In Tanzania, the Rufiji floodplain is populated by people earning their living from agriculture and fishing. Revenues from legal fishing hardly secure food security of households, and don't really allow for other investments or expenses. In order for instance to earn enough money to pay for secondary school fees, many villagers actually need to leave the legal fishing zones and to penetrate in the Selous Reserve, where several lakes abounding in fish are situated. The Reserve has been progressively constituted throughout the twentieth century, but local villagers do not beneficiate from the revenues it generates. New "participatory" approaches and conservation policies are only declarations of interest without concrete effects.