Geology Reports⌕ Search

Geology topics

Theodore R. Castro-Santos

Publications and source records attributed to Theodore R. Castro-Santos.

At least 37 records · Page 2Linked to original sources
USGS2018

Sediment infilling benefits rainbow trout passage in a baffled channel

Fish are thought to exploit low velocity recirculation zones in the wakes of baffles to take refuge from challenging hydraulic conditions in baffled culverts. Here, we investigate how sediment deposition in the wakes of baffles affects passage and behaviors of juvenile rainbow trout in a baffled experimental flume. High temporal resolution 3D fish tracking provided detailed kinematics of adopted trajectories. Stereoscopic particle image velocimetry permitted a finely resolved description of the flow over a clear baffle configuration and the same configuration with sediment wedges placed in their wakes. Controlled station-holding, suggestive of flow-refuging, only occurred when sediment wedges were blocking the baffles’ recirculation region. Also, maximum distances of ascent were higher, and slower ground-speeds were employed in the sediment condition. The results of this study suggest the turbulent recirculatory wakes of the clear bed condition caused postural instabilities and were in many ways detrimental to passage performance. Additional research is required to understand the relationships existing between baffle height, hydrodynamic recirculatory wake metrics, sediment deposition and the behavioral responses of fish interacting with weir baffle wakes.

Ecological Engineering↗
USGS2018

Effectiveness of a fish ladder for two Neotropical migratory species in the Paraná River

We evaluated fish ladder effectiveness at Porto Primavera Dam in the Upper Paraná River, for two Neotropical migratory fish species. Overall, 564 fish (448 Megaleporinus obtusidens and 116 M. piavussu ) were PIT-tagged, released in upstream and downstream areas (on the left and right banks), and monitored continuously for 4 years. The fish performed two-way movements through the fish ladder, ascending from the tailrace and descending from the forebay. We registered 46 M. obtusidens (10.3%) and only 3 M. piavussu (2.6%) from the fish ladder, therefore all analyses were focused on M. obstusidens . Entry proportion ranged from 0 to 48.1% depending on release site and was greatest for fish released downstream near the fish ladder entrance. Entry times ranged from 3.0 to 384.0 days, and median times were 32.9 and 25.8 days for downstream and upstream, respectively. Of fish that entered the fish ladder, passage percentages were 80% for fish release downstream and 100% for fish released upstream, and median transit time was 0.7 and 0.9 hours, respectively. Results suggest that if guidance and entry conditions can be improved, this fish ladder design holds promise as an effective solution for providing passage in both directions.

Marine and Freshwater Research↗
USGS2018

Influence of baffles on upstream passage of brook trout and brown trout in an experimental box culvert

There is much to learn about improving baffle designs to increase successful fish passage through culverts. A fish’s motivation to attempt entry into the culvert is essential. Upon entry, successful passage will largely depend on the physiological ability of the fish to navigate the entire culvert length. In this study, the motivation of brook trout ( Salvelinus fontinalis (Mitchill, 1814)) and brown trout ( Salmo trutta Linnaeus, 1758) to attempt ascent of an experimental flume, which mimics a roadway culvert left bare (smooth) or fitted with either spoiler or weir baffles, is assessed. Performance, measured as maximum distance of ascent within the flume, is also quantified. The bare flume was the most motivating for brook trout, and the weirs were most motivating for brown trout. As a rule, brown trout showed less motivation to stage attempts than brook trout, except within the weir baffle treatments. Performance was greatest in the weirs for smaller trout and in the spoiler baffles for larger trout. Our findings suggest that baffle form influences passage rates at road crossings in ways previously unknown and further stresses the importance of considering fish motivation and performance together when assessing the efficacy of baffle forms.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2018

Environmental, anthropogenic, and dietary influences on fine-scale movement patterns of Atlantic salmon through challenging waters

Partial barriers to migration can affect migratory fish population dynamics and be influenced by many biotic, abiotic, and anthropogenic factors, including nutritional deficiencies. We investigated how such variables (including a thiamine deficiency) impact fine-scale movement of landlocked Atlantic salmon ( Salmo salar ) by treating returning spawners with thiamine and observing their attempts to climb a human-altered, high velocity stretch of river using fine-scale radio telemetry. Multiple re-entries into a river section, along with water temperature, strongly influenced movement rates. High or increasing discharge encouraged downstream movement; males abandoned migratory attempts at a higher rate than females. Although thiamine-injected salmon exhibited greater migratory duration, this did not produce a measurable improvement in passage performance, possibly due to the difficulty associated with this section of river — among 24 tagged salmon staging 10.9 attempts each and lasting 1.5 days per attempt on average, only three traversed the entire reach. This study provides new insights into how biotic and abiotic variables affect fish movement, while suggesting limits to the potential for human intervention (thiamine injections) to assist passage through partial migratory barriers.

