Bycatch and discards from small-scale fisheries (SSF) are usually ignored when compared with industrial fisheries, not only by policy-makers, but also by scientists. Therefore, SSF social, economic and ecological impacts are poorly known and especially in the context of incidental catches, regardless of whether they become bycatch or discards. Such neglect is worrisome due to the role that SSF play in food security and poverty alleviation, particularly in coastal and rural communities in developing countries. In this study, a combination of sampling data and the fishers' behavior (specifically the basis of their decision on where to fish) were used. Bayesian models were applied to understand which variables affect the bycatch per unit effort (BPUE) variation in the shrimp SSF of the southern coast of the state of Bahia (Brazil). Results highlighted how BPUE variability is affected by a set of factors as well as by the specific fisher behavior. In the case of the shrimp fishery assessed here, economic incentives do not influence the decision to land the bycatch, since landed values decrease when bycatch increases. Shadow subsistence values (i.e. non-market values assigned to the consumption value) and the employ of fish as currency added an economic livelihood component to the complex decision regarding bycatch. Mitigation measures for SSF management strategies should be implemented at multiple stages of the bycatch and discarding process, both in the selection of the fishing grounds and the local economic role of the incidentally caught species.