Biological Monitoring
Cedar Creek
| Monitored By | Anoka Conservation District |
| Number of Years Monitored | 6 yrs at Hwy 9, ½ yr at Hwy 22 |
| Background: Cedar Creek originates in south-central Isanti County and flows south. In north-central Anoka County it flows through some areas of high quality natural communities, including the Cedar Creek Natural History Area. Habitat surrounding the stream in other areas is of moderate quality overall. Cedar Creek is a tributary to the Rum River. Cedar Creek is one of the larger streams in Anoka County. Stream widths of 25 feet and depths greater than 2 feet are common at baseflow. The stream bottom is primarily silt. Watershed landuse is moderately developed with scattered single family homes, and continues to develop rapidly. This stream was monitored at two sites in 2003; at Highway 9 in the spring and at Highway 22 in the fall. |
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| Results: Biological data indicated a roughly average condition for Anoka County. The upstream site had a more even community. The number of families (13) at the downstream site was not unusual, but most captures (73%) were of two pollution insensitive families, the clams (pelycapoda) and scuds (taltridae). None of the families present at Highway 22 were very sensitive to pollution. The downstream site, at Highway 9, had seven more families, one more EPT, and a better FBI rating, indicating a slightly above average condition. The differences between the two sites are likely due to seasonal variation. |
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| Discussion: These biological data complement chemical water quality data. The last chemical monitoring was conducted in 1999, and showed about average conditions compared to other nearby streams. At that time it was noted that low dissolved oxygen levels were a chronic problem. Invertebrate life is especially sensitive to dissolved oxygen levels. Habitat degradation is also likely responsible for invertebrate community impairment. The heavily silted stream bottom and lack of overhanging snags and vegetation (except for reed canary grass) at the sampling sites provide little of the habitat types required for a rich stream community. | |
