Return to the river: an ecological vision for the recovery of the Columbia River salmon.

1. INTRODUCTION

   In recent amendments to the Columbia River Basin Fish and Wildlife Program, the Northwest Power Planning Council called on the Bonneville Power Administration to fund an Independent Scientific Group (ISG; now called the Independent Scientific Advisory Board (ISAB)), a panel of 11 senior scientists charged to conduct a biennial review of the science underlying salmon and steelhead recovery efforts in the basin. Salmon and steelhead populations are depressed and declining(1) due, in part, to heavy development of the basin for hydroelectric power and the general failure of mitigation programs for the hydropower system on the Columbia and Snake rivers(2) (Figure 1). The Council also asked us to develop a conceptual foundation for the fish and wildlife program. This conceptual foundation would provide an overall framework of scientific principles and assumptions on which the basin-wide program of mitigation for hydropower development could be based and against which present and proposed mitigation efforts would be evaluated.

   [Figure 1 ILLUSTRATION OMITTED]

   In September 1996, ISG delivered its review and conceptual framework in a report, Return to the River, to the Council in a prepublication form suitable for public comment.(3) While ISG did not make specific management recommendations in Return to the River, we did include example actions consistent with scientific findings and our proposed alternative conceptual foundation. Prior to release of the report to the Council, it was peer reviewed by eight anonymous scientists. During the fall of 1996, the Council held a series of public meetings across the basin at which ISG members presented the main conclusions and entertained questions from Council members, legislators, policy makers, and interested public. Additionally, public and technical comments were solicited by the Council through June 1997. The report is now being revised and prepared for final publication and should be available in late 1998.

   The purpose of this paper is to provide a summary of Return to the River, particularly its proposed conceptual foundation, for those involved with the environmental, legal, and policy aspects of hydropower and salmon recovery. The report focuses especially on the region's efforts to restore salmon and steelhead (hereafter referred to collectively as salmon) in the Basin. It should provide a flavor of the in-depth scientific reviews conducted on topics such as the diversity, structure, and status of salmon populations; freshwater habitats in tributaries and the mainstem; mechanisms of salmon migration; history of restoration efforts; studies of fish passage at dams; losses of migrants to predation; gas bubble disease; the barge/truck transportation alternative to in-river migration; salmon in the estuary and ocean; artificial production (hatcheries); harvest management; flow augmentation and drawdown as river management alternatives; and the role of monitoring and evaluation.

2. THE CONCEPTUAL FOUNDATION

   A conceptual foundation is a set of scientific principles and assumptions that can give direction to management activities, including biological restoration programs. It is the perspective or filter through which information is viewed and interpreted. Recovery measures and research findings will take on different meanings when viewed through different filters or perspectives. It is a blueprint for the assembly of various data sets and other information.

   Conceptual foundations often are not explicitly made, and this has been true for Columbia River fisheries management objectives and hydropower mitigation. Past programs may not have been successful, in part, due to lack of an explicit foundation and related objectives. Without an explicit conceptual foundation, it is difficult to scientifically analyze the basis for the region's efforts or to evaluate the effectiveness of those efforts.

   However, the current suite of programs does have an underlying theme, even if not explicitly stated. Past mitigation efforts have assumed that natural ecological processes that historically led to, and supported, healthy salmon populations could to a large degree be circumvented, simplified, and controlled by humans and still have the salmon populations remain healthy and productive. For example, placing more young fish in the river (from hatcheries) would automatically result in more adult spawners. Salmon production could be increased by actions taken in the river without accounting for conditions in the estuary or ocean, and management actions would not inadvertently damage the environmental attributes of the river system that support salmon.

   This very mechanistic concept has driven management toward actions that are best characterized as technological substitutes for ecological processes. Actions often respond to individual problems in isolation, rather than in the context of full salmon life histories, behaviors, and habitats. Although done in good faith, and often with technological tools and research results appropriate to the narrow situation, they are not sufficient, based on the continued decline of the basin's salmon populations. From this, we concluded that a new conceptual foundation is needed.

3. AN ALTERNATIVE CONCEPTUAL FOUNDATION

   The conceptual foundation we propose departs from that embodied in the current Columbia River Basin Fish and Wildlife Program. Our alternative conceptual foundation emphasizes the importance of the ecological processes which sustain salmon populations. These processes need to be taken in the context of both ecological and social processes that link organisms, including humans, with their environment. In essence, it focuses on restoration of essential features of the environment that the fish need to carry out their entire life history, rather than on the use of technological substitutes for these features. These environments occur throughout the freshwater, estuarine, and ocean habitats where salmon complete their life histories.

   Our alternative conceptual foundation includes a few key concepts. Sustained salmon productivity requires a network of complex and interconnected habitats which are created, altered, and maintained by natural physical and biological processes. Many of these physical and biological processes have been altered or eliminated by human actions. Restoration of habitats will require restoration of these processes to reestablish suitable habitats.

   Diverse and perhaps most importantly interconnected habitats are crucial for spawning, rearing, migration, maintenance of food webs, and predator avoidance by migratory species (including both anadromous and fully-freshwater forms). Evolutionarily, salmon have adapted to the high environmental diversity in the watersheds of...