Author(s): Jose M. Santos; Paulo Branco; Ana L. Quaresma; Filipe Romao; Susana D. Amaral; Marta Santo; Jorge Bochechas; Ana M. Telhado; Francisco Godinho; Joao Padua; Paulo Pinheiro; Ana T. Silva; Teresa Viseu; Pedro R. Almeida; Teresa Ferreira; Antonio Pinheiro
Linked Author(s): José Maria Santos, António Pinheiro
Keywords: No Keywords
Abstract: As in many other countries, river fragmentation by anthropogenic structures in Portugal - with more than 250 large dams and 8000 smaller barriers - has caused fish populations to decline and, in some cases, extirpation of other aquatic organisms unable to effectively disperse between habitats. Mitigating the impacts of river fragmentation on fish movements through the implementation of fishways has thus been an important focus of rehabilitation efforts for fish, due to their economic, ecological and cultural significance. This study analyses and reviews the main research findings from fishway science in Portugal over the past two decades. The main goals were: i) to catalogue the number, type, timing of construction and installation place (e. g., at small barriers, small hydropower plants and dams) of all fishway types, and ii) to resume the main results achieved from ISI Web of Science studies conducted over the different fishway types. Presently, the country holds 95 fishways with almost half being installed at small hydropower plants (46.3%), but also at small weirs (43.2%) and large hydropower plants (10.5%). The most common design is the pool-type (68.4%), followed by nature-like facilities (15.8%), fish locks and combined systems (each 6.3%), fish lifts (2.1%), and eel passes (1.1%). Literature searched from the ISI WoS resulted in a total of 36 published papers, of which 27 (75.0%) were from pool-type fishways (i. e., pool-and-weir and vertical slot designs), 4 (11.1%) from natural fishways, 4 (11.1%) from fish lifts and 1 (2.7%) from fish locks. The findings from this study may have implications for the design and management of different types of fishways elsewhere.
Year: 2024