Climbing for dummies: recommendation for multi‐specific fishways for the conservation of tropical eels and gobies. (6th May 2021)

• Record Type: Journal Article
• Authors: Lagarde, R.; Courret, D.; Grondin, H.; Faivre, L.; Ponton, D.
• Is Part Of: Animal conservation. Volume 24:Number 6(2021)
• Page Start: 970
• Page End: 981
• Publication Date: 2021-05-06
• Subjects: amphidromy -- catadromy -- dam -- fish migration -- river continuum -- upstream passage -- fishways -- eels; Conservation biology -- Periodicals; Wildlife conservation -- Periodicals; Conservation de la biodiversité; Conservation de la faune; Périodique électronique (Descripteur de forme); Ressource Internet (Descripteur de forme); 333.95416
• DOI: 10.1111/acv.12699
• Languages: English
• ISSNs: 1367-9430

Abstract

Abstract: Dams and other man‐made barriers impair upstream fish migration and thus threaten fish populations that need access to upper river reaches to complete their life cycle. For many years, fishways have been used to mitigate this impact. Fishways around the globe are typically built based on recommendations made for northern hemisphere species, particularly salmonids. These recommendations do not consider the locomotor characteristics and skills of other species, especially those living in the tropics. Among tropical species, freshwater eels and gobies of the Sicydiinae subfamily are important cultural and economic species that are particularly sensitive to the impact of man‐made barriers. Our experimental study aimed to test different substrates and slopes for ramp‐like fishways adapted to tropical eels and sicydiines. Among the five substrates tested for 368 eels Anguilla marmorata, elastomer pins appeared to be the most efficient. Elastomer pins also appeared to be more efficient than the fine concrete which is currently used in fishways for sicydiines ( Sicyopterus lagocephalus, N = 1797, and Cotylopus acutipinnis, N = 1303). The slope had a lesser effect on the climbing success of sicydiines compared to substrate type, except for gradients greater than 50° that induced a slight decrease in success. Our results indicated that ramp‐like fishways fitted with 1.0 cm diameter elastomer pins, positioned in staggered rows with a diagonal spacing of 1.3 cm, wetted with low‐flow and angled less than 50°, are well adapted to accommodate the different locomotor characteristics and skills of tropical eels and sicydiines. Abstract : Dams threaten tropical eels' and gobies' migrating to their upstream riverine habitat. Efficient fishways adapted to these diadromous tropical species are presently lacking. Ramps fitted with small‐sized elastomer pins and angled at 50° maximum emerge as an adapted solution.