Nutrients in Salmonid Ecosystems: Sustaining Production and Biodiversity

Toward New Escapement Goals: Integrating Ecosystem and Fisheries Management Goals

John H. Michael


Abstract.—Based on the information presented at the Restoring Nutrients to Salmonid Ecosystems conference in Eugene, Oregon, in April of 2001, it will be necessary to substantially increase and achieve salmon spawner escapement goals in order to meet ecosystem productivity potential. Modeling of recovery rates shows that achievement of even the currently identified spawner escapement goals (much less ecosystem recovery) in less than 50–100 years is unlikely, unless there are substantial shifts in management thought and practice. To speed recovery, it is necessary to achieve consistent rates of increase in spawning escapement not seen in current management activities. Until actual spawner escapements approach levels necessary to support ecosystem function, it will be necessary to utilize alternative methods such as the distribution of salmon carcasses, carcass analogs, or the use of fertilizer to provide the nutrients needed to assist its salmonid population recovery. In addition to restoring absolute numbers, the size and age structures of the fish populations need to be restored in order to successfully utilize the available environment. Simply increasing escapements and resultant nutrient levels, however, is insufficient. Stream flows, whether average, flood, or low, need to be stabilized. Instream and riparian habitats need to be stabilized and restored; this would include allowing normal flood paths to be followed.