Assessing the opportunities for upstream migration of non-salmonid fishes in the weir-regulated River Vecht

The degree of obstruction posed by weirs to potential upstream movements of non-salmonid fish (predominantly cyprinids) in the River Vecht, the Netherlands, was assessed. This rain-fed river showed high variability in discharge, providing opportunities for passage at high discharge when weirs were free flowing. Daily recorded discharge and water levels between 1960 and 1984, and an analysis of swimming capacities and migratory behaviour, were used to assess whether hydraulic conditions each day and for each species were suitable for ascent. The assessment demonstrated that migratory opportunities along the six weirs were extremely limited. Only 10 of 32 species were able to ascend all weirs in 5–30% of the years. Opportunities were the greatest for large-sized species during November–March at the downstream-situated weirs, whereas small-sized species had no opportunities year-round. The approach used is widely applicable for barrier assessment in other rivers, because it requires only basic hydraulic measurements that are often available.     

Activity and energetics of free-swimming fish: insights from electromyogram telemetry

Electromyogram (EMG) telemetry studies that involve remotely monitoring the locomotory activity and energetics of fish are contributing important information to the conservation and management of fisheries resources. Here, we outline the development of this rapidly evolving field and formulate the studies conducted that utilize this technology. To date, more than 60 studies have been conducted using EMG telemetry that spans 18 species. Several general trends were observed in the methodology of the studies that we have highlighted as standards that should be adopted associated with transmitter customization, electrode placement and surgical technique. Although numerous studies have been methodological, there are still some deficiencies in our basic understanding of issues such as the need for individual calibration and the method of reporting or transforming data. Increasingly, this technology is being applied to address issues in conservation, management and aquaculture production. At present, the technology has been most frequently applied to the study of animal activity or energetics and to migration. Several recent studies have also focused on addressing more basic questions in ecological and evolutionary biology (e.g. parental care dynamics) similar to the large body of literature that has been collected for other taxa (e.g. marine mammals, birds), using activity telemetry. Collectively, studies conducted using EMG telemetry have contributed important information on free‐swimming fish that was previously difficult to obtain. EMG telemetry is particularly effective for examining behaviour at temporal and spatial scales that are difficult using other techniques. The development of an ultrasonic transmitter based on the same proven principles as those used in the current radio transmitter technology will permit studies in other environments (i.e. marine, brackish, deep water) and on different species of fish. We encourage the continued development and refinement of devices for monitoring the activity and energetics of free‐swimming fish, and also encourage researchers to consider EMG telemetry as a tool for addressing questions that are not effectively answered with other techniques.     

Behaviour of adult Pacific lamprey in near‐field flow and fishway design experiments

Abstract An experimental fishway was used to examine adult Pacific lamprey, Lampetra tridentata (Gairdner), behaviour in a series of attraction and passage‐performance tests. Among all experiments, lamprey oriented to the fishway floor and walls and were attracted to both ambient and concentrated flow. When confronted with high‐velocity areas (vertical‐slot and submerged‐orifice weirs), many lamprey failed to pass upstream. However, lamprey were able to find and take advantage of low‐velocity refuges when they were provided. Lamprey climbed shallow‐ and steep‐angled ramps when attraction cues were sufficient and other passage routes were restricted. The combined results demonstrated the passage challenges that fishways designed and operated for salmonids present to non‐salmonid species. They also highlight the importance of evaluating trade‐offs between fishway attraction and passage efficiency. The experiments were integrated with tagging studies and development of lamprey‐specific passage structures, a research combination that provided an effective template for fishway performance evaluations.     

Skipjack velocity, dwell time and migration

Apparent velocities (distance travelled/time at liberty) of tagged Pacific skipjack tuna, Katsuwonus pelamis, observed over the 1978 to 1982 Skipjack Survey and Assessment Program (SSAP) of the South Pacific Commission (SPC) were very low (less than 10 cm s^-1in 90% of observations) compared with the minimum swimming speed of skipjack tunas of 70–100 cm s^-1. Such low apparent velocities are not biologically meaningful and therefore the extrapolation of biological properties from mathematical models, such as diffusion and advection models, based on the tagging data is difficult, if not impossible. This paper explores alternative approaches to the 1978 to 1982 SSAP data set. Dwell time and migration analysis indicate a north to south seasonal migratory pattern with the skipjack home range located along an arc from the Solomon Islands, through Fiji and Samoa, to the Marquesas. Ancillary evidence supports a purposeful rather than advective migration pattern that oscillates between southern feeding areas and northern breeding areas. many hands. Most of the previous analyses have focused on the issue of interactions between fisheries for K. pelamis that are in different political jurisdictions (Kleiber et al., 1984) and estimates of the size of the standing crop of K. pelamis (Kleiber et al., 1983; Kearney et al., 1984). Models of interactions between fisheries for K. pelamis in different jurisdictions (Sibert, 1984; Hilborn, 1990) have pointed towards the use of diffusion and advection models in studying fish movements (Sibert and Fournier, 1994; Sibert et al., 1995).     

