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Ecological Engineering 48 (2012) 38– 50

Contents lists available at ScienceDirect

Ecological Engineering

jo u r n al hom ep age: www.elsev ier .com/ locate /ec oleng

cohydraulics of pool-type fishways: Getting past the barriers

osé Maria Santosa,∗, Ana Silvaa,b, Christos Katopodisc, Paulo Pinheiroa,d, António Pinheiroe,orge Bochechas f, Maria Teresa Ferreiraa

Centro de Estudos Florestais, Instituto Superior de Agronomia, Tapada da Ajuda, 1349-017 Lisboa, PortugalFaculty of Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, CanadaKatopodis Ecohydraulics Ltd., 122 Valence Avenue, Winnipeg, MB R3T 3W7, CanadaAQUALOGUS - Engenharia e Ambiente, Rua da Tóbis Portuguesa, n.◦ 8 - Escritório 3, 1750-292 Lisboa, PortugalDepartmento de Engenharia Civil, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisboa, PortugalInstituto da Água, Departamento de Monitorizac ão e Sistemas de Informac ão do Domínio Hídrico, Divisão da Qualidade da Água, Av. Almirante Gago Coutinho n.◦ 30, 1049-066isboa, Portugal

r t i c l e i n f o

rticle history:eceived 3 November 2010eceived in revised form 21 February 2011ccepted 20 March 2011vailable online 4 May 2011

eywords:ydropowercohydraulicsish passageool-type fishways

a b s t r a c t

The construction of pool-type fishways has greatly increased in recent years in response to widespreadriver fragmentation by man-made structures. However, the performance of such facilities has often beenquestioned, particularly for non-salmonid fish fauna, which are frequently the predominant group ofspecies found in rivers. This study presents the main findings from field and experimental research con-ducted over the last 10 years on pool-type fishways in Portugal. Specific goals were: (i) to catalogue andevaluate the effectiveness of pool-type fishways built at small hydropower plants (SHP); (ii) to assesspassage patterns of migrant fish populations through a “highly suitable” facility; (iii) to assess fish usefor submerged orifices and surface notches under different flow regimes in experimental conditions and(iv) to determine the effect of hydraulic parameters on upstream movements of fish within these fish-ways. More than half (n = 19, 51%) of the visited fishways were considered to be unsuitable for the target

otamodromous fishish migration

potamodromous species. Seasonal movements peaked in the spring (>70%) and occurred independentlyof time of day. Laboratory experiments showed a significantly greater proportion of movements occur-ring through submerged orifices rather than surface notches. Of all the analyzed hydraulic parameters, theReynolds shear stress was the one that most influenced fish movements within the fishways investigated.The results of this study provide new information and insights that could have important implications onthe design of future fishways, particularly for larger potamodromous cyprinids.

sNpi(

. Introduction

During recent years, there has been a wide search for renew-ble sources of energy in an attempt to reduce hydrocarbon-basednergy production and increase environmentally sound means ofroviding energy and promoting economic growth in the devel-

ped world. The interest in hydropower to meet such needs hasreatly increased recently and this is reflected in the large numberf hydropower stations that have been built as part of large-

∗ Corresponding author at: Departamento de Engenharia Florestal, Instituto Supe-ior de Agronomia, Tapada da Ajuda, 1349-017 Lisboa, Portugal. Tel.: +351 213 65389; fax: +351 213 653 338.

E-mail addresses: jmsantos@isa.utl.pt (J.M. Santos), anamtsilva@isa.utl.ptA. Silva), KatopodisEcohydraulics@shaw.ca (C. Katopodis), pjpinheiro@isa.utl.ptP. Pinheiro), apinheir@civil.ist.utl.pt (A. Pinheiro), jorge.bochechas@inag.pt (J.ochechas), terferreira@isa.utl.pt (M.T. Ferreira).

aides(frw2hr

925-8574/$ – see front matter © 2011 Elsevier B.V. All rights reserved.oi:10.1016/j.ecoleng.2011.03.006

© 2011 Elsevier B.V. All rights reserved.

cale projects (Jackson and Marmulla, 2001; Nilsson et al., 2005).onetheless, with the potential to accommodate further largerojects becoming limited, many countries are increasingly focus-

ng on the development of small-scale hydropower projects (SHP)<10 MW) (Demirbas, 2007).

River fragmentation by SHP structures, particularly by the damsnd weirs involved, can, however, cause significant environmentalmpacts at the local scale. Indeed, many studies have documentedramatic declines or extinctions of many fish species (Kubeckat al., 1997; Larinier, 2001). Particularly impacted are species thateasonally undergo considerable migrations within river systemspotamodromy) (Poulet, 2007), since dams or weirs hinder themrom reaching their spawning grounds. A significant amount ofesearch has therefore been carried out with the goal of designing

ays to allow fish to pass such obstacles (Clay, 1995; Katopodis,

005). In this context, the construction of fishways emerged asydraulic structures that aid the movement of fish past the bar-iers (FAO/DVWK, 2002). The importance of such devices was

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J.M. Santos et al. / Ecologic

ecently reinforced with the launch of water policy tools, such ashe European Water Framework Directive (EWFD), which requiresffective passage and undisturbed migration of fish as a key com-onent to restore and manage watersheds (European Commission,000). However, studies of fishway effectiveness often focus on fishpecies with high economic and recreational value (e.g. salmonids)Laine et al., 2002; Katopodis, 2005; Naughton et al., 2007), whereastudies on coarse potamodromous fish have often been neglectedue to their low commercial value (Roscoe and Hinch, 2010). This

s rather unfortunate, since these species are an important biologi-al component of fish assemblages and free instream movement isndispensable for their survival (Lucas et al., 2000).

Pool-type fishways are the earliest type of fish passageacilities—the first attempts to build this type of fishway areecorded in Europe during the 17th century (Alvarez-Vázquez et al.,008) and are presently the most common type of fishways builtt small hydropower plants (Larinier, 2008). These facilities consistf a series of consecutive pools, separated by cross-walls arrangedn a stepped pattern, with each step higher than the one immedi-tely downstream (Katopodis et al., 2001). These cross-walls arequipped with surface notches and submerged orifices at the bot-om, which are used by the fish to move from pool to pool. Their

ain purpose is to ensure adequate dissipation of the energy ofhe water and offer resting areas for fish. While simple to con-truct, pool-type fishways are sensitive to flow regime changesith fluctuating water levels (Katopodis, 2005). The suitability ofifferent flow regimes and water velocities depends on the species,izes and swimming ability. In southern European regions, particu-arly in Iberia, many fishways were, however, previously designednd installed according to the criteria developed in central andorthern European rivers, without taking into account specificite conditions and fish assemblage composition, primarily dom-nated by potamodromous cyprinid fishes for which migratoryatterns are poorly known (Ovidio and Philippart, 2002; Katopodis,005; Mallen-Cooper and Brand, 2007). On the other hand, knowl-dge on how these species respond to suitable dimensions andey-hydraulic variables that determine successful passage withinshways is also scarce and has been cited as the principal causef fishway ineffectiveness (Katopodis, 2005). Therefore, given theonsiderable challenges that fisheries engineers will face if thetated problems are to be solved in light of existing legislation, it ismperative that besides obtaining information on fish migrationatterns, fishway effectiveness needs to be adequately assessednd that robust guidelines, aiming to improve such effectiveness,an be developed and implemented in future facilities.