New York, Vermont↗
USGS2017

The future of fish passage science, engineering, and practice

Much effort has been devoted to developing, constructing and refining fish passage facilities to enable target species to pass barriers on fluvial systems, and yet, fishway science, engineering and practice remain imperfect. In this review, 17 experts from different fish passage research fields (i.e., biology, ecology, physiology, ecohydraulics, engineering) and from different continents (i.e., North and South America, Europe, Africa, Australia) identified knowledge gaps and provided a roadmap for research priorities and technical developments. Once dominated by an engineering‐focused approach, fishway science today involves a wide range of disciplines from fish behaviour to socioeconomics to complex modelling of passage prioritization options in river networks. River barrier impacts on fish migration and dispersal are currently better understood than historically, but basic ecological knowledge underpinning the need for effective fish passage in many regions of the world, including in biodiversity hotspots (e.g., equatorial Africa, South‐East Asia), remains largely unknown. Designing efficient fishways, with minimal passage delay and post‐passage impacts, requires adaptive management and continued innovation. While the use of fishways in river restoration demands a transition towards fish passage at the community scale, advances in selective fishways are also needed to manage invasive fish colonization. Because of the erroneous view in some literature and communities of practice that fish passage is largely a proven technology, improved international collaboration, information sharing, method standardization and multidisciplinary training are needed. Further development of regional expertise is needed in South America, Asia and Africa where hydropower dams are currently being planned and constructed.

Fish and Fisheries↗
USGS2017

Swimming behaviour and ascent paths of brook trout in a corrugated culvert

Culverts may restrict fish movements under some hydraulic conditions such as shallow flow depths or high velocities. Although swimming capacity imposes limits to passage performance, behaviour also plays an important role in the ability of fish to overcome velocity barriers. Corrugated metal culverts are characterized by unsteady flow and existence of low‐velocity zones, which can improve passage success. Here, we describe swimming behaviour and ascent paths of 148 wild brook trout in a 1.5‐m section of a corrugated metal culvert located in Raquette Stream, Québec, Canada. Five passage trials were conducted in mid‐August, corresponding to specific mean cross‐sectional flow velocities ranging from 0.30 to 0.63 m/s. Fish were individually introduced to the culvert and their movements recorded with a camera located above the water. Lateral and longitudinal positions were recorded at a rate of 3 Hz in order to identify ascent paths. These positions were related to the distribution of flow depths and velocities in the culvert. Brook trout selected flow velocities from 0.2 to 0.5 m/s during their ascents, which corresponded to the available flow velocities in the culvert at the low‐flow conditions. This however resulted in the use of low‐velocity zones at higher flows, mainly located along the walls of the culvert. Some fish also used the corrugations for sheltering, although the behaviour was marginal and did not occur at the highest flow condition. This study improves knowledge on fish behaviour during culvert ascents, which is an important aspect for developing reliable and accurate estimates of fish passage ability.

River Research and Applications↗
USGS2017

Downstream migration and multiple dam passage by Atlantic Salmon smolts

The purpose of this study was to investigate behavior and survival of radio-tagged wild and hatchery-reared landlocked Atlantic Salmon Salmo salar smolts as they migrated past three hydropower dams equipped with fish bypass solutions in the Winooski River, Vermont. Among hatchery-reared smolts, those released early were more likely to initiate migration and did so after less delay than those released late. Once migration was initiated, however, the late-released hatchery smolts migrated at greater speeds. Throughout the river system, hatchery-reared fish performed similarly to wild fish. Dam passage rates varied between the three dams and was highest at the dam where unusually high spill levels occurred throughout the study period. Of the 50 fish that did migrate downstream, only 10% managed to reach the lake. Migration success was low despite the presence of bypass solutions, underscoring the need for evaluations of remedial measures; simply constructing a fishway is not synonymous with providing fish passage.

