Carl Walters
Encyclopedia
Carl Walters is an American born biologist
known for his work involving fisheries stock assessments, the adaptive management concept, and ecosystem model
ing. Walters has been a professor of Zoology
and Fisheries at the University of British Columbia
since 1969. He is one of the main developers of the computer simulation program Ecosim
and is involved in the Sea Around Us Project
established by Daniel Pauly
, the Quantitative Modeling Group, and the Lenfest Oceans Future Project. His most recent work focuses on how to adjust human behaviors in environments that are full of uncertainty. He is a recent recipient of the Volvo Environment Prize
(2006).
with an A.A in 1963 and continued to Humboldt State College to graduate with a B.S. in 1965. After Walters graduated, he went to Colorado State University
to study the "Distribution and production of midges in an alpine lake" under the advisement of Dr. Robert E. Vincent. After obtaining his M.S. in 1967, Walters stayed on with R.E. Vincent to get his doctorate on the "Effects of fish introduction on invertebrate fauna of an alpine lake" and graduated in 1969. Walters did not go on for a postdoctoral position; instead he almost immediately started working at the University of British Columbia
in Vancouver
, Canada
.
as an Assistant Professor
in the Fisheries Centre
. In 1977, he became an Associate Professor
and then a Professor
in 1982. Prior to his professional appointment at UBC
, Walters worked in the Department of Fish and Game and the Game, Fish and Parks Department and he was also a graduate fellow, a consultant
, and an aide
on numerous occasions. He has taken many sabbaticals to the International Institute of Applied Systems Analysis in Vienna, the University of Florida
, where he is an adjunct professor, and Australia. He has been on the editorial board for multiple journals including the Canadian Journal of Fisheries and Aquatic Sciences, Conservation Ecology, and Ecosystems and has been the associate editor of the Journal of Applied Mathematics and Computation and the Northwest Environmental Journal. Walters also served, and continues to serve, as a consultant
to many government agencies.
ing. One of his goals has been, and continues to be, to try to bridge the gap between fisheries management
, government
, and fishing industries in order to provide accurate information to use in successfully and actively managing fisheries. His work in modeling population dynamics
and active adaptive management has made Walters a valuable member of the scientific community.
Other modeling equations like the Beverton-Holt model
and the "hockey stick" model by Barrowman and Myers (2000) try to explain density dependent effects of juvenile fish populations using processes like recruitment and the number of eggs produced. Fisheries biologists and population ecologists have used the Beverton-Holt model
since the 1960s to describe the "stock-recruitment
" relationship. However, Walters believed that juvenile behavior could also explain the density dependent relationship that Beverton and Holt and Barrowman and Myers described. Walters thought that juvenile behavior, in conjunction with habitat, could explain the density dependency seen when foraging for prey and avoiding predators. Walters wanted to give scientists a better understanding of the processes that drive density dependent fluctuations in ecosystem statistics (birth and death rates). The foraging arena theory is also used, in conjunction with the ecosystem simulation program Ecopath with Ecosim
, to account for the indirect effect
s and trophic cascade
s seen in populations.
Adaptive Management
One of Walters biggest concerns in the rapidly changing environment
is how managers can successfully manage fisheries stocks in lieu of the uncertainty in making decisions. His concept of active adaptive management involves large-scale experimentation, or "learning-by-doing", in order to understand the population dynamics
in fish communities and to aide in the decision-making process done by policy makers. Walters encourages other scientists, managers, and policy makers to embrace the uncertainty in experiments and decisions and to develop ecosystem models based on the uncertainties in order to make multiple hypotheses instead of just one hypothesis
. Although active adaptive management has gained much support from the scientific community, there is still great hesitation from scientists and managers to implement these large-scale experiments. These hesitations arise from large monetary costs for the experiments as well as the monitoring of the experiments, lack of an individual willing to take on the daunting task of organizing the experiments, the limitations of models to perfectly represent an ecosystem, and the conflicting ecological values between different interest groups. Although there are concerns when executing active adaptive management strategies, there is a growing need to modify the current methods for exploring and understanding ecosystems, especially on a larger scale, and active adaptive management strategies aim to do exactly that.
