Human activities are a concern in that they may disrupt these fishes. Dams may impede the migration of these fish both to and from their spawning sites. Gold prospecting may also frighten these large catfishes in the areas where they spawn. Deforestation can also affect the upriver spawning habitats. Because these fish may migrate back to their original tributary, overfishing in a certain area may reduce a whole genetic group. In some areas, catches have been diminishing due to overfishing. "B. rousseauxii" is known to be overfished, and this same situation may apply to other "Brachyplatystoma". Catch rates of "B. filamentosum" have decreased drastically from 1977.