Tropical wetlands are highly threatened socio-ecological systems, where local communities rely heavily on aquatic animal protein, such as fish, to meet food security. Here, we quantify how a ‘win-win’ community-based resource management program induced stock recovery of the world’s largest scaled freshwater fish (Arapaima gigas), providing both food and income. We analyzed stock assessment data over eight years and examined the effects of protected areas, community-based management, and landscape and limnological variables across 83 oxbow lakes monitored along a ~500-km section of the Juruá River of Western Brazilian Amazonia. Patterns of community management explained 71.8% of the variation in arapaima population sizes. Annual population counts showed that protected lakes on average contained 304.8 (±332.5) arapaimas, compared to only 9.2 (±9.8) in open-access lakes. Protected lakes have become analogous to a high-interest savings account, ensuring an average annual revenue of US$10,601 per community and US$1046.6 per household, greatly improving socioeconomic welfare. Arapaima management is a superb window of opportunity in harmonizing the co-delivery of sustainable resource management and poverty alleviation. We show that arapaima management deserves greater attention from policy makers across Amazonian countries, and highlight the need to include local stakeholders in conservation planning of Amazonian floodplains.

Co‐management has been advocated as an effective tool to achieve natural resource conservation worldwide. Yet, the potential of co‐management arrangements can fail to be realized when there is insufficient local engagement. In this perspective paper, we argue that co‐management schemes focusing on culturally important species (CIS) can help overcome this issue by engaging local people's interest. To develop this theory, we explore published data on the outcomes of two management schemes, both encompassing multiple independent initiatives, to discuss CIS‐management effects and benefits. We also show a compilation of CIS examples throughout the world and discuss the potential of CIS‐management to reach a global audience. Based on these data, we argue that CIS‐management can be an effective tool to reconcile the often intractable goals of biodiversity conservation and human welfare.

The remarkable biodiversity of the Brazilian Amazon is poorly documented and threatened by deforestation. When undocumented areas become deforested, in addition to losing the fauna and flora, we lose the opportunity to know which unique species had occupied a habitat. Here we quantify such knowledge loss by calculating how much of the Brazilian Amazon has been deforested and will likely be deforested until 2050 without having its tree flora sufficiently documented. To this end, we analysed 399 147 digital specimens of nearly 6000 tree species in relation to official deforestation statistics and future deforestation scenarios. We find that by 2017, 30% of all the localities where tree specimens had been collected were mostly deforested. Some 300 000 km ² (12%; 485 25 × 25 km grid cells) of the Brazilian Amazon had been deforested by 2017, without having a single tree specimen recorded. An additional 250 000–900 000 km ² of severely under‐collected rainforest will likely become deforested by 2050. If future tree sampling is to cover this area, sampling effort has to increase two‐ to six‐fold. Nearly 255 000 km ² or 7% of rainforest in the Brazilian Amazon is easily accessible but does yet but remain under‐collected. Our study highlights how progressing deforestation increases the risk of losing undocumented species of a hyper‐diverse tree flora.

Significance: Sustainable-use protected areas (PAs) have contributed to tropical biodiversity conservation by deterring deforestation in multiple countries, yet their social and economic benefits to local stakeholders remain poorly understood. Amazonia hosts the largest tropical PA system on Earth, which is intended to safeguard its rich biological and cultural diversity. Aligning biodiversity protection with social aspirations is therefore imperative in this region. Our results demonstrate that sustainable-use PAs can catalyze a wide set of enablers, including multipartnerships, strong local associations, land tenure, comanagement, economic subsidies, strong leadership, public policies, and polycentric governance, resulting in marked improvements in local welfare beyond biodiversity protection. Such a rare conservation bright spot elucidates potential pathways that can foster social and ecological outcomes that are potentially scalable across lowland Amazonia.