Dr. Ellen Pikitch:

The big collapse in the Peruvian anchovy fishery occurred in 1972 and it took about ten years for the stock to recover to its former level of abundance.

These species tend to be short-lived. They only have a few age classes but they are very prolific. They put out a lot of eggs. If the environmental conditions are good, then because they put out so many eggs, there can be a quick recovery. Recovery after that first big collapse took about ten years. What is interesting is that many of the species that depended on the Peruvian anchovy have still not recovered following the 1972 collapse. The sea birds, marine mammals and some of the bigger, longer-lived fish that depended upon those anchovies do not have the same capacity to bounce back quickly. Therefore, the predator populations, in many cases, are still depleted. In the report we go into that case study in a lot more depth. Essentially it is a situation where there was a recovery of the target species but we were left with an impoverished ecosystem. Therefore, it is a win in only a limited sense.

Namibia is a different story altogether where there was a collapse but no recovery. That has led to a lot of changes to the ecosystem overall. One cannot necessarily predict that there will be a recovery or how long it will take.