Fine sediment effects on brook trout egg and alevin survival in Virginia
<p>Detailed information about negative effects of fine sediments on early life stages of brook trout (Salvelinus fontinalis) in southern Appalachian streams is lacking. Information on survival to different stages of egg and alevin development could indicate critical timing of sediment impacts....
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| Format: | Others |
| Language: | en |
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Virginia Tech
2014
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| Online Access: | http://hdl.handle.net/10919/44016 http://scholar.lib.vt.edu/theses/available/etd-07292009-090625/ |
| Summary: | <p>Detailed information about negative effects of fine
sediments on early life stages of brook trout (Salvelinus
fontinalis) in southern Appalachian streams is lacking.
Information on survival to different stages of egg and
alevin development could indicate critical timing of
sediment impacts. This study was designed to determine the
effects of fine sediments (0.43-0.85 rom in diameter) on
survival of brook trout eggs through early development
stages under controlled laboratory and field conditions.
Recently fertilized eggs were loaded into Whitlock-Vibert
(W-V) boxes lined with 0.4 rom Nitex netting that contained
mixtures of gravel and fine sediments. Survival to eyed,
hatched, and emerged stages of development was determined
for six amounts of fine sediment (0-25% by weight) in the
laboratory study and for three amounts of fine sediment (0-20% by weight) in the field study. Survival in laboratory
systems to each stage of development was inversely related
to the percentage of fine sediment; even at low levels of
fine sediment survival was reduced. In the field study, fine sediment may have played a role in the survival success
of developing embryos, but determining a definitive
relationship was confounded by effects of scouring flows and
fungal infestations. The fungus Saprolegnia spp., may have
increased the mortality rate of viable eggs and facilitated
the disintegration of nonviable embryos, especially in the
field study. Brook trout are sensitive to increasing levels
of fine sediment through early development. However under
field conditions such an effect may be difficult detect.</p> === Master of Science |
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