Over-exploitation and subsequent collapse of marine fishes has focused atte
ntion on the ability of affected populations to recover to former abundance
levels(1-3) and on the degree to which their persistence is threatened by
extinction(4,5). Although potential for recovery has been assessed indirect
ly(1), actual changes in population size following long-term declines have
not been examined empirically. Here I show that there is very little eviden
ce for rapid recovery from prolonged declines, in contrast to the perceptio
n that marine fishes are highly resilient to large population reductions(6,
7). With the possible exception of herring and related species that mature
early in life and are fished with highly selective equipment, my analysis o
f 90 stocks reveals that many gadids (for example, cod, haddock) and other
non-clupeids (for example, flatfishes) have experienced little, if any, rec
overy as much as 15 years after 45-99% reductions in reproductive biomass.
Although the effects of overfishing on single species may generally be reve
rsible(1), the actual time required for recovery appears to be considerable
. To exempt marine fishes from existing criteria used to assign extinction
risk(6,7) would be inconsistent with precautionary approaches to fisheries
management and the conservation of marine biodiversity.