No abstracts are to be cited without prior reference to the author.The scope of this paper is to identify, for a wide selection of fleets, fisheries and stocks, the elements of fishing effort that can be attributed to fishing tactics and strategies, and to evaluate the benefits of using adjusted definitions of fishing effort. Indices have been derived to reflect shifts in tactics (within a trip) and in strategies (within a year). The Shannon-Wiener spatial diversity indices of tactics (FT_SW) and strategies (YE_SW) had the greatest impact on catch rates. In particular, FT_SW was negatively correlated to the catch rates of each combination of fleets and species investigated. One may anticipate that during a fishing trip, vessels with high FT_SW have been searching fish aggregations for a long time, while vessels with low FT_SW have been more efficient in finding these aggregations. YE_SW was negatively correlated to the catch rates for most of the combinations of fleets and species investigated. The fishing locations of traditional species are fairly well known by fishermen, and there is little benefit exploring new fishing grounds. This reasoning however does not apply when fishermen harvest species such as roundnose grenadier, for which new aggregations are still being discovered. For the French vessels, a broad distribution of fishing effort may be an appropriate strategy to promote the capture of roundnose grenadier. Adjusting fishing effort generally lead to a gain in the precision of the relationship between fishing mortality and fishing effort. Nevertheless, the coefficient of determination of the regression between log-transformed partial fishing mortality and adjusted fishing effort never exceeded 40%. This indicates that this study goes one step towards the right direction, but also that more research is needed to carry on the development of a reliable fishing effort model.