The main difference between management systems based on TAC’s and quotas and systems based on effort is that effort systems aim at managing the input, the level of harvesting capacity, whereas TAC and quota systems seek to manage the output, the quantity of fish that is extracted from the sea.
However, both systems have the same objective, namely to limit fishing mortality (i.e. the number of fish killed by fishing activity).
By setting a limit to the amount of fishing effort, the amount of fish extracted from the ocean will be limited, and can thus be adjusted to the size of the resource. The method requires that the management authorities have a good knowledge of the quantity of fish caught, depending on type of vessel, its size and the fishing technique used.
In order for the catches not to increase over time, the authorities need to have control over the changes of vessels that may lead to increased capacity to catch fish for a given amount of regulated effort. Hence, in order to balance the fleet capacity with the resource, the total allowable effort needs to be constantly adjusted in order to account for technological changes.
There is potentially a strong incentive for operators to adopt new technologies and substitute uncontrolled inputs for the controlled inputs, resulting in effort creep. That is, if the fishing is profitable there is an economic incentive to increase the exploitation of fish, which could mean more or better equipped vessels. Therefore, just as in the case with the TAC based management system, improvements in control and enforcement continues to be of great importance in a system based on effort management.
Community law defines fishing effort for a vessel as the product of its capacity and its activity, usually expressed as the volume of the vessel in gross tonnage (GT) or its power (KW). For a group of vessels, the fishing effort is defined as the sum of the fishing effort of each vessel. The allowed effort is normally expressed as number of days at sea per year, which has to be adapted to the gears used, the area or zone where the fishing is taking part, target species, the condition of the stock, and the capacity of the vessel.
It is argued that the major advantage of a pure effort system, compared with a system based on TAC:s and quotas, is that the effort system allows the fishermen to land their entire catch and that the system facilitates control. This could potentially minimise discard and the incentive for unreported landings, which in turn would enable the industry to provide fisheries scientists with better data on fish stocks.
Just as the TAC system, the effort system has received much criticism. Environmental advocates often raise concern that it is difficult to assess the effort needed to catch a certain quantity of fish, and the industry is often heard complaining that the system leads to a constant decrease in allowed effort.
The North Sea Regional Advisory Council (NSRAC) has proposed an effort management scheme as an alternative way of managing certain fish stocks in the Kattegat. The EU Commission welcomed this initiative but failed to reach an agreement with the industry. There have therefore not been any trials of pure effort management in this area so far.