鱼类游泳能力测定方法的研究进展

文章综述了鱼类游泳能力的研究概况、鱼类游泳速度的分类和鱼类游泳能力的测定方法,分析比较了各种方法的优劣,以期为进一步优化鱼类游泳能力的评价指标、完善测试鱼类游泳能力的方法与手段提供参考。     

Evaluation of passive integrated transponder tags for marking the bullhead (Cottus gobio), a small benthic freshwater fish: effects on survival, growth and swimming capacity

Abstract –  This study examined potential adverse effects of surgically implanted passive integrated transponder (PIT) tags (12 × 2.1 mm) on bullhead ( Cottus gobio L.) of three different length-classes (I: 50–64 mm, II: 65–79 mm, III: 80–94 mm). During a 7-week laboratory experiment, the rate of PIT tag loss, incision closure time, survival, growth and swimming capacity were tested. The PIT tag weight to fish body weight ratio varied between 1.04% and 4.85%. The mean incision closure time differed significantly among length-classes and varied between 2.8 (I) and 4.3 (III) weeks. Nevertheless, PIT tag retention did not differ among length-classes and was ≥90%. The survival of untagged, sham-tagged and PIT-tagged bullheads was ≥90% and did not differ within or among length-classes. Finally, within each length-class, there was no difference in growth and swimming capacity among treatments. Hence, these results suggest the applicability of PIT tags for individually tagging bullheads ≥50 mm.     

应用于鱼道设计的玉曲河流域裸腹叶须鱼游泳能力探究

探究西藏玉曲河流域裸腹叶须鱼(Ptychobarbus kaznakovi)的游泳能力,可为珍稀鱼类资源保护及鱼道设计提供理论参考。以体长(BL)18~27 cm的裸腹叶须鱼为研究目标,在野外场景下分别测试其感应流速、临界游泳速度、突进游泳速度和持久游泳速度。结果表明：(1)裸腹叶须鱼的感应流速为(0.17±0.01) m/s,平均相对感应游泳速度为(0.78±0.07) BL/s;临界游泳速度为(0.92±0.16) m/s,平均相对临界游泳速度为(4.33±1.20) BL/s;平均突进游泳速度为(1.28±0.39) m/s,平均相对突进游泳速度为(5.81±1.81) BL/s;(2) 流速(V)对裸腹叶须鱼的持续游泳时间(T)有显著性影响,持续游泳时间均随设定流速的递增而明显下降,耐力关系可拟合为:lgT = -5.30V + 6.39,游泳速度(Vs)、鱼道总长度(d)和鱼道内最大流速(Vf)关系式为:Vf = Vs ? d×10(5.3Vs?6.39);(3)裸腹叶须鱼的趋流率(Pre)与流速(V)拟合关系式为:Pre = 14.23V ? 2.51,得出95%裸腹叶须鱼的趋流速度为0.18 m/s;(4)以裸腹叶须鱼为主要过鱼目标时,建议鱼道进口的设计流速为0.9~1.3 m/s,进口的主流长度为2~4 m,鱼道出口流速不低于0.2 m/s,鱼道池室主流流速为0.2~0.8 m/s。结合鱼类在竖缝处的不同上溯模式和持久游泳速度,推荐池室主流长度最大应为5.5 m,竖缝处最大平均流速为1.1 m/s,鱼道长短隔板沿水流方向的最大间隔为40 cm。研究结果可为玉曲河流域珍稀鱼类保护及鱼道关键部位的长度设计和流速要求提供基础数据支撑。     

异齿裂腹鱼游泳能力初探

为了摸清雅鲁藏布江特有种异齿裂腹鱼(Schizothorax oconnori)的游泳能力,以野生鱼种为实验对象,通过丹麦Loligo System公司的环形试验水槽测试了异齿裂腹鱼的临界游泳速度、突进游泳速度和持续游泳速度。结果显示,异齿裂腹鱼的临界游泳速度随体长的增大而增加,相对临界游泳速度随体长的增大而减小,其临界游泳速度与体长的关系为Y1=-39.369+13.23X-0.371X2+0.004X3(Y1是绝对临界游泳速度,X为体长)。突进游泳速度随体长的增加而近似呈线性递增趋势,而相对突进游泳速度随体长的增大而减小。在三个固定流速(60cm/s、80 cm/s、100 cm/s)下,初步确定60 cm/s为异齿裂腹鱼的持续游泳速度,80 cm/s、100 cm/s为耐久游泳速度。研究成果以期为青藏高原地区鱼类行为学的研究提供基础资料,为鱼道等过鱼设施的设计提供参考资料。     

