Efficiency of a dual density studded fish pass designed to mitigate for impeded upstream passage of juvenile European eels (Anguilla anguilla) at a model Crump weir

Abstract

This study demonstrated that juvenile (glass) eels used a specific substrate (eel tiles) to circumvent a model Crump weir under an experimental setting. Upstream passage efficiency was 0 and 67% for the unmodified (no studded eel tiles on the downstream face; control) and modified (with studded eel tiles on the downstream face; treatment) set‐ups, respectively, and was greater for a small (59%) compared to large (41%) stud configuration. Eels were active and motivated to ascend the weir during both control and treatment set‐ups. Approach and attempt rates were elevated during the first few minutes of the treatment compared to control trials. Eels were edge‐oriented under both set‐ups and ascended the weir through the tiles during single burst swimming events (reaching estimated speeds of 68.5 cm·s−1). Eel tiles may provide a cost‐effective solution for mitigating impacts of anthropogenic barriers to juvenile eel migration. Further research is required to determine passage efficiencies under higher flows, for a greater size range of eel, and for other migratory anguilliform fish (e.g. lamprey, Lampretra spp. and Petromyzon marinus L.). The performance of eel tiles should be validated through robust field studies.

Climbing the ladder: an evaluation of three different anguillid eel climbing substrata and placement of upstream passage solutions at migration barriers

“…At present, the alarmingly low densities of upstream‐migrating juvenile eels suggest that immediate actions are required to increase the proportion of eels passing upstream migration barriers. During recent years, several new upstream passage solutions have been developed, but research assessing the performance of these solutions has until recently been completely lacking, and only a handful of studies address this issue (Kerr, Karageorgopoulos & Kemp, ; Vowles et al ., , ; Jellyman, Bauld & Crow, ). In particular, further studies evaluating the effects of upstream passage solution design and placement are needed.…”

“…The features of the ramps, such as climbing substratum and slope, are critical, as the efficiency in aiding the ascent of juvenile eels (both in terms of passage success rate and climbing velocity) may directly affect the performance of the passage solution (Jellyman et al ., ; Anwar, ). Evaluations of single substrata have shown that, for example studded plastic tiles and bristle passes improve passage success at Crump weirs (Kerr et al ., ; Vowles et al ., , ), but few studies have directly compared the performance of different climbing substrata (Jellyman et al ., ). A recent study by Tamario et al .…”

A simple game-theoretic model for upstream fish migration

“…Important such examples include assessing passage efficiency of river reaches and hydraulic structures (Baek et al 2015;Kerr et al 2015;Vowles et al 2015). There exist a series of extensive research results on behavior of fish schools subject to water current under experimental settings by Onitsuka and his coworkers, which can be effectively utilized for development and validation of mathematical models (Onitsuka et al 2009(Onitsuka et al , 2012a.…”

Climbing success of adult Pacific lamprey on a vertical wetted wall

“…Preserving functionality of fishways for organisms with different performance or behavioural constraints is difficult and, in some cases, species‐specific design elements need to be incorporated. This is exemplified by the proliferation of structures to accommodate anguilliform swimmers (Kemp, Russon, Vowles & Lucas, ; Moser, Jackson, Tsuzaki & Kemp, ; Vowles, Don, Karageorgopolous, Worthington & Kemp, ). The ideal fish passage structure will allow natural migration of all species and life stages that encounter a barrier, thereby mitigating habitat fragmentation (Agostinho, Agostinho, Pelicice, deAlmeida & Marques, ; Gollmann et al., ).…”