Carl Walters | |
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Born | Carl John Walters Albuquerque, New Mexico, US |
Alma mater | Colorado State University |
Known for | Fisheries stock assessments, adaptive management, ecosystem modeling |
Awards | Fellow of the Royal Society of Canada (1998), Mote Eminent Scholar at FSU (2000-2001), Pew Fellow in Marine Conservation (2001), Murray A. Newman Award for Marine Conservation (2005), Volvo Environment Prize (2006), American Fisheries Society Award of Excellence (2006), Timothy R. Parsons Medal (2007), Order of British Columbia (2019) |
Scientific career | |
Fields | Zoology, fisheries science, population ecology |
Institutions | UBC Fisheries Centre, University of British Columbia |
Doctoral advisor | Robert E. Vincent |
Notes | |
Carl Walters (born 1944) is an American-born Canadian biologist known for his work involving fisheries stock assessments, the adaptive management concept, and ecosystem modeling. [1] Walters has been a professor of Zoology and Fisheries at the University of British Columbia since 1969. [2] He is one of the main developers of the ecological modelling software Ecopath. [3] His most recent work focuses on how to adjust human behaviors in environments that are full of uncertainty. [1] He is a recent recipient of the Volvo Environment Prize (2006). [4] In 2019, Dr. Walters became a Member of the Order of British Columbia. [5]
Carl Walters graduated from Bakersfield College 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, British Columbia, Canada. [2]
Walters's first professorship was at the University of British Columbia as an Assistant Professor in the UBC Institute for Animal Resource Ecology. In 1977, he became an Associate Professor and then a Professor in 1982. Prior to his professional appointment at UBC, Walters worked for the California Department of Fish and Game and was also a graduate fellow, a consultant, and an aide on numerous occasions. [2] He has taken sabbaticals to the International Institute of Applied Systems Analysis in Vienna, the University of Florida, where he is an adjunct professor, and Australia. [2] 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. [2] He was the editor of the Open Fish Science Journal. Walters also served, and continues to serve, as a consultant to many government agencies.
Walters uses mathematical modeling to understand how to successfully manage harvestable fisheries in a time of high uncertainty. [1] [2] He specializes in fisheries stock assessments (e.g cod, salmon, anchoveta), adaptive management strategies, and ecosystem modeling. [1] [2] [6] [7] 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. [8] [9] [10] Fisheries biologists and population ecologists have used the Beverton-Holt model since the 1960s to describe the "stock-recruitment" relationship. [9] 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. [10] [9] Walters wanted to give scientists a better understanding of the processes that drive density dependent fluctuations in ecosystem statistics (birth and death rates). [10] The foraging arena theory is also used, in conjunction with the ecosystem simulation program Ecopath with Ecosim, to account for the indirect effects and trophic cascades seen in populations. [10]
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. [10] 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. [11] 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. [10] 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. [12] [13] 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. [13] 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.
FishBase is a global species database of fish species. It is the largest and most extensively accessed online database on adult finfish on the web. Over time it has "evolved into a dynamic and versatile ecological tool" that is widely cited in scholarly publications.
A conventional idea of a sustainable fishery is that it is one that is harvested at a sustainable rate, where the fish population does not decline over time because of fishing practices. Sustainability in fisheries combines theoretical disciplines, such as the population dynamics of fisheries, with practical strategies, such as avoiding overfishing through techniques such as individual fishing quotas, curtailing destructive and illegal fishing practices by lobbying for appropriate law and policy, setting up protected areas, restoring collapsed fisheries, incorporating all externalities involved in harvesting marine ecosystems into fishery economics, educating stakeholders and the wider public, and developing independent certification programs.
The goal of fisheries management is to produce sustainable biological, environmental and socioeconomic benefits from renewable aquatic resources. Wild fisheries are classified as renewable when the organisms of interest produce an annual biological surplus that with judicious management can be harvested without reducing future productivity. Fishery management employs activities that protect fishery resources so sustainable exploitation is possible, drawing on fisheries science and possibly including the precautionary principle.
Fisheries science is the academic discipline of managing and understanding fisheries. It is a multidisciplinary science, which draws on the disciplines of limnology, oceanography, freshwater biology, marine biology, meteorology, conservation, ecology, population dynamics, economics, statistics, decision analysis, management, and many others in an attempt to provide an integrated picture of fisheries. In some cases new disciplines have emerged, as in the case of bioeconomics and fisheries law. Because fisheries science is such an all-encompassing field, fisheries scientists often use methods from a broad array of academic disciplines. Over the most recent several decades, there have been declines in fish stocks (populations) in many regions along with increasing concern about the impact of intensive fishing on marine and freshwater biodiversity.
Adaptive management, also known as adaptive resource management or adaptive environmental assessment and management, is a structured, iterative process of robust decision making in the face of uncertainty, with an aim to reducing uncertainty over time via system monitoring. In this way, decision making simultaneously meets one or more resource management objectives and, either passively or actively, accrues information needed to improve future management. Adaptive management is a tool which should be used not only to change a system, but also to learn about the system. Because adaptive management is based on a learning process, it improves long-run management outcomes. The challenge in using the adaptive management approach lies in finding the correct balance between gaining knowledge to improve management in the future and achieving the best short-term outcome based on current knowledge. This approach has more recently been employed in implementing international development programs.
