Previous Article in Journal
A Quantitative Approach to Prior Setting for Relative Biomass (B/k) in CMSY++: Application to Snow Crabs (Chionoecetes opilio) in Korean Waters
Previous Article in Special Issue
Spatio-Temporal Habitat Dynamics of Migratory Small Yellow Croaker (Larimichthys polyactis) in Hangzhou Bay, China
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Fishes
Volume 10
Issue 8
10.3390/fishes10080401
fishes-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Smaller Body Size and Warmer Water Improve Two Temperate Fishes’ Upstream Passage over Wetted Ramps

by
Uli Reinhardt
* and
Grace Scott Halcrow
Department of Biology, Eastern Michigan University, 441 Mark Jefferson Science Complex, Ypsilanti, MI 48197, USA
*
Author to whom correspondence should be addressed.
Fishes 2025, 10(8), 401; https://doi.org/10.3390/fishes10080401
Submission received: 21 April 2025 / Revised: 5 June 2025 / Accepted: 28 July 2025 / Published: 11 August 2025
(This article belongs to the Special Issue New Conservation Strategies for Freshwater and Marine Fishes: Habitat Is the Key)
Browse Figures
Versions Notes

Abstract

Most artificial fishways allow upstream passage of large-bodied, strong-swimming fish species. Wetted ramps, which are moderate in inclination and have little water flow, could allow passage of smaller-bodied fishes over low-head dams and culverts. We observed creek chubs (Semotilus atromculatus) and white suckers (Catostomus commersonii) on wetted ramps in a laboratory setting. Smaller individuals entered the ramps at lower absolute swim velocities but exhibited superior upstream passage due to positive acceleration in the thin (<1 cm) water layer on the ramps. Larger fish displayed more pronounced, probably less efficient, head and tail amplitudes during passage. We argue that the relatively smaller depth of immersion in water was responsible for hampering the larger-bodied individuals on the ramps. Warmer water temperatures (15 °C vs. 10 °C) roughly doubled the mean distance fish traveled up the ramps. Our findings can inform fishway design for small-bodied fishes. In regions with low-head barriers against invasive sea lamprey (Petromyzon marinus), wetted ramps may help connect habitats for native fish species.
Keywords:
sea lamprey; low-head ramped weirs; invasive species; barriers; fish passage; size effects; temperature effects
Key Contribution: Wetted ramps, smooth angled ramps with shallow water flow can assist in the upstream passage of smaller-bodied fishes over instream obstacles.

1. Introduction

The number of freshwater dams and other instream barriers continues to climb worldwide [1,2]. Numerous research studies have sought to improve the passage of aquatic species over these barriers [3,4,5]. Some studies quantified the swimming ability of various fishes to design passage systems that heed the swimming thresholds of those species [6,7,8,9]. One general finding is that larger body sizes of fish can help with upstream passage through a variety of existing fishways. Many economically important species, such as salmonids, migrate upstream at relatively large body sizes. Fishways designed for those larger-bodied and powerfully-swimming fishes are often unsuitable for immature fish and non-salmonid species [10,11,12,13].
Larger fish achieve higher maximum swimming velocities than smaller fish because they generate greater propulsive force and more sustained acceleration due to their greater tail beat amplitudes that prolong the propulsive stages [14]. However, this advantage of larger fish is reduced by their larger body mass, which requires greater energy expenditure to overcome greater inertial forces, and by their higher surface drag [14,15,16]. Sufficient fast-start acceleration and great burst swimming are needed by fish to overcome high-velocity spots found in upstream fish passes. If a fish is unable to reach a velocity greater than that of the water, it will fail to pass. In addition, if it cannot maintain such velocity long enough to navigate the passage, it will also fail [9].
Many amphidromous species, or species that migrate outside the breeding season, do so at body lengths between 2 and 10 cm [10]. These smaller-bodied fishes lack the physical swimming ability of larger fish and are especially disadvantaged in pool-and-weir, vertical-slot, and similar fishways that require strong swimming and/or jumping ability. Nature-like fishways can allow small-bodied fish upstream passage around high-gradient fishways because they replicate the stream’s original flow and discharge characteristics, but they are expensive to build and require an abundance of space [11]. In cases when installing a nature-like fishway is not feasible and the gain in river elevation is small, a chain of simple wetted ramps (sometimes called “low-head ramped weirs”, [17]) has been proposed as a possible solution [10,17,18,19]. The wetted ramp is unique in that it requires fish to swim through a shallow (5–10 mm) film of water over an inclined surface. Characteristics of a wetted ramp include a moderate slope of about 10° and both low (i) discharge and (ii) water velocity, which should benefit weaker-swimming fishes. Unfortunately, field trials with this ramp have not been promising so far. Finfishes attempting to scale a 15° inclined, 1.5 m long wetted ramp at a fishway in the Brule River, Wisconsin, appeared to be largely unable to do so, with only a small percentage of finfishes completing upstream passage [19]. If the wetted ramp is to become a useful tool for passing weaker-swimming fishes over low-head barriers, we must better understand what determines success during the attempted passage.
Here, we examine the effect of fish body size on relative swimming ability on wetted ramps, using two fish species common in temperate North American rivers, creek chub (Semotilus atromaculatus) and white sucker (Catostomus commersoni). We predict that larger fish will have relatively poor passage success, measured by the distance traveled up the ramp. This is because in the shallow film of water on the ramp, larger fish will have relatively less submerged surface area (i.e., a greater proportion of their body sticks out of the water) and therefore will have a harder time generating propulsive force [20]. We also examine the effect of water temperature on passage success by these two species over wetted ramps. Maximum sustained swimming speed is achieved at some optimum temperature, meaning it increases with higher temperatures until reaching a species-specific temperature beyond which swimming performance decreases [21]. High temperatures reduce aerobic performance by lowering oxygen availability and muscle contractility. Low temperatures impair muscle power and lead to earlier fatigue due to faster recruitment of anaerobic fibers [22]. Due to the known relationship between water temperature and maximum aerobic swim speed (Ucrit) in temperate fishes [23,24], as well as temperature and overall metabolic efficiency [25], we predicted that at higher temperatures (15 °C vs. 10 °C) fish would be able to swim higher up the wetted ramp.
The purpose of this laboratory study was twofold:
  • To quantify the effect of fish size on swimming performance on a wetted ramp (Experiment I);
  • To explore the effect of temperature on swimming performance on a wetted ramp (Experiment II).

