From landscape to freshwater invertebrates: understanding the effects of peatland restoration on Atlantic Salmon (Salmo salar) habitat in the Flow Country

Resumen

Peatlands are critical ecosystems that contribute to carbon storage, biodiversity, and water quality regulation. However, they have been severely impacted by various anthropogenic activities, including burning, drainage, over-grazing, and afforestation with non-native conifer plantations. These disturbances have led to well-documented negative effects on ecosystem services, particularly in terms of carbon sequestration, biodiversity, and water quality. Restoration efforts have been initiated across many degraded peatlands to reverse these negative trends. Despite these initiatives, there is limited research on the effects of peatland restoration on freshwater ecology, particularly regarding Atlantic Salmon (Salmo salar) populations that inhabit many peatland-dominated upland river catchments. This study examines the effects of two common peatland restoration techniques, drain blocking and forest-to-bog, within the Flow Country blanket bog. We focused on how these restoration activities impact both stream and river water quality, and the potential consequences these changes could have for aquatic ecosystems, especially freshwater macroinvertebrates and salmon populations. We found that both restoration methods led to statistically significant declines in water quality within streams. However, these declines did not result in ecologically significant impacts for freshwater macroinvertebrates or salmon. Additionally, the water quality declines observed in smaller streams were effectively diluted when joining larger rivers, which continued to meet high water quality standards throughout our study. Our findings suggest that, while short-term water quality declines can occur following peatland restoration, the overall impact on freshwater ecosystems, including key species such as salmon, should not be detrimental when good restoration practices are implemented. We also found evidence that peatland catchments with anthropogenic modifications have salmon populations that are more sensitive to extreme weather events, such as droughts and heat waves. This highlights the importance of ongoing monitoring, adaptive management, and continuing landscape scale restoration efforts to ensure the long-term resilience of peatland ecosystems under climate change.

Fecha de lectura	14 nov 2025
Idioma original	English
Institución de lectura	University of the Highlands and Islands
Patrocinadores	Super DTP
Supervisor	Roxane Andersen (Supervisor) & Paul Gaffney (Supervisor)