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Brian Irwin, PhD

Assistant Unit Leader - Georgia Cooperative Fish and Wildlife Research Unit

Research Interests

My research interests are in the areas of ecological change, fish population dynamics, and decision making linked to conservation and management of natural resources. Current projects involve using quantitative models to explore how populations respond to anthropogenic and natural influences.

Teaching Interests

My courses introduce concepts and analyses relevant to conservation decision making and sustainable use of exploited natural resources.

Professional Experience

  • Assistant Unit Leader, Georgia Cooperative Fish and Wildlife Research Unit, 2012-

Education and Certifications

  • Ph D Cornell University 2006

  • MS Auburn University 2001

  • BS University of Illinois 1998

Science and Products

Fog over the Sante Fe River, Florida

Turning Uncertainty into Useful Information for Conservation Decisions

We routinely encounter uncertainty when we make decisions – from picking a new morning coffee to choosing where to live. Even decisions that are supported by science contain some level of remaining uncertainty. In the context of conservation and wildlife management, the potential for uncertainty to influence decisions is perhaps most obvious when we think about predicting how actions (or...
By
Climate Adaptation Science Centers
Turning Uncertainty into Useful Information for Conservation Decisions

Turning Uncertainty into Useful Information for Conservation Decisions

We routinely encounter uncertainty when we make decisions – from picking a new morning coffee to choosing where to live. Even decisions that are supported by science contain some level of remaining uncertainty. In the context of conservation and wildlife management, the potential for uncertainty to influence decisions is perhaps most obvious when we think about predicting how actions (or non
Learn More
Graduate student measures hybrid striped bass
Graduate student measures hybrid striped bass
Graduate student measures hybrid striped bass
Graduate student measures hybrid striped bass

Graduate student measures hybrid striped bass

Graduate student measures hybrid striped bass

Georgia Cooperative Fish & Wildlife Research Unit graduate student Zoe Scribner measures a Hybrid Striped Bass (Morone chrysops × M. saxatilis), while staff scientist Dr. Troy Simon records data, for a project assisting the Georgia Department of Natural Resources on Carters Lake, Georgia (Nov. 2024).

By
Cooperative Research Units
Graduate student measures hybrid striped bass

Graduate student measures hybrid striped bass

Graduate student measures hybrid striped bass

Georgia Cooperative Fish & Wildlife Research Unit graduate student Zoe Scribner measures a Hybrid Striped Bass (Morone chrysops × M. saxatilis), while staff scientist Dr. Troy Simon records data, for a project assisting the Georgia Department of Natural Resources on Carters Lake, Georgia (Nov. 2024).

By
Cooperative Research Units
Filter Total Items: 26

Warmer Is deadlier: A meta‐analysis reveals increasing temperatures accentuate disease effects on fisheries hosts Warmer Is deadlier: A meta‐analysis reveals increasing temperatures accentuate disease effects on fisheries hosts

Rapid warming could drastically alter host–parasite relationships, which is especially important for fisheries crucial to human nutrition and economic livelihoods, yet we lack a synthetic understanding of how warming influences parasite-induced mortality in these systems. We conducted a meta-analysis using 266 effect sizes from 52 empirical papers on harvested aquatic species and...
Authors
M. Tomamichel, K. Lowe, K. Arnold, M. Frischer, Brian J. Irwin, C. Osenberg, R. Hall, J. Byers
By
Cooperative Research Units

First evidence of natural reproduction and recruitment of reintroduced Lake Sturgeon in the Coosa River, Georgia First evidence of natural reproduction and recruitment of reintroduced Lake Sturgeon in the Coosa River, Georgia

Objective Lake Sturgeon Acipenser fluences became extirpated from the Coosa River system in Georgia and Alabama during the 1970s. The Georgia Department of Natural Resources began stocking hatchery-raised Lake Sturgeon in 2002 with the goal of reestablishing a self-sustaining population. Stocking lapsed in 2020 due to the COVID-19 pandemic, which allowed an opportunity to assess natural
Authors
Martin Hamel, Matthew Phillips, Savannah Perry, Brian J. Irwin, John Damer
By
Cooperative Research Units

