University of Technology, Sydney. Faculty of Science. / In the last 100 years there have been dramatic declines in the range and abundance of native freshwater fish in south-eastern Australia. These declines have been attributed to habitat loss and degradation (including river regulation, water quality, erosion/siltation, instream cover and riparian vegetation), alien fish species, overfishing, and the obstruction of fish passage. In south-eastern Australia there are 86 species of freshwater fish and 36 of these have some migratory component of their life history that requires free passage along streams. The migrations of these fish in this region have been inhibited or prevented by the existence of more than 1500 dams and weirs. To mitigate this impact there are only 69 fishways. Most of these fishways are based on designs suitable for the swimming ability and behaviour of salmonids from the Northern Hemisphere. There are, however, no native salmonids in Australia. I assessed one of these salmonid fishways, at Euston on the Murray River, for its suitability for passing native fish. Fish were trapped at the top and bottom of the fishway over eight paired days. Although this fishway has one of the lowest slopes of the older fishways, and therefore potentially one of the easiest to ascend, very few of the fish that entered the fishway could get to the top. For example, 777 +/- 238 [x +/- s.e.] golden perch (Macquaria ambigua) per day entered the fishway but only 4 +/- 2 per day were collected at the top of the fishway. This and other data highlighted two points: i) the ineffectiveness of the salmonid-type fishways for native fish; and ii) assessing fishways by counting fish at the top only, although widely used throughout the world, is insufficient to assess the performance of a fishway. Counts of fish from the top of a fishway can, however, be useful to monitor fish populations over time. An excellent example of this is provided by long-term monitoring of the Euston fishway, which shows massive declines in the upstream movements of silver perch (Bidyanus bidyanus), Murray cod (Maccullochella peelii peelii) and Macquarie perch (Macquaria australasica) between 1940-45 and 1987-90, indicating corresponding declines in the populations of these species. The failure of salmonid fishways for non-salmonid fishes has been a common experience throughout the world. It stems partly from a lack of knowledge of the migratory patterns of non-salmonid fish, and from a lack of quantitative experimental research into the swimming ability and behaviour of these fish in fishways. To redress this situation for south-eastern Australia, I tested fish in experimental fishways in a hydraulics laboratory. The fishway design tested was the vertical-slot fishway, which is a pool-type fishway where water flows between each pool via a vertical slot. The design was considered to potentially suit the hydrology of Australian rivers and the behaviour of native fish. For these experiments I selected fish species and life stages representative of the migratory fish fauna of the two major drainages of south-eastern Australia. For the south-eastern coastal rivers I chose juvenile Australian bass (Macquaria novemaculeata)[mean lengths of 40, 64 and 93 mm] and barramundi (Lates calcarifer) [43 mm]. These two species are catadromous, with the adults migrating downstream to the estuary to breed and the juveniles migrating upstream. For the large inland Murray-Darling river system I chose adult golden perch (Macquaria ambigua) [441 mm] and silver perch(Bidyanus bidyanus) [258 mm]. At the beginning of this study, adults of these two species were considered to be the main life stage migrating upstream. In the laboratory experiments fish were tested at different water velocities and probit analysis was applied to the proportion of fish that negotiated these velocities. I used this approach to produce values which I called the NV90 and the NV95, which are the maximum water velocities that 90% and 95% of the fish could negotiate in the fishway. For bass, barramundi and golden perch these values ranged from 0.7 to 1.8 m s-1. These values are well below the standard maximum water velocity for salmonid fishways of 2.4 m s-l. The silver perch results were too variable to analyse. The data obtained from the laboratory experiments were used by water resource agencies to build eight new vertical-slot fishways in coastal and inland rivers of southeastern Australia. One of the largest of these new fishways was at Torrumbarry Weir on the Murray River, which consists of 38 pools, each 3 m long, ascending a 6.5 m high weir. The fishway, if successful, would provide access to 350 km of habitat above the weir. To determine whether or not the fishway was successful in passing native migratory fish it was assessed for 2.5 years by: i) sampling monthly above and below the fishway with a standard set of independent, replicated nets; and ii) sampling within the fishway. The netting showed that there were major aggregations of migratory fish below the weir when the fishway was not operational. However, when the fishway was completed and operational, 13 months after the commencement of sampling, there were no further major aggregations of migratory fish below the weir. These data, combined with high numbers of fish successfully ascending the fishway, indicated the success of this vertical-slot fishway design. It was estimated that from February 1991 to June 1993 20,7 14 native fish and 16,595 alien fish (all carp [Cyprinus carpio]) had successfully ascended the fishway. Sampling at the top and bottom