Balanced harvesting: Is it a good idea?
Friday seminar by Matthew Burgess from University of California, Santa Barbara (US)
Balanced harvesting (BH) - harvesting all species and sizes in an ecosystem in proportion to their productivity - has been proposed recently as a fisheries management strategy to increase ecosystem-wide food production while reducing the adverse impacts of fishing on ecosystems. BH is an innovative proposal that has begun to gain significant traction in the scientific community and among some policy makers. However, several fundamental challenges and pitfalls of BH have been largely overlooked. It is unclear if implementing BH - as defined - is physically possible, and how robust proposed benefits would be to imperfect implementation. Even under perfect implementation, the benefits of BH with respect to ecosystem function are not clear. The economic costs of BH are unknown but probably very high, and it is unclear if these costs are offset by the proposed benefits. If the benefits do outweigh the costs, it is unclear who would pay the costs. Because the species- and size-composition of catch would change substantially under BH relative to the status quo, it is unclear where and to what extent any extra yield from BH would be able to offset rising human demands for animal protein. These and other issues must be addressed before balanced harvesting can be taken seriously by policy makers as a viable ecosystem-based fishery management strategy.
Matthew G. Burgess
Sustainable Fisheries Group
Bren School of Environmental Science and Management
Marine Science Institute
University of California, Santa Barbara, CA 93106