Disparities in Perimyotis subflavus body mass between cave and culvert hibernacula in Georgia, USA Disparities in Perimyotis subflavus body mass between cave and culvert hibernacula in Georgia, USA

The tricolored bat (Perimyotis subflavus), once common in the eastern United States, has experienced significant mortality due to white-nose syndrome (WNS), a fungal disease that primarily affects bats hibernating in caves and mines. In coastal regions of the southeastern United States, where caves and mines are scarce, tricolored bats often use roadway culverts as hibernacula. However...
Authors
Emily Ferrall, S. Perea, K.M. Morris, P.E. Pattavina, Brian J. Irwin, J. Hepinstall-Cymerman, S.B. Castleberry
By
Cooperative Research Units

Life-history connections to long-term fish population trends in a species-rich temperate river Life-history connections to long-term fish population trends in a species-rich temperate river

Fishes exhibit a diverse range of traits encompassing life-history strategies, feeding behaviours and spawning behaviours. These traits mediate fish population responses to changing environmental conditions such as those caused by anthropogenic stressors. The Conasauga River, located in northwestern Georgia and southeastern Tennessee, USA, hosts a diverse assemblage of over 75 species of
Authors
Andrew Nagy, Mary Freeman, Brian J. Irwin, Seth J. Wenger
By
Ecosystems Mission Area, Eastern Ecological Science Center

Managing the threat of infectious disease in fisheries and aquaculture using structured decision making Managing the threat of infectious disease in fisheries and aquaculture using structured decision making

Fisheries and aquaculture provide food and economic security, especially in the developing world, but both face challenges from infectious disease. Here, we consider management of disease issues from a structured decision-making perspective to examine how infectious disease can threaten seafood production and influence management decisions. For both wild fisheries and aquaculture...
Authors
Brian J. Irwin, Megan Tomamichel, Marc Frischer, Richard Hall, Alaina Davis, Thomas Bliss, Pejman Rohani, James E. Byers
By
Cooperative Research Units

Refining capture-recapture recruitment estimation methods for Atlantic sturgeon Refining capture-recapture recruitment estimation methods for Atlantic sturgeon

The Atlantic sturgeon Acipenser oxyrinchus oxyrinchus was once of great commercial importance in many coastal rivers of the eastern USA. Over the 19th and 20th centuries, most historical stocks of Atlantic sturgeon were depleted by human activities. Estimating recruitment for the remaining populations is challenging due to sampling constraints, limited age data, and natural variability...
Authors
M.A. Baker, E.C. Ingram, D.L. Higginbotham, Brian J. Irwin, A.G. Fox
By
Cooperative Research Units

Perceived constraints and negotiations to trout fishing in Georgia based on angler specialization level Perceived constraints and negotiations to trout fishing in Georgia based on angler specialization level

Anglers face constraints that influence participation and dropout rates. Some recreational anglers may be able to negotiate constraints by altering the timing or frequency of participation, acquiring new skills, or modifying nonrecreational aspects such as family or work responsibilities. We consider data collected via a mail survey from Georgia-resident trout license holders to identify...
Authors
H. J. TenHarmsel, B. B. Boley, Brian Irwin, Cecil Jennings
By
Cooperative Research Units

Using video survey to examine the effect of habitat on gag grouper encounter Using video survey to examine the effect of habitat on gag grouper encounter

Gag is a reef fish that was declared overfished in the Gulf of Mexico (GOM) in 2009. Although Gag are no longer listed as overfished, fisheries managers are concerned that stocks may not be recovering. Our objective was to identify habitat characteristics important to Gag, and their effect on the probability of Gag occurrence. We obtained data from three separate fisheries-independent...
Authors
G. Alvarez, D. Gandy, Brian J. Irwin, Cecil Jennings, Adam Fox
By
Cooperative Research Units

An importance–satisfaction analysis of trout license holders in Georgia An importance–satisfaction analysis of trout license holders in Georgia