of the fishway showed that the fishway passed almost all the species and sizes classes of native migratory fish, except for Australian smelt (Retropinna semoni). The latter is a small species 15 to 40 mm long that only entered the lower few pools of the fishway. The widespread distribution of this species indicates the migration is facultative. Experiments within the fishway showed that the laboratory experiments had underestimated swimming ability. However, it was discovered that fish still needed over 1.5 hours to ascend the full length of the fishway. In addition, some species only migrated upstream during daylight and if their ascent of the fishway was not completed in daylight the fish moved back down the fishway. I concluded that the original water velocity criterion from the laboratory experiments was appropriate and that future fishways need to consider ascent time and fishway length as well as water velocity. I also concluded that it is more difficult to obtain realistic results from 'off-site' experiments, where fish are transported to a laboratory or other facility, than from in situ experiments where naturally migrating fish are used and are not handled until the end of the experiment. Sampling at Torrumbarry Weir provided detailed information on the biology of the migratory fish species, which is essential to designing effective fishways. Carp(Cyprinus carpio), an introduced or alien species, and bony herring were newly identified as migratory, and golden perch and silver perch were confirmed as migratory. A major finding was that 95% of golden perch and 87% of silver perch moving upstream were immature fish. Previously the upstream movement of immature fish in this river system was considered insignificant. Fortunately the conservative water velocities in the Torrumbarry fishway accommodated these smaller fish(approximately 100 to 300 mm in length). The reason for the large numbers of immature fish migrating upstream is not clear, but it may be to optimise feeding, enhance colonisation, or to compensate for the downstream drift of the pelagic eggs and larvae. Migration of all species was seasonal. Spring, summer and early autumn were the main periods of upstream movement for native fish, and carp moved upstream in spring and early summer. Migration of carp was stimulated by rising water temperature only, but golden perch and silver perch were stimulated to move upstream by small changes in river levels. This small scale variation in streamflow is frequently suppressed by river regulation, and this is likely to have contributed to the significant decrease in the numbers of migrating native fish. Upstream migration of all species often occurred during low flows, as well as higher flows. This also occurs in coastal rivers of southeastern Australia. For both the coastal and inland rivers of this region it will be important to design fishways and environmental flow releases to accommodate this aspect of fish migration and the often semi-arid hydrology of these streams. Golden perch and silver perch were aged using sagittal otoliths and validated using known-age fish. The data showed that the immature fish were all over one year old, suggesting that younger fish are not migrating upstream. More research is needed to determine the location and habitats of the less than one year old fish. Ageing and examination of gonads indicated the size and age at maturity for these fish. This suggested that minimum size limits currently used to regulate the recreational fishery are not allowing fish to reach maturity. Golden perch and silver perch were found to be long-lived fish, up to 26 and 27 years respectively. Interestingly, samples of these two species from other rivers within the Murray-Darling river system show that the maximum sizes of these fish can vary significantly between rivers, suggesting that the ecology of different rivers within this large river system varies considerably. The development of fishways for non-salmonid fishes throughout the world has frequently met with failure. From the work in the present study and from reviewing other work I suggest there are five steps for the development of effective fishways. 1. Determine which fish species are migratory: - it is important to identify the smallest and largest fish that are migratory, as this affects the initial choice of the size of the fishway to test. 2. Test fish in an experimental fishway: - in situ experiments are recommended; - avoid handling of fish before and during experiments. 3 Design the fishway: - first decide on the location of the fishway entrance; - extrapolate research results with caution; - do not reduce pool sizes from the experimental model; - avoid tunnels; - design the fishway to operate over the full range of flows during which fish migrate. 4. Link the fishway with the operation of the dam or weir: - maintain flow and temperature regimes that stimulate migration; - manage flow releases over the spillway to guide fish to the fishway entrance. 5. Assess the fishway: - use quantitative and relevant performance criteria to assess the fishway and not only counts of fish from the top of the fishway. The most common strategy in the past has been to design the fishway and ignore steps 1, 2, 4 and 5. With fishways being increasingly recognised as important tools in the rehabilitation of aquatic biota in temperate river systems, and as a potential tool in the development of water resources in tropical rivers, it is essential that they are appropriately designed, constructed, and assessed. Otherwise the mistakes of the past will very likely be repeated.

