Maximum Sustainable Yield

by

Louis W. Botsford

• LAST REVIEWED: 08 September 2021
• LAST MODIFIED: 30 September 2013
• DOI: 10.1093/obo/9780199830060-0071

Introduction

Maximum Sustainable Yield (MSY) is a statement of two long-standing desirable goals of exploiting a population: (1) attaining the highest possible catch consistent with (2) the population persisting in perpetuity. Note that these two goals are at cross-purposes to each other; in general, the more individuals removed from a population, the less able it will be to persist. The topic of MSY, as described here, involves the search for methods of describing and managing a population to achieve these two goals simultaneously. MSY had its roots primarily in fisheries in the early 20th century, but since its inception it has involved other taxa. The interpretation and application of MSY have changed continuously as fisheries science and management have evolved. By the mid-20th century, MSY was embodied in mathematical models of fish populations and fisheries, and the primary result was a prescription for how hard one should fish to achieve MSY. The value of MSY was obtained as either (1) the point of maximum growth in a logistic model, or (2) the highest practical yield obtainable from a cohort of individuals, a quantity known as yield-per-recruit (a recruit is a fish entering the fishery). The allowable catch that would maintain a population at MSY was referred to as “surplus production.” MSY then began to be widely implemented in fisheries management and international treaties. By the late 1970s, shortcomings of the MSY approach began to be identified. By the 1990s, about a quarter of global fisheries were overfished, empirical evidence that they were not being managed at MSY. As a consequence, a new Precautionary Approach to fisheries management was developed that focused on the detection of declines in population abundance in fisheries by setting reference points against which fishery data were to be compared, and actions were to be taken if they were breached. Under this “feedback control” scheme, prescriptions for MSY were no longer simply optimal fishing efforts from a model, but rather they involved the choice of control rules to describe how management should respond to observed values of reference variables. Another response to the lack of sustainability of some fisheries was a new approach to controlling fishing—spatially explicit management. Marine reserves or marine protected areas—places with no fishing or restricted fishing—were set aside, rather than specifying that fishing rates be the same everywhere. This raised the question of whether MSY would be greater or less with this approach. A third shift in global natural resource management requiring the reformulation of MSY was ecosystem-based management.

Journals

The development of an understanding of Maximum Sustainable Yield (MSY) has taken place primarily in fisheries journals, but it has also been addressed by publications in the general ecology and mathematical biology literature. A number of significant publications regarding the concept of MSY can be found in the Canadian Journal of Fisheries and Aquatic Sciences, with fewer in the ICES Journal of Marine Science, Transactions of the American Fisheries Society, Fisheries Research, and the North American Journal of Fisheries Management. Relevant reviews would appear in Reviews in Fish Biology and Fisheries and Fish and Fisheries. Related topics that were ecologically oriented would appear in Ecological Applications. In addition, much of the development of MSY has been reported in the gray literature.

• Canadian Journal of Fisheries and Aquatic Sciences. 1901–.

  A premier journal in the field of marine and freshwater fisheries, with contributions defining MSY, as well as applications of MSY. Published in Canada by the National Research Council Research Press. Formerly known as the Journal of the Fisheries Research Board of Canada.

• Ecological Applications. 1991–.

  An international journal concerned broadly with the application of ecological science to environmental problems. Published by the Ecological Society of America.

• Fish and Fisheries. 2000–.

  An international journal that publishes reviews on fish and fisheries. Published by Wiley.

• Fisheries Research. 1981–.

  An international journal publishing articles on fisheries science, technology, and management. Published by Elsevier.

• ICES Journal of Marine Science. 1903–.

  A leading journal in the publication of articles on fisheries management and conservation in the marine environment. Published by Oxford Press on behalf of the International Council for the Exploration of the Sea (ICES)/Conseil International pour l’Exploration de la Mer. Formerly known as the Journal du Conseil.

• North American Journal of Fisheries Management. 1981–.

  A journal started in 1981 to promote communication among fishery managers. Published by Taylor & Francis on behalf of the American Fisheries Society.

• Reviews in Fish Biology and Fisheries. 1991–.

  An international journal that publishes reviews on fish biology and fisheries. Published by Springer.

• Transactions of the American Fisheries Society. 1872–.

  A highly regarded journal publishing articles on a variety of topics associated with fisheries. Published by Taylor & Francis on behalf of the American Fisheries Society.