Journal Publications
Can. J. Fish. Aquat. Sci. 62(6): 1320-1336.
Biologist
A biologist is a scientist devoted to and producing results in biology through the study of life. Typically biologists study organisms and their relationship to their environment. Biologists involved in basic research attempt to discover underlying mechanisms that govern how organisms work...
known for his work involving fisheries stock assessments, the adaptive management concept, and ecosystem model
Ecosystem model
An ecosystem model is an abstract, usually mathematical, representation of an ecological system , which is studied to gain a deeper understanding of the real system.Ecosystem models are formed by combining known ecological relations An ecosystem model is an abstract, usually mathematical,...
ing. Walters has been a professor of Zoology
Zoology
Zoology |zoölogy]]), is the branch of biology that relates to the animal kingdom, including the structure, embryology, evolution, classification, habits, and distribution of all animals, both living and extinct...
and Fisheries at the University of British Columbia
University of British Columbia
The University of British Columbia is a public research university. UBC’s two main campuses are situated in Vancouver and in Kelowna in the Okanagan Valley...
since 1969. He is one of the main developers of the computer simulation program Ecosim
Ecosim
EcosimPro is a simulation tool developed by Empresarios Agrupados A.I.E for modelling simple and complex physical processes that can be expressed in terms of Differential algebraic equations or Ordinary differential equations and Discrete event simulation....
and is involved in the Sea Around Us Project
Sea Around Us Project
The Sea Around Us Project is an international research group based at the University of British Columbia Fisheries Centre that is devoted to studying the impacts of fisheries on the world's marine ecosystems...
established by Daniel Pauly
Daniel Pauly
Daniel Pauly is a French-born marine biologist, well-known for his work in studying human impacts on global fisheries. He is a professor and the project leader of the Sea Around Us Project at the Fisheries Centre at the University of British Columbia. He also served as Director of the Fisheries...
, the Quantitative Modeling Group, and the Lenfest Oceans Future Project. His most recent work focuses on how to adjust human behaviors in environments that are full of uncertainty. He is a recent recipient of the Volvo Environment Prize
Volvo Environment Prize
Volvo Environment Prize is an annual international award originating in Sweden. The prize is awarded to individuals who explore the way to a sustainable world...
(2006).
Education
Carl Walters graduated from Bakersfield CollegeBakersfield College
Bakersfield College is a public community college located in Bakersfield, California, USA. Bakersfield College has an official Twitter account at @bcrenegades and an official...
with an A.A in 1963 and continued to Humboldt State College to graduate with a B.S. in 1965. After Walters graduated, he went to Colorado State University
Colorado State University
Colorado State University is a public research university located in Fort Collins, Colorado. The university is the state's land grant university, and the flagship university of the Colorado State University System.The enrollment is approximately 29,932 students, including resident and...
to study the "Distribution and production of midges in an alpine lake" under the advisement of Dr. Robert E. Vincent. After obtaining his M.S. in 1967, Walters stayed on with R.E. Vincent to get his doctorate on the "Effects of fish introduction on invertebrate fauna of an alpine lake" and graduated in 1969. Walters did not go on for a postdoctoral position; instead he almost immediately started working at the University of British Columbia
University of British Columbia
The University of British Columbia is a public research university. UBC’s two main campuses are situated in Vancouver and in Kelowna in the Okanagan Valley...
in Vancouver
Vancouver
Vancouver is a coastal seaport city on the mainland of British Columbia, Canada. It is the hub of Greater Vancouver, which, with over 2.3 million residents, is the third most populous metropolitan area in the country,...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
.
