鲢幼鱼通过水流速度障碍的模拟

鱼类能否通过水流速度障碍直接影响过鱼设施的过鱼效果。利用计算机技术,综合水力因素、鱼类行为、地理特征及环境因子,展开鱼类通过水流速度障碍的模拟,有助于过鱼设施的优化设计。以国外涵洞式鱼道模拟软件Fish Xing为切入点,结合主要模块和关键因子,对我国特有鱼类鲢幼鱼进行模拟,得到鲢通过不同水流速度障碍的成功率;对比鲢在物理模型中的游泳表现,从模型主要模块和影响鱼类游泳表现的关键因子角度,分析影响鱼类通过水流速度障碍模拟的因素。结果表明,Fish Xing软件不能精确模拟鲢通过水流速度障碍的表现。分析表明,该软件在地理要素、管道特征和水力信息等参数方面具备独特的优势,但对我国鱼类有一定局限性,主要体现在鱼类的生物学信息如鱼类游泳特征等方面存在不足;进行鱼过障碍的模拟需要深入研究目标鱼类的生理特征、游泳能力及其与水力环境因子的响应关系。     

基于Matlab的鱼类游泳动力学分析

鱼类游泳动力学分析研究对解决鱼道等工程应用中水力学设计方面的关键问题有着重要的意义,利用计算机技术对鱼类游泳动力学进行分析有助于研究目标鱼类的生理特性、游泳能力及其与水力环境因子的响应关系。基于MATLAB软件对我国特有鱼类鲢幼鱼进行游泳动力学分析,借助鲢幼鱼游泳时的摆尾行为,得到不同水流速度下鲢幼鱼的摆尾频率、摆尾幅度、游泳速度和加速度;对比人工计数和手动跟踪分析方法,从实际操作复杂程度和实验数据准确性的角度,分析各数据采集方法的优劣性。结果表明基于Matlab软件采用跟踪鱼的身体中线的思路能更高效的获取大量的运动参数,比如摆尾频率、摆尾幅度、游泳速度和加速度等指标。文章介绍了一种基于Matlab开发的鱼类游泳动力学分析方法,有助于为以后鱼类游泳动力学研究提供依据。     

异齿裂腹鱼上溯过程中的折返行为及其与水力条件的关系

解析鱼类上溯过程中的游泳行为及其对鱼道水力学条件的响应是优化鱼道设计、提高鱼类上溯效率和成功率的关键。本文以异齿裂腹鱼为研究对象,通过将流场、紊动能场、应变率场与鱼类上溯及折返轨迹相叠加,分析各水力学因子对折返行为及重新上溯的影响,并结合鱼类上溯过程中的能量消耗率进一步探讨折返行为的内在原因。结果表明:鱼类在上溯过程中普遍存在折返行为,其折返行为大多是为了搜寻合适的上溯路径。鱼道流速是引发折返行为的主导因素,鱼类折返行为集中发生在高流速区域,折返后倾向于选取低流速区域重新上溯;紊动能在折返运动导向方面有显著贡献,鱼类趋向于从低紊动能区域折返,并选择较高紊动能区域重新上溯;水流应变率对鱼类折返行为的影响相对较小。鱼类上溯轨迹点处的水力因子与能量消耗率相关性分析表明,高能量消耗和生理压力是引发折返行为的内在原因。     

