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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The role of fish physiology, behaviour, and water discharge on the attraction and passage of adult sockeye salmon (Oncorhynchus nerka) at the Seton River dam fishway, British Columbia

Pon, Lucas Benjamin 05 1900 (has links)
In many rivers, dams have interrupted the connectivity of migration routes for fish. While fishways can provide access between downstream and upstream habitats, it is important that passage can occur with minimal delay, energy expenditure, and physiological stress. The research presented here is based on investigations into fishway attraction and passage for the Gates Creek sockeye salmon (Oncorhynchus nerka, Walbaum) stock at the Seton River dam in British Columbia. The first part of this thesis examined the effect of changes in water discharge from the dam on the relationship between the physiological condition of sockeye and their behaviour in approaching the fishway entrance. Fish were caught and non-lethally biopsied under three normal operating discharge conditions at Seton River dam, and subsets of sampled fish were implanted with radio transmitters and released downstream of the dam. Indices of physiological stress and exhaustive exercise (e.g. plasma cortisol, glucose, lactate, osmolality and hematocrit) did not differ among the water discharge levels that were examined. Fish delayed in the tailrace below the fishway entrance significantly longer under intermediate discharge (19.9 h @ 12.7 m³s‾¹) than either the high discharge (9.3 h @ 15.8 m³s‾¹), or the low discharge (7.0 h @11.0 m³s‾¹;) conditions (P = 0.022, and P = 0.015, respectively). Delay time was similar under high and low discharge conditions (P = 0.617), and passage success was found to be independent of discharge (P = 0.356). The second part of this thesis investigated how prior physiological condition and subsequent swimming energetics and behaviours effected fishway passage success. Fish were captured and biopsied, before being implanted with electromyogram (EMG) transmitters and released near the downstream entrance of the fishway. Very few differences existed between successful and unsuccessful fish in body size, initial plasma physiology and energy state, and mean swim speed and energy use during passage. However, plasma Na+ concentration was significantly lower in unsuccessful fish (P = 0.022), which is suggestive of a depressed ionic state for unsuccessful fish. Generally, fish did not employ burst swimming during successful or failed attempts at passage, indicating that failure was probably not related to metabolic acidosis.
2

Beteende hos lekvandrande lax i Klarälven – utvärdering av en fiskfälla / Behaviour of the migrating salmon in the river Klarälven - evaluation of a fish trap

Wolfbrandt, Jeanette January 2014 (has links)
During the migration season in 2013 a study on spawning migrating salmon and the effect of water flow on the behavior was conducted of the salmon at the Forshaga hydropower station in the River Klarälven. The River Klarälven with its nine hydropower plants on the Swedish side, constituting migration obstacles for the migrating salmon. Fortum Generation AB has together with the County Administrative Board restored a salmon trap at the lowermost hydropower station in Forshaga, aiming at making it possible for the salmon to swim into the trap, and thereafter be transported by truck past the power plants and then continue their journey to the spawning grounds on their own. Unfortunately, it is believed that the trap does not work as well as it should. In this study, I focused on salmon position in relation to water flow and if the number of salmon that swam into the fish trap differed between salmon with previous experience of the trap (experienced) and salmon without experience (unexperienced). My results showed that there were significantly more inexperienced salmon that entered the trap than experienced salmon. The salmon, regardless of experience, chose a position where the flow was highest. To increase catches of salmon in the fish trap I suggest that one use more attraction water and keep the trap open more hours. My results should be of interest to managers as the trap efficiency has never been evaluated, and no earlier studies about the effect of salmon experience on trap efficiency exist. / Vandringssäsongen 2013 genomfördes en studie på lekvandrande lax och hur vattenflödet påverkade laxens beteende vid Forshaga kraftstation i Klarälven. Klarälven med dess 9 vattenkraftverk på den svenska sidan utgör vandringshinder för den lekvandrande laxen. Fortum har tillsammans med Länsstyrelsen renoverat en laxfälla i det mest nedströms liggande kraftverket i Forshaga. Syftet med fällan är att laxen ska simma in i fällan till en uppsamlingsbassäng och därefter köras med lastbil förbi kraftverken, för att därefter fortsätta vandringen på egen hand. Fiskfällans effektivitet är ifrågasatt och man vet inte hur effektiv den är. I denna studie fokuserade jag på laxens ståndplats i relation till varifrån det huvudsakliga flödet kom, samt om antalet laxar som simmar in i fiskfällan skiljde sig mellan lax med tidigare erfarenhet av fällan (erfaren) och lax utan erfarenhet av fällan (oerfaren). Mina resultat visade att det var signifikant fler oerfarna laxar än erfarna laxar som simmade in i fällan. Laxen, oavsett erfarenhet, valde ståndplats där flödet var som högst. För att öka fångsterna av lax i fiskfällan skulle mer lockvatten och fler timmar då fällan är öppen kunna bidra med mer fångst. Denna studie borde vara av intresse för inblandade aktörer i laxens förvaltning eftersom fällans effektivitet aldrig utvärderats tidigare, och dessutom har man inte studerat om tidigare erfarenhet av en fälla påverkar laxen.
3

