Capelin are one of the more difficult species to forecast and, therefore, to manage. They have relatively short life spans. The populations often consist of a few key age groups, so you will have kind of a big population and then a couple of years with a small population. That means it's quite variable.
A lot of the fluctuations we see are more driven by environmental factors than they are by fishing activity itself. That is not to say that fishing activity doesn't play a role, but whereas fishing activity is easy to monitor, often the environmental conditions are not.
It is one that has a wider margin of error than some of the species we manage that live longer or are much more predictable.