This study presents the main findings from field research con-ucted on pool-type fishways over the last 10 years in Portugal.

n addition, research was also conducted in a full-scale prototypeuilt at the National Laboratory for Civil Engineering (LNEC), Lis-oa, to assess in more detail the effects of hydraulics on the passageuccess of fish. The use of a full-scale experimental facility alloweds to mimic conditions that occur in the field, as well as the manip-lation of the variables of interest while confounding variablesre controlled (Kemp et al., 2006). Specific goals were: (i) to cat-logue and evaluate the effectiveness of pool-type fishways builtt SHP; (ii) to assess passage patterns (i.e. seasonal and diel) ofigrant cyprinid fish populations through a “highly suitable” facil-

ty; (iii) to assess fish use of submerged orifices and surface notchesnder different flow regimes in experimental conditions and (iv) toetermine the effect of hydraulic parameters – water velocity, tur-ulent kinetic energy (TKE) and Reynolds shear stress (RSS) – on

sh upstream movements within the fishway, in particular on howhey relate to fish transit time, i.e. the amount of time spent in aell. Lastly, knowledge gaps in fish passage through pool-type fish-ays are discussed in terms of how they are limiting the ability to

a(bn

ineering 48 (2012) 38– 50 39

urther understand fish movements and behaviour and what futureesearch steps may be needed.

. Methods

.1. Field study

Thirty-seven pool-type fishways were visited once or twicerom May to July to record target parameters (Fig. 1). These facil-ties were built as part of SHP (all but one commissioned after990) and were located in medium-sized rivers primarily domi-ated by small resident (Squalius spp.) and larger potamodromousyprinids such as the straight-mouth nases Pseudochondrostomapp. and the Iberian barbel Barbus bocagei. Upon each visit, sev-ral design and connectivity parameters were recorded by a teamf three researchers. Design parameters included pool dimensions,otch width and height (m), orifice area (m2) and mean head dropetween two pools (m). These data were first obtained from theational Forest Authority database, and later confirmed in situ, by

he use of a meter ruler, to check if they were in compliance with theroject. Whenever possible, the design discharge of each fishwayas obtained in advance and used to generate hydraulic parame-

ers such as the maximum flow velocity created by drops betweenhe pools (m/s), discharges through the submerged notches and ori-ces (m3/s), the head at the notches (m) and the volumetric powerissipation (VPD, W/m3). Calculations were performed using thequations and methods outlined in Larinier (2002) and Bos (1990)hat describe flow discharge through a submerged orifice (1) and aectangular notch (2):

o = CdoS(2gDH)0.5 (1)

n = Cdnb(2g)0.5H11.5 (2)

here Qo and Qn are the flow discharge (m3/s) through a sub-erged orifice and a surface notch, respectively; S is the area of

he orifice (m2), g is the acceleration due to gravity (9.8 m/s2), DHs the drop between the pools (m), H1 is the head at the notch,nd Cdo and Cdn are respectively, the discharge coefficients of therifices and notch. Connectivity parameters, included: (a) the fish-ay entrance attraction, evaluated in situ by direct observation

ccording to the location of the fishway in relation to the obstruc-ion, and scored as: “nil” = 0, “insufficient” = 1, “sufficient” = 3 orgood” = 5; (b) the presence of obstacles (subjectively evaluated asnone” = 3 (no obstacles), “few” = 1 (less than three obstacles) ormany” = 0 (three or more obstacles)), such as small weirs, waterills and waterfalls, in the river segment downstream that could

otentially hinder upstream fish movements, derived from aerialmages (Google Earth, Google Inc.) through visual assessment ofiver segments; and the presence of (c) debris load (<2 mm) and (d)oarse elements (e.g. logs, boulders) that could obstruct the notchesnd orifices. These were visually evaluated and rated as “none” = 3totally cleared), “few” = 1 (less than 20% of the area obstructed)r “excessive” = 0 (more than 20% of the area obstructed). In addi-ion, the accessibility to a fishway, a vital criterion for ensuringuccessful fish passage operation (Clay, 1995; Katopodis, 2005),as also evaluated and scored as “too difficult” = 0, “difficult” = 1,

acceptable” = 2 or “easy” = 3. For consistency, the same researcherserformed the visual inspections through each entire visit and forll visits. The scores of all the connectivity parameters were thenummed to produce the estimated effectiveness of each fishway

s follows: “highly suitable” (18–20), “adequate” (13–17), “low”6–12) and “impassable” (0–5). Fishways with rated effectivenesselow “adequate” (i.e. “low” and “impassable”) were consideredot hydraulically suitable for fish passage.

40 J.M. Santos et al. / Ecological Engineering 48 (2012) 38– 50

pe fish

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Fig. 1. Location of the 37 visited pool-ty

Following the assignment of fishway effectiveness, a “highlyuitable” device (Janeiro de Cima, fishway #36) was chosen to studyhe characteristics of migrant species, namely the seasonal andaily upstream movements of their populations across an annualycle. The fishway is 63 m long, 1.5 m wide on a 9% slope, and fea-ures 25 pools. To prevent large debris from entering the pass, aoarse screen was placed at the upstream exit.

Fish passage was monitored from June 2002 to May 2003y means of an infrared fish counter device, the RiverwatcherRW). The counter uses a simple scanner principle: once a fishass through a diode-composed frame and breaks the plane of

ight beams, a passage event is recorded to an operating displaynit, including the fish shape and information on passage timing,irection of movement and water temperature. The counter wasreviously tested and calibrated during 6 days before the moni-oring programme was formally initiated, by comparing migrantounts with fish trapped just upstream in a standard fyke net. Aotal of 267 individual nase (Pseudochondrostoma polylepis) (here-fter referred to as nase) were captured, measured for total lengthnd height for ratio calculation and returned alive to the river sec-ion upstream.

In order to compare with the fish counter records andence validate fishway effectiveness, a 250 m long river segment

mmediately downstream of the fishway was surveyed monthlysing a combination of both multimesh gill nets (n = 2, dimen-ions = 30 m × 2.5 m, mesh sizes = 30, 39, 50, 65 and 85 mm fromnot to knot) and electrofishing. Gill nets were placed before dusk

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ways built at SHP. See codes in Table 3.

n a large (70 m × 40 m) deep pool immediately downstream ofhe SHP and lifted after dawn. Further downstream, electrofishingas performed according to CEN (2003) standards, to encompass

epeating habitat types (riffles and runs).