过鱼设施设计中的鱼类行为研究与问题

水利水电工程对鱼类的洄游和基因交流产生了一定影响,过鱼设施是一项重要的缓解措施,而鱼类游泳特性和趋向特征等行为学研究是过鱼设施设计的重要依据。本文阐释了鱼类游泳特性和趋向特征的基本概念,分析了鱼类行为研究方法的优缺点及影响因素(水流速度、水流形态、水温等),探讨了鱼类行为研究在过鱼设施应用中存在的4个问题,并提出了相应建议:(1)实际过鱼设施内流场十分复杂,因而需要加强复杂流场条件下鱼类行为学研究;(2)运动训练可能提高鱼类游泳能力,因而可以利用其规律提高鱼类通过过鱼设施的成功率;(3)不同目标鱼类游泳能力有差异,因而需要提出新的设计使单个过鱼设施满足所有目标鱼类的过鱼需求;(4)各研究单位使用着不同的鱼类行为数据处理方法,造成各研究结果之间难以直接用于比较分析,因而亟需政府有关部门和业内人士尽快深入研究并以行业内规范、导则或其他方式将鱼类行为研究数据处理方法标准化。     

温度对鳙幼鱼疲劳引起的生理变化和游泳能力的影响研究(英文)

鳙(花鲢)在自然环境中分布于中国南部流域至阿穆尔河,是重要的经济性鱼类,具江湖生殖洄游特性。大坝建设阻碍了其洄游产卵繁殖通道,导致自然环境中其繁殖力的下降,需要有效的过鱼设施帮助鳙通过大坝等水流屏障。为了设计高效的鱼道引导鳙通过,本文通过自制密封的鱼类游泳实验装置,研究了鳙幼鱼游泳能力。测定了5个温度(5、10、15、20和25℃)下鳙幼鱼的临界游泳速度。通过测定不同温度下,疲劳前后血清总蛋白(TP)、血糖(GLU)和甘油三酯(TG)含量,评价疲劳运动引起的生理胁迫。结果表明,在试验温度范围内,随着温度的升高,临界游泳速度显著提高(P0.05)。25℃时临界游泳速度最大,为7.01 BL/s(1.19 m/s)。在疲劳运动后,血清总蛋白、血糖和甘油三酯含量显著升高(P0.05)。水温低于15℃与高于15℃相比,鳙疲劳运动后血清总蛋白、血糖和甘油三酯含量显著升高。以鳙幼鱼为研究对象,研究了非适宜温度环境和疲劳运动胁迫下鱼类的生理反应。以期为鱼类生理学研究和渔业保护管理等领域提供理论依据,为制定有效的鱼道提供数据参考。     

鱼道进口不同补水形式对齐口裂腹鱼上溯行为的影响

修建补水设施是提高鱼道过鱼效果的有效措施之一,不同补水形式如何改变鱼的游泳行为策略从而吸引其进入鱼道进口是国内外关注热点。本研究基于鱼道进口概化模型,以齐口裂腹鱼(Schizothorax prenanti)为研究对象,采用进口内部侧面补水、旁道补水和旁道顶部补水3种形式,探究不同流量和补水距离下补水方式对鱼道进口附近处目标鱼上溯行为的影响。结果表明:与没有补水的工况相比,补水距离为1 m的旁道补水和补水距离为0.65 m的旁道顶部补水,鱼类在鱼道进口通过次数显著提升(P0.05)。通过提取目标鱼成功上溯路径上对应的水流速度场和紊动场发现,齐口裂腹鱼上溯偏好流速0.6～0.8m·s~(-1),优先选择低紊动区(0.01 m~2·s~(-2)),且明显逃离高紊动区(0.04 m~2·s~(-2))进行上溯。本研究验证了紊动能和流速是影响鱼类上溯的重要水力因子,为鱼道进口补水设计及其优化提供了重要参考。     