鲢幼鱼游泳能力及游泳行为的试验研究

为了探究四大家鱼的游泳能力,指导鱼道水力学设计,提高鱼道过鱼成功率,增殖鱼类资源总量,以四大家鱼之一的鲢(Hypophthalmichthys molitrix)为试验对象,研究其游泳能力及游泳行为。在(30±1)℃水温下,采用流速递增法,鲢的体长7.3~16.8 cm,体重6.10~66.50 g,按体长将鲢分为(8.17±0.59)cm、(10.09±0.53)cm、(11.84±0.67)cm、(13.94±0.68)cm、(15.90±0.64)cm共计5个试验组。结果表明,鲢的临界游泳速度为52~100 cm/s,相对临界游泳速度为5.90~7.14 BL/s,摆尾频率为98.7~432.2次/min。鲢的临界游泳速度随体长增加而增大,其线性拟合方程为Ucrit=4.908L+17.63(R2=0.998);其相对临界游泳速度随体长增加而减小,线性拟合方程为U'crit=-0.130L+8.025(R2=0.979);在整个试验过程中,根据鱼类对水流速度的游泳行为响应,鲢摆尾频率随水流速度的增大而增加,两者呈线性关系;在相同流速下,较长个体鲢的摆尾频率显著小于较小的个体。     

An analysis of the effect of diet and genotype on protein and energy utilization by the black tiger shrimp,Penaeus monodon – why do genetically selected shrimp grow faster?

Selected (G8) and wild‐type (W) genotypes of black tiger shrimp (Penaeus monodon) juveniles (initial weight G8 = 9.14 ± 0.36 g per animal and W = 8.44 ± 0.10 g per animal) were fed either of two diet types in a clear‐water tank trial to examine the effects of diet type and genetics on growth and feed utilization parameters. Animals were fed twice daily at one of the five ration levels from starvation to apparent satiety. All uneaten feed was accounted for and moults removed. Starved animals were measured after 3 weeks; those fed were measured at both three and 6 weeks. Diet type varied by protein content, raw material choice and the presence [high‐specification diet (HSD)] or absence [low‐specification diet (LSD)] of bioactive substances. At the end of the study, faecal samples were also collected to determine the digestible protein and energy content of each diet by each genotype. Whole animal protein and energy content were also assessed from samples from the initial populations and those from each tank. Growth after 6 weeks of those animals fed to satiety showed that the G8 animals fed the HSD diet had grown at a rate of 2.56 g week^?1, significantly faster than any other treatment. Those G8 animals fed the LSD diet (1.81 g week^?1) had grown significantly faster than the W animals fed the HSD diet (1.25 g week^?1), while those W animals fed the LSD diet (0.61 g week^?1) grew the slowest. Using the data from the varying ration levels, we were able to define that the growth gains of the G8 animals were achieved not only by a greater appetite, but also through lower maintenance energy costs (29 versus 57 kJ kg^?0.8 day^?1) and a more efficient energy conversion (19.5% versus 11.6% when fed the HSD diet). Use of a low‐specification diet with the G8 and W shrimps limited their growth and impaired their potential as demonstrated by a curvilinear response of growth to intake. By comparison, those shrimp fed the HSD diet had a relatively linear growth response to intake.     

中国花鲈幼鱼的耐流特性

目的探究中国花鲈幼鱼的游泳能力,以及流速对中国花鲈幼鱼游泳行为的影响。方法以体长为(9.61±0.74) cm的中国花鲈为对象,使用鱼类行为实验循环水槽,测试了其临界游泳速度(U_crit)、爆发游泳速度(U_burst)和续航游泳时间,并研究了14个形态特征与游泳能力的关系。根据鱼类行为学的研究方法,分别分析了中国花鲈在不同流速下的摆尾频率、游泳状态及游泳轨迹。结果中国花鲈的绝对U_crit和绝对U_burst分别为(0.69±0.05) m/s和(0.86±0.05) m/s,相对U_crit和相对U_burst分别为(7.12±0.40) BL/s和(9.09±0.48) BL/s (BL为实验鱼的体长,BL/s为实验鱼每秒游过的体长倍数)。当流速为0.6 m/s时,中国花鲈的续航游泳时间为(200.83±45.73) min,流速达到0.7 m/s时这一时间大幅下降。除第一背鳍长、第二背鳍长、腹鳍长、尾鳍长与绝对U_burst无显著相关性外,绝对U_crit和绝对U_burst与其他形态特征均呈显著正相关。摆尾频率与流速呈显著正相关;当流速大于等于4 BL/s时,中国花鲈的游泳状态、游泳轨迹均产生了显著变化。结论根据游泳能力研究结果判断,在进行放养时,除体长外,可以选择尾长、头长、躯干长等局部形态特征指标为确定游泳能力的依据;中国花鲈幼鱼养殖设施内的流速上限不应超过6.24 BL/s,若考虑到流速对其行为的具体影响,养殖设施内的流速应控制在4 BL/s以内。     