.2. Experimental study

On April 21, 2005, forty-five upstream-migrating Iberian barbelhereafter referred to as barbel) were captured in the river Sorraia,entral Portugal (N 38◦43′, W 009◦12′) by means of electrofish-ng and brought to the experimental pool-type fishway at LNEC.ish were transported in containers with aerated river water toinimize transportation stress and thereafter introduced in three

olding tanks (800 L) at 15 ind/tank. Fish sizes among tanks wereimilar (mean total length (TL) ± SD: tank A = 18.6 ± 3.1 cm, tank

= 20.7 ± 2.4 cm and tank C = 19.6 ± 3.1 cm; ANOVA, F = 2.13, d.f. = 2, > 0.05), which allowed for valid comparisons between experi-ents. Fish were kept in the tanks and acclimated to ambient

emperature (difference between the collection site and the tanksr fishway <2 ◦C) and natural photoperiod for a minimum of 7 days.ater was permanently monitored by a multiparametric probe

Hydrolab, Quanta model), aerated and filtered in a closed circuitith a turnover rate of 200 L per day. Food (Tetra Pond sticks)

as provided three times a week, but was halted 24 h before the

xperiments commenced.On May 3 2007, eighty barbel were captured from the same

ite as in 2005 using the same methods. Fish were brought to

J.M. Santos et al. / Ecological Engineering 48 (2012) 38– 50 41

and (

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Fig. 2. Layout of (a) experimental pool-type fishway at LNEC

he LNEC facilities, separated in two size-classes – small adultsn = 40; 15 < TL < 25 cm) and large adults (n = 40; 25 ≤ TL < 35 cm) –nd introduced in 4 holding tanks (800 L) at 20 ind/tank. Acclima-ion and feeding procedures were the same as in 2005.

The experimental pool-type fishway consisted of a full-scaleodel, 10 m long, 1 m wide and 1.2 m high with a steel frame

nd fibreglass-viewing panels on both side-walls (Fig. 2). It wasositioned at a 8.5% slope, which is within the range of those com-only used for this type of fishway (Larinier, 2008). The fishway

onsists of 6 pools, each 1.9 m long, except the most downstreamnd upstream ones: the former is 1.8 m long, whereas the lat-er measures 0.6 m but further extends for an additional 1.2 mpstream section of zero slope, making up a total of 1.8 m. Theools are divided by five PVC cross-walls, each incorporating aubmerged orifice and a surface notch of adjustable area. Orificesere positioned in an offset arrangement as this was the pattern

ound in all visited facilities. The fishway also encompassed anpstream and a downstream chamber. The former included a slotate to control the discharge entering the flume, whereas the lat-er (4.0 m × 3.0 m × 4.0 m), separated from the flume by two meshanels, allowed acclimation of fish prior to the start of each exper-

ment.

.2.1. Use of orifices versus notchesFour experiments (A1–A4) were initially conducted to assess the

se of barbel to the simultaneous presence of orifices and notches.xperiments took place from April 28 to May 10, 2005, betweenusk and early night (17h00 to 22h00), thereby reflecting the noc-urnal nature of adult species migration (Santos et al., 2005). Therifice dimensions (width × height) were fixed at 0.20 m × 0.20 m,hereas for surface notches, a combination of two different dimen-

ions – 0.20 m × 0.30 m and 0.30 m × 0.30 m – with two different

ow regimes – plunging or streaming were employed. Flow inool-type fishways can be in plunging or streaming flow regimesClay, 1995; Rajaratnam et al., 1988), as well as several transitionalow regimes (Ead et al., 2004). In the plunging flow regime, the

2

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b) cross-walls with adjustable orifice and notch dimensions.

ater level in the pool immediately below the cross-wall (pro-ucing the plunging flow) is below the crest of the notch. In thetreaming flow mode, a surface stream appears to flow over therest of the notches, skimming over the water surface of the poolsn between (Rajaratnam et al., 1988). Thus, by controlling the flowischarge and water level within the flume, both plunging andtreaming flow regimes could be generated. Fish preferences forlunging and streaming flow regimes were tested in these exper-

ments, while transitional flow regimes were not. Dimensions ofrifices and notches were previously determined from calculationso approximately match velocities between the two pass openings.hree replicates of each experiment (notch width × flow regime)ere tested, each one using barbel from a different tank (Table 1).ischarge (Q) was kept constant among replicates and was previ-usly determined to create a head drop between the pools (�h) of.16 m. All individuals (n = 15) from each tank were first introduced

nto the downstream chamber and provided with a 12 h acclima-ion period. Once the discharge was brought to the desired level,he mesh panels were removed and fish were allowed to ascendhe fishway. Movements through orifices or notches were thenontinuously monitored by visual observations and video record-ngs through the fishway glass sidewalls. Visual observations were

ade at 1 m distance from the flume, discreetly approaching andeaving the observation points before and after each experiment.or video recordings three video cameras were used (Panasonic,V BP-100 model); they were connected to two time-lapse video

ecorders (Panasonic AG-6720A model) and focused on both fish-ay openings of the two uppermost cross-walls. Five infrared

amps, scheduled to operate from 20h30 onwards, aided the moni-oring procedure when natural light was no longer sufficient. Theseamps have been used elsewhere, with no effects on fish behaviourSantos et al., 2005).

.2.2. Effects of hydraulics on fish movementsThree-dimensional (x, y and z) velocity measurements in two

lanes parallel to the bottom of the flume (25% and 80% of pool

42 J.M. Santos et al. / Ecological Engineering 48 (2012) 38– 50

Table 1Experimental conditions tested in the full-scale fishway model in 2005 to assess barbel use for orifices and notches.

Experiment # Replicates Ao (m2) Notch width Q (l/s) Flow regime Mean velocity (m/s)

Orifices Notches

A1 3 0.04 0.20 70.6 Plunging 1.14 1.07A2 3 0.04 0.20 90.3 Streaming 1.14 1.10A3 3 0.04 0.30 83.2 Plunging 1.14 0.96A4 3 0.04 0.30 108.3 Streaming 1.14 1.01

Table 2Experimental conditions (orifice area (Ao), flow discharge (Q), volumetric power dissipation (VPD) and pool mean water depth (hm)) tested in the full-scale fishway model in2007 to determine the effects of hydraulic parameters on the upstream movements of barbel. The mean size and standard deviation (SD) of tested individuals is also shown.