2. Materials and Methods

2.1. Collection Methods

We collected creek chubs (Semotilus atromaculatus) and white suckers (Catostomus commersonii) bi-weekly from the Saline River near the Michigan DNR Saline Fisheries Station in Saline, Michigan. Fishing methods included electrofishing with an electroshock backpack and beach seines. We selected the two species based on local availability and a wide range of available body sizes. Immature creek chubs and white suckers used in the experiments ranged from 10 to 24 cm and from 11 to 25 cm in fork length, respectively. The collected fish were housed in a recirculating tank for a maximum of 30 h at experimental temperatures. Each fish was used in only one trial.

2.2. Experimental Setup

Experiment 1 took place June to August at the Michigan DNR Saline Fisheries Station, and Experiment 2 took place October–November at the Aquatic Ecology Research facility at Eastern Michigan University. The acrylic ramp we used for Experiment I (Size Effects) measured 1 m in length by 0.3 m in width, with a ramp angle of 8.5° and a maximum viewable distance by the camera of 0.7 m. A high-speed camera (recording at 90 fps) and infrared lighting were set up above the ramps. The ramp and downstream holding tank (0.4 m × 0.4 m with 0.3 m water depth) were supplied with water from the Saline River at a flow rate of 2 L/s and an ambient temperature ranging between 15 °C and 25 °C over the course of the 3-month experiment and cooling from start to end of recordings by ~2 °C each night. The water depths/velocities on this ramp were approximately 8 mm/0.80 m per second at the top and 4 mm/1.5 m per second at the 0.10 m downstream entry point. These flow values allowed for the filming of swimming behavior and were comparable to previous studies on wetted ramps [10,18,19] (but less than [17]). The top of the ramp was closed off so that individuals who reached the top had to fall back down. Filming took place from dusk to 1:00 a.m. No motivating factors other than flow attraction were used to encourage the fish to swim up the ramps in either of the experiments. The ramp we used in Experiment II (Temperature Effects) was installed in a 500 L tank measuring 2.44 m in length × 1.22 m in width and a water depth of 0.17 m. De-chlorinated city water was supplied via a 140 L sump, chiller, and recirculating pumps (Figure 1). A grated wall created a downstream staging tank of 1.2 m × 0.8 m. A ramp made from acrylic extended from the downstream tank and measured 1 m in length by 0.3 m in width, with a ramp angle of 10°. If fish managed to swim the total length of the ramp, they entered an upstream holding tank that they could return from (downstream over the ramp) at will. Water was recirculated over the ramp at a rate of 1.9 L/s and maintained at either 10 °C or 15 °C (fluctuating by +/−1 °C, auto-regulated via sensors in the chiller units and verified daily with handheld thermometers). The water velocity averaged 1 m/s over the length of the ramp, and water depth on the ramp was ~10 mm. Infrared lights and an infrared-sensitive camera (recording at 30 fps) were mounted over the tank. The cameras began recording at 6:00 pm and stopped at 4:00 am. Observations for both experiments took place at night under IR illumination because pilot laboratory observations had shown very little fish activity under normal daylight conditions.