Career
Walters first professorship was at the University of British ColumbiaUniversity of British Columbia
The University of British Columbia is a public research university. UBC’s two main campuses are situated in Vancouver and in Kelowna in the Okanagan Valley...
as an Assistant Professor
Professor
A professor is a scholarly teacher; the precise meaning of the term varies by country. Literally, professor derives from Latin as a "person who professes" being usually an expert in arts or sciences; a teacher of high rank...
in the Fisheries Centre
Fisheries Centre
The Fisheries Centre, located at the University of British Columbia, promotes multidisciplinary study of aquatic ecosystems and broad-based collaboration with maritime communities, government, NGOs and other partners...
. In 1977, he became an Associate Professor
Professor
A professor is a scholarly teacher; the precise meaning of the term varies by country. Literally, professor derives from Latin as a "person who professes" being usually an expert in arts or sciences; a teacher of high rank...
and then a Professor
Professor
A professor is a scholarly teacher; the precise meaning of the term varies by country. Literally, professor derives from Latin as a "person who professes" being usually an expert in arts or sciences; a teacher of high rank...
in 1982. Prior to his professional appointment at UBC
University of British Columbia
The University of British Columbia is a public research university. UBC’s two main campuses are situated in Vancouver and in Kelowna in the Okanagan Valley...
, Walters worked in the Department of Fish and Game and the Game, Fish and Parks Department and he was also a graduate fellow, a consultant
Consultant
A consultant is a professional who provides professional or expert advice in a particular area such as management, accountancy, the environment, entertainment, technology, law , human resources, marketing, emergency management, food production, medicine, finance, life management, economics, public...
, and an aide
Aide
Aide may refer to:* A person who assists another; an assistant. In military contexts; an officer who acts as assistant to a more senior one; an aide-de-camp.* Aide , a purported Basque deity....
on numerous occasions. He has taken many sabbaticals to the International Institute of Applied Systems Analysis in Vienna, the University of Florida
University of Florida
The University of Florida is an American public land-grant, sea-grant, and space-grant research university located on a campus in Gainesville, Florida. The university traces its historical origins to 1853, and has operated continuously on its present Gainesville campus since September 1906...
, where he is an adjunct professor, and Australia. He has been on the editorial board for multiple journals including the Canadian Journal of Fisheries and Aquatic Sciences, Conservation Ecology, and Ecosystems and has been the associate editor of the Journal of Applied Mathematics and Computation and the Northwest Environmental Journal. Walters also served, and continues to serve, as a consultant
Consultant
A consultant is a professional who provides professional or expert advice in a particular area such as management, accountancy, the environment, entertainment, technology, law , human resources, marketing, emergency management, food production, medicine, finance, life management, economics, public...
to many government agencies.
Interests
Walters uses mathematical modeling to understand how to successfully manage harvestable fisheries in a time of high uncertainty. He specializes in fisheries stock assessments (i.e. cod and juvenile steelhead trout), adaptive management strategies, and ecosystem modelEcosystem model
An ecosystem model is an abstract, usually mathematical, representation of an ecological system , which is studied to gain a deeper understanding of the real system.Ecosystem models are formed by combining known ecological relations An ecosystem model is an abstract, usually mathematical,...
ing. One of his goals has been, and continues to be, to try to bridge the gap between fisheries management
Fisheries management
Fisheries management draws on fisheries science in order to find ways to protect fishery resources so sustainable exploitation is possible. Modern fisheries management is often referred to as a governmental system of appropriate management rules based on defined objectives and a mix of management...
, government
Government
Government refers to the legislators, administrators, and arbitrators in the administrative bureaucracy who control a state at a given time, and to the system of government by which they are organized...
, and fishing industries in order to provide accurate information to use in successfully and actively managing fisheries. His work in modeling population dynamics
Population dynamics of fisheries
A fishery is an area with an associated fish or aquatic population which is harvested for its commercial or recreational value. Fisheries can be wild or farmed. Population dynamics describes the ways in which a given population grows and shrinks over time, as controlled by birth, death, and...
and active adaptive management has made Walters a valuable member of the scientific community.