As anglers become increasingly diverse, fisheries managers are challenged to find ways to satisfy users with divergent preferences while conserving a limited resource on a limited budget. With this management challenge in mind, this study combines previous angler specialization research with an importance–satisfaction analysis (ISA) to aid fisheries managers in better understanding users...
Authors
H. TenHarmsel, B. Boley, Brian Irwin, Cecil Jennings
By
Cooperative Research Units

Age truncation of alewife in Lake Michigan Age truncation of alewife in Lake Michigan

Empirical evidence has shown increased variability in harvest and recruitment of exploited fish populations, which can result directly from exploitation or indirectly from interactions between external drivers and the internal dynamics of age-structured populations. We investigated whether predation in a freshwater system could affect a prey fish population, in the same way fishing...
Authors
T. Vidal, Brian Irwin, Charles Madenjian, S. Wenger
By
Ecosystems Mission Area, Cooperative Research Units, Great Lakes Science Center

The dream and the reality: Meeting decision-making time frames while incorporating ecosystem and economic models into management strategy evaluation The dream and the reality: Meeting decision-making time frames while incorporating ecosystem and economic models into management strategy evaluation

Atlantic herring (Clupea harengus) in the Northwest Atlantic have been managed with interim harvest control rules (HCRs). A stakeholder-driven management strategy evaluation (MSE) was conducted that incorporated a broad range of objectives. The MSE process was completed within 1 year. Constant catch, conditional constant catch, and a biomass-based (BB) HCR with a 15% restriction on the...
Authors
J.J. Deroba, S.K. Gaichas, Min-Yang Lee, Rachael Feeney, D. Boelke, Brian Irwin
By
Cooperative Research Units

Integrating management strategy evaluation into fisheries management: Advancing best practices for stakeholder inclusion based on an MSE for Northeast US Atlantic herring Integrating management strategy evaluation into fisheries management: Advancing best practices for stakeholder inclusion based on an MSE for Northeast US Atlantic herring

The New England Fishery Management Council used management strategy evaluation (MSE) to evaluate possible harvest control rules for Atlantic herring (Clupea harengus), the first MSE in the US and perhaps globally to use open-invitation, public workshops for input. Stakeholder inclusion can increase both realism and likelihood of use by managers, but inclusivity is not achieved easily...
Authors
Rachael Feeney, Deirdre Boelke, Jonathan Deroba, Sarah Gaichas, Brian Irwin, Min-Yang Lee
By
Cooperative Research Units

Science and Products

Fog over the Sante Fe River, Florida

Turning Uncertainty into Useful Information for Conservation Decisions

We routinely encounter uncertainty when we make decisions – from picking a new morning coffee to choosing where to live. Even decisions that are supported by science contain some level of remaining uncertainty. In the context of conservation and wildlife management, the potential for uncertainty to influence decisions is perhaps most obvious when we think about predicting how actions (or...
By
Climate Adaptation Science Centers
Turning Uncertainty into Useful Information for Conservation Decisions

Turning Uncertainty into Useful Information for Conservation Decisions

We routinely encounter uncertainty when we make decisions – from picking a new morning coffee to choosing where to live. Even decisions that are supported by science contain some level of remaining uncertainty. In the context of conservation and wildlife management, the potential for uncertainty to influence decisions is perhaps most obvious when we think about predicting how actions (or non
Learn More
Graduate student measures hybrid striped bass
Graduate student measures hybrid striped bass
Graduate student measures hybrid striped bass
Graduate student measures hybrid striped bass

Graduate student measures hybrid striped bass

Graduate student measures hybrid striped bass

Georgia Cooperative Fish & Wildlife Research Unit graduate student Zoe Scribner measures a Hybrid Striped Bass (Morone chrysops × M. saxatilis), while staff scientist Dr. Troy Simon records data, for a project assisting the Georgia Department of Natural Resources on Carters Lake, Georgia (Nov. 2024).

By
Cooperative Research Units
Graduate student measures hybrid striped bass

Graduate student measures hybrid striped bass

Graduate student measures hybrid striped bass

Georgia Cooperative Fish & Wildlife Research Unit graduate student Zoe Scribner measures a Hybrid Striped Bass (Morone chrysops × M. saxatilis), while staff scientist Dr. Troy Simon records data, for a project assisting the Georgia Department of Natural Resources on Carters Lake, Georgia (Nov. 2024).

