Oral Presentation International Conference on River Connectivity (Fish Passage 2018)

Megadams and goliath catfish management in Amazonian scale: “running against the wind” (#22)

Lisiane Hahn 1 , Eduardo G Martins 2 , Luís F Câmara 1 , Lilian P Vasconcelos 3 , Diego C Alves 3 , Leonardo D Nunes 1 , Leonardo S Machado 1
  1. Neotropical Environmental Consulting, Passo Fundo, RIO GRANDE DO SUL, Brazil
  2. Freshwater Fish Ecology Laboratory, University of Northern British Columbia, Prince George, British Columbia, Canada
  3. Department of Biology, University of Maringá, Maringá, Paraná, Brazil

Biodiversity conservation in the Amazon River basin is historically an unparalleled task but in the last decade, due to the construction of big dams, management of long distance migratory fish is proving even more challenging. The “dourada” Brachyplatystoma rousseauxii is a goliath catfish species that performs the longest potamodrous migration (5,700 km) in the world. However, since adults reach the spawning areas located in the Andean tributaries, they probably do not return to lower portions of the basin and its behavior after spawning is still unknown. In the Madeira River, one of the main routes to spawning areas, two hydropower plants (without river-free stretch between them) started to run very recently (2011/2013). A large-scale telemetry and egg and larvae studies are investigating the behavior of goliath catfish species in the area after the impoundments. Douradas captured downstream the Santo Antônio Dam, tagged with combined acoustic and radio transmitters (CART) were not detected passing the 900 m long fishway. In the Santo Antônio reservoir, dourada´s larvae in different development stages (pre-flexion to juvenile) were collected throughout the year. Based on this evidence and in the data presented above, it is supposed that larvae collected in the Santo Antônio´s reservoir are product of spawning that occurred in the headwaters of tributaries of Madeira River. Considering the scenario where numerous new dams are planned for the upper portion of the Madeira River basin, the data gathered in this study is an important contribution for the management and conservation of goliath catfish in Amazon basin.