An ecosystem model is an abstract, usually mathematical, representation of an ecological system, which is studied to better understand the real system.
Milner Baily ("Benny") Schaefer, is notable for his work on the 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 migration. It is the basis for understanding changing fishery patterns and issues such as habitat destruction, predation and optimal harvesting rates. The population dynamics of fisheries is used by fisheries scientists to determine sustainable yields.
Ecosystem-based management is an environmental management approach that recognizes the full array of interactions within an ecosystem, including humans, rather than considering single issues, species, or ecosystem services in isolation. It can be applied to studies in the terrestrial and aquatic environments with challenges being attributed to both. In the marine realm, they are highly challenging to quantify due to highly migratory species as well as rapidly changing environmental and anthropogenic factors that can alter the habitat rather quickly. To be able to manage fisheries efficiently and effectively it has become increasingly more pertinent to understand not only the biological aspects of the species being studied, but also the environmental variables they are experiencing. Population abundance and structure, life history traits, competition with other species, where the stock is in the local food web, tidal fluctuations, salinity patterns and anthropogenic influences are among the variables that must be taken into account to fully understand the implementation of a "ecosystem-based management" approach. Interest in ecosystem-based management in the marine realm has developed more recently, in response to increasing recognition of the declining state of fisheries and ocean ecosystems. However, due to a lack of a clear definition and the diversity involved with the environment, the implementation has been lagging. In freshwater lake ecosystems, it has been shown that ecosystem-based habitat management is more effective for enhancing fish populations than management alternatives.
Ecopath with Ecosim (EwE) is a free and open source ecosystem modelling software suite, initially started at NOAA by Jeffrey Polovina, but has since primarily been developed at the formerly UBC Fisheries Centre of the University of British Columbia. In 2007, it was named as one of the ten biggest scientific breakthroughs in NOAA's 200-year history. The NOAA citation states that Ecopath "revolutionized scientists' ability worldwide to understand complex marine ecosystems". Behind this lie more than three decades of development work in association with a thriving network of fisheries scientists such as Villy Christensen, Carl Walters and Daniel Pauly, and software engineers around the world. EwE is funded through projects, user contributions, user support, training courses and co-development collaborations. Per November 2021 there are an estimated 8000+ users across academia, non-government organizations, industry and governments in 150+ countries.
Tony J Pitcher is a fisheries scientist, well known for his work on the impacts of fishing, the management appraisal of fisheries, and how shoaling behaviour impacts fisheries.
Ray Hilborn is a marine biologist and fisheries scientist, known for his work on conservation and natural resource management in the context of fisheries. He is currently professor of aquatic and fishery science at the University of Washington. He focuses on conservation, natural resource management, fisheries stock assessment and risk analysis, and advises several international fisheries commissions and agencies.
Villy Christensen is an ecosystem modeller with a background in fisheries science. He is known for his work as a project leader and core developer of Ecopath, an ecosystem modelling software system widely used in fisheries management. Ecopath was initially an initiative of the NOAA, but since primarily developed at the UBC Fisheries Centre of the University of British Columbia. In 2007, it was named as one of the ten biggest scientific breakthroughs in NOAA's 200-year history. The citation states that Ecopath "revolutionized scientists' ability worldwide to understand complex marine ecosystems".
Fishing down the food web is the process whereby fisheries in a given ecosystem, "having depleted the large predatory fish on top of the food web, turn to increasingly smaller species, finally ending up with previously spurned small fish and invertebrates".
The Pacific North Coast Integrated Management Area is one of five Large Ocean Management Areas (LOMAs), areas of high ecological, social and economic importance, that have been identified by Fisheries and Oceans Canada (DFO) as priority regions for marine planning as part of Canada’s Oceans Action Plan.
SeaLifeBase is a global online database of information about marine life. It aims to provide key information on the taxonomy, distribution and ecology of all marine species in the world apart from finfish. SeaLifeBase is in partnership with the WorldFish Center in Malaysia and the UBC Institute for the Oceans and Fisheries at the University of British Columbia. Daniel Pauly is the principal investigator and it is coordinated by Maria Lourdes D. Palomares. As of March 2023, it included descriptions of 85,000 species, 59,400 common names, 15,500 pictures, and references to 39,300 works in the scientific literature. SeaLifeBase complements FishBase, which provides parallel information for finfish.
Raymond (Ray) John Heaphy Beverton CBE FRS was an important founder of fisheries science. He is best known for the book On the Dynamics of Exploited Fish Populations (1957) which he wrote with Sidney Holt. The book is a cornerstone of modern fisheries science and remains much used today. Beverton's life and achievements are described in detail in several obituaries written by prominent figures in fisheries science.
Sidney J. Holt was a British biologist who was a founder of fisheries science. He was best known for the book On the Dynamics of Exploited Fish Populations which he published with Ray Beverton in 1957. The book is a cornerstone of modern fisheries science and remains much used today. Holt served with the FAO in 1953 and with other UN agencies for another 25 years. After his retirement in 1979, Holt remained active in work related to the International Whaling Commission and conservation of whales in general, also publishing his views about whaling and fisheries management in academic journals.
The following outline is provided as an overview of and topical guide to fisheries:
Jeffrey Alexander Hutchings FRSC was a Canadian fisheries scientist. He was a professor of biology, and the Izaak Walton Killam Memorial Chair in Fish, Fisheries, and Oceans at Dalhousie University.