2.3. Experimental Procedure

In each trial, three fish of visibly different lengths were introduced to each tank. The fork length of the fish was measured at the end of each trial to minimize handling stress prior to observations. In Experiment I, photo-optic light gates placed near the water level of each ramp were used to trigger recordings of 8 s in duration at a recording rate of 90 fps. The footage was reviewed after each trial and each attempt to swim up the ramp was analyzed. To be considered an ‘Attempt’, the fish snout had to reach at least the 10 cm mark on the ramp. We ignored events where the fish snout did not reach the 10 cm mark. We treated fish reversing direction on the ramp (going down head-first) as ‘Attempts’ in the same manner as the more common occurrence of fish falling back (going down sideways or tail-first). Each ramp had prominent lines at 5 cm intervals, visible on recorded footage to determine the distance each fish swam on the ramp plane, measured by the maximum upstream distance on the ramp the snout reached. For each attempt on the Experiment I ramp, the following parameters were extracted from the recordings, using Image J software (ImageJ.net): maximum distance traveled up the ramp, fish size class (for identification purposes), on- ramp amplitude of the fish lateral body movement, fish entry and on-ramp velocity, acceleration, and snout and tail amplitudes (Table 1). Entry velocities were determined by counting the frames it took each fish to travel the first 10 cm past the photo-electric eye. Acceleration was the difference in velocity between each successive 10 cm segment. All velocity/acceleration measurements refer to swim speed over the ground. The on-ramp acceleration of each fish was analyzed using “best-performance” acceleration, which was defined as the acceleration of the attempt in which the fish reached its maximum observed distance on the ramp. For each attempt on the Experiment II ramp, the fish size (small, medium, or large) and the maximum distance traveled up the ramp were extracted from the video. From these data, the fish size class was then cross-referenced with the fork-length measurements conducted after each trial.

2.4. Data Analysis

In all analyses, one replicate represents the behavior of one tested fish. To analyze the effect of fish size on on-ramp swimming behavior, a multiple linear regression was performed to regress body length and water temperature during each trial vs. the mean distance traveled up the ramp for each tested fish. Additional linear regressions were used to regress fish length for both species versus maximum initial velocity (highest entry velocity measured for each fish). Simple linear regressions comparing fish length and best-performance acceleration were performed for both chubs and suckers. To evaluate the effect of fish length on on-ramp swimming behavior, a linear regression was used to relate chub length to relative head amplitude (amplitude of lateral movement divided by fish length), and relative tail amplitude, on the ramp. Suckers were excluded from this analysis due to an unsatisfactory number of usable high-speed video recordings.
To assess the impact of temperature on the ability to swim up wetted ramps (Experiment II), the mean distance traveled on the ramp was evaluated, using only data from individuals who attempted passage at least three times, i.e., using the greatest distance traveled on the ramp for each attempt and calculating a mean value for each individual that attempted more than twice. An inverse transformation on the distances was applied to normalize data, and ANCOVA was used to analyze the effect of the two temperatures on the mean distance traveled up the wetted ramp, after removing the covariant of fork length and testing for homogeneity of the regression slopes.

3. Results

3.1. Effect of Fish Length on Distance Traveled, Initial Velocity, and On-Ramp Acceleration

We found a strong negative relationship between fish length and mean distance traveled for both chubs (p < 0.001, N = 73) and suckers (p = 0.003, N = 31) (Figure 2). Distance traveled decreased as fish length increased by approximately 2.3 cm and 3.3 cm for each 1 cm additional length of chubs vs. suckers, respectively. The effect of water temperature was not significant in this analysis. The linear regression equations were as follows: y = 62.4 − 2.3 body length + 0.51 °C for chubs and y = 69.7768 − 3.3 body length + 0.8 °C for suckers. Chub body length and maximum initial velocity were strongly positively correlated (p = 0.003, N = 48); however, no significant relationship was found between sucker length and maximum initial velocity (p = 0.56, N = 23) (Figure 3). The maximum initial velocity for chubs increased by approximately 4.2 cm/s per 1 cm increase in chub length. There was a strong negative relationship between chub length and on-ramp acceleration (p < 0.001, N = 44); however, we found no significant relationship between sucker length and on-ramp acceleration (p = 0.775, N = 20) (Figure 4). For chubs, acceleration decreased at a rate of about 3 cm × s−1 × s−1 per 1 cm increase in body length, so fish above about 15 cm were not achieving positive acceleration on the ramp.

3.2. Effect of Fish Length on Relative Tail and Head Amplitude

There was a strong positive relationship between chub length and relative head amplitude (p < 0.001, N = 30) (Figure 5). There was also a positive relationship between chub length and relative tail amplitude (p = 0.05, N = 30). For suckers, we did not obtain a large enough sample size due to a limited number of usable video recordings for this analysis.

3.3. Effect of Temperature on Distance Traveled

Most experimental subjects tried at least once to swim up the ramp in Experiment II (88% of tested fish at 10 °C, 92% at 15 °C). Among those individuals, the mean rate of observed attempts per fish was 1.7/hr (Stdev = 1.8) at 10 °C and 0.5/hr (Stdev = 0.6) at 15 °C. As in Experiment I, we found a negative relationship between fish length and distance traveled up the wetted ramps at both experimental temperatures (Figure 6). The mean distance traveled for the fish at 15 °C was 68 cm, while at 10 °C it was approximately 35 cm. After controlling for the effect of body length, the two temperatures led to different mean distances traveled on the ramp (ANCOVA of mean distance traveled in cm with body length as covariant, F1,56 = 26.12, p < 0.005).

