Geology topics

Theodore R. Castro-Santos

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

At least 19 recordsLinked to original sources

USGS2023

Environmental factors influencing detection efficiency of an acoustic telemetry array and consequences for data interpretation

Background Acoustic telemetry is a commonly used technology to monitor animal occupancy and infer movement in aquatic environments. The information that acoustic telemetry provides is vital for spatial planning and management decisions concerning aquatic and coastal environments by characterizing behaviors and habitats such as spawning aggregations, migrations, corridors, and nurseries, among others. However, performance of acoustic telemetry equipment and resulting detection ranges and efficiencies can vary as a function of environmental conditions, leading to potentially biased interpretations of telemetry data. Here, we characterize variation in detection performance using an acoustic telemetry receiver array deployed in Wellfleet Harbor, Massachusetts, USA from 2015 to 2017. The array was designed to study benthic invertebrate movements and provided an in situ opportunity to identify factors driving variation in detection probability. Results The near-shore location proximate to environmental monitoring allowed for a detailed examination of factors influencing detection efficiency in a range-testing experiment. Detection ranges varied from < 50 to 1,500 m and efficiencies varied from 0 to 100% within those detection ranges. Detection efficiency was affected by distance, wind speed and direction, wave height and direction, water temperature, water depth, and water quality. Conclusions Performance of acoustic telemetry systems is strongly contingent on environmental conditions. Our study found that wind, waves, water temperature, water quality, and depth all affected performance to an extent that could seriously compromise a study if these effects were not taken into consideration. Other unmeasured factors may also be important, depending on the characteristics of each site. This information can help guide future telemetry study designs by helping researchers anticipate the density of receivers required to achieve study objectives. Researchers can further refine and document the reliability of their data by incorporating continuously deployed range-testing tags and prior knowledge on varying detection efficiency into movement and occupancy models.

Massachusetts↗

USGS2023

Survival, healing, and swim performance of juvenile migratory sea lamprey (Petromyzon marinus) implanted with a new acoustic microtransmitter designed for small eel-like fishes

Background Little is known about the transformer stage of the parasitic lampreys, a brief but critical period that encompasses juvenile out-migration from rivers to lakes or oceans to begin parasitic feeding. Information about this life stage could have significant conservation implications for both imperiled and invasive lampreys. We investigated tag retention, survival, wound healing, and swim performance of newly transformed sea lamprey ( Petromyzon marinus ) implanted with a new micro-acoustic transmitter, the eel–lamprey acoustic transmitter (ELAT), in a controlled laboratory environment. Results The 61-day survival of our tagged subjects was 71%, within the range reported in similar studies of juvenile lampreys. However, survival was significantly lower in the tagged animals (vs control), with no effect statistically attributable to measures of animal length, mass, condition, or population of origin (Great Lakes vs. Atlantic drainage). Mortality in tagged fish was concentrated in the first four days post-surgery, suggesting injury from the surgical process. An unusually long recovery time from anesthesia may have contributed to the increased mortality. In a simple burst swim assay, tagged animals swam significantly slower (− 22.5%) than untagged animals, but were not significantly different in endurance swim tests. A composite wound healing score at day four was a significant predictor of maximum burst swim speed at day 20, and wound condition was related to animal mass, but not length, at the time of tagging. Conclusions Impairments to survival and swim performance of juvenile sea lamprey implanted with the ELAT transmitter were within currently reported ranges for telemetry studies with small, difficult to observe fishes. Our results could be improved with more refined anesthesia and surgical techniques. The ability to track migratory movements of imperiled and pest populations of parasitic lampreys will improve our ability to estimate vital rates that underlie recruitment to the adult population (growth, survival) and to investigate the environmental factors that regulate the timing and rates of movement, in wild populations.