Experiment # Replicates Ao (m2) Notch width (m) Q (l/s) VPD (W/m3) 25% hm (m) 80% hm (m) Small adultsMean ± SD (cm)

Large adultsMean ± SD (cm)

B1 10 0.03 N/A 38.50 37.00 0.20 0.63 19.07 ± 1.76 28.87 ± 2.59

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B2 10 0.04 N/A 47.50 47.80

B3 10 0.05 N/A 62.70 63.10

B4 10 0.06 N/A 77.00 78.40

ean water depth (hm)) were first conducted in April 2007. Annstantaneous 3D Acoustic Doppler Velocimeter (ADV) (Nortek AS)riented vertically down was used at a sampling frequency of5 Hz, to determine water velocity (WV) vectors, turbulent kineticnergy (TKE) and Reynolds shear stress (RSS) and hence character-ze existing hydraulic conditions. A sampling duration of 90 s wasonsidered representative, as the ADV did not register significantariation in the mean velocity after 30 s. A particle rich environ-ent in the water was guaranteed during the experiments to

mprove data quality measured by the ADV (Yagci, 2010). This waschieved by monitoring, the “signal-to-noise ratio (SNR)” whichas continuously above 15 dB as recommended (Nortek AS, 2002).

n addition, bubble levels within the pools entrained from the pumpystem contributed to maintaining an adequate SNR level, ensuringccurate velocity readings. Measurements were performed for dif-erent flow discharges (38.5–77.0 l/s) and submerged orifice areas0.03–0.06 m2) (Table 2). As the 2005 experiments revealed speciesvoidance for surface notches (see Section 3), such structuresemained closed throughout the 2007 experiments. Measurementsere made on the second downstream pool which was considered

o be representative of the fishway due to identical flow patternsnd head drops between the pools (�h = 0.16 m) (Fig. 3). To allowor comparisons, all hydraulic parameters (WV, TKE and RSS) were

ade dimensionless by dividing corresponding maximum valuesy the maximum flow velocity at the orifice (Vo) (Liu et al., 2006).o better understand the major forces acting on the body surface ofsh and hence driving their upstream movements, the RSS was fur-

her resolved in its three components: longitudinal (XY) (−�u′v′),ertical (XZ) (−�u′w′) and transversal (YZ) (−�v′w′), with � beinghe water density and u′, v′ and w′ the fluctuating velocities in the

ig. 3. Location of velocity measurement points along the horizontal layers at theepresentative pool of the experimental pool-type fishway.

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0.21 0.68 19.85 ± 2.49 28.44 ± 3.110.21 0.68 19.74 ± 2.14 28.67 ± 2.890.21 0.67 19.65 ± 2.41 28.25 ± 3.07

, Y and Z directions, respectively. Data were further analyzed andespiking was performed by using the “Phase-Space Thresholdingethod” (Nikora and Goring, 2002) as modified by Wahl (2003),

n the WinADV32 software (Nortek AS, 2002), a post-processingreeware package designed specifically for the analysis of ADV files.

From May 10 to 18, 2007, four experiments (B1–B4) were car-ied out with 10 replicates each, giving a total of 40 trials. Eachrial was conducted by using simultaneously one adult fish of eachize-class, randomly removed from the holding tanks and placedn the acclimation chamber where they were allowed 12 h to set-le. At the start of a trial, the mesh panels were removed to enablesh access to the fishway and movements were then continuouslyonitored by visual observations (same procedures as in 2005)

nd video recording. For this, three video cameras were used: 2ere positioned at 2 m from each side-wall, whereas the other waslaced 3 m above the water surface. To aid the video recording pro-ess, a 1.90 m × 1.00 m reference grid with 15 numbered cells waslaced above the pool. Each fish was followed by registering theime taken to (a) enter the flume, (b) ascend from one pool to theext and (c) successfully negotiate the fishway. Video records werenalyzed using the IVision Labview software (http://www.ni.com).

.3. Data analysis

.3.1. Fish dataThe number of individual fish ascending the pool-type fishway

as initially graphed on a monthly basis to search for the exis-ence of seasonal migration periods. In addition, the presence of

non-random pattern on diel fish migration was assessed by aon-parametric Mann–Whitney U-test between diurnal (06h00 to8h00) and nocturnal (18h00 to 06h00) number of movementser day. A stepwise multiple regression analysis (Zar, 1996) wasmployed to test the effect of environmental variables on fish dailyumbers ascending the fishway (dependent variable). Fishway dis-harge (obtained by using a PDCR830 pressure transducer and aytec7100 ultrasonic velocity meter), precipitation (obtained from

he nearest weather station), water temperature (obtained fromhe RW records) and head- and tailwater levels (measured daily byelescope levelling) were the independent variables.

.3.2. Experimental data

Mann–Whitney U-tests were performed to test the following

ull hypotheses on the experimental facility: (a) the proportion ofsh that used the submerged orifices and surface notches was simi-

ar; (b) the proportion of fish that used the orifices and notches was

J.M. Santos et al. / Ecological Engineering 48 (2012) 38– 50 43

F ay (#n ature.

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ig. 4. Total number of nase migrating through the Janeiro de Cima pool-type fishwets and electrofishing (open bars). The solid thin line represents the water temper

imilar for both notch widths (0.20 and 0.30 m); (c) the proportionf fish that used the orifices and notches was similar for both flowegimes (plunging and streaming) and (d) the time taken to enterhe fishway was similar when using orifices or notches.

To analyse the effects of hydraulics on fish movements, corre-ation analysis between fish transit time and hydraulic parameters

WV, TKE and three-dimensional RSS – were assessed by thepearman rank coefficient. Data were pooled over the four 2007xperiments, as a previous pilot study revealed WV vectors toe spatially similar among experiments, though increasing pro-ortionally (magnitude) with increasing flow discharge. Only dataollected at 0.25 hm were used for these analyses, as visual obser-ation and video monitoring showed all fish movements to occurlose to the bottom of the fishway.

. Results

.1. Field data

Fishway effectiveness was assigned as follows: eight (22%)ere classified as “highly suitable”, 10 (27%) “adequate”, 13 (35%)

low” and six (16%) were considered as being “impassable for fish”Table 3). This means that more than half (51%) of the fishwaysere not hydraulically suitable for fish passage.

More than 3000 individual nase ascended the “highly suit-ble” pool-type fishway (Janeiro de Cima, fishway #36) from June002 to May 2003 (Fig. 4). Fish counter data and direct cap-ures were positively correlated across the period (r = 0.87, n = 12,

< 0.05). Upstream movements were found to occur mainly inhe spring (73.9%), with a peak passage in May (46.4% of theotal movements). No significant differences in nase upstream

ovements were observed between diurnal (mean number of indi-iduals = 12.9) and nocturnal (mean number of individuals = 10.5)ime periods (Mann–Whitney U-test, P > 0.05). Stepwise multipleegression analysis revealed water temperature to be the only sig-

ificant variable correlated to nase movements (F-test, r2 = 0.38,

< 0.05), showing a pronounced activity at temperatures between5 ◦C and 17 ◦C. No autocorrelation was found in the residuals ofhe regression (D = 1.53).

v(ow

36) assessed by the RW fish counter (solid bars) and captured downstream by gill

.2. Experimental data

.2.1. Use of orifices versus notchesA total of 1781 (76%) barbel upstream movements took place

hrough the submerged orifices and this pattern was non-randomMann–Whitney U-test, P < 0.05) (Table 4). The use of a widerotch did not yield an overall higher number of upstream move-ents either by the submerged orifices or by the surface notches

Mann–Whitney U-test, P > 0.05). Experiments conducted withlunging flow conditions revealed an unequal proportion of fishsing both fishway openings, with a significantly higher propor-ion using the former (Mann–Whitney U-test, P < 0.05, Table 4), buthis was not true for streaming conditions. The time taken for fisho enter the fishway after they were introduced in the acclimationhamber was lower when fish used the submerged orifices (52 s to5 min.) than when they used the surface notches (25 min to 3 h)Mann–Whitney U-test, P < 0.05).