中国花鲈幼鱼耐流特性研究

[目的]探究中国花鲈幼鱼的游泳能力,以及流速对中国花鲈幼鱼游泳行为的影响。[方法]本研究以体长为(9.61±0.74) cm的中国花鲈为研究对象,使用鱼类行为实验循环水槽,测试了其临界游泳速度(Ucrit)、爆发游泳速度(Uburst)和续航游泳时间,并研究了14个形态特征与游泳能力的关系。根据鱼类行为学的研究方法,分别分析了中国花鲈在不同流速下的摆尾频率、游泳状态及游泳轨迹。[结果]中国花鲈的绝对Ucrit和绝对Uburst分别为(0.69±0.05) m/s和(0.86±0.05) m/s,相对Ucrit和相对Uburst分别为(7.12±0.40) BL/s和(9.09±0.48) BL/s (BL为实验鱼的体长,BL/s为实验鱼每秒游过的体长倍数)。当流速为0.6 m/s时,中国花鲈的续航游泳时间为(200.83±45.73) min,流速达到0.7 m/s时这一时间大幅下降。除第一背鳍长、第二背鳍长、腹鳍长、尾鳍长与绝对Uburst无显著相关性外,绝对Ucrit和绝对Uburst与其他形态特征均呈显著的正相关。摆尾频率与流速呈显著正相关;当流速大于等于4 BL/s时,中国花鲈的游泳状态、游泳轨迹均产生了显著变化。[结论]根据游泳能力研究结果判断,在进行放养时,除体长外,可以选择尾长、头长、躯干长等局部形态特征指标为确定游泳能力的依据;中国花鲈幼鱼养殖设施内的流速上限不应超过6.24 BL/s,若考虑到流速对其行为的具体影响,养殖设施内的流速应控制在4 BL/s以内。     

Upstream passage of fish through a vertical-slot fishway in an Australian subtropical river

The effectiveness of a vertical-slot fishway on the Burnett River barrage for facilitating migration of fish was assessed. In 100 samples taken at the top and bottom of the fishway, over 52 000 fish representing 34 species were collected at a maximum rate of 4500 fish per day. In contrast, less than 2000 fish ascended the original pool-and-weir fishway in 128, 24 h samples at the top between 1984 and 1987. Juvenile size classes dominated the abundance of many species in the present study and fish between 24 and 930 mm in length ascended the vertical-slot fishway. However, passage of small fish was restricted and for new fishways on tidal barriers a further reduction in head loss between pools is recommended. Importantly, the width of the vertical-slots was too small for effective upstream passage of large Queensland lungfish, Neoceratodus forsteri (Krefft). The greatest diversity of fish species was found during low river flows. The findings suggest that vertical-slot fishways with wide pools and low turbulence pass a diverse range of fish fauna present in subtropical coastal rivers.     

基于Ecopath模型的海州湾三疣梭子蟹增殖生态容量研究

为科学开展生态型增殖放流,对海州湾海域三疣梭子蟹(Portunus trituberculatus)开展生态容量评估。根据2018-2019年海州湾渔业资源调查数据,构建了由20个功能群组成的海州湾生态系统Ecopath模型,并对模型进行了不确定性及参数敏感性分析检验,系统分析了生态系统的总体特征、功能群间的营养关系和关键功能群,并评估了三疣梭子蟹的增殖生态容量。结果表明,Ecopath模型可信度Pedigree指数为0.482。三疣梭子蟹目前不是海州湾生态系统的关键功能群,其他底层鱼类、软体动物(Molluscs)以及底栖甲壳类(Benthic crustaceans)是海州湾生态系统的关键功能群。三疣梭子蟹生物量的增加对棘头梅童鱼(Collichthys lucidus)以及其他中上层鱼类产生正影响,对底层鱼类以及小黄鱼(Larimichthys polyactis)产生负影响;虾虎鱼科(Gobiidae)、口虾蛄(Oratosquilla oratoria)生物量的增加对三疣梭子蟹有较大负影响,多毛类(Polychaetes)生物量的增加对三疣梭子蟹有较大正影响。三疣梭子蟹的增殖...