The instantaneous rate of fish deaths due to fishing a component of the fish stock. F reference points may be applied to entire stocks or segments of the stocks, and should match the scale of management unit (for example, total biomass or spawning biomass). Instantaneous fishing mortality rates of 0.1, 0.5, 1.0, and 2.0 are equivalent to annual exploitation rates of 9.5 per cent, 39.3 per cent, 63.2 per cent and 86.5 per cent respectively. See also Mortality, Natural mortality.