By
Cooperative Research Units
Filter Total Items: 26

Warmer Is deadlier: A meta‐analysis reveals increasing temperatures accentuate disease effects on fisheries hosts Warmer Is deadlier: A meta‐analysis reveals increasing temperatures accentuate disease effects on fisheries hosts

Rapid warming could drastically alter host–parasite relationships, which is especially important for fisheries crucial to human nutrition and economic livelihoods, yet we lack a synthetic understanding of how warming influences parasite-induced mortality in these systems. We conducted a meta-analysis using 266 effect sizes from 52 empirical papers on harvested aquatic species and...
Authors
M. Tomamichel, K. Lowe, K. Arnold, M. Frischer, Brian J. Irwin, C. Osenberg, R. Hall, J. Byers
By
Cooperative Research Units

First evidence of natural reproduction and recruitment of reintroduced Lake Sturgeon in the Coosa River, Georgia First evidence of natural reproduction and recruitment of reintroduced Lake Sturgeon in the Coosa River, Georgia

Objective Lake Sturgeon Acipenser fluences became extirpated from the Coosa River system in Georgia and Alabama during the 1970s. The Georgia Department of Natural Resources began stocking hatchery-raised Lake Sturgeon in 2002 with the goal of reestablishing a self-sustaining population. Stocking lapsed in 2020 due to the COVID-19 pandemic, which allowed an opportunity to assess natural
Authors
Martin Hamel, Matthew Phillips, Savannah Perry, Brian J. Irwin, John Damer
By
Cooperative Research Units

Disparities in Perimyotis subflavus body mass between cave and culvert hibernacula in Georgia, USA Disparities in Perimyotis subflavus body mass between cave and culvert hibernacula in Georgia, USA

The tricolored bat (Perimyotis subflavus), once common in the eastern United States, has experienced significant mortality due to white-nose syndrome (WNS), a fungal disease that primarily affects bats hibernating in caves and mines. In coastal regions of the southeastern United States, where caves and mines are scarce, tricolored bats often use roadway culverts as hibernacula. However...
Authors
Emily Ferrall, S. Perea, K.M. Morris, P.E. Pattavina, Brian J. Irwin, J. Hepinstall-Cymerman, S.B. Castleberry
By
Cooperative Research Units

Life-history connections to long-term fish population trends in a species-rich temperate river Life-history connections to long-term fish population trends in a species-rich temperate river

Fishes exhibit a diverse range of traits encompassing life-history strategies, feeding behaviours and spawning behaviours. These traits mediate fish population responses to changing environmental conditions such as those caused by anthropogenic stressors. The Conasauga River, located in northwestern Georgia and southeastern Tennessee, USA, hosts a diverse assemblage of over 75 species of
Authors
Andrew Nagy, Mary Freeman, Brian J. Irwin, Seth J. Wenger
By
Ecosystems Mission Area, Eastern Ecological Science Center

Managing the threat of infectious disease in fisheries and aquaculture using structured decision making Managing the threat of infectious disease in fisheries and aquaculture using structured decision making

Fisheries and aquaculture provide food and economic security, especially in the developing world, but both face challenges from infectious disease. Here, we consider management of disease issues from a structured decision-making perspective to examine how infectious disease can threaten seafood production and influence management decisions. For both wild fisheries and aquaculture...
Authors
Brian J. Irwin, Megan Tomamichel, Marc Frischer, Richard Hall, Alaina Davis, Thomas Bliss, Pejman Rohani, James E. Byers
By
Cooperative Research Units

Refining capture-recapture recruitment estimation methods for Atlantic sturgeon Refining capture-recapture recruitment estimation methods for Atlantic sturgeon

