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Brandon K. Peoples Molly B. Tainer Emmanuel A. Frimpong 《Environmental Biology of Fishes》2011,90(4):379-391
Aquatic biodiversity continues to decline as humans modify the landscape, mainly because of stream habitat alterations and
loss caused by urban development. Bluehead chubs may mitigate some effects of instream habitat degradation by providing clean
gravel substrate via their spawning nests. We used path analysis, an extension of multiple linear regression, to explore the
relationships among instream habitat degradation, adult chub abundance, chub nesting activity, and chub reproductive performance.
Age-0 chub abundance was best explained by small adult abundance and nest abundance. Habitat disturbance indirectly and negatively
influenced age-0 chub abundance through adult chubs and nest abundance. Percentages of pool and run habitat also had indirect
negative effects on age-0 chub abundance. Several metrics of chub nesting activity (nest density [proportion of substrate
occupied by nests], average nest size, and number of nests) were explained by both adult chub abundance and nesting site conditions.
Variability among stream systems described significant variation in adult chub abundance and nesting characteristics and,
if unaccounted for, would have resulted in large unexplained variability. Chub nesting activity served as a link between habitat
degradation, adult chub abundance, and their reproductive performance. Our study provides preliminary evidence that bluehead
chubs’ nesting activity may be a mechanism of their persistence in degraded stream reaches. We recommend confirmatory studies
through in-stream manipulative experiments. 相似文献