The role of fish physiology, behaviour, and water discharge on the attraction and passage of adult sockeye salmon (Oncorhynchus nerka) at the Seton River dam fishway, British Columbia

Pon, Lucas Benjamin 05 1900 (has links)
In many rivers, dams have interrupted the connectivity of migration routes for fish. While fishways can provide access between downstream and upstream habitats, it is important that passage can occur with minimal delay, energy expenditure, and physiological stress. The research presented here is based on investigations into fishway attraction and passage for the Gates Creek sockeye salmon (Oncorhynchus nerka, Walbaum) stock at the Seton River dam in British Columbia. The first part of this thesis examined the effect of changes in water discharge from the dam on the relationship between the physiological condition of sockeye and their behaviour in approaching the fishway entrance. Fish were caught and non-lethally biopsied under three normal operating discharge conditions at Seton River dam, and subsets of sampled fish were implanted with radio transmitters and released downstream of the dam. Indices of physiological stress and exhaustive exercise (e.g. plasma cortisol, glucose, lactate, osmolality and hematocrit) did not differ among the water discharge levels that were examined. Fish delayed in the tailrace below the fishway entrance significantly longer under intermediate discharge (19.9 h @ 12.7 m³s‾¹) than either the high discharge (9.3 h @ 15.8 m³s‾¹), or the low discharge (7.0 h @11.0 m³s‾¹;) conditions (P = 0.022, and P = 0.015, respectively). Delay time was similar under high and low discharge conditions (P = 0.617), and passage success was found to be independent of discharge (P = 0.356). The second part of this thesis investigated how prior physiological condition and subsequent swimming energetics and behaviours effected fishway passage success. Fish were captured and biopsied, before being implanted with electromyogram (EMG) transmitters and released near the downstream entrance of the fishway. Very few differences existed between successful and unsuccessful fish in body size, initial plasma physiology and energy state, and mean swim speed and energy use during passage. However, plasma Na+ concentration was significantly lower in unsuccessful fish (P = 0.022), which is suggestive of a depressed ionic state for unsuccessful fish. Generally, fish did not employ burst swimming during successful or failed attempts at passage, indicating that failure was probably not related to metabolic acidosis.
4

Efetividade da escada para peixes de uma barragem no rio Paraná para duas espécies migradoras neotropicais / Effectiveness of the fish ladder at a dam in the paraná river for two neotropical migratory species

