Evidence and Consequences of Increased Variability in Fish Populations

Investigations of climate effects on fisheries are typically focused on unidirectional changes in productivity (e.g., decreased recruitment, geographic shifts), but many fishery resources are exhibiting recent increases in variability associated with climate, making forecasts more difficult. Life history strategy is naturally adapted to respond to increased variability. Several changes in the population ecology of fishes that have intensified in recent years. Examples are provided from freshwater and marine populations. Case studies also include methods to analyze time series that contain periods of increased variability as well as the management consequences of the increased variability. The reasons for the increased variability may be a changing climate or fishing or both. In both cases, the species is adapting to these changes according to its life history strategy.