Many top-predator fish stocks in both freshwater and marine systems have been decimated due to over-harvesting. In lakes, recovery strategies involving stocking of top predators have generally had poor long-term success. In agreement with recently developed theory we show that for predators feeding on prey that exhibit food-dependent growth culling of prey is a more effective recovery strategy than stocking. A short-term experimental prey-fish thinning in a large, low-productive lake caused an overcompensating increase in individual prey growth leading to increased availability of small-sized prey fish. Our data analysis reveals that this increase improved food conditions for and allowed the recovery of the top predator. The shift in community state has been sustained for more than 15 years after stopping the prey fish culling and represents the first experimental demonstration of an alternative stable state (ASS) in a large scale field system. As most animal organisms exhibit food-dependent growth , ASS due to overcompensating prey growth should be the rule rather than the exception in nature and may require counter-intuitive management strategies to recover from unwanted community states.