Vermont↗
USGS2017

Novel, continuous monitoring of fine‐scale movement using fixed‐position radiotelemetry arrays and random forest location fingerprinting

Radio‐tag signals from fixed‐position antennas are most often used to indicate presence or absence of individuals, or to estimate individual activity levels from signal strength variation within an antenna's detection zone. The potential of such systems to provide more precise information on tag location and movement has not been explored in great detail in an ecological setting. By reversing the roles that transmitters and receivers play in localization methods common to the telecommunications industry, we present a new telemetric tool for accurately estimating the location of tagged individuals from received signal strength values. The methods used to characterize the study area in terms of received signal strength are described, as is the random forest model used for localization. The resulting method is then validated using test data before being applied to true data collected from tagged individuals in the study site. Application of the localization method to test data withheld from the learning dataset indicated a low average error over the entire study area (<1 m), whereas application of the localization method to real data produced highly probable results consistent with field observations. This telemetric approach provided detailed movement data for tagged fish along a single axis (a migratory path) and is particularly useful for monitoring passage along migratory routes. The new methods applied in this study can also be expanded to include multiple axes ( x , y , z ) and multiple environments (aquatic and terrestrial) for remotely monitoring wildlife movement.

New York↗
USGS2017

The effects of horizontally and vertically oriented baffles on flow structure andascent performance of upstream-migrating fish

Considerable effort has been expended to construct culverts and fishways that allow for fish passage. However, the designs have seldom considered behaviour, energetics, and biomechanics of fish. In this study, we performed controlled experiments, in which upstreammigrating Alewife (Alosa pseudoharengus) and Brook Trout (Salvelinus fontinalis) were allowed to volitionally enter either one of two open channels. These channels were outfitted with horizontally and vertically oriented baffles. The flow structure was characterized using acoustic Doppler velocimeter measurements. The added baffles had a marked influence on the flow field, which was distinct between horizontal and vertical baffles, indicative of horizontally and vertically orientated vortices, respectively. Passage success was measured, both in terms of attraction and ascent performance under each flow condition. The results indicated that Alewife and Brook Trout staged significantly more attempts into the vertical baffled channel compared to the horizontal baffled channel. However, Alewife traversed greater distances swimming in the channel with the horizontal baffles at the lower flow condition. Brook Trout also swam further under low flow but traversed similar dtistances in both channels. This information furthers our understanding of both ascent performance and behavioural responses of fish in relation to turbulent flow and roughness orientation.

Journal of Ecohydraulics↗
USGS2017

Migratory behavior of adult sea lamprey and cumulative passage performance through four fishways

This article describes a study of PIT-tagged sea lamprey ( Petromyzon marinus ) ascending four fishways comprising three designs at two dams on the Connecticut River, USA. Migration between dams was rapid (median migration rate = 23 km·day −1 ). Movement through the fishways was much slower, however (median = 0.02–0.33 km·day −1 ). Overall delay at dams was substantial (median = 13.6–14.6 days); many fish failed to pass (percent passage ranged from 29% to 55%, depending on fishway), and repeated passage attempts compounded delay for both passers and failers. Cox regression revealed that fishway entry rates were influenced by flow, temperature, and diel cycle, with most lampreys entering at night and at elevated flows, but with no apparent effect of sex or length. Overall delay was influenced by slow movement through the fishways, but repeated failures were the primary factor determining delay. These data suggest that although some lamprey were able to pass fishways, they did so with difficulty, and delays incurred as they attempted to pass may act to limit their distribution within their native range.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2017

Is motivation important to brook trout passage through culverts?

Culverts can restrict movement of stream-dwelling fish. Motivation to enter and ascend these structures is an essential precursor for successful passage. However, motivation is challenging to quantify. Here, we use attempt rate to assess motivation of 447 brook trout ( Salvelinus fontinalis ) entering three culverts under a range of hydraulic, environmental, and biological conditions. A passive integrated transponder system allowed for the identification of passage attempts and success of individual fish. Attempt rate was quantified using time-to-event analysis allowing for time-varying covariates and recurrent events. Attempt rate was greatest during the spawning period, at elevated discharge, at dusk, and for longer fish. It decreased during the day and with increasing number of conspecifics downstream of the culvert. Results also show a positive correlation between elevated motivation and successful passage. This study enhances understanding of factors influencing brook trout motivation to ascend culverts and shows that attempt rate is a dynamic phenomenon, variable over time and among individuals. It also presents methods that could be used to investigate other species’ motivation to pass natural or anthropogenic barriers.

Quebec↗
USGS2016

Reinforcement and validation of the analyses and conclusions related to fishway evaluation data from Bunt et al.: ‘Performance of fish passage structures at upstream barriers to migration’

Detailed re-examination of the datasets that were used for a meta-analysis of fishway attraction and passage revealed a number of errors that we addressed and corrected. We subsequently re-analysed the revised dataset, and results showed no significant changes in the primary conclusions of the original study; for most species, effective performance cannot be assured for any fishway type.