.2.2. Effects of hydraulics on fish movementsVelocity patterns at the plane closest to the flume bottom

0.25 hm) revealed two hydraulic regions (Fig. 5): a jet region char-cterized by higher velocities with maximum values occurring at.40 m downstream from the orifice (max = 0.83 m/s), and a large

ow-velocity recirculation region, extending from the jet line to thepposite side-wall. At a higher plane (0.80 hm), a uniform recircu-ation region (0.50–0.77 m/s) could be noted, with higher velocitiesbserved in the vicinity of the downstream cross-wall. The analysisf velocity variation across the different planes produced distinctatterns (Fig. 6): on planes parallel to the fishway floor (XY) veloc-

ties decreased from the bottom to the surface and this patternecame better defined with increasing discharge; on vertical planesXZ) velocities peaked in the vicinity of the side-wall adjacent to therifice and decreased towards the opposite side-wall; on transver-al planes (YZ), velocities were maximum in the vicinity of bothross-walls. The variation of TKE was similar to the one of water

elocity, i.e. at the level close to the bottom (0.25 hm) it was higher>0.14 Vo) along the jet path between two consecutive submergedrifices and decreasing (0.08–0.10 Vo) towards the opposite side-all, in the recirculation area. The variation (absolute values) of the

44J.M

. Santos

et al.

/ Ecological

Engineering 48 (2012) 38– 50

Table 3Summary results of the design and connectivity parameters collected at the 37 visited pool-type fishways.

Fishway#

Fishway name Fishwayentranceattraction

Downstreamobstructions

Debris load Coarse elements Headdrops(m)

Pooldimensions(m)

Notchwidth(m)

Orificearea(m2)

Max.flowvel.(m/s)

Notchflow(m3/s)

Orificeflow(m3/s)

Headat thenotch(m)

VPD(W/m3)

Accessibilityto fish pass

Estimatedeffectiveness

Notches Orifices

1 Paus Insufficient Few Few None Few 0.30 1.70 × 1.28 0.60 0.026 2.4 0.088 0.037 0.38 203 Too difficult Low2 Rendufe Nil Few None Few Few [1] [1] [1] [1] [1] [1] [1] [1] [1] Acceptable Low3 Trutas Good None None Few Few 0.30 1.80 × 1.40 0.30 0.040 2.4 [1] [1] 0.30 152 Easy Adequate4 Nunes Sufficient None None None None 0.30 2.10 × 1.74 0.20 0.023 2.4 0.154 0.021 0.75 93 Easy Highly suitable5 Torga Good None None None Few 0.30 1.85 × 1.42 0.25 0.063 2.4 0.092 0.091 0.35 224 Acceptable Adequate6 Canedo Good None None None None 0.25 2.50 × 1.50 0.30 0.040 2.3 [1] [1] 0.25 130 Easy Highly suitable7 Pte Bico Sufficient Few None None None 0.30 2.40 × 2.00 0.38 0.079 2.4 0.185 0.115 0.44 84 Acceptable Adequate8 Penide Nil Few Excessive Few Excessive [1] [1] [1] [1] [1] [1] [1] [1] [1] Acceptable Impassable9 Bragadas Nil Many Excessive None Few 0.30 2.00 × 1.30 0.25 0.023 2.4 0.142 0.033 [1] 191 Too difficult Impassable

10 Casal Insufficient Many Few Few Few 0.30 1.50 × 1.00 0.15 0.017 2.4 0.055 0.025 0.32 105 Easy Low11 Ac ude do Viseu Sufficient Few None None None 0.25 2.70 × 2.55 0.40 0.105 2.3 [1] [1] 0.28 171 Easy Adequate12 Rego Naval Good None None None None 0.26 2.50 × 2.35 0.40 0.040 2.3 0.406 0.069 0.26 188 Easy Highly suitable13 Terragido Insufficient None None Few Few 0.30 2.00 × 1.20 0.20 0.023 2.4 0.131 0.033 [1] 199 Easy Low14 Sra Salto Insufficient None Few Excessive Few 0.60 2.10 × 1.20 0.25 0.023 3.4 0.089 0.046 0.62 354 Acceptable Low15 Ucanha Good None None None None 0.31 1.75 × 1.20 0.20 0.023 2.5 0.117 0.033 0.47 194 Acceptable Highly suitable16 Bateira Good None None None None 0.20 2.30 × 1.60 0.30 0.040 2.0 [1] [1] [1] [1] Easy Highly suitable17 Pereira Sufficient Many Few None None 0.30 1.50 × 1.20 0.20 0.060 2.4 0.058 0.023 0.30 95 Too difficult Low18 Pte Nova Nil Many None None None 0.30 2.60 × 1.50 0.23 0.023 2.4 0.167 0.033 0.57 129 Acceptable Low19 V Soeiro Good Few None None None 0.30 2.22 × 1.97 0.22 0.040 2.4 0.122 0.058 0.48 117 Difficult Adequate20 Fraguas Sufficient Few Excessive Excessive Excessive 0.30 1.55 × 1.24 0.73 0.023 2.4 0.092 0.033 0.42 196 Easy Adequate21 Águas Frias Insufficient Few None None Few 0.30 1.50 × 1.20 0.20 0.070 2.4 [1] [1] 0.30 122 Difficult Low22 Pego Good Few None None Few 0.25 2.30 × 1.30 0.25 0.029 2.3 [1] [1] 0.25 152 Easy Adequate23 Paredes Nil Few Few Few Few 0.30 0.95 × 1.05 0.24 0.036 2.4 0.073 0.052 0.30 312 Acceptable Low24 Ribafeita Nil Few Excessive Excessive Few [2] [2] [2] [2] [2] [2] [2] [2] [2] Too difficult Impassable25 Pte Vouguinha Nil Few Few Few Excessive 0.30 2.40 × 1.40 0.40 0.123 2.4 [1] [1] 0.30 126 Too difficult Impassable26 SP Sul Good None None None None 0.30 1.80 × 1.50 0.40 0.160 2.4 0.101 0.233 0.70 207 Acceptable Highly suitable27 Valgode Nil Few Few Excessive Excessive 0.32 3.15 × 1.80 0.40 0.090 2.5 0.495 0.099 [1] 92 Easy Impassable28 Cercosa Nil Many Excessive None Few 0.30 1.90 × 1.24 0.19 0.023 2.4 0.092 0.033 0.42 201 Acceptable Low29 Talhadas Nil Many Excessive Excessive Excessive 0.45 1.70 × 1.25 0.20 0.023 2.4 0.092 0.033 0.41 180 Too difficult Impassable30 Pte Fagilde Sufficient Few None None Excessive 0.27 2.20 × 1.40 0.26 0.040 2.3 0.145 0.055 [1] 158 Acceptable Low31 Levadinha Sufficient Many None Few None 0.22 2.10 × 1.00 0.30 0.040 2.1 [1] [1] 0.22 [1] Acceptable Low32 Soutinho Insufficient Many Few Few Few 0.30 1.74 × 1.24 0.20 0.038 2.4 0.090 0.055 0.34 210 Easy Low33 Manteigas Good Few None Few None 0.35 3.20 × 1.00 0.60 0.000 2.6 0.133 0.041 0.35 204 Easy Adequate34 Avô Good Few None None Few 0.30 2.85 × 2.50 0.40 0.040 2.4 [1] [1] [1] [1] Easy Adequate35 Barroca Good None None None None 0.30 2.95 × 1.80 0.40 0.090 2.4 [1] [1] 0.30 175 Easy Highly suitable36 Janeiro Cima Good Few None None None 0.30 2.50 × 1.50 0.32 0.040 2.4 0.192 0.058 0.42 238 Easy Highly suitable37 Rib de Alge Sufficient Few None None None 0.30 2.20 × 1.25 0.20 0.023 2.4 [1] [1] 0.30 165 Easy Adequate