Atlantic Ocean, Connecticut River, Laurentian Grea↗

USGS2023

Tracking anadromous fish over successive freshwater migrations reveals the influence of tagging effect, previous success and abiotic factors on upstream passage over barriers

Predicting and mitigating the impact of anthropogenic barriers on migratory fish requires an understanding of the individual and environmental factors that influence barrier passage. Here, the upstream spawning migrations of iteroparous twaite shad Alosa fallax were investigated over three successive spawning migrations in a highly fragmented river basin using passive acoustic telemetry (n=184). More fish approached and passed barriers in the lower river reaches than further upstream, with the median cumulative weir passage time (IQR) of 4.6 (1.8 - 9.2) days representing 18% of their time in river. Returning fish in their second year had significantly higher weir passage rates than in their tagging year, with passage rates also positively influenced by previous passage success. Higher water temperature and river level also had positive impacts on passage rates. Lower weir passage rates by newly tagged individuals suggests that reliance on within-year passage estimates in telemetry-based barrier impact assessments could result in conservative results, while higher passage rates of previously successful versus unsuccessful individuals suggests a conserved motivation and/or inherent ability to pass barriers.

Canadian Journal of Fisheries and Aquatic Sciences↗

USGS2022

Fish-inspired segment models for undulatory swimming

Many aquatic animals swim by undulatory body movements and understanding the diversity of these movements could unlock the potential for designing better underwater robots. Here, we analyzed the steady swimming kinematics of a diverse group of fish species to investigate whether their undulatory movements can be represented using a series of interconnected multi-segment models, and if so, to identify the key factors driving the segment configuration of the models. Our results show that the steady swimming kinematics of fishes can be described successfully using parsimonious models, 83% of which had fewer than five segments. In these models, the anterior segments were significantly longer than the posterior segments, and there was a direct link between segment configuration and swimming kinematics, body shape, and Reynolds number. The models representing eel-like fishes with elongated bodies and fishes swimming at high Reynolds numbers had more segments and less segment length variability along the body than the models representing other fishes. These fishes recruited their anterior bodies to a greater extent, initiating the undulatory wave more anteriorly. Two shape parameters, related to axial and overall body thickness, predicted segment configuration with moderate to high success rate. We found that head morphology was a good predictor of its segment length. While there was a large variation in head segments, the length of tail segments was similar across all models. Given that fishes exhibited variable caudal fin shapes, the consistency of tail segments could be a result of an evolutionary constraint tuned for high propulsive efficiency. The bio-inspired multi-segment models presented in this study highlight the key bending points along the body and can be used to decide on the placement of actuators in fish-inspired robots, to model hydrodynamic forces in theoretical and computational studies, or for predicting muscle activation patterns during swimming.

Bioinspiration & Biomimetics↗

USGS2022

BIOTAS: BIOTelemetry Analysis Software, for the semi-automated removal of false positives from radio telemetry data

Introduction Radio telemetry, one of the most widely used techniques for tracking wildlife and fisheries populations, has a false-positive problem. Bias from false-positive detections can affect many important derived metrics, such as home range estimation, site occupation, survival, and migration timing. False-positive removal processes have relied upon simple filters and personal opinion. To overcome these shortcomings, we have developed BIOTAS (BIOTelemetry Analysis Software) to assist with false-positive identification, removal, and data management for large-scale radio telemetry projects. Methods BIOTAS uses a naïve Bayes classifier to identify and remove false-positive detections from radio telemetry data. The semi-supervised classifier uses spurious detections from unknown tags and study tags as training data. We tested BIOTAS on four scenarios: wide-band receiver with a single Yagi antenna, wide-band receiver that switched between two Yagi antennas, wide-band receiver with a single dipole antenna, and single-band receiver that switched between five frequencies. BIOTAS has a built in a k -fold cross-validation and assesses model quality with sensitivity, specificity, positive and negative predictive value, false-positive rate, and precision-recall area under the curve. BIOTAS also assesses concordance with a traditional consecutive detection filter using Cohen’s κ "> κ κ . Results Overall BIOTAS performed equally well in all scenarios and was able to discriminate between known false-positive detections and valid study tag detections with low false-positive rates (< 0.001) as determined through cross-validation, even as receivers switched between antennas and frequencies. BIOTAS classified between 94 and 99% of study tag detections as valid. Conclusion As part of a robust data management plan, BIOTAS is able to discriminate between detections from study tags and known false positives. BIOTAS works with multiple manufacturers and accounts for receivers that switch between antennas and frequencies. BIOTAS provides the framework for transparent, objective, and repeatable telemetry projects for wildlife conservation surveys, and increases the efficiency of data processing.

