The term fishing effort is descriptive of the hard work and drive that have been the foundation of the Icelandic fisheries for centuries. Only the strongest and healthiest of men could be fishermen with all the toil, hardship and danger that they were exposed to. It was the hunting instinct and the hope of a good catch that kept them going. As the fisheries became technically more advanced the level of fishing effort also increased at a rapid rate and eventually it became necesssary to find ways of limiting the fishing effort and at the same time to adjust the total catch from the most important stocks to the level of their recruitment and make every effort to maintain fishing at sustainable levels. It is now clear that in the past few decades the fishing effort was often excessive and as a result the fisheries were not as economic as they might have been and stock utilization was sometimes beyond scientific recommendations.
Fishing effort is a complex term.
Scientists often consider fishing mortality to be a measure of effort and it is therefore considered one of the biological indicators for effort. Economists, on the other hand, consider the use of various inputs that have an economic value and find this to be reasonably well correlated with the fishing mortality. The economic inputs are found to correlate well with the fishery costs but they are complex and it is difficult to find a good, universal input indicator. The biological and the economic factors have a useful common denominator in the estimate for catch per unit of effort. The catch from a given stock per unit of effort is usually calculated for each type of fishing gear.