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
Breaking the speed limit--comparative sprinting performance of brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta)
Sprinting behavior of free-ranging fish has long been thought to exceed that of captive fish. Here we present data from wild-caught brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta), volitionally entering and sprinting against high-velocity flows in an open-channel flume. Performance of the two species was nearly identical, with the species attaining absolute speeds > 25 body leng
Authors
Theodore Castro-Santos, Francisco Javier Sanz-Ronda, Jorge Ruiz-Legazpi
A barrier to upstream migration in the fish passage of Itaipu Dam (Canal da Piracema), Paraná River basin
The majority of the fish passages built in the Neotropical region are characterised by low efficiency and high selectivity; in many cases, the benefits to fish populations are uncertain. Studies conducted in the Canal da Piracema at Itaipu dam on the Parana River indicate that the system component designated as the Discharge channel in the Bela Vista River (herein named Canal de deságue no rio Bel
Authors
Theodore R. Castro-Santos, Hélio Martins Fontes Júnior, Sergio Makrakis, Luiz Carlos Gomes, João Dirço Latini
Culverts in paved roads as suitable passages for neotropical fish species
Improperly installed or poorly maintained culverts can pose a serious threat to fish by disrupting their habitat and endangering spawning success. Road culverts that are not designed for fish passage frequently can become obstacles. This can be especially problematic for migratory species, but can lead to fragmentation of resident populations as well. This study evaluated 40 culverts of 29 sites w
Authors
Sergio Makrakis, Theodore R. Castro-Santos, Maristela Cavicchioli Makrakis, Ricardo Luiz Wagner, Mauricio Spagnolo Adames
Passage performance of long-distance upstream migrants at a large dam on the Paraná River and the compounding effects of entry and ascent
This paper presents results of a fishway evaluation performed at the Engenheiro Sérgio Motta Hydroelectric Power Plant (known as Porto Primavera) - CESP, Paraná River, Brazil. The evaluation was designed to quantify entry and passage proportions of 4 long-distance migratory fish species: Brycon orbignyanus (piracanjuba), Piaractus mesopotamicus (pacu), Prochilodus lineatus (curimba), and Rhinelepi
Authors
Ricardo Luiz Wagner, Sergio Makrakis, Theodore R. Castro-Santos, Maristela Cavicchioli Makrakis, João Henrique Pinheiro Dias, René Fuster Belmont
Time-to-event analysis as a framework for quantifying fish passage performance
Fish passage is the result of a sequence of processes, whereby fish must approach, enter, and pass a structure. Each of these processes takes time, and fishway performance is best quantified in terms of the rates at which each process is completed. Optimal performance is achieved by maximizing the rates of approach, entry, and passage through safe and desirable routes. Sometimes, however, it is ne
Authors
Theodore R. Castro-Santos, Russell W. Perry
Using mark-recapture models to estimate survival from telemetry data: Chapter 9.2
Analyzing telemetry data within a mark–recapture framework is a powerful approach for estimating demographic parameters (e.g., survival and movement probabilities) that might otherwise be difficult to measure. Yet many studies using telemetry techniques focus on fish behavior and fail to recognize the potential of telemetry data to provide information about fish survival. The sophistication of bot
Authors
Russell W. Perry, Theodore R. Castro-Santos, Christopher M. Holbrook, Benjamin P. Sandford
Unintended consequences and trade-offs of fish passage
We synthesized evidence for unintended consequences and trade-offs associated with the passage of fishes. Provisioning of fish passageways at dams and dam removals are being carried out increasingly as resource managers seek ways to reduce fragmentation of migratory fish populations and restore biodiversity and nature-like ecosystem services in tributaries altered by dams. The benefits of provisio
Authors
Robert L. McLaughlin, Eric R. Smyth, Theodore Castro-Santos, Michael L. Jones, Marten A. Koops, Thomas C. Pratt, Luis-Antonio Vélez-Espino
Performance of fish passage structures at upstream barriers to migration
Attraction and passage efficiency were reviewed and compared from 19 monitoring studies that produced data for evaluations of pool-and-weir, Denil, vertical-slot and nature-like fishways. Data from 26 species of anadromous and potamodromous fishes from six countries were separated by year and taxonomic family into a matrix with 101 records. Attraction performance was highly variable for the follow
Authors
C.M. Bunt, T. Castro-Santos, A. Haro
Evaluation of nature-like and technical fishways for the passage of alewives at two coastal streams in New England
Nature-like fishways have been designed with the intent to reconnect river corridors and provide passage for all species occurring in a system. The approach is gaining popularity both in Europe and North America, but performance of these designs has not been quantitatively evaluated in a field setting for any North American species. Two nature-like fishways and three technical fishways in New Engl
Authors
Abigail E. Franklin, Alex Haro, Theodore R. Castro-Santos, John Noreika
Passage of American shad: paradigms and realities
Despite more than 250 years of development, the passage of American shad Alosa sapidissima at dams and other barriers frequently remains problematic. Few improvements in design based on knowledge of the swimming, schooling, and migratory behaviors of American shad have been incorporated into passage structures. Large-scale technical fishways designed for the passage of adult salmonids on the Colum
Authors
Alex Haro, Theodore Castro-Santos
Adaptive fishway design: A framework and rationale for effective evaluations.
No abstract available.