The Atlantic sturgeon Acipenser oxyrinchus oxyrinchus was once of great commercial importance in many coastal rivers of the eastern USA. Over the 19th and 20th centuries, most historical stocks of Atlantic sturgeon were depleted by human activities. Estimating recruitment for the remaining populations is challenging due to sampling constraints, limited age data, and natural variability...
Authors
M.A. Baker, E.C. Ingram, D.L. Higginbotham, Brian J. Irwin, A.G. Fox
By
Cooperative Research Units

Perceived constraints and negotiations to trout fishing in Georgia based on angler specialization level Perceived constraints and negotiations to trout fishing in Georgia based on angler specialization level

Anglers face constraints that influence participation and dropout rates. Some recreational anglers may be able to negotiate constraints by altering the timing or frequency of participation, acquiring new skills, or modifying nonrecreational aspects such as family or work responsibilities. We consider data collected via a mail survey from Georgia-resident trout license holders to identify...
Authors
H. J. TenHarmsel, B. B. Boley, Brian Irwin, Cecil Jennings
By
Cooperative Research Units

Using video survey to examine the effect of habitat on gag grouper encounter Using video survey to examine the effect of habitat on gag grouper encounter

Gag is a reef fish that was declared overfished in the Gulf of Mexico (GOM) in 2009. Although Gag are no longer listed as overfished, fisheries managers are concerned that stocks may not be recovering. Our objective was to identify habitat characteristics important to Gag, and their effect on the probability of Gag occurrence. We obtained data from three separate fisheries-independent...
Authors
G. Alvarez, D. Gandy, Brian J. Irwin, Cecil Jennings, Adam Fox
By
Cooperative Research Units

An importance–satisfaction analysis of trout license holders in Georgia An importance–satisfaction analysis of trout license holders in Georgia

As anglers become increasingly diverse, fisheries managers are challenged to find ways to satisfy users with divergent preferences while conserving a limited resource on a limited budget. With this management challenge in mind, this study combines previous angler specialization research with an importance–satisfaction analysis (ISA) to aid fisheries managers in better understanding users...
Authors
H. TenHarmsel, B. Boley, Brian Irwin, Cecil Jennings
By
Cooperative Research Units

Age truncation of alewife in Lake Michigan Age truncation of alewife in Lake Michigan

Empirical evidence has shown increased variability in harvest and recruitment of exploited fish populations, which can result directly from exploitation or indirectly from interactions between external drivers and the internal dynamics of age-structured populations. We investigated whether predation in a freshwater system could affect a prey fish population, in the same way fishing...
Authors
T. Vidal, Brian Irwin, Charles Madenjian, S. Wenger
By
Ecosystems Mission Area, Cooperative Research Units, Great Lakes Science Center

The dream and the reality: Meeting decision-making time frames while incorporating ecosystem and economic models into management strategy evaluation The dream and the reality: Meeting decision-making time frames while incorporating ecosystem and economic models into management strategy evaluation

Atlantic herring (Clupea harengus) in the Northwest Atlantic have been managed with interim harvest control rules (HCRs). A stakeholder-driven management strategy evaluation (MSE) was conducted that incorporated a broad range of objectives. The MSE process was completed within 1 year. Constant catch, conditional constant catch, and a biomass-based (BB) HCR with a 15% restriction on the...
Authors
J.J. Deroba, S.K. Gaichas, Min-Yang Lee, Rachael Feeney, D. Boelke, Brian Irwin
By
Cooperative Research Units

Integrating management strategy evaluation into fisheries management: Advancing best practices for stakeholder inclusion based on an MSE for Northeast US Atlantic herring Integrating management strategy evaluation into fisheries management: Advancing best practices for stakeholder inclusion based on an MSE for Northeast US Atlantic herring

The New England Fishery Management Council used management strategy evaluation (MSE) to evaluate possible harvest control rules for Atlantic herring (Clupea harengus), the first MSE in the US and perhaps globally to use open-invitation, public workshops for input. Stakeholder inclusion can increase both realism and likelihood of use by managers, but inclusivity is not achieved easily...
Authors
Rachael Feeney, Deirdre Boelke, Jonathan Deroba, Sarah Gaichas, Brian Irwin, Min-Yang Lee
By
Cooperative Research Units
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