Gutfreund, Carola 18 April 2017 (has links)
Submitted by Edineia Teixeira (edineia.teixeira@unioeste.br) on 2018-04-13T14:51:51Z No. of bitstreams: 2 Carola_Gutfreund2017.pdf: 2632451 bytes, checksum: 73a0a3864936cf1f3347866fcda5f49f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-04-13T14:51:51Z (GMT). No. of bitstreams: 2 Carola_Gutfreund2017.pdf: 2632451 bytes, checksum: 73a0a3864936cf1f3347866fcda5f49f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-04-18 / Large hydroelectric dams along the Paraná River have caused severe impacts on fish communities as they represent obstacles to long-range migratory species that need to migrate to complete their life cycle. Dams can bring numerous problems through the interception of migratory routes and reduction of spawning areas. The most common measures used to mitigate the effect of these physical obstacles is the implementation of fish ladders. It is not only important to implement these structures, but also to monitor them. This study was performed at the Engenheiro Sergio Motta Hydroelectric Power plant in the Upper Paraná River during December/2012 and March/2016. The aim of it was to evaluate the effectiveness of this structure in relation to the attractiveness rate and passage efficiency of to two Neotropical fish species in the fish ladder. In total, 563 fish of genus Leporinus (447 Leporinus obtusidens and 116 Leoporinus piavussu) were tagged and released with the implementation of 32-mm programmable transponders (PIT-tags). Radio Frequency Identification (RFID) was used to monitor the system. The attractiveness of the ladder was 8.7%. The minimum time to find it was 1.49 days for the fish released upstream and the maximum time was 449.86 days for the individuals released downstream. The release site had a significant influence on the entry rate of fish released on the other side of the river. No detection was observed for fish released downstream and upstream on the right bank of the river. Only the fish released on the same site where the fish ladder is located were detected, suggesting low attractiveness of the ladder in relation to the studied species. In the course of this study it was verified that for the two species studied it would be extremely important to increase the attractiveness at the entrance of the ladder, as well as to build a second ladder for fish on the right side of the river. / As grandes hidrelétricas ao longo do Rio Paraná têm causado impactos severos nas comunidades de peixes, pois representam obstáculos para as espécies migradoras de longa distância, que precisam migrar para completar seu ciclo de vida. As barragens podem trazer inúmeros problemas por meio da intercepção das rotas migratórias e redução das áreas de desova. As medidas mais comuns utilizadas para mitigar o efeito desses obstáculos físicos é a implementação de escadas para peixes. Não é somente importante a implementação dessas estruturas, como também o monitoramento. Esse estudo realizado na escada para peixes da Usina Hidrelétrica Engenheiro Sérgio Motta no alto Rio Paraná no período de dezembro/2012 a março/2016 teve como objetivo avaliar a efetividade dessa estrutura em relação a taxa de atratividade e eficiência de passagem para duas espécies de peixes migradores neotropicais. No total, foram marcados e liberados 563 peixes do gênero Leporinus (447 Leporinus obtusidens e 116 Leoporinus piavussu) com a implantação de transponders com códigos programáveis (PIT-tags) de 32 mm. Foi utilizado o sistema de rádio frequência (RFID Radio Frequency Identification) para o monitoramento do sistema. A atratividade da escada foi de 8,7%. O tempo mínimo para encontrar a escada correspondeu a 1,49 dias para os peixes liberados a montante e o tempo máximo foi de 449,86 dias para os indivíduos liberados a jusante. O local de liberação influenciou significativamente a taxa de entrada dos peixes liberados na margem oposta do rio, sendo que nenhuma detecção foi observada para peixes liberados na margem direita, tanto a jusante como a montante. Foram detectados apenas os peixes liberados na mesma margem onde a escada para peixes está localizada, sugerindo baixa atratividade da escada para as espécies analisadas. No decorrer deste estudo verificou-se que para as duas espécies estudadas seria extremamente importante aumentar a atratividade na entrada da escada, como também a construção de uma segunda escada para peixes no lado direito do rio.
5

The role of fish physiology, behaviour, and water discharge on the attraction and passage of adult sockeye salmon (Oncorhynchus nerka) at the Seton River dam fishway, British Columbia

Pon, Lucas Benjamin 05 1900 (has links)
In many rivers, dams have interrupted the connectivity of migration routes for fish. While fishways can provide access between downstream and upstream habitats, it is important that passage can occur with minimal delay, energy expenditure, and physiological stress. The research presented here is based on investigations into fishway attraction and passage for the Gates Creek sockeye salmon (Oncorhynchus nerka, Walbaum) stock at the Seton River dam in British Columbia. The first part of this thesis examined the effect of changes in water discharge from the dam on the relationship between the physiological condition of sockeye and their behaviour in approaching the fishway entrance. Fish were caught and non-lethally biopsied under three normal operating discharge conditions at Seton River dam, and subsets of sampled fish were implanted with radio transmitters and released downstream of the dam. Indices of physiological stress and exhaustive exercise (e.g. plasma cortisol, glucose, lactate, osmolality and hematocrit) did not differ among the water discharge levels that were examined. Fish delayed in the tailrace below the fishway entrance significantly longer under intermediate discharge (19.9 h @ 12.7 m³s‾¹) than either the high discharge (9.3 h @ 15.8 m³s‾¹), or the low discharge (7.0 h @11.0 m³s‾¹;) conditions (P = 0.022, and P = 0.015, respectively). Delay time was similar under high and low discharge conditions (P = 0.617), and passage success was found to be independent of discharge (P = 0.356). The second part of this thesis investigated how prior physiological condition and subsequent swimming energetics and behaviours effected fishway passage success. Fish were captured and biopsied, before being implanted with electromyogram (EMG) transmitters and released near the downstream entrance of the fishway. Very few differences existed between successful and unsuccessful fish in body size, initial plasma physiology and energy state, and mean swim speed and energy use during passage. However, plasma Na+ concentration was significantly lower in unsuccessful fish (P = 0.022), which is suggestive of a depressed ionic state for unsuccessful fish. Generally, fish did not employ burst swimming during successful or failed attempts at passage, indicating that failure was probably not related to metabolic acidosis. / Forestry, Faculty of / Graduate
6

