Negative influences of predacious egg-eating worms, Haplotaxis ichthyophagous, and fine sediments on coho salmon, Oncorhynchus kisutch, in natural and artificial redds
Sparkman MD. 2003. Negative influences of predacious egg-eating worms, Haplotaxis ichthyophagous, and fine sediments on coho salmon, Oncorhynchus kisutch, in natural and artificial redds. Humboldt State University
A Master of Science thesis from Humboldt State University, California. The study was conducted in the Prairie Creek basin in Redwood National and State Parks. From the Abstract: "Measurements of emergence from natural coho salmon redds and fieldexperiments with artificial redds were used to investigate redd production and survival in relation to biotic and abiotic intergravel variables. Coho salmon emerged from 64% of natural redds, number of individuals emerging from 15 trapped redds ranged from 0 to 2,671. Number of fry emerging from trapped redds was negatively related to fine sediments < 3.33 mm (g) and the presence of an egg-eating oligochaete worm, Haplotaxis ichthyophagous. Survival of eyed eggs in artificial redds declined over time, and was 70% at hatching and 52% at emergence. Survival to hatching was negatively related to fine sediments < 2.8 mm (g) that intruded into egg containers, and the presence of H. ichthyophagous. Worm infestation in egg containers increased over the sampling period, and survival to alevin and emergent fry stages was mostly controlled by presence of worms. Worms invaded all egg containers in some redds, and few to none in other redds. Egg survival in redds with worms averaged 9%, while in redds without worms survival averaged 78%. Fine sediments and worms had a significant negative influence on survival of eggs in redds."
- Type
- Academic
- Authors
- Sparkman, Michael
- Date of Issue
- 2003-12
- Publisher
- Humboldt State University
- Units
- REDW
- Keywords
- Coho Salmon, egg predation, egg survival, fine sediment, Fish Studies, Haplotaxis ichthyophagous, Impacts, oligochaete worms, Oncorhynchus kisutch, Prairie Creek Basin, Prairie Creek Bibliography, redd production, redd survival, Thesis, Threatened Species