Fred H. Everest

Physiological Effects on Coho Salmon and Steelhead of Exposure to Suspended Solids

Abstract Yearling coho salmon Oncorhynchus kisutch and steelhead Salmo gairdneri were exposed to high (2–3 g/L) or low (0.4–0.6 g/L) concentrations of three kinds of suspended solids (topsoil, kaolin clay, and volcanic ash) as long as 7–8 d. Such exposure did not cause mortality, but plasma cortisol concentrations were temporarily elevated in both species after exposure to 2–3 g/L of suspended topsoil, indicating that such exposure may have been stressful to the fish. Feeding rates of both species were reduced at high exposure concentrations. Exposure of yearling steelhead for 2 d to high or low concentrations of suspended topsoil, kaolin clay, or volcanic ash induced similar elevations of plasma cortisol levels, and, in groups exposed to high concentrations, blood hematocrits were increased. Osmoregulatory performance in fresh water and after transfer to 26‰ seawater was unaffected, and gill tissue appeared normal, after exposure to suspended solids. Exposure of yearling steelhead to high concentrations ...

Diversity of Juvenile Anadromous Salmonid Assemblages in Coastal Oregon Basins with Different Levels of Timber Harvest

Abstract We examined the relationships of timber harvest, stream habitat complexity, and diversity of juvenile anadromous salmonid assemblages in 14 small- to intermediate-sized basins in coastal Oregon between 1985 and 1989. Diversity (the inverse of a species dominance index) of assemblages in streams in basins with low harvest levels (≤25% of the basin area harvested) was greater than in streams in basins with high harvest levels (>25% of the basin area harvested) (P = 0.02). Assemblages in basins with high levels of harvest were more dominated by a single species than were assemblages in basins with low harvest, Percent of basin harvested was more strongly associated with assemblage diversity (P = 0.07) than were basin area (P = 0.90) or gradient (P = 0.22) when the influence of the other two factors was controlled. Habitat features were compared between three pairs of streams. Streams in basins with low timber harvest had more complex habitat, as manifested by more large pieces of wood per 100 m (P <...

Working with knowledge at the science/policy interface: a unique example from developing the Tongass Land Management Plan

Abstract An innovative, knowledge-based partnership between research scientists and resource managers in the U.S. Forest Service provided the foundation upon which the Forest Plan was developed that will guide management on the Tongass National Forest for the next 10–15 years. Criteria developed by the scientists to evaluate if management decisions were consistent with the available information base were applied to major components of the emerging final management strategy for the Forest. While the scientists remained value neutral on the contents of the Forest Plan and the management directions provided in it, their evaluation indicated that the decisions it contained for riparian and fish sustainability, wildlife viability, karst and cave protection, slope stability, timber resources, social/economic effects, and monitoring achieved a high degree of consistency with the available scientific information. The Forest Plan, revised to conform with existing scientific knowledge, represents a management strategy designed to sustain the diversity and productivity of the ecosystem while producing goods and services commensurate with the agency’s multiple-use mandate. Execution of this research/management partnership highlighted the role of scientific knowledge in forestry decision-making and provided a new mechanism to input such information into the decision making process. The partnership continues as the scientists are addressing high priority information needs generated by the planning effort in order to have additional information available for plan implementation and revision through adaptive management over the next 3–5 years.