Úprava toku – návrh migrační cesty pro vodní faunu (rybího přechodu) / Adjust the flow - design migration path

Špaček, Jakub January 2013 (has links)
This thesis describes the design of fish ladder on the river Mohelka near the village Chocnějovice. The first section describes the general characteristics of the river-basin and the selected section. It is written introduction to the design, construction and service of the fish ladder. For the task were developed two alternatives. These alternatives were described and compared each other. Included are the input and output data of the given structure modeling using HEC-RAS. The last part is then researched drawings to objects.
7

Revitalizace vybraného úseku vodního toku / Revitalization of the selected section of the River

Bakala, Filip January 2013 (has links)
This thesis deals with revitalization of the selected part of river Drevnice. Main scopes of the work are proposals of fish passages through migration barriers. The work is conceived on four levels. The first of them is dealing with the general characteristics of selected segment and with description of objects on watercourse. The second level is dealing with revitalization, where the basic information about migration and efficiency of fishes are described. In this chapter basic distribution of fish ladders is included. In third part, which is the most comprehensive, I design a boulder fish ramp and bypass channel. The last chapter contains drawings documentation of watercourse Drevnice and my own proposed revitalization elements.
8

Byggandet av fiskvägar och möjligheten för samordning med betongunderhåll

Johansson, Lucas January 2022 (has links)
Många av Sveriges vattenkraftverk drivs med gamla tillstånd. Detta har letttill att regeringen tvingat fram en omprövning av alla elproducerandevattenkraftverk mot miljöbalken och moderna miljövillkor. En av de storaåtgärderna som kommer behöva utföras vid många av anläggningarna för attanpassa kraftverket till moderna miljövillkor är byggnation av fiskvägar.Detta medför en betydande kostnad för verksamhetsutövaren och det blirdärför viktigt att hitta lösningar för att hålla ned dessa kostnader så mycketsom möjligt. Ett sätt att spara pengar är genom samordning mellanbyggandet av fiskväg med det återkommande betongunderhållet. Dennarapport undersöker möjligheterna för denna samordning med fokus på tidenför utförande och hur stor kostnadsökningarna faktiskt blir förverksamhetsutövaren. Det visar sig att över majoriteten av kraftverken haråtgärdsbehov i form av betongrenoveringar som ligger väl i tiden för attsamordnas med byggandet av eventuella fisktrappor. Att upphandla bådaåtgärderna under samma upphandling visar sig ha goda chanser förkostnadsbesparing. / Many of Swedens hydropower constructions operates on old permissions.This have led to a national reconsideration for every hydropower stationwhether or not they operates with modern environmental conditions or not.Interviews suggest that the main action that will be required probably is tobuild fish-ladders. This will be a large cost for the operator and therefore itis important to keep the cost as low as possible. One way of saving money isto bundle different projects to reduce costs. This paper investigates whetheror not bundling between building of fish-ladders and the recurring concretemaintenance would be economically advantageous and prefarable for theowner. The focus is to examine the possibility of bundling in terms of thetime-frame of both the construction of the fish-ladder and the concretemaintenance and check the difference in cost between these two actions.The results suggests that a majority of the examined hydropower-stationshave renovation measures to deal with within the same time-frame as theintended construction of fish-ladders. To bundle the two operations alsoseems like an economically preferable choice.
9

När hjulen slutat snurra : Hur principer för hållbar utveckling appliceras i tillsyn och tillståndsprocesserna för småskaliga vattenkraftverk

