Atlantic salmon in regulated rivers: Understanding river management through the ecosystem services lens

Abstract

Known as the "king of fishes," the Atlantic salmon (Salmo salar, Salmonidae) is an iconic freshwater species whose contribution to human well-being has long been recognized, as have widespread declines in its abundance, partly due to river regulation.To understand how salmon conservation has been addressed within the ecosystem services (ES) framework, we synthesized the peer-reviewed literature on ES provided by salmon in regulated rivers. We developed a search string to capture allusions to provisioning, regulating, supporting and cultural ES and assessed the results to identify knowledge gaps. The effects of hydropower on fisheries catches and on modelled populations were shown in several publications. Overall, few studies focused explicitly on ES from salmon and hydropower; this is surprising given the considerable body of literature on salmon in regulated rivers. Wild salmon as a food source and other provisioning services are less important today than historically. Because predators such as salmon are important for facilitating biodiversity by cycling nutrients and controlling food webs, there is a scope of work for future assessments of these regulating and supporting services. Few papers explicitly addressed cultural ES, despite the salmon's longstanding iconic status; this is a knowledge gap for future ES assessments in relation to hydropower. The influence of ES assessments for policy makers is growing through the Intergovernmental Panel for Biodiversity and Ecosystem Services (IPBES) and the post-2020 biodiversity strategy. Explicitly addressing ES poses an opportunity for river managers to raise awareness of aquatic conservation efforts and well-informed decision-making for sustaining ES.

Growth and mortality of sympatric Atlantic salmon and brown trout fry in fluctuating and stable flows

“…Also, we showed that trout were more negatively affected than salmon. The study thereby highlights the need for life stage-and species-specific considerations to conserve culturally and economically important riverine fish species (Liu et al, 2019;Watz et al, 2022).…”

The diadromous watersheds-ocean continuum: Managing diadromous fish as a community for ecosystem resilience

“…As such, a more holistic understanding of the (1) role of the diadromous community in connecting ecosystems and the ecosystem services they provide, (2) range of threats affecting the diadromous community, and (3) global, local, and cumulative impacts of these stressors is essential. As scientists increase our understanding of these aspects, opportunities to strengthen EBM implementation are emerging (Hare et al, 2021;Link, 2021;Watz et al, 2021). The complexity of working at the ecosystem scale can be overwhelming (DeFries and Nagendra, 2017), but we propose a four steps DWOC roadmap (Figure 8) to explore the broken links within the watersheds-ocean continuum.…”

(Un)sustainable Wildlife Conservation

“…The private resource model works best for wildlife species that do not need to migrate over long distances unless they can be relied upon to return to specific breeding or feeding areas (Thurman 1981;Lueck 1995b). Before the advent of open ocean commercial fishing, for example, American Indian tribes were able to farm salmon by controlling access to their river migration routes and spawning streams (Johnsen 2009), a type of private resource conservation management still used today, primarily for sport fishing, in parts of Europe (Watz et al 2022). Nesting birds like eiders have been similarly sustainably conserved by the owners of their nesting grounds so they can continue to harvest their down and eggs in perpetuity (Smith 1981).…”