Diss. Luleå : Luleå tekniska universitet, 2008. / Härtill 6 uppsatser.

Thesis (M.S. in civil engineering)--Washington State University, December 2006. / Includes bibliographical references (p. 198-208).

Thesis (M.S.)--Montana State University--Bozeman, 2007. / Typescript. Chairperson, Graduate Committee: Thomas E. McMahon. Includes bibliographical references (leaves 58-63).

Abstract In this thesis, I examine two important aspects surrounding salmonid reproductive ecology, namely: (i) the problems with passing obstructions during migratory spawning runs and (ii) how the early life stages in boreal streams are influenced by increased levels of fine-grained particulate matter from drained peatlands. These aspects are not only critical to salmonid reproductive success but have grave implications regarding environmental quality and species conservation. Spawning runs can be re-established by constructing fishways at obstructions but the efficiency of fishways depends on several factors. The passage of multi-sea-winter salmon was enhanced in the Isohaara fishway by increasing its water flow and by creating a small waterfall at the entrance. The fishway, which consists of vertical slot and Denil sections, proved to be unsuitable for most freshwater fish, whitefish and river lamprey, whereas salmonids, once they had entered, successfully negotiated the fishway. In fishway design, the migratory behaviour and the demands of the species of interest should be considered. For salmonids, priority should be given to the attractiveness of the fish entrance. When there is a migration corridor, the availability and the quality of spawning and rearing habitats has a major effect on the success of restoration projects. In the humic rivers studied, the survival of incubated brown trout eggs was lower in riffles susceptible to increased levels of fine-grained particulate matter from drained peatlands. Additionally, an increase in the Fe content of high molecular weight dissolved organic matter followed by its precipitation and sedimentation was proposed to be involved. Correspondingly, the recapture rates of stocked yearling salmon were lower in the affected riffles, individual salmon being smaller and thinner and having less food in their stomachs than reference salmon. Based on these results, it seems probable that peatland drainage, by influencing the incubation success of salmonid embryos and the foraging, growth and survival of juveniles, eventually affects the number and quality of smolts produced. In future, such water pollution control measures should be implemented that would enhance the success of natural spawning and help ensure environmental quality.

Fishways are devices that are increasingly being used worldwide to assist aquatic biofauna to migrate through man-made barriers such as weirs and large-scale dams that are used for water storage, electricity generation etc. and have a negative impact on both the upstream and downstream movement of aquatic organisms. Fishways are usually low gradient channels with evenly placed chambers which allow such migrating aquatic species minimal stress on their passage over these barriers. Despite the existence of national and regional policies for their provision, their construction has often been inhibited through a lack of local assessment of the available designs, and use of ineffective international designs. As part of a larger national research programme, sponsored by the Water Research Commission, to develop a protocol for fishway design and implementation, this study sought to investigate the suitability of vertical slot and sloping baffle designs to assist the migrations of juvenile catadromic fish species in the ebb and flow region of rivers in the Eastern Cape, South Africa. These fishways were initially tested under controlled conditions at the Experimental Fish Farm at the Department of Ichthyology and Fisheries Science, Rhodes University using various fish species. Using the performance data thus collected they were then installed and monitored in the field for the catadromic Myxus capensis (freshwater mullet) and Monodactylus falciformis (cape moony) migrations during March and November of 2005 at the Kowie River ebb and flow weir. The laboratory tests showed that there was a significantly higher level of migration success in the vertical slot compared with the sloping baffle fishway under all conditions (F=82.157; p<0.001). There was, however, a slow decline in levels of success with increased discharge in the vertical slot fishway. This was in contrast to the sloping baffle design where success increased as discharge increased at a steep gradient (F=74.894; p<0.005). The level of success with the M. capensis was related to the size of the fish for both systems with success increasing from the small to the large fish (F=17.755; p<0.001). For the M. falciformis higher levels of success were found to occur in the vertical slot fishway compared to the sloping baffle fishway (F=11.792; p<0.00086), with no significant differences being found with an increase in discharge. Field data indicated similar trends with higher migration success using the vertical slot fishway. M. capensis were better able to negotiate both devices compared to the M. falciformis and overall levels of success were higher for both species in the field than under laboratory conditions where the migration urge may have declined.