[1] It was not possible to calculate the hydraulic parameters due to insufficient data in SHP reports.[2] It was not possible to calculate the hydraulic parameters due to partial destruction of the fish pass.

J.M. Santos et al. / Ecological Engineering 48 (2012) 38– 50 45

Table 4Number of barbel movements through the orifices and notches upon different notch widths and flow regimes tested.

Experiment Notch width (m) Flow regime Number of movements Total

Orifices Notches

A1 0.20 Plunging 413 79 492A2 0.20 Streaming 354 118 472A3 0.30 Plunging 601 98 699A4 0.30 Streaming

Total

Fta

hl(sct

t

alsutsrucaticsacIvrr

4

fi1oot(t1

F(

ig. 5. Water velocity vectors (Q = 47.5 l/s) at two horizontal planes in the pools ofhe experimental facility: (a) 0.25 hm and (b) 0.80 hm . Flow from the orifice enterst the bottom left of the diagram.

orizontal and vertical component of RSS were found to be simi-ar across the depth of the pools, i.e. it decreased from the bottom0.25 hm) – where it was greater at the flow inlet – towards theurface (0.80 hm) (Fig. 7). In contrast, variation in the transverse

omponent of RSS was negligible along the pool depth throughouthe experiments.

Overall, fish exhibited a high capacity to ascend the fishway,hough some size-related differences were observed (Fig. 8): larger

aeop

ig. 6. Variation of dimensionless maximum water velocity (0.25 hm) at different planes inb) vertical plane (XZ); (c) transversal plane (YZ). See Table 2 for experiment (B1–B4) code

413 264 677

1781 559 2340

dults showed a higher rate of success (mean = 79%) and tookess time to ascend the facility (mean ± SD (min): 5.7 ± 1.3) thanmaller individuals (mean = 59%; 8.0 ± 0.4 min). Both size-classessed low WV (0.20–0.40 m s−1) cells. This variable was also foundo correlate negatively with fish transit time, in particular formall adults (Spearman correlation: r = −0.30, P < 0.05; large adults:

= −0.27, P < 0.05). A similar pattern was found for TKE, i.e. fishsed mainly areas with low TKE (<0.05 m2/s2), therefore a signifi-ant negative correlation with fish transit time was observed (smalldult: r = −0.39, P < 0.01; large adults: r = −0.35, P < 0.01). The rela-ion between the three components of RSS with fish transit timen each cell yielded different results (Fig. 9): a highly significantorrelation with the horizontal component was noted for bothize-classes, namely for small adults r = −0.45 (P < 0.001); and largedults: r = −0.36 (P < 0.001). Overall, individuals spent less time inells with higher RSS (absolute values ranged from 20 to 60 N/m2).n contrast, no significant correlations were found either for theertical component (small adults: r = −0.22, P > 0.05; large adults:

= −0.19, P > 0.05) or for the transverse component (small adults: = −0.21, P > 0.05; large adults: r = −0.18, P > 0.05).

. Discussion

The present research focused on the main findings from botheld and laboratory experimental research conducted over the last0 years on pool-type fishways. These facilities represent the bestption when physical site conditions do not allow the installationf nature-like fishways, which in many cases would be an effec-ive solution when several potamodromous species are presentKatopodis, 2005; Larinier, 2008). Fishway effectiveness was ini-ially evaluated at each site by visual observations (Elvira et al.,998), taking into account several connectivity parameters, such

s the suitability of dimensions of openings for target species, fishntrance attraction and the presence of obstructions in notches andrifices (Porcher and Travade, 2002). However, attention was alsoaid to the hydraulic conditions within the fishways, which are crit-

the pools of the experimental facility: (a) plane parallel to the flume bottom (XY);s.

46 J.M. Santos et al. / Ecological Engineering 48 (2012) 38– 50

F ols of

p (d) vep

ittvtt

wwirSr1psomtpirdmpTLi

cwhtriwcdhcnl

idlp(a

tpcsTedfitmtiwttaat2sr

ntoewwhw

ig. 7. Variation of dimensionless Reynolds shear stress at different planes in the polane parallel to the flume bottom (XY) at 0.80 hm; (c) vertical plane (XZ) at 0.25 hm;lane (YZ) at 0.80 hm . Flow enters from the right of the diagram.

cal for species movements, and hence will determine their abilityo negotiate the fishway (Katopodis, 2005; Yagci, 2010). Thoughhe methods used in hydraulic calculations only give approximatealues, due to turbulence patterns in the pools, it is believed thathe precision achieved is generally acceptable and reliable enougho evaluate fishway effectiveness (Clay, 1995; Katopodis, 2005).

Fish passage monitoring at a “highly suitable” pool-type fish-ay revealed a clear pattern of seasonal nase migration activityithin the facility, with most of the fish movements occurring

n the spring (April–June), with peak passage in May. Similaresults were reported for other Iberian rivers (Lobón-Cerviá, 1982;antos et al., 2005), describing these upstream movements aseproductive migrations (Rodriguez-Ruiz and Granado-Lorencio,992). Nonetheless, nase diel activity was not consistent with theatterns described in the literature, as in the present study thepecies was found to migrate continuously throughout 24-h peri-ds, whereas in previous studies (e.g. Santos et al., 2002, 2005),igrations were reported to occur preferentially during night and

wilight periods when survival chances from visual predators areresumably higher (Prignon et al., 1998). Although not quantified,

t is possible that the frequently observed high water turbidity ofivers, particularly in warmer months, could have lowered lightiffusion (Reichard et al., 2001), thereby increasing diurnal naseovements. The study also indicated the importance of water tem-

erature as the main factor driving upstream nase movements.his agrees with previous studies (Rodriguez-Ruiz and Granado-orencio, 1992; Santos et al., 2002), highlighting temperature as anmportant cue controlling the intensity of fish migration.

