Cultivation, Allee effect and resilience of large demersal fish populations

摘要: In the marine environment, small forage species can predate on, or compete with, pre-recruits of their larger predators. The "cultivation effect" hypothesis proposes that this mechanism slow down recovery depleted populations large demersal fishes by creating Allee effects lower recruitment success. Using an individual based fish community model applied to southern Benguela ecosystem, we simulate situations potential cultivation effect on a population shallow water hake Merluccius capensis. We search for evidence due and investigate how complex trophic interactions could influence underlying mechanisms impact. resilience was measured following variations ratio R/S (the number recruits over spawners) when size decreases predators competitors were identified. Simulations suggest are likely emerge within ecosystem. Our twelve emphasizes result from influences predation competition different pre-recruit stages, whose role depends both body geographical distribution. For realistic linkages between pre-recruits, occurring in limits predicted delay several decades. These significant delays not characterized decrease at low stock size, which is sign usually tracked looking effects. study suggests play major dynamics overexploited pleads development improved detection techniques these processes.