Corrugated steel pipe (CSP) culverts are widely used as an economical alternative for conveying streams and small rivers through road embankments. While passage of the design flow is generally the primary goal for culvert design, consideration must also be given to maintaining connectivity within the aquatic environment for fish and other aquatic organisms. In Canada, the design criteria for fish passage through culverts are generally specified in terms of a maximum mean flow velocity corresponding to the weakest swimming fish expected to be found at a specific location. Studies have shown, however, that the velocity distribution within a CSP culvert may provide sufficient areas of lower velocity flow near the culvert boundary to allow for fish passage, even when the mean flow velocity may exceed a fishs swimming ability. Improved knowledge of the hydraulic conditions within CSP culverts, combined with research into fish swimming capabilities and preferences, may make it possible to better tailor culvert designs for fish passage while at the same time decreasing construction costs. To meet the requirements of regulators, various measures may be taken to reduce culvert flow velocities. Embedding, or setting the invert of a culvert below the normal stream bed elevation, is a simple and inexpensive method of increasing the flow area in a culvert flowing partially full, thereby decreasing flow velocity. Fish traversing through an embedded culvert benefit not only in terms of lower mean flow velocities, but also even lower flow velocities in the near boundary region. In the province of Saskatchewan culvert embedment is regularly used as a means to improve fish passage conditions. In this study, a laboratory scale model was used to study the velocity distribution within a non-embedded and embedded CSP culvert. An acoustic Doppler velocimeter was used to measure point velocities throughout the flow cross section at several longitudinal locations along the culvert. The hydraulic conditions were varied by changing the discharge, culvert slope and depth of embedment. The point velocity data were analyzed to determine patterns of velocity and turbulence intensity at each cross section, as well as along the length of the culvert. The results from the embedded culvert tests were compared with the results from the equivalent non-embedded tests, so that initial conclusions could be made regarding the use of embedment to improve conditions for fish passage. Analysis of the cross section velocity distributions showed that, even the non-embedded culvert had a significant portion of the flow area with flow velocity less than the mean velocity. The results from the embedded tests confirmed that embedding the culvert reduced the flow velocity throughout each cross section, although the effect was most significant for the cross sections located greater than one culvert diameter downstream from the inlet. This variation in effectiveness of embedment at reducing flow velocities is attributed to the length of the M1 backwater profile relative to the culvert length, and thus the differential increase in flow depth that occurred at each measurement location along the culvert. For both the non-embedded and embedded culvert the peak point magnitudes of turbulence intensity were found to be located near the culvert inlet where the flow was contracting. In terms of the cross section average turbulence intensity, in the non-embedded culvert turbulence increased with distance downstream from the inlet and was highest at the cross sections located near the culvert outlet. Embedding the culvert was found to either have no impact, or to slightly increase, the cross section average turbulence intensity near the inlet. Again, a result that is attributed to the tapering out of the M1 backwater profile at locations near the inlet under the flow conditions tested. However, beyond eight culvert diameters downstream from the inlet, embedment did result in lower cross section average turbulence intensity when compared to the non-embedded culvert. The measured velocity profiles for the non-embedded tests were found to compare well to the theoretical log-law velocity distribution using a ks value of between 0.012 m and 0.022 m, or approximately one to two times the corrugation amplitude, when the datum for analysis was considered to be located at the crest of the pipe corrugation. The cross section velocity distributions for the non-embedded tests compared very well to the model proposed by Ead et al. (2000). Based on this assessment, it appears that the Ead et al. model is potentially suitable for use in predicting the amount of the cross sectional area in a non-embedded culvert with flow velocity less than the design target for culvert fish passage design purposes. Overall, the results of the study confirm that, embedding a CSP culvert may be an effective way to improve fish passage conditions in terms of both flow velocity and turbulence intensity.

