Iowa River, fish, macroinvertebrates, sewage, total ammonia, un-ionized ammonia
The effect of the Marshalltown municipal sewage effluent on Iowa River water quality and fauna was evaluated from July 1976 through August 1977. The effluent contains high total ammonia and un-ionized ammonia concentrations due to ammonia-rich discharges from meat packinghouses. Dissolved oxygen, pH, temperature, total ammonia nitrogen, and un-ionized ammonia data were collected at.12 sampling stations extending 18 km downstream from the sewage effluent discharge. Wild fish collections were made by using electrofishing, seines, and hoopnets. Thirty-eight fish species were collected during the study. Channel catfish. (Ictalurus punctatus) and smallmouth bass (Micropterus dolomieus) were the most common gamefish. No consistent depression in wild fish diversity was seen below the sewage discharge point. Eight hundred thirty caged channel catfish were used in conducting 13 4-day field toxicityty tests at 5 different river stations. Only 2% mortality was observed. Macroinvertebrate diversity and density were determined by using artificial substrate samplers placed at 5 river stations during 2 3-week exposure periods in the summer of 1976. Macroinvertebrate diversity recovered 770-1550 m downstream from the sewage discharge point. The applicability of the EPA un-ionized ammonia criterion and the Iowa total ammonia nitrogen standard is evaluated in light of the findings from this study.
Proceedings of the Iowa Academy of Science
© Copyright 1982 by the Iowa Academy of Science, Inc.
Govro, Keith; Moore, Marianne V.; and Olson, Craig L.
"Effects of an Ammonia-Rich Municipal Sewage Effluent on Iowa River Fauna Near Marshalltown, Iowa,"
Proceedings of the Iowa Academy of Science: Vol. 89:
, Article 7.
Available at: http://scholarworks.uni.edu/pias/vol89/iss4/7