River Research and Applications↗
USGS2016

Migratory delay leads to reduced passage success of Atlantic salmon smolts at a hydroelectric dam

Passage of fish through hydropower dams is associated with mortality, delay, increased energy expenditure and migratory failure for migrating fish and the need for remedial measures for both upstream and downstream migration is widely recognised. A functional fish passage must ensure safe and timely passage routes that a substantial portion of migrating fish will use. Passage solutions must address not only the number or percentage of fish that successfully pass a barrier, but also the time it takes to pass. Here, we used radiotelemetry to study the functionality of a fish bypass for downstream-migrating wild-caught and hatchery-released Atlantic salmon smolts. We used time-to-event analysis to model the influence of fish characteristics and environmental variables on the rates of a series of events associated with dam passage. Among the modelled events were approach rate to the bypass entry zone, retention rates in both the forebay and the entry zone and passage rates. Despite repeated attempts, only 65% of the tagged fish present in the forebay passed the dam. Fish passed via the bypass (33%), via spill (18%) and via turbines (15%). Discharge was positively related to approach, passage and retention rates. We did not detect any differences between wild and hatchery fish. Even though individual fish visited the forebay and the entry zone on multiple occasions, most fish passed during the first exposures to these zones. This study underscores the importance of timeliness to passage success and the usefulness of time-to-event analysis for understanding factors governing passage performance.

Ecology of Freshwater Fish↗
USGS2016

Ascent ability of brown trout, Salmo trutta , and two Iberian cyprinids − Iberian barbel, Luciobarbus bocagei , and northern straight-mouth nase, Pseudochondrostoma duriense − in a vertical slot fishway

Passage performance of brown trout ( Salmo trutta ), Iberian barbel ( Luciobarbus bocagei ), and northern straight-mouth nase ( Pseudochondrostoma duriense) was investigated in a vertical slot fishway in the Porma River (Duero River basin, Spain) using PIT telemetry. We analysed the effects of different fishway discharges on motivation and passage success. Both cyprinid species ascended the fishway easily, performing better than the trout despite their theoretically weaker swimming performance. Fishway discharge affected fish motivation although it did not clearly influence passage success. Observed results can guide design and operation criteria of vertical slot fishways for native Iberian fish.

Castilla y León region↗
USGS2016

Brook trout passage performance through culverts

Culverts can restrict access to habitat for stream-dwelling fishes. We used passive integrated transponder telemetry to quantify passage performance of >1000 wild brook trout ( Salvelinus fontinalis ) attempting to pass 13 culverts in Quebec under a range of hydraulic and environmental conditions. Several variables influenced passage success, including complex interactions between physiology and behavior, hydraulics, and structural characteristics. The probability of successful passage was greater through corrugated metal culverts than through smooth ones, particularly among smaller fish. Trout were also more likely to pass at warmer temperatures, but this effect diminished above 15 &deg;C. Passage was impeded at higher flows, through culverts with steep slopes, and those with deep downstream pools. This study provides insight on factors influencing brook trout capacity to pass culverts as well as a model to estimate passage success under various conditions, with an improved resolution and accuracy over existing approaches. It also presents methods that could be used to investigate passage success of other species, with implications for connectivity of the riverscape.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2016

Analysis of brook trout spatial behavior during passage attempts in corrugated culverts using near-infrared illumination video imagery

We used video recording and near-infrared illumination to document the spatial behavior of brook trout of various sizes attempting to pass corrugated culverts under different hydraulic conditions. Semi-automated image analysis was used to digitize fish position at high temporal resolution inside the culvert, which allowed calculation of various spatial behavior metrics, including instantaneous ground and swimming speed, path complexity, distance from side walls, velocity preference ratio (mean velocity at fish lateral position/mean crosssectional velocity) as well as number and duration of stops in forward progression. The presentation summarizes the main results and discusses how they could be used to improve fish passage performance in culverts.

Conference Paper↗
USGS2015

Sprinting performance of two Iberian fish: Luciobarbus bocagei and Pseudochondrostoma duriense in an open channel flume

This paper presents sprinting data from Iberian barbel ( Luciobarbus bocagei ) and northern straight-mouth nase ( Pseudochondrostoma duriense ), volitionally swimming against high velocity flows (1.5, 2.5 and 3 m s &minus;1 ) in an open channel flume. Swimming endurance and speed greatly exceeded previously published observations with both species attaining swim speeds >20 body lengths s &minus;1 . Flow velocity was the primary variable limiting the distance both species were able to traverse. Barbel swam greater distances than nase at higher flow velocities, with longer individuals attaining greater distances than smaller ones. The results challenge established fish passage guidelines, suggesting that in some cases these species are capable of passing much higher velocities than was previously believed.

Vadacondes↗