Authors
Rishi
Sharma
Ray Hilborn
Report Reference
#Can.
J. Fish. Aquat. Sci. 58: 1453–1463 (2001)
Publication Date
21 June
2001
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Empirical
relationships between watershed characteristics and coho salmon (Oncorhynchus
kisutch) smolt abundance in 14 western Washington streams
Abstract |
| We assembled
data on coho salmon (Oncorhynchus kisutch) from 14 streams in western
Washington, including annual smolt counts and annual escapement, either
as absolute counts or as an index. We also compiled data on large
woody debris (number·km-1 of stream), road densities
in the watersheds (km road·km-2), gradient of the
streams (%), valley slope adjacent to the stream (%), drainage area
in the watershed (km2), and pool, pond, and lake areas
(m2·km-1). We explored the relationships
between habitat variables and two measures of coho production, the
maximum production of smolts in the stream (capacity) and the maximum
smolts/spawner (productivity). Using the 11 streams with pool and
pond counts, we found that pool and pond densities served as good
predictors of smolt density (r 2 = 0.85 for pools and 0.68
for ponds, independently). Pools produced 0.39 smolts·m-2
and ponds produced 0.07 smolts·m-2 in the multiple regression
fit, accounting for 92% of the residual error. We also found that
lower valley slopes, lower road densities, and lower stream gradients
were correlated with higher smolt density. |
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