Population recovery, seasonal site fidelity, and daily activity of pirarucu (Arapaima spp.) in an Amazonian floodplain mosaic

Abstract

Pirarucu (Arapaima spp.) are the world's largest scaled freshwater fish, reaching 3 m in length and >200 kg in weight. Historical overfishing has devastated populations of this remarkable fish across Amazonian floodplains, but community‐based management programmes are now stimulating the recovery of wild populations. Pirarucu have evolved a unique set of life history traits, some of which have important implications for population management. Individuals exhibit lateral annual migration patterns during the prolonged annual flood pulse, entering flooded forests to reproduce and forage. During this period, although managed fish stocks become less monopolisable by local communities responsible for managing protected lakes, pirarucu can occupy and reproduce in new environments and thus potentially contribute to population recovery. Here, we show a strong pattern of pirarucu (Arapaima cf. gigas) population recovery under community‐based management in an area along the Juruá River, in western Brazilian Amazonia. We show evidence of population recovery even outside formal protected areas, reinforcing the suitability of pirarucu community‐based management as a powerful tool for both biodiversity conservation and the improvement of local livelihoods. We also show pirarucu movements across a floodplain mosaic—including lakes, the main river channel, tributary streams, and flooded forests—during the wet season. Our results support evidence of site fidelity among migrating pirarucu, justifying the high effort invested by local communities in seasonally protecting lakes from poachers and illegal fishers. Finally, restricted daily movement patterns by pirarucu support the suitability of population estimates based on day‐time counts because the chance of double counting is substantially reduced during the day when these counts are conducted. We highlight the strong suitability of this species for community‐based management, since they can: (1) replenish new environments during the wet season through migration and possibly also reproduction; and (2) be efficiently harvested during the dry season, delivering social and ecological benefits at large spatial scales. Positive examples of fisheries management, which align biodiversity conservation and social development, are important for building optimism, and influencing local and international stakeholders. Our study shows how engaging and empowering local communities to help monitor the movement ecology of target species can be an effective strategy to support the sustainable management of aquatic resources in tropical environments.

Management of Pirarucu (Arapaima gigas, Teleostei, Osteoglossidae) in Sustainable Use Units as a proposal for the restoration of aquatic ecosystems

“…It was also validated by the authors Campos-Silva et al (2019), who demonstrated in their studies along the Juruá River in the western Brazilian Amazon a recovery pattern of the pirarucu population through the use of management programs carried out by the ribeirinha community. This reaffirmed the data found in previous studies and Unini River Resex, that community-based shared management is a powerful tool for biodiversity conservation and local livelihoods.…”

“…This instrument, initiated in SUU in the State of Amazonas, with its participative nature that avoids severe environmental modifications, becomes more efficient in the maintenance, allowing sustainable resource use (McGrath & Castello, 2015;Campos-Silva et al, 2019). Besides, it avoids the removal of key species, which is one of the major impacts on aquatic ecosystems.…”

Assessing the sustainability of yellow anaconda (Eunectes notaeus) harvest in northeastern Argentina

“…While wildlife management has been perceived as key missing tool for sustainable use of Neotropical resources 56,57 , few studies have been published on the subject to date 3,58 . In this study, we have shown that: (1) the total number of harvested snakes, the number of hunters, and the hunting season duration decreased since the implementation of Programa Curiyú in 2002;…”

Fishes and cowboy boots: An optimistic view

“…Large‐scale population recovery has been documented in many areas (eg. Campos‐Silva & Peres, 2016; Castello, Viana, Watkins, Pinedo‐Vasquez, & Luzadis, 2009; Petersen, Brum, Rossoni, Silveira, & Castello, 2016), reaching over 420% in some locations (Campos‐Silva, Hawes, & Peres, 2019). Even outside protected areas, wild populations have recovered following the establishment of no‐take areas fully protected by indigenous peoples and traditional communities (Campos‐Silva et al, 2019), although declining trends in landings and size of arapaima can also be found outside community‐based arrangements (Cavole, Arantes, & Castello, 2015).…”

“…Campos‐Silva & Peres, 2016; Castello, Viana, Watkins, Pinedo‐Vasquez, & Luzadis, 2009; Petersen, Brum, Rossoni, Silveira, & Castello, 2016), reaching over 420% in some locations (Campos‐Silva, Hawes, & Peres, 2019). Even outside protected areas, wild populations have recovered following the establishment of no‐take areas fully protected by indigenous peoples and traditional communities (Campos‐Silva et al, 2019), although declining trends in landings and size of arapaima can also be found outside community‐based arrangements (Cavole, Arantes, & Castello, 2015). In addition to arapaima, other species including black caiman ( Melanosuchus niger ) and freshwater turtles ( Podocnemis expansa and P. sexturbeculata ) benefit from habitat protection by local communities and are more abundant in managed areas relative to open‐access lakes (Campos‐Silva & Peres, 2016; Miorando, Rebêlo, Pignati, & Pezzuti, 2013).…”