基于雅砻江两种裂腹鱼游泳能力的鱼道设计

为探究雅砻江两种裂腹鱼的游泳能力,给过鱼设施设计和鱼类游泳行为学研究提供基础参数,本研究采用递增流速法对长丝裂腹鱼、齐口裂腹鱼的感应流速、临界游泳速度、突进游泳速度进行测试,采用固定流速法对长丝裂腹鱼的耐久游泳速度进行测试。结果表明: 长丝裂腹鱼与齐口裂腹鱼的感应流速随着体长的增加均出现了先增加后平稳的趋势,但最大感应流速均小于0.2 m·s^-1;长丝裂腹鱼的临界游泳速度与突进游泳速度分别为(0.81±0.20)和(1.49±0.26) m·s^-1,相对临界游泳速度为(4.90±1.73) BL·s^-1,相对突进游泳速度为(9.77±1.72) BL·s^-1(BL为体长);齐口裂腹鱼的临界游泳速度与突进游泳速度分别为(0.73±0.24)和(1.17±0.39) m·s^-1,相对临界游泳速度为(6.88±2.82) BL·s^-1,相对突进游泳速度为(11.75±2.77) BL·s^-1。耐久测试发现,随着流速增加(0.7～1.5) m·s^-1,长丝裂腹鱼持续游泳时间与水流速度呈负相关,疲劳时间(T)与水流速度(V)的关系可以拟合为lgT=-2.52V+5.59,预测鱼道长度(d)与鱼道内可通过的最大平均水流速度(V_fmax)的关系式为V_{f max}=-0.17lnd+1.74。根据试验结果,当以长丝裂腹鱼和齐口裂腹鱼为主要过鱼对象时,建议鱼道内最小水流速度应大于0.2 m·s^-1,进口及竖缝处水流速度为0.73～1.67 m·s^-1,休息池主流水流速度为0.2～0.7 m·s^-1。     

基于视频跟踪的竖缝式鱼道内鱼类运动行为分析

竖缝式鱼道过鱼对象运动行为与鱼道池室内水力条件是否相适应是进行鱼道设计的关键。研究通过视频跟踪法对竖缝式鱼道中目标鱼的运动轨迹进行实时跟踪, 获取鱼的运动加速度、运动速度, 并和人工手动跟踪的鱼类运动轨迹进行对比, 证明基于视频跟踪法的鱼类运动分析程序既能较好的应用于竖缝式鱼道中, 获取鱼类运动行为, 又可减少大量的人工操作, 有助于为竖缝式鱼道设计提供重要基础数据。     

五种淡水鱼类幼鱼游泳能力的比较

为了探讨栖息于不同生境中鱼类的游泳能力和偏好游泳速度及其生理机制,本研究以中华倒刺鲃(Spinibarbus sinensis)、异育银鲫(Carassius auratus gibelio)、岩原鲤(Procypris rabaudi)、青鱼(Mylopharyngodon piceus)和胭脂鱼(Myxocryprinus asiaticus) 5种鱼的幼鱼为对象,在(25±1)℃条件下测定了5种鱼类的标准代谢率(SMR)、最大代谢率(MMR)、有氧代谢范围(MS)、临界游泳速度(U_crit)、最大匀加速游泳速度(U_cat)和偏好游泳速度(U_pref)。结果发现:5种实验鱼中,中华倒刺鲃的游泳能力最强,游泳能力较差的为青鱼和胭脂鱼; 5种鱼之间的代谢和游泳能力差异显著,其偏好游泳速度主要集中在(10～24.5cm·s^-1)区域。研究表明,鱼类游泳能力的种间差异可能主要由心鳃系统相关的呼吸能力和体型相关的游泳效率所决定。本研究提供的有关鱼类游泳能力、偏好游泳速度等资料对于鱼道设计等有一定的参考价值...     

