Passage Performance of Technical Pool-Type Fishways for Potamodromous Cyprinids: Novel Experiences in Semiarid Environments

Sanz-Ronda Sanz-Ronda,Sánchez-Pérez Sánchez-Pérez,Torralva Torralva,Fernandes-Celestino Fernandes-Celestino,Oliva-Paterna Oliva-Paterna,García-Vega García-Vega,Bravo-Córdoba Bravo-Córdoba,Valbuena-Castro Valbuena-Castro

doi:10.3390/w11112362

Sanz-Ronda Sanz-Ronda, Sánchez-Pérez Sánchez-Pérez + Show 6 more

Open Access

https://doi.org/10.3390/w11112362

Copy DOI

Journal: Water	Publication Date: Nov 11, 2019
Citations: 20	License type: CC BY 4.0

Affiliation: University of Valladolid, University of Murcia

Abstract

Endemic freshwater fish from semiarid environments are among the most threated species in the world due to water overexploitation and habitat fragmentation problems. Stepped or pool-type fishways are used worldwide to reestablish longitudinal connectivity and mitigate fish migration problems. Many of them are being installed or planned in rivers of semiarid environments, however, very few studies about fish passage performance through pool-type fishways has been carried out to date on these regions. The present work focuses on the passage performance of two potamodromous cyprinids endemic of these regions, with different ecological and swimming behavior: southern Iberian barbel (Luciobarbus sclateri) and Iberian straight-mouth nase (Pseudochondrostoma polylepis). These are assessed in two of the most common types of stepped fishways: vertical slot and submerged notch with bottom orifice fishways. Experiments were carried out during the spawning season in the Segura River (southeastern Spain), using a passive integrated transponder (PIT) tag and antenna system. Ascent success was greater than 80%, with a median transit time lower than 17 minutes per meter of height in all trials, and for both species and fishway types. Results show that both types of fishways, if correctly designed and constructed, provide interesting alternatives for the restoration of fish migration pathways in these regions.

Highlights

Rivers in semiarid environments are subjected to strong seasonal variability—long drought periods alternated with large but brief floods [1,2]
Near-future scenarios suggest more water demand and the exacerbation of human stressors [10,11]. In these areas, freshwater fish fauna present a high degree of endemism and are characterized by a low number of families, with most of the species belonging to the Cyprinidae family [12,13,14,15]
The present study focuses on the passage performance of two potamodromous cyprinids from a semiarid region of the Iberian Peninsula, Southern Iberian barbel and Iberian straight-mouth nase, in the two main typologies of pool-type fishways: vertical slot (VS) and submerged notch with bottom orifice (SNBO)

Summary

Introduction

Rivers in semiarid environments are subjected to strong seasonal variability—long drought periods alternated with large but brief floods [1,2]. Water resources are strongly exploited, and rivers are highly affected by barriers and flow regulation [3,4] Transverse barriers, such as dams, weirs, and gauging stations, and the involved habitat fragmentation are considered the main threats to ichthyofauna worldwide [5,6], including in semiarid regions [7,8,9]. Near-future scenarios suggest more water demand and the exacerbation of human stressors [10,11] In these areas (i.e., from the circum-Mediterranean region to Central Asia), freshwater fish fauna present a high degree of endemism and are characterized by a low number of families, with most of the species belonging to the Cyprinidae family [12,13,14,15].

Methods

Results

Conclusion