A Coarse Screening Process for Evaluation of the Effects of Land Management Activities on Salmon Spawning and Rearing Habitat in ESA Consultations
Spring, summer, and fall chinook salmon in the Snake River Basin have been listed as ‘endangered’ under the Endangered Species Act (ESA) by the National Marine Fisheries Service (NMFS). The ESA requires that activities authorized, funded, or carried out by federal agencies do not adversely modify critical habitat for listed species. The interim policy of NMFS is that the aggregate effect of all land use activities should result in improved habitat conditions and survival for the listed salmon species. The Coarse Screening Process provides objective, measurable criteria to evaluate the consistency of single and combined land management activities with these legal and policy goals. Although salmon populations are affected by a variety of activities throughout the migratory range of the listed salmon, the Coarse Screening Process focuses only on land management activities and their effect on salmon survival in spawning and rearing habitat.
The Coarse Screening Process relies on three sets of criteria. Biologically-based habitat standards are used to determine the need for improvement in habitat conditions. Land management standards are used to determine the consistency of activities with protection and improvement of habitat conditions and, in some cases, are contingent on habitat conditions. The screening process also requires that data exist for all land management and habitat conditions set as standards that can potentially be affected by single or combined activities. Under the screening process, activities are deemed consistent with ESA habitat policies only when all three sets of criteria are satisfied.
Potential habitat standards were reviewed for their effects on salmon survival and production, their linkages to management activities, and their relevance to conditions in the Snake River Basin. Where land management standards could adequately protect key habitat attributes, they were set in lieu of quantitative habitat standards. Habitat standards were recommended based on the habitat requirements of the listed salmon. Habitat attributes reviewed for their potential utility as screening elements included metrics for channel substrate, pools, large woody debris, bank stability, water temperature, miscellaneous pollutants, water quantity and timing. Quantitative habitat standards were recommended for channel substrate, water temperature, and bank stability. It is recommended that where these standards are not met, that any activity that can potentially delay improvement in habitat condition should be deferred or curtailed until the habitat standard is met or a statistically improving trend is documented through monitoring over at least five years.
Approaches to developing habitat standards based on the ‘range of natural variability’ were reviewed, but are not recommended because such approaches do not adequately protect salmon populations.
Potential land management standards were reviewed for their effects on salmon habitat. Land management standards were recommended for riparian reserves, estimated sediment delivery, roads, grazing, and roadless reserves. Approaches based on ‘Equivalent Clearcut Areas’ were not recommended as land management standards.
Application of the screening process to the John Day, Umatilla, and Clearwater River Basins is recommended to provide refugia for potential salmon colonists to and from the area currently designated as critical habitat.
Land management standards are recommended to remain in effect until habitat conditions in at least 90% of the managed watersheds in the Snake River Basin either meet habitat standards or exhibit a statistically significant improving trend as documented through monitoring over at least 5 years.
The screening process should be applied at scales representing logical units of salmon production, which may generally include watersheds of approximately 4th to 6th order streams.
Rhodes, J.J., D.A. McCullough, and F.A. Espinosa Jr. 1994. A Coarse Screening Process for Evaluation of the Effects of Land. Columbia River Inter-Tribal Fish Commission Report reference #94-04, Portland, Oregon.