4. Discussion

Our study demonstrates that both body size and water temperature significantly impact the performance of stream-dwelling finfish on wetted ramps. Smaller individuals of the two species we tested were better suited for upstream passage over the wetted ramp because they exhibited superior acceleration in the thin layer of flowing water. With increasing body length, the distance traveled up the ramp plane decreased at a rate of 2.3 cm (creek chubs) to 3.3 cm (white suckers) per cm body length increase. In Experiment II, fish in warmer water managed to swim higher up the wetted ramp.
While the performance of smaller-bodied individuals in Experiment I varied considerably, the larger chubs and suckers we observed appeared to have a distinct disadvantage swimming in a partially submerged environment. As expected, larger individual chubs entered the ramp at a higher initial velocity (Figure 4). Larger fish should hold an advantage as far as maximum swimming velocity is concerned in a fully submerged environment like the holding tank below each ramp [26,27]. The larger fish’s inability to translate this greater initial velocity into greater distance traveled suggests that on-ramp acceleration is crucial for successful passage over the wetted ramp. Larger creek chub individuals were unable to accelerate on the ramp (Figure 4); those longer than 15 cm relied mostly on their entry velocity onto the ramp for passage. Smaller individuals tended to enter the ramp at half the absolute swim velocity of the largest individuals but managed to accelerate once on the ramp. This was similar to the pattern found in a different study of the same two species swimming on wetted ramps [18], where swim velocity on the ramp was reduced by 25% for every 10 cm increase in fish length. In the white suckers, some of the performance metrics we studied were not significantly impacted by body size. This could have been caused by the smaller size range of suckers we used in Experiment I and a limited sample size, or their more tubular body shape. It could also be that for white suckers, the passage performance in fishways is less dependent on body size than in other temperate-region freshwater fishes studied so far. Neither Haro et al. [9] nor Castro-Santos [8] found a significant effect of the body size of white suckers on passage success in their experimental fishways. Contrary to our findings, another study reported larger individuals of galaxiid fish having better passage success on a similar wetted ramp [10]. However, the fishes used in the study were smaller overall (1.5–9.5 cm total length), the ramps were longer (3–6 m) and steeper, and one of the species climbed at steeper angles using pectoral suckers.
Smaller fish may have two important factors working in their favor when scaling a wetted ramp. They have considerably less mass to move against gravity, as mass increases exponentially with increasing length [15], and they have relatively more submerged propulsive surface area. Figure 7 illustrates this by showing the relationship between the total length, body mass, and estimated submerged body surface area of salmon in three water depths (based on data from Kane, 1988, Tucker et al., 2002, and Jones et al., 1999) [28,29,30]. Salmon can be used to illustrate this relationship because they have a fusiform shape like creek chubs and white suckers. The graph shows that submerged surface area increases with body length for all depths, but at a much smaller rate than body mass increases. In this model, an 8 cm long fish has 40% of its body surface submerged at 6 mm water depth versus a 25 cm fish that is only 21% submerged. Finfish swimming in the sub-carangiform manner, such as suckers and chubs, generate forward thrust through the propagation of propulsive waves down the fish’s body towards the caudal fin [27]. Forward thrust is then generated by the backward force of water adjacent to the propulsive surfaces (caudal fin, peduncle, etc.). Larger fish have relatively less submerged propulsive surface area in partially submerged environments like wetted ramps; thus, they probably generate less thrust per body mass. The effect of this is seen in salmonids of the Pacific Coast, where shallow stream areas become inaccessible to larger-bodied species [31,32,33].
Larger fish appeared to use greater relative head and tail beat amplitudes when attempting to scale the ramp (Figure 5). This means that larger fish bent their body more during swim strokes on the ramp. More curved bodies are less efficient during swim strokes because they open more of the body to surface drag [34,35]. It is possible that these greater body undulations are not the cause of the reduced passage success but a behavioral reaction to poor progress on the ramp. Larger fish decelerated on the ramp and potentially responded by using wider, more drastic but less efficient swimming movements. The short, controlled body undulations resulting in smaller relative head and tail beat amplitudes that we saw mostly in the smaller fish appear to enhance success on the wetted ramp.
We found the same pattern of smaller fish swimming farther up the ramps in Experiment II, where we used a similar ramp but tanks of different dimensions and somewhat different water depths/velocities on the ramps. In that experiment, the fish also showed an improved ability to scale the ramp at warmer water temperatures (15 vs. 10 °C). In Experiment 1, water temperature did not significantly affect passage performance on the wetted ramp in a linear fashion. Further experiments under better-controlled thermal conditions are needed to determine if this was caused by a plateau of a curvilinear performance profile in that higher temperature range (15 °C to 25 °C). Numerous studies have assessed the effect of water temperature on swimming performance in fish [21,24,36,37,38,39]. Most studies reported improved aerobic swimming performance at higher temperatures, assessed as Ucrit in swim tunnel experiments; and some studies have shown a decline in maximum sustained swim speed at the higher end of experimental temperatures [22,24,38,39]. Haro et al. [9] studied the ability of various temperate-region fish species to pass open-channel flumes and found a significant positive effect of water temperature on volitional upstream passage for several species (but not white suckers). Clearly, the expected range of water temperatures at the time of upstream migration of targeted fish species needs to be considered when designing upstream passage devices, such as the wetted ramp.