Animal Biotelemetry↗

USGS2022

Applied aspects of locomotion and biomechanics

Locomotion is the act and process of moving from place to place, which is fundamental to the life history of all mobile organisms. While the field of biomechanics encompasses the study of the physical constraints of what animals are capable of, ecological contexts require an integrated view that includes ecology and behavior. This chapter provides an overview of some of the areas where locomotion and biomechanics of fish movement interface with the rapidly evolving changes that humans impose on aquatic environments. These changes include fundamental alterations to the environment such as altered flows, fragmentation of riverine habitats, and invasive species, but also direct interactions that occur with capture fisheries. We explore each of these areas, considering both challenges and opportunities informed by the study of locomotion and biomechanics, emphasizing how this field can contribute to conservation of fishes in the Anthropocene. We then turn to technology, where important advances are aiding in our understanding of fish movement. In some cases those advances have themselves led to novel technologies, where biomimetic robots and related devices offer novel opportunities, both for conservation and for other pursuits.

Book chapter↗

USGS2021

Culverts delay upstream and downstream migrations of river herring (Alosa spp.)

Alewife ( Alosa pseudoharengus ) and blueback herring ( Alosa aestivalis ) are iteroparous anadromous fish found throughout the East Coast of North America. The phenology of anadromous fish migrations is important for fitness, and the duration of spawning migrations has been compressed in recent years in response to climate change. Anthropogenic barriers to movement, such as dams and culverts at road-stream crossings, can further disrupt migration phenology by delaying movement and increasing predation risk. We used passive integrated transponder (PIT) telemetry to quantify upstream and downstream migratory delay at five road-stream-crossing culverts on the Herring River (MA, USA). Groundspeeds were reduced at all culverts in both directions, confirming that the culverts impede movement despite high passage proportions. The cumulative delay of the culverts on the upstream migration was sufficient to more than double the amount of time required to traverse the river if the culverts had been absent. Furthermore, the presence of snapping turtles ( Chelydra serpentina ) ambushing river herring within one of the culverts resulted in reduced passage rates beyond the reduction in movement caused by the physical structure itself. This highlights that physical barriers can create cascading ecological consequences and the importance of taking a holistic approach to understanding barrier effects.

Massachusetts↗

USGS2021

Activity patterns of anadromous fish below a tide gate: Observations from high‐resolution imaging sonar

The construction of dams and tide gates on waterways has altered the physical structure of many coastal, estuarine, and freshwater systems. These changes have come at a cost to fish populations, most notably diadromous species, which rely on connectivity between marine and freshwater systems. These anthropogenic structures can have direct effects on migrating fish, such as blocking fish passage, or have more subtle effects, such as changing movement patterns. This study used a high‐resolution Adaptive Resolution Imaging Sonar to examine the behavior of Striped Bass Morone saxatilis , a large coastal predator, and Alewife Alosa pseudoharengus and Blueback Herring Alosa aestivalis (collectively known as river herring), which are forage fish, below a tide gate structure on the Herring River in Wellfleet, Massachusetts, during the river herring spring spawning run. Striped Bass were persistently present downstream of the tide gate and exhibited strong diurnal and tidal patterns. Activity of Striped Bass was highest at night and during ebb tides. During peak outflow periods, river herring were observed milling downstream of the dam in a scour pool, indicating delayed upstream passage. River herring upstream migration was primarily associated with daytime and during incoming tides. Downstream‐migrating river herring were primarily observed during nighttime hours. While it was documented that the tide gates provided a physical impediment to migration, their effect on predator behavior could pose an additional challenge to migrating river herring, further complicating their recovery efforts. Due to the prevalence of obstructed waterways, studying the behavior of fish around anthropogenic structures is important in understanding the full range of impacts that these systems have under varying ecological conditions and on ecological relationships.