Fish captured downstream, along with comparisons with fishounter records at the upstream end, provided a measure of fish-ay effectiveness and validated the previous classification (i.e.ighly suitable) based on hydraulic criteria. As fishway effec-iveness is a qualitative concept depending on the biologicalequirements of existing populations, checking that the facilitys capable of allowing the passage of non-diadromous species,

ithin the range of observed environmental conditions is suffi-ient (Larinier, 2001). Although fishway effectiveness has not beenefined in terms of minimum standards (Larinier, 2008), the much

igher numbers of fish counter records when compared to the fishaptures downstream, clearly point out that a fairly “reasonable”umber of fish used the fishway, thereby potentially ensuring the

ong-term sustainability of the target population.

ctci

the experimental facility: (a) plane parallel to the flume bottom (XY) at 0.25 hm; (b)rtical plane (XZ) at 0.80 hm; (e) transversal plane (YZ) at 0.25 hm and (f) transversal

The results of these experiments provide new information andnsights that are useful and have important implications for theesign of fishways for barbel that can also be extended to other

arge cyprinids species, such as the nases. Indeed, both species areotamodromous and have very similar critical swimming speedsMateus et al., 2008; Romão, 2009). In addition, both are benthicnd spawn on gravel bed grounds (Doadrio, 2001).

Overall, barbel showed a significantly greater use and took lessime to enter in the fishway when using submerged orifices com-ared to surface notches. This is consistent with other studiesonducted on salmonid species (Guiny et al., 2003, 2005), wherepecies were offered similar velocities for both fishway openings.hough data on velocity vectors were not available during the 2005xperiments, it is believed that orifice velocities, particularly in theeepest layer, provided a stronger directional cue to approachingsh, a situation often confirmed during in situ and video observa-ions. The type of flow regime also seemed to influence upstream

ovements, as a significantly higher proportion of fish were seeno use the orifices relative to notches when the flow was in plung-ng mode but this was not true during streaming flow conditions

here proportions were equivalent. Under these hydraulic condi-ions, the presence of a continuous surface stream flowing overhe crest of the notches would require a reduced effort by barbel,

species with lower swimming capabilities (Doadrio, 2001), byllowing individuals to swim rather than leap over the notches. Fur-her research employing electromyogram telemetry (Cooke et al.,004; Brown et al., 2006) would be needed to clarify patterns ofpecies movements during obstacle negotiation with different flowegime types.

Fishway configurations without the influence of surfaceotches, exhibited a high percentage of successful fish passage, par-icularly for larger adults (ca. 80%), demonstrating the importancef submerged orifices for passing fish observed in the previousxperiments. The following hydraulic variables WV, TKE and RSS,ere all negatively correlated with fish transit time but the effectsere more pronounced on the smaller size-class as shown by aigher correlation coefficient. Specifically, barbel occupied cellsith low WV (0.20–0.40 m/s) and TKE (<0.05 m2/s2) and these

onditions could be found near the flume bottom (0.25 hm) onhe recirculation area. Some studies have shown that these areasan become a “trap” for fish by inducing disorientation and thusncreasing the transit time in each pool and compromising fishway

J.M. Santos et al. / Ecological Eng

Ftt

pnetipi

mhfiafioafi6milp

l2tttohatcbfmis

ilfttFtbtmwmbfnfitistfiio–ffiaalfitapsasfittcffRq

ig. 8. (a) Proportion (%) of fish that successfully ascended the experimental pool-ype fishway, small adults (open bars) and large adults (solid bars), and (b) timeaken for complete ascension.

assage (e.g. Tarrade et al., 2008). It is indeed possible that this phe-omenon might have reduced the performance of some of the fish,specially the smaller individuals. However, given the high propor-ions of fish that negotiated the fishway, even at lower discharges,t is believed that most of the fish used these areas for resting pur-oses before moving upstream through the higher velocities at and

n the vicinity of the orifices.The effects of three-dimensional RSS on the upstream move-

ents of barbel varied according to the component considered. Theorizontal RSS component displayed the highest correlation withsh transit time, highlighting the importance of this hydraulic vari-ble as a key-parameter influencing fish movement in pool-typeshways. It is likely that those shear stresses, resulting from thebserved non-uniform horizontal velocity patterns in the pools,cted upon the components of the forces that are parallel to thesh body surface (Odeh et al., 2002). The observed values (up to0 N/m2), though higher than those occurring in natural environ-

2

ents (ca. 30 N/m ) are far from the critical ones reported to causenjuries or mortalities (ca. 700 N/m2) (Cada et al., 2006). Nonethe-ess, they could cause minor disorientation in some of the fish,articularly on smaller individuals, due to the effect of larger turbu-

omTh

ineering 48 (2012) 38– 50 47

ence vortex systems on their smaller body surface (see Lupandin,005 for a detailed explanation and schematic view), as shown byhe lower passage rates relative to larger fish. These vortexes areypically confined to areas of higher turbulence (Lupandin, 2005), inhe present case located along the jet path area between the orificesn the bottom of the flume. Though not quantified, the expectedigher proportion of time spent in this area, likely affected bal-nce and swimming performance of smaller individuals, as somehese fish were seen to adopt a “defence” behaviour at higher dis-harges, by spreading their pectoral fins in an attempt to stabilizeody position. It is clear that future research should consider ways –or example by placing bottom substrates to assist upstream move-

ents (Heimerl et al., 2008) – in an attempt to reduce turbulence,n particular the horizontal RSS, within the pools for easier andhorter passage of smaller species.

The present study provided an overview of experience gainedn fish passage through pool-type fishways in Portugal. The col-ection of a set of design and connectivity-based criteria and theirurther comparison with standard recommendations available inhe literature, allowed the diagnosis of fishways effectiveness byaking into account existing fish species, mainly potamodromous.or such species that are now afforded legislative protection underhe EWFD, more than half of the existing facilities were evaluated aseing unsuitable (i.e. of “low” effectiveness or “impassable”), a facthat highlighted the need for more intensive research and develop-

ent. The results of experiments carried out in a full-scale modelere essential and may have important implications for improve-ent and design of future pool-type fishways aiming to be passable

y potamodromous cyprinids. The use of submerged orifices wasound to be much more beneficial for fish movements than surfaceotches. Attention should therefore be paid in maintaining the ori-ces free of any debris or fine elements, to avoid obstruction andhus limitations to fish movements. This action assumes particularmportance during spring and early summer periods when inten-ive reproductive migration occurs in response to rises in wateremperature. If, however, surface notches are to be used and suf-cient water is available, streaming flow conditions – achieved by

ncreasing fishway discharge and allowing submersion of the crestf the notches due to increased water level of the downstream pools