应用于鱼道设计的马口鱼(Opsariichthys bidens)游泳能力

马口鱼(Opsariichthys bidens)广泛存在于长江流域,是体型较小的重要经济鱼种。游泳耐力、临界游泳速度、冲刺游泳速度是鱼类重要的游泳能力参数。本文利用鱼类游泳能力测试环形水槽,在实验水温21.4±0.3℃条件下,用固定流速法对128尾(全长TL:9.60~15.10 cm)测试鱼进行游泳耐力测试,用流速递增法分别对31尾(TL:9.16~15.91cm)、56尾(TL:8.78~16.81 cm)测试鱼进行临界游泳速度、冲刺游泳速度测试。结果表明:在游泳耐力测试中,84%以上测试鱼持续游泳时间集中分布在0~10 min和200 min的范围内;疲劳时间(E)、游泳速度(V)、全长(TL)之间的关系可拟合为lg E=1.603-0.025V+0.146TL(R~2=0.562,P0.001),根据拟合关系式预测全长为9.60 cm(最小长度)测试鱼可连续通过的鱼道长度与允许最大鱼道内平均水流速度的关系曲线为V_(fmax)=223.3973-17.3609ln(d-0.0130);测试鱼的临界游泳速度值为61.07~120.03 cm·s~(-1)(相对临界游泳速度6.57~12.65 BL·s~(-1));冲刺游泳速度范围为65.03~155.07 cm·s~(-1)(相对冲刺游泳速度5.31~17.95 BL·s~(-1)),78%的实验鱼其冲刺游泳速度大于1 m·s~(-1),平均冲刺游泳速度约为平均临界游泳速度的1.23倍。本试验方法和结果可为鱼道设计提供相关依据。     

Effect of thermo-velocity barriers on fish: influence of water temperature,flow velocity and body size on the volitional swimming capacity of northern straight-mouth nase (Pseudochondrostoma duriense)

Water temperature and flow velocity directly affect the fish swimming capacity, and thus, both variables influence the fish passage through river barriers. Nonetheless, their effects are usually disregarded in fishway engineering and management. This study aims to evaluate the volitional swimming capacity of the northern straight-mouth nase (Pseudochondrostoma duriense), considering the possible effects of water temperature, flow velocity and body size. For this, the maximum distance, swim speed and fatigue time (FT) were studied in an outdoor open-channel flume in the Duero River (Burgos, Spain) against three nominal velocities (1.5, 2.5 and 3 m s⁻¹) and temperatures (5.5, 13.5 and 18.5°C), also including the changes between swimming modes (prolonged and sprint). Results showed that a nase of 20.8 cm mean fork length can develop a median swim speed that exceeds 20.7 BL s⁻¹ (4.31 m s⁻¹) during a median time of 3.4 s in sprint mode, or 12.2 BL s⁻¹ (2.55 m s⁻¹) for 23.7 s in prolonged mode under the warmest scenario. During prolonged swimming mode, fish were able to reach further distances in warmer water conditions for all situations, due to a greater swimming speed and FT, whereas during sprint mode, warmer conditions increased the swim speed maintaining the FT. In conclusion, the studied temperature range and flow velocity range influence fish swimming performance, endurance and distance travelled, although with some differences depending on the swimming mode. The provided information goes a step forward in the definition of real fish swimming capacities, and in turn, will contribute to establish clear passage criteria for thermo-velocity barriers, allowing the calculation of the proportion of fish able to pass a barrier under different working scenarios, as well designing of the optimized solutions to improve the fish passage through river barriers.     

Evaluation of Adult White Sturgeon Swimming Capabilities and Applications to Fishway Design

Concern over passage of sturgeon barriers, has focused attention on fishway design that accommodates its swimming performance. In order to evaluate swimming performance, regarding fish ladder type partial barriers, wild adult sturgeons, Acipenser transmontanus; 121–76m fork length, were captured in the San Francisco Bay Estuary and Yolo Bypass toe drain. Hydrodynamic forces and kinematic parameters for swimming performance data were collected in a laboratory flume under three flow conditions through barriers and ramp. The experiments were conducted in a 24.4 m long, 2.1 m wide, and 1.62 m deep aluminum channel. Two geometric configurations of the laboratory model were designed based on channel characteristics that have been identified in natural river systems. At a given swimming speed and fish size, the highest guidance efficiencies of successful white sturgeon passage as a function of flow depth, flow velocity, turbulence intensity, Reynolds number, Froude number and shear velocity observed in the steady flow condition, tested with the horizontal ramp structure, occurred at an approach velocity of 0.33 ms^-1. The guidance efficiency of successful sturgeon passage increased both with increasing flow velocity and Froude number, and decreased both with the flow depth and the turbulence intensity. This study also provides evidence that tail beat frequency increases significantly with swimming speed, but tail beat frequency decreases with fish total length. Stride length increases both with swimming speed and fish total length. The importance of unsteady forces is expressed by the reduced frequency both with swimming speed and fish total length. Regression analysis indicates that swimming kinematic variables are explained by the swimming speed, the reduced frequency and the fish total length. The results emphasize the importance of fish ladder type patchiness when a fishway is designed for the passage of sturgeon.     

