Ichthyofauna of the major urban forest fragment of the Amazon: Surviving concrete and pollution

Abstract

The urban area of Manaus city, in the Amazonas state, the main metropolis of the Brazilian Amazonian, has few forest remnants with preserved streams and most of them are seriously threatened by human activities. The checklist of the aquatic fauna of the streams is an important tool for learning about the biodiversity of these fragile environments. Fish samplings were made between 2007 and 2017 in 10 streams of the Forest Fragment of the Federal University of Amazonas (UFAM), which has approximately 700ha. A total of 23 fish species of 6 orders, 10 families and 19 genera were collected, including an exotic and an allochthonous species. Preserved streams presented the occurrence of 4 to 10 species, with an average abundance of 54.8 (±25.1) individuals, density of 2.87 individuals/m3 (±1.85), high diversity (H›=1.41±0.35), and low dominance (d=0.47±0.14). In polluted streams, a maximum of 2 species was found. These streams show average abundance of 176 (±216.1) individuals, density of 7.43 individuals/m3 (±9.14), low diversity (H›=0.02±0.03), and high dominance (d=1.00±0.005). This study shows that, despite the anthropogenic disturbances detected in remnant borders, the studied area accomplish a fundamental role in the conservation of native fish species of streams of the urban area.

Keywords: diversity, fish, deforestation, monitoring, conservation.