Abstract
The construction of dams and other river infrastructures is threatening
migratory fish stocks in many parts of the world by greatly reducing
river-floodplain connectivity. Fishways are technical tools that can
restore river connectivity for migratory fishes, but their effectiveness
is often limited by a lack of biological information on their target
species, especially in developing countries of South East Asia. We
sought to inform the design of a vertical-slot fishway for Myanmar
migratory fishes, by using a flume-based vertical-slot fishway to
determine if (1) their passage ability is influenced by hydraulic
conditions (such as depth and head differential or ‘headloss’ between
cells); and (2) fish size influences passage ability for each species.
This was achieved by comparing passage success under headloss options of
50-mm and 100-mm, and by assessing the relationship between size and
ability to pass the flume – in four representative migratory species: Pangasius pangasius (pangas catfish), Notopterus notopterus (featherback fish), Puntius chola (swamp barbs) and Esomus danrica (flying barbs). Our results indicated that flume passage ability was greater under the 50-mm headloss for Pangasius pangasius, Notopterus notopterus and Puntius chola; and that flume passage ability increased in larger individuals for Pangasius pangasius and Notopterus notopterus. In comparison, Esomus danrica
could not ascend under either the 50-mm or 100-mm headloss options. The
inter-specific variability in these results empirically demonstrates
the importance of obtaining baseline biological information on the
target species for planned fishways in order to optimise their
effectiveness.
Original language | English |
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Article number | 106680 |
Number of pages | 5 |
Journal | Fisheries Research |
Volume | 262 |
Early online date | 28 Feb 2023 |
DOIs | |
Publication status | Published - Jun 2023 |