Massachusetts↗

USGS2021

Effects of plunge pool configuration on downstream passage survival of juvenile blueback herring

Anadromous alosines are widespread throughout the Northern Hemisphere. Juveniles of this clade are notoriously fragile animals that are at high risk of injury and death associated with passage at hydroelectric facilities. Although turbine mortality is a common concern, conditions encountered when bypassed around these routes may also be hazardous. Downstream bypass structures typically discharge into plunge pools, which are highly turbulent and may cause mechanical injury. We subjected live, actively migrating juvenile blueback herring to a suite of realistic plunge pool conditions (3 m drop, pool depth of 60–180 cm, and discharge of 0.28–1.70 m 3 /s) and monitored them for ≥ 96 h. Survival was generally higher than expected (>80% in all cases). However, both plunge pool volume and total discharge affected survival with elevated discharge and shallow conditions associated with increased mortality. Mortality was often delayed: rates remained elevated throughout the monitoring period, indicating that survival studies based on shorter periods underestimate total mortality.

Aquaculture and Fisheries↗

USGS2021

Convergence of undulatory swimming kinematics across a diversity of fishes

Fishes exhibit an astounding diversity of locomotor behaviors from classic swimming with their body and fins to jumping, flying, walking, and burrowing. Fishes that use their body and caudal fin (BCF) during undulatory swimming have been traditionally divided into modes based on the length of the propulsive body wave and the ratio of head:tail oscillation amplitude: anguilliform, subcarangiform, carangiform, and thunniform. This classification was first proposed based on key morphological traits, such as body stiffness and elongation, to group fishes based on their expected swimming mechanics. Here, we present a comparative study of 44 diverse species quantifying the kinematics and morphology of BCF-swimming fishes. Our results reveal that most species we studied share similar oscillation amplitude during steady locomotion that can be modeled using a second-degree order polynomial. The length of the propulsive body wave was shorter for species classified as anguilliform and longer for those classified as thunniform, although substantial variability existed both within and among species. Moreover, there was no decrease in head:tail amplitude from the anguilliform to thunniform mode of locomotion as we expected from the traditional classification. While the expected swimming modes correlated with morphological traits, they did not accurately represent the kinematics of BCF locomotion. These results indicate that even fish species differing as substantially in morphology as tuna and eel exhibit statistically similar two-dimensional midline kinematics and point toward unifying locomotor hydrodynamic mechanisms that can serve as the basis for understanding aquatic locomotion and controlling biomimetic aquatic robots.

Proceedings of the National Academy of Sciences↗

USGS2021

Surface water with more natural temperatures promotes physiological and endocrine changes in landlocked Atlantic salmon smolts

Hatchery salmonid smolts are often reared using groundwater with elevated temperatures to maximize growth. Previous work has shown that rearing hatchery smolts in surface water with a more natural thermal regime resulted in increased return rates of adult landlocked Atlantic salmon ( Salmo salar ). We evaluated whether landlocked Atlantic salmon reared in surface water with a natural temperature regime have altered physiological smolt characteristics compared with fish reared in groundwater with elevated winter temperatures. Hatchery fish were sampled three consecutive years from January to May. Additional fish were released as smolts, recaptured, and compared with fry-stocked smolts. Surface water smolts had earlier peaks of plasma T 4 , lower T 3 levels, later peak cortisol, and lower gill Na + /K + -ATPase activity as compared with groundwater smolts. After release and recapture, surface water fish had elevated plasma T 4 and gill Na + /K + -ATPase activity compared with groundwater fish, but less than stream-reared fish. Elevated plasma T 4 in surface water fish in the hatchery and after release may have promoted imprinting and other aspects of smolt development, contributing to the higher adult return rates of a cohort reared in surface water.