5. Conclusions

Our observations show that the wetted ramp could be a useful tool for helping smaller-bodied fishes pass upstream over in-stream barriers. Many fishways are designed with large jumping species in mind [10,11], hence having a fishway to assist juveniles and/or smaller fish species could help reduce problems with river connectivity caused by dams and other barriers [6]. The modular characteristic of the wetted ramp could help serve a large variety of fish species and life stages across stream sizes. The wetted ramp could also become useful in the management of invasive sea lamprey (Petromyzon marinus) in the Laurentian Great Lakes by passing finfish over the low-head barriers that are commonly used to block the upstream spawning migration of adult sea lamprey [18,19,40]. Sea lampreys do not climb like some other lamprey species [41] and are unable to swim up smooth wetted ramps longer than about half their total length, as they cannot generate sufficient thrust when their dorsal-ventral fins are not fully submerged [19,40]. Wetted ramps could be used to selectively pass smaller native fishes, whereas other fishways could be used in tandem to cater to larger native species/individuals at these lamprey barriers [42]. Further studies, ideally conducted under field conditions, are still needed to assess the feasibility of using such wetted ramps, including the specific flow conditions that maximize upstream passage of desired fish species, including laterally compressed species (e.g., sunfishes) that we did not test.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/fishes10080401/s1, the contents of Excel tables represent raw datas.

Author Contributions

Conceptualization, U.R.; methodology, U.R.; formal analysis, U.R.; investigation, U.R.; resources, U.R.; data curation, U.R.; writing—original draft preparation, U.R. and G.S.H.; writing—review and editing, U.R. and G.S.H.; visualization, G.S.H. and U.R.; supervision, U.R.; project administration, U.R. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Institutional Review Board Statement

This research was reviewed by the Eastern Michigan University Institutional Animal Care and Use Committee (IACUC) on 5 November 2015 for adherence to animal care and handling protocols. IACUC approval number: 2015-071.

Informed Consent Statement

Not applicable.

Data Availability Statement

The original contributions presented in this study are included in the Supplementary Materials. Further inquiries can be directed to the corresponding author.

Acknowledgments

We acknowledge Levi Kivari for carrying out Experiment I for his MSc thesis at Eastern Michigan University [43]. Experiment II was carried out by the students of Eastern Michigan University’s Bio 482/582 class in the fall of 2021 and 2023. We thank Nick Thorns and Larkin Pence for technical support in building and getting the experimental system running. Comments by anonymous reviewers on an earlier version helped us improve the manuscript. The authors have reviewed and edited the output and take full responsibility for the content of this publication.

Conflicts of Interest

The authors declare no conflicts of interest.

Abbreviations

The following abbreviations are used in this manuscript:
ANCOVAAnalysis of Covariance
UCritMaximum aerobic swim speed