should be encouraged in lieu of plunging flows. Upon searchingor an optimal design of cross-walls in an experimental pool-typeshway, Kim (2001) found that orifices and notches installed in

straight configuration were preferable to the ones in an offsetrrangement due to greater flow stability. However, such resultsacked validation through previous testing with fish. This is there-ore a worthy research subject that needs to be taken into accountn future experiments. The placement of bottom substrates nearhe orifices in order to smooth the horizontal velocity and hencettenuate the higher RSS remains a promising option to enhanceassage and deserves further attention. Also, the placement oftructural elements on the recirculation region to reduce its sizend their potential “trap” effect has proven successful in vertical-lot fishways and their application could be considered in pool-typeshways. Kemp et al. (2009) emphasised the need to incorporatehe influence of fish behaviour in response to hydraulic parameterso further improve fishway design. Upon developing fish passageriteria for the European eel Anguilla Anguilla L., these authorsound that specific behavioural characteristics were responsibleor delays on their movements, even by very small obstructions.epeated delays are likely to increase energetic expense and conse-uently the risk of predation. It seems clear that, the quantification

f fish behaviour, though on its infancy, may provide sound infor-ation that may aid engineers to improve current fishway design.

he use of physiological telemetry to assess whether passage itselfas negative effects on fitness that prevent species from reaching

48 J.M. Santos et al. / Ecological Engineering 48 (2012) 38– 50

F s (−�a ).

tu

A

twschEeoaAciSB

R

A

B

B

C

C

C

C

D

D

E

E

E

F

G

ig. 9. Distribution of fish transit time per cell(s) according to Reynolds shear stresdults (15 < TL < 25 cm) and (d), (e), (f) respectively, for large adults (25 ≤ TL < 35 cm

heir spawning grounds, remains a powerful tool in advancing ournderstanding of fish responses to different hydraulic conditions.

cknowledgements

The authors wish to thank Filipa Reis and Susana Santos forheir help in the collection of hydraulic data of all visited fish-ays. António Albuquerque and Luis Lopes assisted on the fish

ampling in the field. Thanks are also extended to all techni-al staff of SHP and forestry rangers for assistance and practicalelp in the field work and to the National Laboratory for Civilngineering (LNEC) for their valuable inputs and for providingssential facilities, hydraulic equipment and assistance through-ut the study. A special thank goes also to Adolfo Franco forssistance in designing the experiments. The Portuguese Forestuthority (AFN) provided the video equipment and the infrared fishounter. This study was partially funded by the Portuguese Min-stry of Agriculture, Rural Development and Fisheries. José Mariaantos was supported by two grants from FCT (BD/852/2000 andPD/26417/2006).

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José Maria Santos is an assistant researcher at InstitutoSuperior de Agronomia, Technical University of Lisbon,Portugal. His research interests focus primarily on ecohy-draulics, fish passes and freshwater fish ecology. His PhD(2004) was focused on the effects of flow regulations onfish population and communities and the role of differ-ent types of fish passes. Since 1997, he has collaboratedin several research projects encompassing specific areassuch as ecohydraulics, monitoring and evaluation of fishpasses and spatio-temporal organization of fish commu-nities and populations. He has over 15 ISI peer-reviewedpublications and more than 10 conference proceedingsand technical reports.

Ana Silva is a postdoctoral researcher on ecohydraulicsat Technical University of Lisbon (Instituto Superior deAgronomia), at University of Manitoba (Faculty of Engi-neering) and at University of Southampton (Faculty ofEngineering and the Environment-International Centrefor Ecohydraulics Research). Her research areas includefish ecology, fish conservation and restoration, fishpassage engineering, anthropogenic changes to aquaticsystems and environmental turbulence. She is particu-larly interested in issues regarding the enhancement offish attraction and fishways efficiency and the effects ofturbulence on fish behaviour, swimming performance andenergetic.

Christos (Chris) Katopodis, is a Professional Engineer,Consultant and Adjunct Professor. He formed KatopodisEcohydraulics Ltd. in 2010; he worked at the Freshwa-ter Institute, Winnipeg, Canada from 1975 to 2010. Hehas extensive experience with ecohydraulics interdis-ciplinary research and applications to water resourcesprojects. He collaborated with consulting companies, aca-demic institutions and government agencies in severalcountries. He presented invited lectures at more than15 countries. He contributed over 50 primary publica-tions, numerous conference papers and technical reports.He received the Canadian Society for Civil EngineeringDagenais Award, for “. . .outstanding contributions to the

evelopment and practice of hydrotechnical engineering in Canada” in 2007.

Paulo Pinheiro is a Master of Science at Instituto Superiorde Agronomia, Technical University of Lisbon, Portugal.He is also an environmental consultant at Aqualogus– Engineering and Environment Ltd. Paulo did his MScthesis on the evaluation of new technologies for study-ing fish pass effectiveness on pool-type fishways, withspecial emphasis on the use of infrared counter devicesand radio telemetry. He has collaborated in several ISIpeer-reviewed publications, conference proceedings andtechnical reports.

António Pinheiro is an Associate Professor of Hydraulicsand Hydraulics Structures at the Civil EngineeringDepartment, Instituto Superior Técnico (IST), TechnicalUniversity of Lisbon (UTL). He is a member of the Scien-tific Council of IST and UTL. He has extensive experiencein teaching and researching with hydraulics of structuresand ecohydraulics. He contributed to launch the PhD pro-gram on River Management and Restoration of UTL. Hecollaborates with consulting companies and governmentinstitutions in dam design projects and ecohydraulics

studies. He contributed over 70 journal and conferencepapers. He was a former president of the PortugueseWater Resources Association and, presently, integrates

he Portuguese Commission for Dam Safety.

5 al Eng

0 J.M. Santos et al. / Ecologic

Jorge Bochechas is currently the Head of Division ofWater Quality of the Portuguese Water Institute. He coor-dinated the Division of Inland Waters Fisheries of theNational Forest Authority for more than 12 years. Hehas an extensive experience in ecohydraulics and in thedesigning and monitoring of fish passes. He collaborated

in numerous projects encompassing ecohydraulics andtechnical evaluation of fish passes. He is the Portugueserepresentative of the European Inland Fisheries AdvisoryCommission (EIFAC). He contributed over 50 journal, con-ference papers and technical reports.

ineering 48 (2012) 38– 50

M. Teresa Ferreira is an Associate Professor at the For-est of Natural Resources, Environment and Landscape,School of Agriculture, Technical University of Lisbon.She was responsible or collaborator in 26 undergradu-ation courses, on 25 Master courses and a number ofshort courses. Her research includes the distribution pat-terns of ecological quality evaluation and monitoring,riparian vegetation and wetland woods, ecohydraulics of

fish, effects of regulation on fish communities and riverrestoration practices. She contributed over 100 interna-tional peer-reviewed publications and conference papers.She is member specialist of the National Water Counciland consultant for several government institutions.