River Crake (at Bouthrey Bridge) freeze coring report
This is the River Crake (at Bouthrey Bridge) freeze coring report produced by Lancaster University in 1999. This study looks at fine materials in river Crake at Bouthrey Bridge that may have to be considered detrimental to successful salmonid spawning. Following an observed decline in quality of salmonid fisheries at the site an investigation was initiated to assess the extent of ingress of fine sediments into the spawning gravels. Fine sediments from one potential source, upstream riverbanks, are also compared to those isolated from the spawning gravels. The percentage by weight of fine sediments for the six freeze cores, was found to be lower than first expected, given the visual appearance of the reach. However the fines were found to be distributed evenly down the cores with a marked absence of an upper, coarse gravel armour layer. In addition the median grain size (D50) of the six samples was generally low, falling to 6mm for core 5. The low median grain size and the absence of coarse grained upper strata are considered detrimental to the success rate of salmonid spawning.
| Main Authors: | , |
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| Format: | monograph biblioteca |
| Language: | English |
| Published: |
Lancaster University
1999
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| Subjects: | Fisheries, Limnology, Management, England, Crake, Inland waters, Rivers, Freshwater fish, Migratory species, Sediment cores, Environmental assessment, Water quality, |
| Online Access: | http://hdl.handle.net/1834/27229 |
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