Use of a self-propelled,fish-shaped,computer model to study the effects of shape and tail-beat frequency on torque and velocity in salmon-shaped fish

The relationship between fish shape, swimming ability and energy consumption during swimming in fish is complex and not well understood. In this paper, we show how a self-propelled 3-D fish model can be used to examine the effect of controlled changes in some shape parameters. Parameters of the model fish are modified and the resulting fish activated for short swimming episodes during which swimming velocity, torque and energy expenditure are calculated in the computer environment. The effect of shape was determined for two different fish shapes swimming at three different tail-beat frequencies (1.43, 0.94 and 0.64?Hz). The simulation results indicate that fish model one (based on a salmon) has stronger swimming ability than fish model two (a modified salmon fish shape) even though energy expenditure of fish shape two is greater than that of fish shape one. In the same fish types, the fish-swimming velocity and energy expenditure are proportional to tail-beat frequency. This model has the potential to be useful, particularly for predicting fish behavior in fish swim ways and the tail-water of energy turbines.     

Warm water and cool nests are best. How global warming might influence hatchling green turtle swimming performance

For sea turtles nesting on beaches surrounded by coral reefs, the most important element of hatchling recruitment is escaping predation by fish as they swim across the fringing reef, and as a consequence hatchlings that minimize their exposure to fish predation by minimizing the time spent crossing the fringing reef have a greater chance of surviving the reef crossing. One way to decrease the time required to cross the fringing reef is to maximize swimming speed. We found that both water temperature and nest temperature influence swimming performance of hatchling green turtles, but in opposite directions. Warm water increases swimming ability, with hatchling turtles swimming in warm water having a faster stroke rate, while an increase in nest temperature decreases swimming ability with hatchlings from warm nests producing less thrust per stroke.     

Flow preferences of individual blacknose dace (Rhinichthys atratulus); influence of swimming ability and environmental history

Fish from lotic environments generally have a variety of flow velocities available to them in their immediate environment. Other than prey availability or predator presence, little is known about what factors determine where in this mosaic of flows an individual fish will choose to locate. Since individuals of a species can have substantially different swimming abilities, and interspecific differences in flow velocity selection have been related to differential swimming abilities, one possibility is that an animal??s physical condition constrains the flow environments it chooses to occupy. Additionally, since the flow in an animal??s environment can contribute to swimming ability, there could also be environmental control over flow selection behavior. This study examined whether flow velocity selection by individual blacknose dace (Rhinichthys atratulus) is a repeatable trait in the laboratory, and whether it is a function of either the animal??s swimming ability or the magnitude of flow in their home stream reach. Blacknose dace from two populations, collected from each of two separate reaches with substantially different flows from within their home streams, exhibited significantly repeatable flow velocity selection over the course of 1?day in the laboratory. The flow velocity selected by the fish varied significantly among individual dace. Some of this variance was accounted for by fish from the slower stream reaches choosing significantly faster flows than did those from faster reaches. There were no significant differences in flow selection behavior between populations. There was also no relationship between sprinting ability and the flow velocity selected by a fish.     