References

  1. Bednarek, A.T. Undamming Rivers: A review of the ecological impacts of dam removal. Environ. Manag. 2001, 27, 803–814. [Google Scholar] [CrossRef]
  2. Pringle, C.M. Hydrologic connectivity and the management of biological reserves: A global perspective. Ecol. Appl. 2001, 11, 981–998. [Google Scholar] [CrossRef]
  3. Cushman, S.A. Effects of habitat loss and fragmentation on amphibians: A review and prospectus. Biol. Conserv. 2006, 128, 231–240. [Google Scholar] [CrossRef]
  4. Fahrig, L. Effects of habitat fragmentation on biodiversity. Annu. Rev. Ecol. Evol. Syst. 2003, 34, 487–515. [Google Scholar] [CrossRef]
  5. Roni, P.; Hanson, K.; Beechie, T. Global review of the physical and biological effectiveness of stream habitat rehabilitation techniques. N. Am. J. Fish Manag. 2008, 28, 856–890. [Google Scholar] [CrossRef]
  6. Knapp, M.; Haxton, T.; Chu, C. Fish passage hydrodynamics: Insights into overcoming migration challenges for small-bodied fish. J. Ecohydraul. 2019, 4, 43–55. [Google Scholar] [CrossRef]
  7. Akanyeti, O.; Liao, J.C. The effect of flow speed and body size on Kármán gait kinematics in rainbow trout. J. Exp. Biol. 2013, 216, 3442–3449. [Google Scholar] [CrossRef] [PubMed]
  8. Castro-Santos, T. Quantifying the combined effects of attempt rate and swimming capacity on passage through velocity barriers. Can. J. Fish. Aquat. Sci. 2004, 61, 1602–1615. [Google Scholar] [CrossRef]
  9. Haro, A.; Castro-Santos, T.; Noreika, J.; Odeh, M. Swimming performance of upstream migrant fishes in open-channel flow: A new approach to predicting passage through velocity barriers. Can. J. Fish. Aquat. Sci. 2004, 61, 1590–1601. [Google Scholar] [CrossRef]
  10. Baker, C.F.; Boubée, J.A.T. Upstream passage of inanga Galaxias maculatus and redfin bullies Gobiomorphus huttoni over artificial ramps. J. Fish Biol. 2006, 69, 668–681. [Google Scholar] [CrossRef]
  11. Calles, E.O.; Greenberg, L.A. Evaluation of nature-like fishways for re-establishing connectivity in fragmented salmonid populations in the river Emån. Riv. Res. Appl. 2005, 21, 951–960. [Google Scholar] [CrossRef]
  12. Noonan, M.J.; Grant, J.W.A.; Jackson, C.D. A quantitative assessment of fish passage efficiency. Fish Fish. 2012, 13, 450–464. [Google Scholar] [CrossRef]
  13. Cuenco, M.L.; McCullough, D.A. Framework for Estimating Salmon Survival as a Function of Habitat Conditions; revised ed.; Columbia River Inter-Tribal Fish Commission Technical Report; Columbia River Inter-Tribal Fish Commission: Portland, OR, USA, 1997; Volume 96, 119p.
  14. Webb, P.W. The effect of size on the fast-start performance of rainbow trout Salmo gairdneri, and a consideration of piscivorous predator-prey interactions. J. Exp. Biol. 1976, 65, 157–177. [Google Scholar] [CrossRef]
  15. Froese, R. Cube law, condition factor and weight-length relationships: History, meta-analysis and recommendations. J. Appl. Ichthyol. 2006, 22, 241–253. [Google Scholar] [CrossRef]
  16. Moutopoulos, D.K.; Stergiou, K.I. Length-weight and length-length relationships of fish species from the Aegean Sea (Greece). J. Appl. Ichthyol. 2002, 18, 200–203. [Google Scholar] [CrossRef]
  17. Amaral, S.D.; Branco, P.; Katopodis, C.; Ferreira, M.T.; Pinheiro, A.N.; Santos, J.M. Passage performance of potamodromous cyprinids over an experimental low-head ramped weir: The effect of ramp length and slope. Sustainability 2019, 11, 1456. [Google Scholar] [CrossRef]
  18. Sherburne, S.; Reinhardt, U.G. First test of a species-selective adult sea lamprey migration barrier. J. Great Lakes Res. 2016, 42, 893–898. [Google Scholar] [CrossRef]
  19. Reinhardt, U.G.; Corniuk, J. Wetted ramps selectively block upstream passage of adult sea lampreys. Fishes 2024, 9, 293. [Google Scholar] [CrossRef]
  20. Cowan, W.R.; Rankin, D.E.; Gard, M. Evaluation of Central Valley spring-run Chinook salmon passage through lower Butte Creek using hydraulic modelling techniques. River Res. Appl. 2017, 33, 328–340. [Google Scholar] [CrossRef]
  21. Myrick, C.A.; Cech Jr, J.J. Swimming performances of four California stream fishes: Temperature effects. Environ. Biol. Fishes 2000, 58, 289–295. [Google Scholar] [CrossRef]
  22. Randall, D.J.; Brauner, C.J. Effects of environmental factors on exercise in fish. J. Exp. Biol. 1991, 160, 113–126. [Google Scholar] [CrossRef]
  23. Wardle, C.S.; Videler, J.J. Fish Swimming. In Aspects of Animal Movement; Elder, H.Y., Trueman, E.R., Eds.; Cambridge University Press: Cambridge, UK, 1980; pp. 113–136. [Google Scholar]
  24. Brett, J.R. The respiratory metabolism and swimming performance of young sockeye salmon. J. Fish. Res. Board Can. 1964, 21, 1183–1226. [Google Scholar] [CrossRef]
  25. Riyanto, M.; Yanase, K.; Arimoto, T. Temperature and fatigue effect on the maximum swimming speed of jack mackerel Trachurus japonicus. Fish. Sci. 2014, 80, 53–59. [Google Scholar] [CrossRef]
  26. Wardle, C.S. Limit of fish swimming speed. Nature 1975, 255, 725–727. [Google Scholar] [CrossRef]
  27. Webb, P.W. The swimming energetics of trout. I. thrust and power output at cruising speeds. J. Exp. Biol. 1971, 55, 489–520. [Google Scholar] [CrossRef] [PubMed]
