Culverts in paved roads as suitable passages for Neotropical fish species

Neotropical Ichthyology

Theodore Castro-Santos¹  Maristela Cavicchioli Makrakis²  Sergio Makrakis²  Maurício Spagnolo Adames²  Ricardo Luiz Wagner² 

[1] ;Universidade Estadual do Oeste do Paraná;

关键词: Barriers;    Criteria for culverts;    Road crossing;    Stream;   

DOI  :  10.1590/S1679-62252012000400009

来源: DOAJ

【 摘 要 】

Improperly installed or poorly maintained culverts can pose a serious threat to fish by disrupting their habitat and endangering spawning success. Road culverts that are not designed for fish passage frequently can become obstacles. This can be especially problematic for migratory species, but can lead to fragmentation of resident populations as well. This study evaluated 40 culverts of 29 sites within a 25-km radius from Toledo city, Paraná State, southern Brazil, with respect to their likely effects on movement of the local ichthyofauna. We collected data on the shape and length of culverts, culvert material, waterfall height, water column depth, slope, and estimated flow velocity. Culverts were categorized by level of barrier risk for upstream migration: high, medium, low, and impassable, as well as the type of barrier posed (fall height, depth, length and velocity). Most of culverts analyzed were considered potential barriers to fish movement, with 45% classified as impassible, 45% as high risk, 10% as medium risk, and no culverts as low risk. Brazilian culverts as fishways will require additional monitoring and studies to corroborate the premises proposed in the present study. Road culvert projects that are properly built and maintained will be able to simultaneously improve function of roadways and protect fish populations.

【 授权许可】

Unknown