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Pacific Salmon, Nutrients, and the Dynamics of Freshwater and Riparian Ecosystems
Ecosystems (2002)
  • James M. Helfield, Western Washington University
  • Robert J. Naiman
  • Robert E. Bilby
  • Daniel E. Schindler
Pacific salmon ( Oncorhynchus spp.) accumulate sub­stantial nutrients in their bodies as they grow to adulthood at sea. These nutrients are carried to predominantly oligotrophic lakes and streams, where they are released during and after spawning. Research over more than 3 decades has shown that the annual deposition of salmon-borne marine-derived nutrients (MD-nutrients) is important for the productivity of freshwater communities throughout the Pacific coastal region. However, the pathways and mechanisms for MD-nutrient transfer and ac­cumulation in freshwater and riparian ecosystems remain virtually unexplored, consequently, there are many uncertainties in this area. This article addresses three related topics. First, we summarize recent advances in our understanding of the link­ ages among MD-nutrients, freshwater (including riparian) ecosystems, and community dynamics by addressing the importance of MD-nutrients to lakes and streams and by then reviewing large-scale and long-term processes in the atmosphere and ocean that govern variability in salmon populations. Second, we evaluate the validity of the discoveries and their implications for active ecosystem manage­ment, noting areas where extrapolation from these results still requires great caution. Finally, we out­line five key research issues where additional discoveries could greatly augment our understanding of the processes shaping the structure and dynamics of salmon populations and the characteristics of their freshwater habitat and associated riparian zones. Collectively, the data suggest that the fresh­ water portion of the salmon production system is intimately linked to the ocean. Moreover, for the system to be sustainable, a holistic approach to management will be required . This holistic approach will need to treat climate cycles, salmon, riparian vegetation, predators, and MD-nutrient flowpaths and feedbacks as an integrated system.
  • Anadromous fishes,
  • Pacific salmon,
  • Oncorhynchus,
  • Marine nutrients,
  • Stable isotopes,
  • Lake,
  • Stream,
  • Riparian ecosystems,
  • Aquatic produc­tivity,
  • Resource management
Publication Date
June, 2002
Publisher Statement
Published by: Springer Stable URL:
Citation Information
James M. Helfield, Robert J. Naiman, Robert E. Bilby and Daniel E. Schindler. "Pacific Salmon, Nutrients, and the Dynamics of Freshwater and Riparian Ecosystems" Ecosystems Vol. 5 Iss. 4 (2002)
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