Vermont↗

USGS2021

Tide gates form physical and ecological obstacles to river herring (Alosa spp.) spawning migrations

River herring ( Alosa spp.) are anadromous fish that enter North American Atlantic coastal rivers and lakes each spring to spawn. Anthropogenic structures such as dams and tide gates serve as physical obstacles that limit river herring access to spawning habitat. This study examined the physical and ecological components affecting herring passage through a tide gate by applying a time-to-event analysis framework to multiple movement behaviors derived from telemetry data. Herring had higher passage success early in the season (78%) than later (16%). Key behaviors that govern passage varied with diel period, tide, and flow direction through the gates. Furthermore, these behaviors shifted as the season progressed, consistent with the hypothesis that predator avoidance may be driving passage failure late in the spawning season.

Canadian Journal of Fisheries and Aquatic Sciences↗

USGS2020

Wait and snap: eastern snapping turtles (Chelydra serpentina) prey on migratory fish at road-stream crossing culverts

There is growing evidence that culverts at road-stream crossings can increase fish density by reducing stream width and fish movement rates, making these passageways ideal predator ambush locations. In this study, we used a combination of videography and δ 13 C stable isotope analyses to investigate predator–prey interactions at a road-stream crossing culvert. Eastern snapping turtles ( Chelydra serpentina ) were found to regularly reside within the culvert to ambush migratory river herring ( Alosa spp.). Resident fish species displayed avoidance of the snapping turtles, resulting in zero attempted attacks on these fish. In contrast, river herring did not display avoidance and were attacked by a snapping turtle on 79% of approaches with a 15% capture rate. Stable isotope analyses identified an apparent shift in turtle diet to consumption of river herring in turtles from culvert sites that was not observed in individuals from non-culvert sites. These findings suggest that anthropogenic barriers like culverts that are designed to allow passage may create predation opportunities by serving as a bottleneck to resident and migrant fish movement.

Biology Letters↗

USGS2020

How lipid content and temperature affect American shad (Alosa sapidissima) attempt rate and sprint swimming: Implications for overcoming migration barriers

How seasonal effects such as temperature increases and reduced lipid content affect the ability of anadromous fishes to traverse high-velocity barriers and sprint swimming is poorly understood. We evaluated American shad ( Alosa sapidissima ) swimming performance in a flume against high flow velocities (2.5–3.7 m·s −1 ) during the upstream migration period (April–May; temperatures 11.1–21.4 °C) to determine how their willingness to enter a velocity barrier (attempt rate) and their swimming endurance changed during migration. American shad did not make attempts at low temperatures, and attempt rate gradually increased throughout the migration as temperatures warmed. American shad displayed two distinct, nonsustained swimming modes (prolonged and sprint swimming), and endurance was different between sexes. At warmer temperatures, females swam at prolonged speeds more often and longer females displayed a lower endurance. Males primarily swam at sprint speeds and were affected by swimming speed, fork length, and lipid content. Our results indicate that American shad motivation and swimming endurance change over the course of the migration as conditions change, potentially limiting their ability to pass barriers.

Canadian Journal of Fisheries and Aquatic Sciences↗

USGS2019

Body shape is related to the attempt rate and passage success of brook trout at in-stream barriers

The ability to move between habitats has important implications for fitness in many species. In-stream barriers such as culverts can impede movements of riverine fishes and thus reduce connectivity between habitats. The ability of fish to overcome barriers is related to the features of the environment and the barrier itself, but also to physiological, morphological and behavioural traits of the fish. Among these, body shape varies among and within species, and influences swimming ability, a key component of passage performance through culverts. We conducted an experimental study on wild brook trout ( Salvelinus fontinalis ) to assess the effects of individual body shape on attempt rate and passage success through culverts on six streams. A more streamlined body shape was associated with an increased motivation to enter and ascend the culverts, and, to a lesser extent, with the probability of successful passage once an attempt was staged. Motivation and successful passage were also influenced by the density of conspecifics below the culvert, time of day, fish body size and water velocity. Policy implications. While fish body shape is expected to influence swimming performance, our research shows the most important effect of body shape to be on an individual's motivation to stage passage attempts at culverts. This study points to an important connection between behaviour and morphological traits that influence passage success and suggests that in-stream barriers may be an important agent of selection on behaviour and morphology in wild fish populations.

