From forests to cattail: how does the riparian zone influence stream fish?

Author(s)

Casatti, Lilian ^[1] ; Teresa, Fabricio Barret ^[2] ; Goncalves-Souza, Thiago ^[1] ; Bessa, Eduardo ^[3] ; Manzotti, Angelo Rodrigo ^[1] ; Goncalves, Cristina da Silva ^[4] ; Zeni, Jaquelini de Oliveira ^[1]

Affiliation

^[1] Univ Estadual Paulista UNESP, Lab Ictiol, Dept Zool & Bot, IBILCE, BR-15054000 Sao Jose Do Rio Preto, SP - Brazil

^[2] UEG, Unidade Univ Porangatu, BR-76550000 Porangatu, Go - Brazil

^[3] Univ Estado Mato Grosso UNEMAT, Lab Ecol Comportamental Reprod, BR-78300000 Tangara Da Serra, MT - Brazil

^[4] Univ Estadual Paulista UNESP, Dept Zool, BR-13506900 Rio Claro, SP - Brazil

• Document type: Journal article
• Source: Neotropical Ichthyology; v. 10, n. 1, p. 205-214, JAN-MAR 2012.
• Web of Science Citations: 43

Abstract

The aim of this study was to verify whether taxonomic and functional composition of stream fishes vary under three different preservation conditions of riparian zone: preserved (PRE), intermediate condition (INT), and degraded (DEG). Five stream stretches representing each condition were selected. Samples were taken from each stream in three occasions during the dry seasons from 2004 to 2007. Electro fishing (PRE and INT), sieves, dip nets, and hand seines (DEG) were used according to the characteristics of each sampled site. Overall, 46 species were registered. Differences in the taxonomic and functional species composition among groups were found, following the condition of riparian zones. The ichthyofauna recorded in the PRE was typical to pristine environments, consisting of species with specialized habits, notably benthic insectivores, intolerant, and rheophilics. In the INT group, replacement of riparian forest with shrubs and/or grasses created environmental conditions which favor the occurrence of tolerant species but also harbor a residual fauna of sensitive species. DEG streams presented mostly detritivores, tolerant, small sized fishes which occupy the surface and preferred slow water flux. Changes in the species composition were represented by the occurrence and dominance of tolerant species in detriment of the more sensitive and specialist species, following the gradient of degradation in the riparian zone. Forested streams act as unique habitats to many specialized species and it can be presumable that the degradation of riparian vegetation can generate biotic homogenization which may reduce species diversity and ecosystem services. (AU)

• FAPESP's process: 09/11169-0 - Does the trophic structure reflect the physical structure in streams?
• Grantee: Jaquelini de Oliveira Zeni
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 08/03583-9 - Composition and functional diversity of stream fish assemblages
• Grantee: Fabrício Barreto Teresa
• Support Opportunities: Scholarships in Brazil - Doctorate