Contributions
Foraging Arena TheoryOther modeling equations like the Beverton-Holt model
Beverton-Holt model
The Beverton–Holt model is a classic discrete-time population model which gives the expected number n t+1 of individuals in generation t + 1 as a function of the number of individuals in the previous generation,...
and the "hockey stick" model by Barrowman and Myers (2000) try to explain density dependent effects of juvenile fish populations using processes like recruitment and the number of eggs produced. Fisheries biologists and population ecologists have used the Beverton-Holt model
Beverton-Holt model
The Beverton–Holt model is a classic discrete-time population model which gives the expected number n t+1 of individuals in generation t + 1 as a function of the number of individuals in the previous generation,...
since the 1960s to describe the "stock-recruitment
Recruitment
Recruitment refers to the process of attracting, screening, and selecting qualified people for a job. For some components of the recruitment process, mid- and large-size organizations often retain professional recruiters or outsource some of the process to recruitment agencies.The recruitment...
" relationship. However, Walters believed that juvenile behavior could also explain the density dependent relationship that Beverton and Holt and Barrowman and Myers described. Walters thought that juvenile behavior, in conjunction with habitat, could explain the density dependency seen when foraging for prey and avoiding predators. Walters wanted to give scientists a better understanding of the processes that drive density dependent fluctuations in ecosystem statistics (birth and death rates). The foraging arena theory is also used, in conjunction with the ecosystem simulation program Ecopath with Ecosim
Ecosim
EcosimPro is a simulation tool developed by Empresarios Agrupados A.I.E for modelling simple and complex physical processes that can be expressed in terms of Differential algebraic equations or Ordinary differential equations and Discrete event simulation....
, to account for the indirect effect
Indirect effect
Indirect effect describes a situation where national courts are required to interpret national law in line with an unimplemented or badly implemented directive, as opposed to ignoring national law in preference to the directive as occurs when direct effect is invoked...
s and trophic cascade
Trophic cascade
Trophic cascades occur when predators in a food web suppress the abundance of their prey, thereby releasing the next lower trophic level from predation...
s seen in populations.
Adaptive Management
One of Walters biggest concerns in the rapidly changing environment
Environment (biophysical)
The biophysical environment is the combined modeling of the physical environment and the biological life forms within the environment, and includes all variables, parameters as well as conditions and modes inside the Earth's biosphere. The biophysical environment can be divided into two categories:...
is how managers can successfully manage fisheries stocks in lieu of the uncertainty in making decisions. His concept of active adaptive management involves large-scale experimentation, or "learning-by-doing", in order to understand the population dynamics
Population dynamics
Population dynamics is the branch of life sciences that studies short-term and long-term changes in the size and age composition of populations, and the biological and environmental processes influencing those changes...
in fish communities and to aide in the decision-making process done by policy makers. Walters encourages other scientists, managers, and policy makers to embrace the uncertainty in experiments and decisions and to develop ecosystem models based on the uncertainties in order to make multiple hypotheses instead of just one hypothesis
Hypothesis
A hypothesis is a proposed explanation for a phenomenon. The term derives from the Greek, ὑποτιθέναι – hypotithenai meaning "to put under" or "to suppose". For a hypothesis to be put forward as a scientific hypothesis, the scientific method requires that one can test it...
. Although active adaptive management has gained much support from the scientific community, there is still great hesitation from scientists and managers to implement these large-scale experiments. These hesitations arise from large monetary costs for the experiments as well as the monitoring of the experiments, lack of an individual willing to take on the daunting task of organizing the experiments, the limitations of models to perfectly represent an ecosystem, and the conflicting ecological values between different interest groups. Although there are concerns when executing active adaptive management strategies, there is a growing need to modify the current methods for exploring and understanding ecosystems, especially on a larger scale, and active adaptive management strategies aim to do exactly that.