我国过鱼设施建设需求、成果及存在的问题

本文首先阐述了水利水电工程对河流连通性的影响以及修建过鱼设施的对策,然后从河流破碎化程度和鱼类洄游习性的角度分析了国内建设过鱼设施的需求,介绍了国内建设过鱼设施的成果,最后提出了6点过鱼设施相关问题和建议:(1)利用多指标量化评价的方法,科学地确定过鱼对象;(2)以复杂流场为背景条件,贴合实际地推进鱼类上溯行为研究;(3)对过鱼设施加大资金投入,扩大设施规模,加大过鱼设施过水流量(至少应为河流流量的1%);(4)为鱼类下行、低水头水工建筑物引起的跌水河段建设过鱼设施;(5)扩大过鱼效果评估的覆盖面,提高监测时长和频率,提出有广泛适用性的监测评估方法;(6)栖息地修复、增殖放流、生态调度、分层取水等多手段联动,确保鱼类通过过鱼设施后仍然能够生存。     

Measuring Ucrit and endurance: equipment choice influences estimates of fish swimming performance

This study compared the critical swimming speed (U_crit) and endurance performance of three Australian freshwater fish species in different swim‐test apparatus. Estimates of U_crit measured in a large recirculating flume were greater for all species compared with estimates from a smaller model of the same recirculating flume. Large differences were also observed for estimates of endurance swimming performance between these recirculating flumes and a free‐surface swim tunnel. Differences in estimates of performance may be attributable to variation in flow conditions within different types of swim chambers. Variation in estimates of swimming performance between different types of flumes complicates the application of laboratory‐based measures to the design of fish passage infrastructure.     

Endurance swimming of European eel

A long‐term swim trial was performed with five female silver eels Anguilla anguilla of 0·8–1·0 kg ( c . 80 cm total length, L _T) swimming at 0·5 body lengths (BL) s⁻¹, corresponding to the mean swimming speed during spawning migration. The design of the Blazka‐type swim tunnel was significantly improved, and for the first time the flow pattern of a swim tunnel for fish was evaluated with the Laser‐Doppler method. The velocity profile over three different cross‐sections was determined. It was observed that 80% of the water velocity drop‐off occurred over a boundary layer of 20 mm. Therefore, swim velocity errors were negligible as the eels always swam outside this layer. The fish were able to swim continuously day and night during a period of 3 months in the swim tunnel through which fresh water at 19° C was passed. The oxygen consumption rates remained stable at 36·9 ± 2·9 mg O₂ kg⁻¹ h⁻¹ over the 3 months swimming period for all tested eels. The mean cost of transportation was 28·2 mg O₂ kg⁻¹ km⁻¹. From the total energy consumption the calculated decline in fat content was 30%. When extrapolating to 6000 km this would have been 60%, leaving only 40% of the total energy reserves for reproduction after arriving at the spawning site. Therefore low cost of transport combined with high fat content are crucial for the capacity of the eel to cross the Atlantic Ocean and reproduce.     

Turbulence: does vorticity affect the structure and shape of body and fin propulsors?

Over the past century, many ideas have been developed on the relationships between water flow and the structure and shape of the body and fins of fishes, largely during swimming in relatively steady flows. However, both swimming by fishes and the habitats they occupy are associated with vorticity, typically concentrated as eddies characteristic of turbulent flow. Deployment of methods to examine flow in detail suggests that vorticity impacts the lives of fishes. First, vorticity near the body and fins can increase thrust and smooth variations in thrust that are a consequence of using oscillating and undulating propulsors to swim. Second, substantial mechanical energy is dissipated in eddies in the wake and adaptations that minimize these losses would be anticipated. We suggest that such mechanisms may be found in varying the length of the propulsive wave, stiffening propulsive surfaces, and shifting to using median and paired fins when swimming at low speeds. Eddies in the flow encountered by fishes may be beneficial, but when eddy radii are of the order of 0.25 of the fish's total length, negative impacts occur due to greater difficulties in controlling stability. The archetypal streamlined "fish" shape reduces destabilizing forces for fishes swimming into eddies.