Lower Mississippi River Environmental Program. Report 7. An Ecological Evaluation of Five Secondary Channel Habitats in the Lower Mississippi River
ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS ENVIRONMENTAL LAB
Pagination or Media Count:
Chemical, physical, and biological attributes of the aquatic habitat of five Lower Mississippi River secondary channels were surveyed during summer July 1984 two of the channels were resurveyed during fall October. Dikes at least partially restricted flow through two of the channels Lakeport Towhead and Cottonwood Bar, river miles 470 and 528, respectively flow through the remaining three Wolf Island, river mile 935 Island 8, river mile 915 Profit Island, river mile 250 was not restricted. The channel at which flow was most restricted, Lakeport Towhead, showed both physical and chemical differences from the others. Electroshocking catches of fish were highest at Profit Island due to unusually large collections of catfishes. The macroinvertebrate assemblages found within the channels were similar overall, and they appeared to reflect the current speed and substrate conditions. The dike macrofauna was similar to that noted in earlier studies on the Lower Mississippi River. Dikes that block or greatly restrict flow through secondary channels produce habitats in which the macroinvertebrate and fish assemblages are quite different from undiked channels, at least when river stages are near or lower than the controlling elevation of the dikes.
- Hydrology, Limnology and Potamology