Jonsson, Carl January 2016 (has links)
Småskaliga vattenkraftverk har varit en viktig del för landsbygden på många platser runt om i Värmland under en lång tid. Men vad som en gång var en vital del för landsbygdens utveckling är idag något som hotar de naturliga bestånden av fisk och vattenlevande fauna. Småskaliga kraftverk som inte är miljöanpassade står ofta i vägen för att ett vattendrag ska kunna uppnå god ekologisk status enligt EU:s miljömål. Detta görs för att skapa en hållbar utveckling för en hållbar framtid. Men att miljöanpassa ett kraftverk är en process som är mycket utmanande, tidskrävande och dyr för de enskilda kraftverksägarna. Bara processen kan kosta över hundra tusen kronor och då är inte kostnaderna för miljöanpassningarna inräknade. Miljöanpassningarna som ofta utgörs av konstruerandet av fiskvandringsvägar kan uppnå kostnader på flera miljoner kr. Om inte kraftverksägaren kan, vill eller tillåts tillståndsprövas hotas verksamheten av utrivning vilket även det resulterar i dyra kostnader och eventuellt polisanmälan för verksamhetsägaren. Hur än ägarna gör så är de ovilligt satta i situationer där de på ett och ett annat sätt kommer förlora stora summor och utsättas för psykiskt påfrestande processer. Denna uppsats ämnar att kritiskt granska just hur de ekologiska, ekonomiska och sociala principerna i hållbar utveckling vägs mot varandra i tillsyn och tillståndsprocesserna gällande småskaliga vattenkraftverk i Värmland. / Small scale hydropower stations have been a vital part for the rural areas in Värmland, Sweden for a long time. But what once was a vital part for the rural development in the areas is today threatening the natural habitats and species in the rivers. Small scale hydropower stations that are not environmentally adapted often hinder the streams they are in to achieve good ecological status according to the environmental goals set forth by the European Union. This is done so that sustainable development and a sustainable future can be set in motion. But to adapt a small scale hydropower station is no easy feat. It's a highly challenging, expensive and time demanding for the individual owners. The process itself can cost up to several hundreds of thousands in Swedish crowns, and that's without counting the environmental adaptations that might be installed. Fish ladders are often the preferred choice and the cost of constructing one could cost several millions of Swedish crowns. if the owner of the power plant is unable, not willing or not allowed to have his/hers power plant authorized the dam risks being torn down and the owner risk getting charged with criminal activity. Whatever the owners choose to act they are stuck in between a rock and a hard place. They are forced to pay huge sums regardless of the outcome not to speak of the mental strain the processes places upon the owners. This essay aims to critically review how the ecological, economic and social principles of sustainable development are weighed against one another in the oversight process and the permission process regarding small scale hydropower stations.
10

Efetividade da escada para peixes da UHE Engenheiro Sergio Motta - CESP para espécies de peixes migradoras neotropicais / Efetividade da escada para peixes da UHE Engenheiro Sergio Motta - CESP para espécies de peixes migradoras neotropicais / Effectiveness of the fish ladder Engenheiro Sergio Motta Hydroelectric Power Plant - CESP for neotropical migratory fish species / Effectiveness of the fish ladder Engenheiro Sergio Motta Hydroelectric Power Plant - CESP for neotropical migratory fish species