Journal of Applied Ecology↗

USGS2019

Alternative sea lamprey barrier technologies: History as a control tool

Currently, application of lampricides and installation of low-head barriers are the only proven means of sea lamprey ( Petromyzon marinus ) control in the Great Lakes. While sea lamprey cannot climb or jump over low-head barriers, many desirable migratory species also cannot traverse barriers and are unintentionally blocked. Recently, there has been a push to reduce reliance on chemical controls as well as increase stream connectivity and flood conveyance. In response, the Great Lakes Fishery Commission (GLFC) continues to seek alternative methods of control. Great Lakes basin resource managers often request consideration of alternatives to both lampricide use and low-head barriers. Seasonal operation and alternative barrier designs (e.g. velocity barriers and electrical barriers) that incorporate additional features such as selective fish passage or flood conveyance are among the most commonly requested options. To date, alternative barrier technologies have been intermittently successful in the sea lamprey control program directed by the GLFC, yet continue to be proposed as alternatives to conventional low-head barriers. This document provides a comprehensive review on the current state of knowledge regarding the effectiveness of current and alternative barrier technologies and their historical use in the sea lamprey control program. This synthesis provides resource managers and sea lamprey control agents a reference and some tools to facilitate decision making around barriers that balance the critical need for invasive species control and fishery restoration.

Great Lakes↗

USGS2018

Assessing risks from harbor dredging to the northernmost population of diamondback terrapins using acoustic telemetry

The northern diamondback terrapin ( Malaclemys terrapin terrapin ) is a saltmarsh-dependent turtle that occupies coastal habitats throughout much of the Atlantic coast of North America. We used a novel application of acoustic telemetry to quantify both mobility and occupancy of terrapins within a dredged harbor and surrounding habitats, and used these metrics to quantify relative risk to individuals posed by harbor dredging. Terrapins showed strong fidelity to brumating areas within subdrainages, but extensive movements between these zones during the active period. Activity was greatest in late spring and early summer, declining to near zero by December. Occupancy of the dredge zone was also greatest during spring and summer and declined throughout the autumn months to an annual minimum during winter. Taken together, these data indicate that risks from harbor dredging are minimized during the autumn and early winter months.

Massachusetts↗

USGS2018

Influencia de factores ambientales y biométricos en la capacidad de nado del barbo ibérico (Luciobarbus bocagei Steindachner, 1864), un ciprínido potamódromo endémico de la Península Ibérica

El presente trabajo analiza la capacidad voluntaria de nado del barbo ibérico ( Luciobarbus bocagei Steindachner, 1864) en un canal abierto durante su época de migración, relacionándola con factores ambientales y biométricos. La temperatura del agua, la velocidad de flujo y la longitud del pez fueron los factores de mayor importancia que condicionaron la velocidad de nado de los barbos y su tiempo de fatiga. Dentro del rango de valores estudiado, el barbo ibérico pudo mantener velocidades de nado en sprint (> 15 BL/s) durante 3-10 s, y de 17-117 s en el modo de natación prolongada (7-15 BL/s). Los resultados aportados pueden ser empleados como una herramienta útil para la gestión de sus poblaciones, principalmente para el diseño de pasos para peces. This paper analyzes the volitional swimming capacity of the Iberian barbel ( Luciobarbus bocagei Steindachner, 1864) in an open flume during its migration period, in relation to environmental and biometric factors. Water temperature, flow velocity and fish length were the most important factors which affected the swimming speed of barbels and their fatigue time. Within the range of values studied, the Iberian barbel was able to maintain sprint swim speeds (> 15 BL/s) for 3-10 s, and 17-117 s in prolonged swim mode (7-15 BL/s). The results can be used as a tool for the management of barbel populations, mainly in the design of fishways.

Limnetica↗