Corrugated steel pipe (CSP) culverts are widely used as an economical alternative for conveying streams and small rivers through road embankments. While passage of the design flow is generally the primary goal for culvert design, consideration must also be given to maintaining connectivity within the aquatic environment for fish and other aquatic organisms. In Canada, the design criteria for fish passage through culverts are generally specified in terms of a maximum mean flow velocity corresponding to the weakest swimming fish expected to be found at a specific location. Studies have shown, however, that the velocity distribution within a CSP culvert may provide sufficient areas of lower velocity flow near the culvert boundary to allow for fish passage, even when the mean flow velocity may exceed a fishs swimming ability. Improved knowledge of the hydraulic conditions within CSP culverts, combined with research into fish swimming capabilities and preferences, may make it possible to better tailor culvert designs for fish passage while at the same time decreasing construction costs. To meet the requirements of regulators, various measures may be taken to reduce culvert flow velocities. Embedding, or setting the invert of a culvert below the normal stream bed elevation, is a simple and inexpensive method of increasing the flow area in a culvert flowing partially full, thereby decreasing flow velocity. Fish traversing through an embedded culvert benefit not only in terms of lower mean flow velocities, but also even lower flow velocities in the near boundary region. In the province of Saskatchewan culvert embedment is regularly used as a means to improve fish passage conditions. In this study, a laboratory scale model was used to study the velocity distribution within a non-embedded and embedded CSP culvert. An acoustic Doppler velocimeter was used to measure point velocities throughout the flow cross section at several longitudinal locations along the culvert. The hydraulic conditions were varied by changing the discharge, culvert slope and depth of embedment. The point velocity data were analyzed to determine patterns of velocity and turbulence intensity at each cross section, as well as along the length of the culvert. The results from the embedded culvert tests were compared with the results from the equivalent non-embedded tests, so that initial conclusions could be made regarding the use of embedment to improve conditions for fish passage. Analysis of the cross section velocity distributions showed that, even the non-embedded culvert had a significant portion of the flow area with flow velocity less than the mean velocity. The results from the embedded tests confirmed that embedding the culvert reduced the flow velocity throughout each cross section, although the effect was most significant for the cross sections located greater than one culvert diameter downstream from the inlet. This variation in effectiveness of embedment at reducing flow velocities is attributed to the length of the M1 backwater profile relative to the culvert length, and thus the differential increase in flow depth that occurred at each measurement location along the culvert. For both the non-embedded and embedded culvert the peak point magnitudes of turbulence intensity were found to be located near the culvert inlet where the flow was contracting. In terms of the cross section average turbulence intensity, in the non-embedded culvert turbulence increased with distance downstream from the inlet and was highest at the cross sections located near the culvert outlet. Embedding the culvert was found to either have no impact, or to slightly increase, the cross section average turbulence intensity near the inlet. Again, a result that is attributed to the tapering out of the M1 backwater profile at locations near the inlet under the flow conditions tested. However, beyond eight culvert diameters downstream from the inlet, embedment did result in lower cross section average turbulence intensity when compared to the non-embedded culvert. The measured velocity profiles for the non-embedded tests were found to compare well to the theoretical log-law velocity distribution using a ks value of between 0.012 m and 0.022 m, or approximately one to two times the corrugation amplitude, when the datum for analysis was considered to be located at the crest of the pipe corrugation. The cross section velocity distributions for the non-embedded tests compared very well to the model proposed by Ead et al. (2000). Based on this assessment, it appears that the Ead et al. model is potentially suitable for use in predicting the amount of the cross sectional area in a non-embedded culvert with flow velocity less than the design target for culvert fish passage design purposes. Overall, the results of the study confirm that, embedding a CSP culvert may be an effective way to improve fish passage conditions in terms of both flow velocity and turbulence intensity.

