Fishing throws targeted species off balance, Scripps s...(s even though the swordfish are clearly ...)

In the extreme case, the danger of such unstable dynamics for certain populations for management is that harvest targets may lag the population, potentially making things worse, said Sugihara. A high harvest target may be set after an especially abundant period when the population may be poised to decline on its own. Likewise future abundant periods may represent missed opportunities, despite current low abundances. As senior officials of the Canadian Department of Fisheries and Oceans have said, we are often a year behind in our stock projections.

Sugihara cautioned that nonlinearity is not unique to fished species. Nonequilibrium overshooting and undershooting occurs in unexploited stocks, but to a lower extent. Therefore, classical single-species population models that require equilibrium are unlikely to be very successful in stock forecasts, except perhaps in the very short term.

"Other methods that do not rely on these assumptions may be more promising," suggests Christian Anderson, paper co-author.

'/>"/>