently, the actual Ca²⁺ influx of larvae in solutions of 0.2 mM Ca²⁺ are suppressed by 32–45%. Also, 3 day-old larvae were more sensitive to internally accumulated Cd²⁺ than 0 day-old larvae. Although the Ca²⁺ influx in 0 and 3 day-old larvae may be restored to the levels of their respective controls with 24h of being transferred to a 20 µg l^-1 Cd²⁺ solution, total body Ca²⁺ content was significantly reduced in 3 day-old larvae. Increased Ca²⁺ uptake efficiency ensures sufficient Ca²⁺ for normal growth. However, rapid increase in Ca²⁺ influx after hatching also leads to higher Cd²⁺ uptake. Exposure to Cd²⁺ will lead to a drop in body Ca²⁺ content resulting in retardation of larval growth. Therefore, we conclude that if Ca²⁺ uptake is interfered with at this critical stage of development, larvae will not be able to maintain normal levels of body Ca²⁺ and will show signs of Cd²⁺ poisoning.     

Migratory dynamics of stream-spawning longnose gar (Lepisosteus osseus)

Abstract– Literature evidence suggests that lake-dwelling longnose gar (Lepisosteus osseus) enter tributary streams to spawn, Until the present study, the dynamics of this breeding migration had never been investigated quantitatively. During the summers of 1991 and 1992, longnose gar were captured as they entered Weaubleau Creek, Missouri, a tributary of Harry S. Truman Reservoir. The in-stream spawning migration began in early April and ended in late May, and was positively correlated with stream flow and water level, and negatively correlated with water temperature. In-stream residence times ranged from 15 to 94 days, with males exhibiting longer residence times than females. Once in-stream, longnose gar travelled as far as 10 km upstream and occupied certain pools at greater relative frequencies. Although the reason for this preferential utilization is not completely understood, it may relate to pool depth and riffle proximity. Longnose gar disperse from the spawning stream great distances, with gar captured in Weaubleau Creek being recaptured up to 48 km away. This information should provide fisheries biologists the means to consider the reproductive ecology of this species in their conservation and management decisions.     

美人鱼发光杆菌对凡纳滨对虾非特异性 免疫功能及抗病力的影响

在基础饲料中分别添加0.1%和1%美人鱼发光杆菌灭活菌、0.1%美人鱼发光杆菌活菌配制成3种免疫实验饲料,以基础饲料为空白对照组饲料,每组设3个平行样。对个体质量为(4.83±0.36)g的凡纳滨对虾进行为期20 d的饲养实验,分别在0、5、10、15和20d进行取样,以血清中的酚氧化酶(PO)、酸性磷酸酶(ACP)、碱性磷酸酶(AKP)、超氧化物歧化酶(SOD)和溶菌酶(UL)活性为免疫指标,探讨了美人鱼发光杆菌作为免疫制剂对凡纳滨对虾非特异性免疫效应的影响;在投喂免疫饲料后的第22天,按0.004 2 kg/kg体重的剂量,直接投喂对虾白斑综合征病毒(WSSV)病料,并记录累积死亡率。结果表明,美人鱼发光杆菌免疫实验组对凡纳滨对虾血清中PO、ACP、AKP、UL和SOD活性影响明显高于对照组,并且在饲料中添加美人鱼发光杆菌后,明显提高了对虾抵御WSSV感染的能力。其中0.1%美人鱼发光杆菌活菌实验组的抗病毒感染能力最强,WSSV感染14d内累计死亡率为63.3%±5.8%;而对照组为96.7%±3.3%。研究表明,美人鱼发光杆菌添加在对虾饲料中能提高凡纳滨对虾非特异性免疫水平,增强抵抗疾病的能力,将其作为对虾免疫增强剂具有良好的应用前景。