  28. Kane, T.R. Length–weight relationship of hatchery-reared Atlantic salmon. Prog. Fish-Cult. 1988, 50, 28–30. [Google Scholar] [CrossRef]
  29. Tucker, C.S.; Sommerville, C.; Wootten, R. Does size really matter? effects of fish surface area on the settlement and initial survival of Lepeophtheirus salmonis, an ectoparasite of Atlantic salmon Salmo salar. Dis. Aquat. Organ. 2002, 49, 145–152. [Google Scholar] [CrossRef]
  30. Jones, R.E.; Petrell, R.J.; Pauly, D. Using modified length–weight relationships to assess the condition of fish. Aquacult. Eng. 1999, 20, 261–276. [Google Scholar] [CrossRef]
  31. Nagtegaal, D.A.; Candy, J.R.; Riddell, B. A preliminary report on the chinook productivity study conducted on the Cowichan River during 1993. In Canadian Manuscript Report of Fisheries and Aquatic Sciences 2315; Fisheries and Oceans Canada: Ottawa, ON, Canada, 1995; 84p. [Google Scholar]
  32. Vadas, R.L., Jr. Instream-flow needs for anadromous salmonids and lamprey on the Pacific coast, with special reference to the Pacific Southwest. Environ. Monit. Assess. 2000, 64, 331–358. [Google Scholar] [CrossRef]
  33. Vadas, R.L., Jr.; Beecher, H.A.; Boessow, S.N.; Kohr, H. Coastal Cutthroat Trout redd counts impacted by natural water supply variations. N. Am. J. Fish. Manag. 2016, 36, 900–912. [Google Scholar] [CrossRef]
  34. Hertel, H. Structure, Form, Movement; Reinhold Publishing Corporation: New York, NY, USA, 1966; 251p. [Google Scholar]
  35. Liu, Y.; Jiang, H. Research development on fish swimming. Chin. J. Mech. Eng. 2022, 35, 114. [Google Scholar] [CrossRef]
  36. Sobenes, C.; Link, O.; Habit, E.; Górski, K.; Tonkin, J.D.; Monsalve, A.; Arismendi, I.; Laborde, A. Critical swimming speed at different temperatures for small-bodied freshwater native riverine fish species. Sci. Rep. 2024, 14, 5355. [Google Scholar] [CrossRef] [PubMed]
  37. Claireaux, G.; Couturier, C.; Groison, A.L. effect of temperature on maximum swimming speed and cost of transport in juvenile European sea bass (Dicentrarchus labrax). J. Exp. Biol. 2006, 209, 3420–3428. [Google Scholar] [CrossRef] [PubMed]
  38. Johansen, J.L.; Jones, G.P. Increasing ocean temperature reduces the metabolic performance and swimming ability of coral reef damselfishes. Glob. Change Biol. 2011, 17, 2971–2979. [Google Scholar] [CrossRef]
  39. Koumoundouros, G.; Sfakianakis, D.G.; Divanach, P.; Kentouri, M. Effect of temperature on swimming performance of sea bass juveniles. J. Fish Biol. 2002, 60, 923–932. [Google Scholar] [CrossRef]
  40. Reinhardt, U.G.; Binder, T.R.; McDonald, D.G. Ability of adult sea lamprey to climb inclined surfaces. Am. Fish. Soc. Symp. 2009, 72, 125–138. [Google Scholar] [CrossRef]
  41. Reinhardt, U.G.; Eidietis, L.; Friedl, S.E.; Moser, M. Pacific lamprey climbing behavior. Can. J. Zool. 2008, 86, 1264–1272. [Google Scholar] [CrossRef]
  42. Great Lakes Fisheries Commission: Fish Pass. Available online: https://www.glfc.org/fishpass.php (accessed on 15 April 2025).
  43. Kivari, L. The Wetted Ramp as a Useful Tool to Service Smaller-Bodied Finfishes at Low-Head Aquatic Barriers. Master’s Thesis, Eastern Michigan University, Ypsilanti, MI, USA, 2016; 68p. [Google Scholar]
Fishes 10 00401 g001
Figure 1. Overhead view of tank from Experiment II including lower and upper holding tanks, separated by a grated divider, segmented acrylic ramp, and water pump. Three individuals of visibly different sizes were used to allow differentiation in the video recordings.
Figure 1. Overhead view of tank from Experiment II including lower and upper holding tanks, separated by a grated divider, segmented acrylic ramp, and water pump. Three individuals of visibly different sizes were used to allow differentiation in the video recordings.
Fishes 10 00401 g001
Fishes 10 00401 g002
Figure 2. The relationship between fish length and mean distance traveled on the wetted ramp by creek chubs (solid best-fit line) and white suckers (dashed line) in Experiment I. Maximum distance traveled decreased significantly with body length in both species (chubs: N = 73, suckers: N = 31).
Figure 2. The relationship between fish length and mean distance traveled on the wetted ramp by creek chubs (solid best-fit line) and white suckers (dashed line) in Experiment I. Maximum distance traveled decreased significantly with body length in both species (chubs: N = 73, suckers: N = 31).
Fishes 10 00401 g002
Fishes 10 00401 g003
Figure 3. The relationship between fish length and swim velocity upon entry of the wetted ramp for creek chubs and white suckers in Experiment I. Each data point is the highest velocity observed among one individual’s passage attempts. For chubs alone, there was a significant positive relationship between body length and initial velocity. (chubs: N = 48, suckers: N = 23). Regression equation: Velocity = 18.1 + 4.2 body length.
Figure 3. The relationship between fish length and swim velocity upon entry of the wetted ramp for creek chubs and white suckers in Experiment I. Each data point is the highest velocity observed among one individual’s passage attempts. For chubs alone, there was a significant positive relationship between body length and initial velocity. (chubs: N = 48, suckers: N = 23). Regression equation: Velocity = 18.1 + 4.2 body length.
