Theodore Castro-Santos
Research Ecologist at the Eastern Ecological Science Center's S.O. Conte Research Laboratory in Turners Falls, MA
Human activities have caused extensive fragmentation of riverine corridors. Dams, culverts, and other barriers prevent migratory and riverine fishes from accessing key habitats. This is particularly problematic for diadromous fishes like Atlantic salmon and American shad that must transition between fresh- and saltwater habitats in order to complete their life cycles. Swimming performance and behavioral responses to hydraulic conditions (turbulence, velocity, etc.) are major interests, as is development of quantitative methods for identifying and characterizing barriers. This work has broad relevance, not only to stewardship and management of aquatic resources, but also to understanding fundamental aspects of the ecology and evolution of fishes. Some current projects include:
- Sprint-swimming performance of migratory and riverine species
- Effects of turbulence on swimming performance, biomechanics, and behavior
- Modeling fish passage through culverts
- Bioenergetics models of anadromous fish migration
Professional Experience
US Geological Survey (1995-present)
U.S. Fish and Wildlife Service (1992-1995)
Education and Certifications
PhD Organismic and Evolutionary Biology; University of Massachusetts Amherst (2002)
MS Wildlife Biology Washington State University (1991)
BA Colgate University (1987)
Affiliations and Memberships*
American Fisheries Society
Society for Integrative and Comparative Biology
Science and Products
Filter Total Items: 76
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-
Authors
Derrick Alcott, Elsa Goerig, Theodore R. Castro-Santos
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 reg
Authors
Amy M. Regish, William R. Ardren, Nicholas R Staats, Henry Bouchard, Jonah L. Withers, Theodore R. Castro-Santos, Stephen D. McCormick
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, o
Authors
Christopher B. Rillahan, Derrick Alcott, Theodore R. Castro-Santos, Pingguo He
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 anal
Authors
Derrick Alcott, Elsa Goerig, Christopher Rillahan, Pingguo He, Theodore R. Castro-Santos
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 δ13C stable isotope analyses to investigate predator–prey interactions at a road-stream crossing culvert. Eastern snapping turtles (Chelydra serp
Authors
Derrick James Alcott, Michael Long, Theodore R. Castro-Santos
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 i
Authors
Theodore R. Castro-Santos, Kevin Mulligan, Micah Kieffer, Alexander Haro
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 fi
Authors
Elsa Goerig, Ben A. Wasserman, Theodore R. Castro-Santos, Eric P. Palkovacs
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
Authors
Daniel P. Zielinski, Robert McLaughlin, Theodore R. Castro-Santos, Bhuwani Paudel, Pete J. Hrodey, Andrew M. Muir
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
Authors
D.P. Zielinski, R. L. McLaughlin, Theodore R. Castro-Santos, B. Paudel, Pete J. Hrodey, A. M. Muir
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 det
Authors
Shannon Michael Bayse, Stephen D. McCormick, Theodore R. Castro-Santos
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
Authors
Theodore R. Castro-Santos, M. Bolus, A. J. Danylchuk
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 t
Authors
Jason Duguay, Brendan Foster, R.W. Jay Lacey, Theodore R. Castro-Santos
Science and Products
Filter Total Items: 76
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-
Authors
Derrick Alcott, Elsa Goerig, Theodore R. Castro-Santos
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 reg
Authors
Amy M. Regish, William R. Ardren, Nicholas R Staats, Henry Bouchard, Jonah L. Withers, Theodore R. Castro-Santos, Stephen D. McCormick
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, o
Authors
Christopher B. Rillahan, Derrick Alcott, Theodore R. Castro-Santos, Pingguo He
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 anal
Authors
Derrick Alcott, Elsa Goerig, Christopher Rillahan, Pingguo He, Theodore R. Castro-Santos
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 δ13C stable isotope analyses to investigate predator–prey interactions at a road-stream crossing culvert. Eastern snapping turtles (Chelydra serp
Authors
Derrick James Alcott, Michael Long, Theodore R. Castro-Santos
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 i
Authors
Theodore R. Castro-Santos, Kevin Mulligan, Micah Kieffer, Alexander Haro
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 fi
Authors
Elsa Goerig, Ben A. Wasserman, Theodore R. Castro-Santos, Eric P. Palkovacs
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
Authors
Daniel P. Zielinski, Robert McLaughlin, Theodore R. Castro-Santos, Bhuwani Paudel, Pete J. Hrodey, Andrew M. Muir
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
Authors
D.P. Zielinski, R. L. McLaughlin, Theodore R. Castro-Santos, B. Paudel, Pete J. Hrodey, A. M. Muir
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 det
Authors
Shannon Michael Bayse, Stephen D. McCormick, Theodore R. Castro-Santos
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
Authors
Theodore R. Castro-Santos, M. Bolus, A. J. Danylchuk
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 t
Authors
Jason Duguay, Brendan Foster, R.W. Jay Lacey, Theodore R. Castro-Santos
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government