Abstract
Long-term data are crucial for understanding ecological responses to climate and land use change; they are also vital evidence for informing management. As a migratory fish, Atlantic salmon are sentinels of both global and local environmental change. This paper reviews the main insights from six decades of research in an upland Scottish stream (Girnock Burn) inhabited by a spring Atlantic salmon population dominated by multi-sea-winter fish. Research began in the 1960s providing a census of returning adults, juvenile emigrants and in-stream production of Atlantic salmon. Early research pioneered new monitoring techniques providing new insights into salmon ecology and population dynamics. These studies underlined the need for interdisciplinary approaches for understanding salmon interactions with physical, chemical and biological components of in-stream habitats at different life-stages. This highlighted variations in catchment-scale hydroclimate, hydrology, geomorphology and hydrochemistry as essential to understanding freshwater habitats in the wider landscape context. Evolution of research has resulted in a remarkable catalogue of novel findings underlining the value of long-term data that increases with time as modelling tools advance to leverage more insights from “big data”. Data are available on fish numbers, sizes and ages across multiple life stages, extending over many decades and covering a wide range of stock levels. Combined with an unusually detailed characterization of the environment, these data have enabled a unique process-based understanding of the controls and bottlenecks on salmon population dynamics across the entire lifecycle and the consequences of declining marine survival and ova deposition. Such powerful datasets, methodological enhancements and the resulting process understanding have informed and supported the development of fish population assessment tools which have been applied to aid management of threatened salmon stocks at large-catchment, regional and national scales. Many pioneering monitoring and modelling approaches developed have been applied internationally. This history shows the importance of integrating discovery science with monitoring for informing policy development and assessing efficacy of management options. It also demonstrates the need to continue to resource long-term sites, which act as a focus for inter-disciplinary research and innovation, and where the overall value of the research greatly exceeds the costs of individual component parts.
Original language | English |
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Article number | e15105 |
Number of pages | 24 |
Journal | Hydrological Processes |
Volume | 38 |
Issue number | 3 |
Early online date | 17 Mar 2024 |
DOIs | |
Publication status | Published - Mar 2024 |
Bibliographical note
Open Access via the Wiley AgreementC. Soulsby is grateful to The Leverhulme Trust for the Fellowship enti-tled“Atlantic Salmon as environmental sentinels.”The Girnock fishtraps and associated data collection on freshwater fish populationsand their habitats are managed and funded by the Scottish Govern-ment Marine Directorate under Service Level Agreement FW01T.
Data Availability Statement
The data that support the findings of this study are available from thecorresponding author upon reasonable request.Keywords
- Atlantic salmon
- catchment science
- climate change
- Girnock Burn
- long term monitoring