Fishes 10 00401 g003
Fishes 10 00401 g004
Figure 4. The relationship between fish length and on-ramp acceleration for creek chubs and white suckers in Experiment I. Chubs showed a significant negative relationship, with larger fish tending to accelerate less on the ramp. Regression equation: Acceleration = 44.2–3 body length. For suckers, the regression was not significant. (chubs: N = 44, suckers: N = 20).
Figure 4. The relationship between fish length and on-ramp acceleration for creek chubs and white suckers in Experiment I. Chubs showed a significant negative relationship, with larger fish tending to accelerate less on the ramp. Regression equation: Acceleration = 44.2–3 body length. For suckers, the regression was not significant. (chubs: N = 44, suckers: N = 20).
Fishes 10 00401 g004
Fishes 10 00401 g005
Figure 5. The relationship between the body length of creek chubs and their relative head and tail amplitude on the wetted ramp in Experiment I. There was a significant positive relationship between body length and relative head and tail amplitude. (N = 30). Regression equations: Head amplitude = −0.08 + 0.01 body length, Tail amplitude = 0.35 + 0.006 body length.
Figure 5. The relationship between the body length of creek chubs and their relative head and tail amplitude on the wetted ramp in Experiment I. There was a significant positive relationship between body length and relative head and tail amplitude. (N = 30). Regression equations: Head amplitude = −0.08 + 0.01 body length, Tail amplitude = 0.35 + 0.006 body length.
Fishes 10 00401 g005
Fishes 10 00401 g006
Figure 6. The relationship between fish length (data for creek chubs and white suckers combined) and mean distance traveled up the ramp at 10° and 15 °C on the wetted ramp in Experiment II (10 °C: N = 36, 15 °C: N = 22). Regression equations: Distance = 66.9 − 1.5 body length for 10 °C and distance = 130.3 − 3.3 body length for 15 °C.
Figure 6. The relationship between fish length (data for creek chubs and white suckers combined) and mean distance traveled up the ramp at 10° and 15 °C on the wetted ramp in Experiment II (10 °C: N = 36, 15 °C: N = 22). Regression equations: Distance = 66.9 − 1.5 body length for 10 °C and distance = 130.3 − 3.3 body length for 15 °C.
Fishes 10 00401 g006
Fishes 10 00401 g007
Figure 7. The estimated relationship between total body length, body weight (secondary y-axis), and submerged body surface area for fusiform fishes in three water depths. The model was based on literature-derived data on length, height, weight, and surface area for Atlantic and Chinook salmon in the size range of the fish we tested [28,29,30].
Figure 7. The estimated relationship between total body length, body weight (secondary y-axis), and submerged body surface area for fusiform fishes in three water depths. The model was based on literature-derived data on length, height, weight, and surface area for Atlantic and Chinook salmon in the size range of the fish we tested [28,29,30].
Fishes 10 00401 g007
Table 1. Measurements used in the Video Analysis and their Definitions.
Table 1. Measurements used in the Video Analysis and their Definitions.
MeasurementDefinition
Distance traveledThe greatest distance the fish’s snout traveled on the ramp plane during one attempt. One replicate in the analysis represents the mean of all observed attempts for an individual fish.
Fish SizeFork length of the fish.
Entry VelocityThe number of video frames recorded for travel between two successive 10 cm lines on the ramp, measured between 10 and20 cm above the water line.
AccelerationDifference in ground speed between successive 10 cm intervals on the ramps.
Head AmplitudeThe total lateral distance the head moved in one direction plus the total lateral distance moved in the opposite direction during a swim stroke [25].
Tail AmplitudeThe total lateral distance the tail moved in one direction plus the total lateral distance moved in the opposite direction during a swim stroke.
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Reinhardt, U.; Halcrow, G.S. Smaller Body Size and Warmer Water Improve Two Temperate Fishes’ Upstream Passage over Wetted Ramps. Fishes 2025, 10, 401. https://doi.org/10.3390/fishes10080401

AMA Style

Reinhardt U, Halcrow GS. Smaller Body Size and Warmer Water Improve Two Temperate Fishes’ Upstream Passage over Wetted Ramps. Fishes. 2025; 10(8):401. https://doi.org/10.3390/fishes10080401

Chicago/Turabian Style

Reinhardt, Uli, and Grace Scott Halcrow. 2025. "Smaller Body Size and Warmer Water Improve Two Temperate Fishes’ Upstream Passage over Wetted Ramps" Fishes 10, no. 8: 401. https://doi.org/10.3390/fishes10080401

APA Style

Reinhardt, U., & Halcrow, G. S. (2025). Smaller Body Size and Warmer Water Improve Two Temperate Fishes’ Upstream Passage over Wetted Ramps. Fishes, 10(8), 401. https://doi.org/10.3390/fishes10080401

Article Metrics

Back to TopTop