Recent publications
Books- Walters, C.J. 1986. Adaptive Management of Renewable Resources. MacMillan Pub. Co, New York, USA. (374 pp).
- Hilborn, R. and Walters C.J. 1991. Quantitative Fisheries Stock Assessment and Management. Chapman-Hall, Pub. Co., New York, USA. (580 pp).
- Walters C.J. and Martell S. 2004. Fisheries Ecology and Management. Princeton, New Jersey, Princeton University Press.
Journal Publications
- Walters C.J. and,Juanes F. 1993. Recruitment limitation as a consequence of optimal risk-taking behaviour by juvenile fish. Can. J. Fish. Aquat. Sci. 50:2058-2070.
- Walters, C.J. 1997. Challenges in adaptive management of riparian and coastal ecosystems. Conservation Ecology (online) 1(2): 1.
- Walters, C.J. and Green, R. 1997. Valuing large scale management experiments for natural resources. J. Wildl. Mgmt. 61:987-1006.
- Perry I., Walters C.J. and Boutillier J. 1999. A framework for providing scientific advice for the management of new and developing fisheries. Rev. Fish Biol. Fisheries 9:1-26.
- Perry R.I., Walters C.J., and Boutillie J.A. 1999. A framework for providing scientific advice for the management of new and developing invert fisheries. Rev. Fish Biol. Fisheries. 9: 125-150.
- Walters C.J. and Korman J. 1999. Revisiting the Beverton-Holt recruitment model from a life history and multispecies perspective. Rev. Fish Biol. Fisheries 9:187-202.
- Pauly D., Christensen V., Walters C.J. 2000. Ecopath, ecosim, and ecospace as tools for evaluating ecosystem impact of fisheries. ICES J. Mar. Sci. 57:697-706.
- Walters C.J. 2001. Implications for marine population and community dynamics of natural selection for predation avoidance tactics. Marine Ecology Progress series. 208:309-313.
- Walters C.J. and Martell S.J.D. 2002. Stock assessment needs for sustainable fisheries management. Bulletin of marine science. 70(2): 629.
- Christensen V. and Walters C.J. 2004. Trade-offs in Ecosystem-scale Optimization of Fisheries Management Policies. Bulletin of Marine Science. 74(3): 549-562.
- Walters C.J. 2005. Is Adaptive Management Helping to Solve Fisheries Problems?
Can. J. Fish. Aquat. Sci. 62(6): 1320-1336.
- Coggins L.G., Catalano M.J., Allen M.S., Pine W.E., Walters C.J. 2007. Effects of cryptic mortality and the hidden costs of using length limits in fishery management. Fish and Fisheries. 8(3): 196-210.
Awards
- Wildlife Society award for best paper in fish ecology and management: Walters, C.J. and Hilborn R. 1976. Adaptive control of fishing systems, J. Fish. Res. Bd. Canada 33(1): 145-159.
- Fellow of the Royal Society of CanadaRoyal Society of CanadaThe Royal Society of Canada , may also operate under the more descriptive name RSC: The Academies of Arts, Humanities and Sciences of Canada , is the oldest association of scientists and scholars in Canada...
(1998) - Pew Fellow in Marine Conservation (2001–2004)
- Mote Eminent Scholar - Florida State University and Mote Marine Laboratory (2001–2002)
- Murray A. Newman Award for Marine Conservation (Vancouver Aquarium) (2005)
- Volvo Environment Prize - shared with Daniel Pauly and Ray Hilborn (2006)
- American Fisheries Society Award of Excellence (2006)
- Timothy R. ParsonsTimothy R. ParsonsTimothy Richard Parsons, OC, FRSC is a Canadian oceanographer and the first Canadian to receive a Japan Prize.Born in Colombo, Ceylon, he received a Bachelor of Science degree in 1953, a Master of Science degree in 1955, and a Ph.D...
Medal (2007)
External links
- http://www.ecopath.org/
- http://www.seaaroundus.org/