Freshwater Biodiversity Toolbox
Wildlife Passage – Provision of Passage at Natural Barriers
Habitat fragmentation is a major threat to aquatic ecosystems. Natural barriers the prevent movement of fish and aquatic organisms can harm populations and ecosystems just as man-made dams do. Natural barriers, like debris obstructions or waterfalls, may not completely impede but still significantly limit passage and access to essential habitat for spawning or migration. Fish ways, slots, weird, and other passage infrastructure have been installed as a way to provide habitat access and maintain population dynamics for targeted fish species. However, even with these structures in place, successful passage may not be possible due to the physical constraints and behaviour of certain fish species that prevent their effective use. Mortality during crossings is a key concern regarding the efficacy of these passage structures. The potential benefits, risks and mitigation options associated are reviewed here.
Rating:
Zielinski et al. (2020) scored poorly across all CEESAT elements demonstrating limitations in the rigour and the transparency in which these reviews were conducted (i.e., no a-priori protocol, critical appraisal, or search strategy provided).
Zielinski et al. (2020) received a Gold score in all elements of RASCAT except for one, where the synthesis failed to demonstrate consideration of implications, practical advice, or recommendations for decision-makers.