Thesis (doctoral)--Swedish University of Agricultural Sciences, 2005. / Thesis documentation sheet inserted. Appendix includes six papers and manuscripts co-authored with others. Also issued electronically via World Wide Web in PDF format; online version lacks appendix of papers.

The Swedish national plan for reapproval of hydropower describes that hydropower plants (HPPs) are required to be reassessed to ensure that modern environmental conditions are set for the permits. Since dams and HPPs create barriers for migrating fish and consequently disfavor biological diversity, one consequence of the national plan is that fishways are being constructed. This, in combination with an old, unfinished approval procedure from the 1960’s, resulted in the construction of three up- and downstream fishways in Mora municipality, at the HPPs in Spjutmo, Blyberg and Väsa. To fulfill requirements in regard to the fishway’s incline and safety, but at the same time minimize the need of space, the fishways have new, innovative and not yet tested design features. One of these features is the “parking garage” layout of the upstream fishway. Despite these features, the fishways take up a large amount of space and thus require large amounts of blasting, excavation and materials such as concrete and steel parts. These are climate impact influence intensive procedures and materials, but the construction has so far not been evaluated from a climate impact perspective. This, in combination with a lack of studies on the climate impact of fishways, has resulted in this project.The aim of this project was to examine the climate impact caused by the fishways in Spjutmo and Blyberg, to identify what affects the total climate impact as well as providing measures that could reduce the climate impact for future similar fishways. To provide an extensive overview of the climate impact that the fishways cause during their entire lifetime, the method life cycle analysis (LCA) was used. The construction of the fishways at Väsa HPP starts later than for Spjutmo and Blyberg, and therefore Väsa is excluded from the scope due to the lack of required information.The fishways in Spjutmo and Blyberg have the same design features, but the material consumptions differ due to their differences in head. Spjutmo’s head is 21,4 meter and Blyberg’s is 11 meter. A larger head generally results in a longer fishway which in turn results in a more material consuming construction. This resulted in the total life cycle climate impact being twice as big for Spjutmo as for Blyberg, 2 807 tonne CO2-eq respectively 1 361 tonne CO2-eq. The resource extraction is the LCA- phase that contributes the most. Concrete and its reinforcement have the biggest share of that impact, followed by mechanical parts and other steel products, road construction process in Spjutmo and the excavation process in Blyberg. Based on this result, it can be concluded that the materials and components contribute more to the fishways’ total climate impact, rather than processes. Roughly 80 % of the total climate impact origins from the upstream fishway, while the rest either stems from the downstream fishway or others. Sensitivity analyses include the climate impact caused by the fishways using some water that otherwise could have been used to generate electricity from, and the result indicates that all examined alternative energy sources would result in larger climate impact compared to if the electricity was generated by hydropower.One of the result’s uncertainties is that the fishways were under construction while this project was performed. Therefore some assumptions was made to compensate for lack of data. For example, the future electricity consumption was scaled up based off the then used electricity data. However, even if some amounts of required materials and processes changed as time went by, the changes did not make a significant difference from the bigger perspective. Sensitivity analyses that examined the climate impact of a delay in the construction also showed that the processes that are most likely to continue turned out to have a relatively small climate impact. Thus, this issue might not be as problematic as initially thought.Although the result is presented in total values, the result is also provided per a functional unit (FU) level in accordance with traditional LCA methodology. This was to facilitate a comparison for future LCAs on other fishways. The FU in this project was decided to be “One meter head for a technical, stationary, up- and downstream fishway in connection to a medium or large run-of-river hydropower plant in a cold tempered climate zone”. For future studies, LCAs on different types of fishways using the proposed FU is recommended.