The fishing effort of a particular vessel is generally accepted as the product of the
fishing power and an appropriate measure of fishing activity (Galbraith and Stewart, 1995).
The parameters that measure the fishing power are known as ‘capacity parameters’ and
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result from vessel and fishing gear characteristics. The activity measure may be expressed
by the number of fishing trips, fishing time, duration of the trips, number of sets, which in
turn depend on the vessel characteristics and fishing method (Parente, 2004). Fishing power
is the ability of a fishing unit to catch fish (Galbraith and Stewart, 1995) but since
calculating it in absolute terms is not possible, it has been defined as a relative measure.
Relative fishing power may be defined as the ratio of the quantity caught by an individual
vessel per unit fishing time to that by a vessel selected as a standard reference (Beverton and
Holt, 1957).
Catch per pot