Authors
Theodore R. Castro-Santos
Swimming and other activities: applied aspects of fish swimming performance
Human activities such as hydropower development, water withdrawals, and commercial fisheries often put fish species at risk. Engineered solutions designed to protect species or their life stages are frequently based on assumptions about swimming performance and behaviors. In many cases, however, the appropriate data to support these designs are either unavailable or misapplied. This article provid
Authors
Theodore R. Castro-Santos
Science and Products
Filter Total Items: 76
Breaking the speed limit--comparative sprinting performance of brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta)
Sprinting behavior of free-ranging fish has long been thought to exceed that of captive fish. Here we present data from wild-caught brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta), volitionally entering and sprinting against high-velocity flows in an open-channel flume. Performance of the two species was nearly identical, with the species attaining absolute speeds > 25 body leng
Authors
Theodore Castro-Santos, Francisco Javier Sanz-Ronda, Jorge Ruiz-Legazpi
A barrier to upstream migration in the fish passage of Itaipu Dam (Canal da Piracema), Paraná River basin
The majority of the fish passages built in the Neotropical region are characterised by low efficiency and high selectivity; in many cases, the benefits to fish populations are uncertain. Studies conducted in the Canal da Piracema at Itaipu dam on the Parana River indicate that the system component designated as the Discharge channel in the Bela Vista River (herein named Canal de deságue no rio Bel
Authors
Theodore R. Castro-Santos, Hélio Martins Fontes Júnior, Sergio Makrakis, Luiz Carlos Gomes, João Dirço Latini
Culverts in paved roads as suitable passages for neotropical fish species
Improperly installed or poorly maintained culverts can pose a serious threat to fish by disrupting their habitat and endangering spawning success. Road culverts that are not designed for fish passage frequently can become obstacles. This can be especially problematic for migratory species, but can lead to fragmentation of resident populations as well. This study evaluated 40 culverts of 29 sites w
Authors
Sergio Makrakis, Theodore R. Castro-Santos, Maristela Cavicchioli Makrakis, Ricardo Luiz Wagner, Mauricio Spagnolo Adames
Passage performance of long-distance upstream migrants at a large dam on the Paraná River and the compounding effects of entry and ascent
This paper presents results of a fishway evaluation performed at the Engenheiro Sérgio Motta Hydroelectric Power Plant (known as Porto Primavera) - CESP, Paraná River, Brazil. The evaluation was designed to quantify entry and passage proportions of 4 long-distance migratory fish species: Brycon orbignyanus (piracanjuba), Piaractus mesopotamicus (pacu), Prochilodus lineatus (curimba), and Rhinelepi
Authors
Ricardo Luiz Wagner, Sergio Makrakis, Theodore R. Castro-Santos, Maristela Cavicchioli Makrakis, João Henrique Pinheiro Dias, René Fuster Belmont
Time-to-event analysis as a framework for quantifying fish passage performance
Fish passage is the result of a sequence of processes, whereby fish must approach, enter, and pass a structure. Each of these processes takes time, and fishway performance is best quantified in terms of the rates at which each process is completed. Optimal performance is achieved by maximizing the rates of approach, entry, and passage through safe and desirable routes. Sometimes, however, it is ne
Authors
Theodore R. Castro-Santos, Russell W. Perry
Using mark-recapture models to estimate survival from telemetry data: Chapter 9.2
Analyzing telemetry data within a mark–recapture framework is a powerful approach for estimating demographic parameters (e.g., survival and movement probabilities) that might otherwise be difficult to measure. Yet many studies using telemetry techniques focus on fish behavior and fail to recognize the potential of telemetry data to provide information about fish survival. The sophistication of bot
Authors
Russell W. Perry, Theodore R. Castro-Santos, Christopher M. Holbrook, Benjamin P. Sandford
Unintended consequences and trade-offs of fish passage
We synthesized evidence for unintended consequences and trade-offs associated with the passage of fishes. Provisioning of fish passageways at dams and dam removals are being carried out increasingly as resource managers seek ways to reduce fragmentation of migratory fish populations and restore biodiversity and nature-like ecosystem services in tributaries altered by dams. The benefits of provisio
Authors
Robert L. McLaughlin, Eric R. Smyth, Theodore Castro-Santos, Michael L. Jones, Marten A. Koops, Thomas C. Pratt, Luis-Antonio Vélez-Espino
Performance of fish passage structures at upstream barriers to migration
Attraction and passage efficiency were reviewed and compared from 19 monitoring studies that produced data for evaluations of pool-and-weir, Denil, vertical-slot and nature-like fishways. Data from 26 species of anadromous and potamodromous fishes from six countries were separated by year and taxonomic family into a matrix with 101 records. Attraction performance was highly variable for the follow
Authors
C.M. Bunt, T. Castro-Santos, A. Haro
Evaluation of nature-like and technical fishways for the passage of alewives at two coastal streams in New England
Nature-like fishways have been designed with the intent to reconnect river corridors and provide passage for all species occurring in a system. The approach is gaining popularity both in Europe and North America, but performance of these designs has not been quantitatively evaluated in a field setting for any North American species. Two nature-like fishways and three technical fishways in New Engl
Authors
Abigail E. Franklin, Alex Haro, Theodore R. Castro-Santos, John Noreika
Passage of American shad: paradigms and realities
Despite more than 250 years of development, the passage of American shad Alosa sapidissima at dams and other barriers frequently remains problematic. Few improvements in design based on knowledge of the swimming, schooling, and migratory behaviors of American shad have been incorporated into passage structures. Large-scale technical fishways designed for the passage of adult salmonids on the Colum
Authors
Alex Haro, Theodore Castro-Santos
Adaptive fishway design: A framework and rationale for effective evaluations.
No abstract available.
Authors
Theodore R. Castro-Santos
Swimming and other activities: applied aspects of fish swimming performance
Human activities such as hydropower development, water withdrawals, and commercial fisheries often put fish species at risk. Engineered solutions designed to protect species or their life stages are frequently based on assumptions about swimming performance and behaviors. In many cases, however, the appropriate data to support these designs are either unavailable or misapplied. This article provid
Authors
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