A multivariate approach for defining fishing tactics from commercial catchand effort data

Fishing tactics correspond to fishing practices at the scale of the fishing operation. In the case of mixed fisheries, they are defined as a combinati on of target species, gear, and fishing location, at a given time of the ye ar. This paper proposes an approach to determine fishing tactics from the a nalysis of commercial catch and effort data. The approach is based on typol ogies of fishing operations involving multivariate descriptive methods like factorial analyses and classification techniques. The obtained types of fi shing operations are considered as fishing tactics. The approach is applied to two contrasting examples, a small-scale Senegalese fishery and a Celtic Sea fishery that operates at a larger scale. Catch per species and fishing effort are computed per tactic. Results emphasize the importance of fishin g location and seasonal effects for characterizing fishing tactics.