Wagner, Ricardo Luiz 21 December 2010 (has links)
Made available in DSpace on 2017-07-10T18:13:27Z (GMT). No. of bitstreams: 1 Ricardo Luiz Wagner.pdf: 1019072 bytes, checksum: 6377d42be0063e946162dbb8d2ac2332 (MD5) Previous issue date: 2010-12-21 / Transposition systems for fishes at the dam hydroelectric power plants are designed to mitigate impacts, however, it is necessary for these systems to be evaluated and monitored. This study, conducted at the fish ladder of the Engenheiro Sergio Motta Hydroelectric Power Plant - CESP, during the period from November 2009 to April 2010, aimed to analyze the effectiveness of this system, considering two aspects needed for analysis: the rate of attractiveness, and subsequently, the efficiency of the fish ladder. The rate of attractiveness considered the percentage of individuals who found the entry, while the efficiency was calculated from the percentage ascending along the fish ladder through the Ascend Function. The Risk Function was used to identify sites that might hinder the ascent of the species studied. The RFID (Radio Frequency Identification) system was utilized in the study, with the installation of eight antennae along the fish ladder and transponders (PIT tags) of 32mm were implanted in four long-distance migratory fish species. We considered two sites for the release after the tagging: in the first, designated as the ramp, situated approximately 1,100m downstream the entrance to the fish ladder, 757 individuals were tagged, of which 151 were Brycon orbignyanus, 204 Piaractus mesopotamicus, 196 Prochilodus lineatus and 206 Rhinelepis aspera. At the second site, the pool 11 of the ladder, 317 individuals were tagged distributed in 100 P. mesopotamicus, 109 P. lineatus and 108 R. aspera. The results of the attractiveness for individuals released in the ramp were 15.89% for B. orbignyanus, 55.39% for P. mesopotamicus, 7.4% for P. lineatus and 24.73% for R. aspera. The results of the estimates of efficiency whith the use of the Ascend Function were differentiated for part of the species studied. For B. orbignyanus released in the ramp efficiency was 79%. P. mesopotamicus obtained 94% when released in the ramp, and 78% for the fishes released in the pool 11. The results for P. lineatus was 100% for the fishes released in the ramp and 69% for the pool 11. For the R. aspera percentages of 43 and 31% were observed in the ramp and in pool 11, respectively. Significant differences were verified between species regarding the time of arrival at the fish ladder: R. aspera (lowest time) differed from all the species and B. orbignyanus differed from P. mesopotamicus. The times spent traveling along the fish ladder were different for P. mesopotamicus and P. lineatus, with greater time accumulated by R. aspera. In the risk estimates, the highest values occurred in the initial portion, i.e., up the third antenna, suggesting that some hydrological variable may exist in this segment imposing greater restrictions upon the species studied. The assessments and monitoring of the effectiveness of the fish ladder in the Engenheiro Sergio Motta Hydroelectric Power Plant, for the species studied, as well as other target species, should be continued over the long term, in order to verify if this passage permits the fishes, within the reproductive period (piracema) to find and overcome the passage in good time to undertake their reproduction in the tributaries situated upstream of the dam. / Sistemas de transposição para peixes em barragens de hidrelétricas são projetados a fim de mitigar alguns impactos, no entanto, faz-se necessário a avaliação e monitoramento desses sistemas. Este estudo realizado na escada para peixes da UHE Engenheiro Sergio Motta CESP, no período de novembro/2009 a abril/2010, objetivou analisar a efetividade deste sistema, considerando dois aspectos necessários para análise: a taxa da atratividade e posteriormente, a eficiência da escada para peixes. Para o cálculo da atratividade foi considerada a porcentagem de indivíduos que encontraram a entrada e para a eficiência foi calculado o percentual de ascensão ao longo da escada para peixes, através da Função de Ascensão. A Função de Risco foi utilizada para identificar os locais que possam dificultar a ascensão das espécies estudadas. Foi utilizado o sistema de rádio freqüência (RFID Radio Frequency Identification) no estudo, com instalação de oito antenas ao longo da escada para peixes e transponders (PIT-tags) de 32mm foram implantados em quatro espécies de peixes migradores de longa distância. Foram considerados dois locais de soltura após a marcação: no primeiro, denominado rampa, aproximadamente 1.100m a jusante da entrada da escada, 757 indivíduos foram marcados, sendo 151 Brycon orbignyanus, 204 Piaractus mesopotamicus, 196 Prochilodus lineatus e 206 Rhinelepis aspera. E, no segundo local, o tanque 11 da escada, foram marcados 317 indivíduos distribuídos em 100 P. mesopotamicus, 109 P. lineatus e 108 R. aspera. Os resultados da atratividade para indivíduos liberados na rampa foram de 15,89% para B. orbignyanus, 55,39% para P. mesopotamicus, 7,4% para P. lineatus e de 24,73% para R. aspera. Os resultados das estimativas da eficiência, com uso da Função de Ascensão, foram diferenciados para parte das espécies estudadas. Para B. orbignyanus liberadas na rampa, a eficiência foi de 79%. P. mesopotamicus obteve 94%, quando liberados na rampa e 78% para os peixes liberados no tanque 11. Para P. lineatus resultou em 100% para os liberados na rampa e 69% para o tanque 11. Já para R. aspera percentagens de 43 e 31% foram observadas na rampa e tanque 11, respectivamente. Diferenças significativas foram constatadas quanto ao tempo de chegada à escada, entre as espécies: R. aspera (menor tempo) diferenciou de todas as espécies e B. orbignyanus foi distinta de P. mesopotamicus. Os tempos de deslocamento ao longo da escada foram diferentes para P. mesopotamicus e P. linetaus, com maior tempo acumulado para R. aspera. Para estimativas do risco, os valores mais elevados ocorreram na porção inicial, ou seja, até a terceira antena, sugerindo que nesse segmento possa haver alguma variável hidrológica que imponha maior restrição às espécies estudadas. As avaliações e monitoramento da efetividade da escada para peixes da UHE Engenheiro Sergio Motta para as espécies estudadas, bem como, as demais espécies alvo, devem ser continuadas, em longo prazo, com objetivo de verificar se esta passagem possibilita os peixes, no período reprodutivo (piracema), encontrarem e vencerem a passagem em tempo hábil, para realizarem a reprodução nos tributários existentes a montante da barragem.

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