Professionalism in Fishery Biology

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142028/1/naaq0044.pd

Some Chemical Characteristics of Iowa Lakes and Reservoirs

Chemical analyses were made of the surface waters of 61 Iowa lakes and reservoirs during the summer of 1964. With the exception of one bog lake, they all had typical hard waters of the bicarbonate type. Their average composition was similar to the 10-year average compositions of the Iowa and Cedar rivers. There was a tendency for the lakes lying within the Wisconsin glacial drift sheet to have higher values for all parameters measured, although the differences were not considered biologically significant

A New Name for a Continuing Publication

With this issue, the former Proceedings of the Iowa Academy of Science becomes The Journal of the Iowa Academy of Science, a change which coincides with the l00th annual meeting of the Academy. This concludes a process started in 1971 when the Proceedings became a quarterly periodical which also included papers that had not been presented at the previous annual meeting

Thermal Structure of Clear Lake, Iowa

Summer water temperatures in the shallow areas of Clear Lake were slightly higher and had a greater daily range than temperatures measured in the limnetic zone. The lake was not thermally stratified, although small differences sometimes were found between surface and bottom temperatures at the deepest point. Temperatures measured in the Clear Lake Water Treatment Plant were representative of those measured in the limnetic zone of the lake and provide a useful index of temperature conditions in the lake as a whole. The average annual temperature curve is asymmetrical, with the highest temperature falling on August 5 and the lowest occurring 119 days later on November 30. The median and mean lake temperatures were 51° and 53.7°F. The median date of ice breakup was April 3 and the median date of freezing was November 27

UPTAKE OF Zn 65 AND PRIMARY PRODUCTIVITY IN MARINE BENTHIC ALGAE

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109843/1/lno1960540349.pd

Influence of Coal Mining on Water Quality in Marion and Mahaska Counties, Iowa

In the spring and summer of 1976, a water-sampling program was carried out on the streams of Marion and Mahaska counties, where a significant portion of the coal mining in Iowa has occurred. Streams with underground mines or combinations of underground and surface mines in their watersheds had decreased values for alkalinity and increased values for specific conductance and sulfates, indicating the presence of acid mine drainage. Unless reclamation procedures are incorporated into standard mining operations, an expansion of Iowa coal mining could lead to an increase in the severity of this problem

Growth of the Fathead Minnow (Pimephales promelas) in Tertiary Treatment Ponds

A series of experimental ponds, utilizing treated sewage effluent as a water source, have been constructed at the Ames Water Pollution Control Plant. Fathead minnow fry were introduced into the ponds in the summer of 1969 and observations were made on their growth rates, reproduction, and food habits during the summer months. Growth was comparable to that previously reported for hatchery ponds. The fish matured by mid-summer and successfully produced a second crop of fry. The use of tertiary ponds for fish production seems to be a useful approach to the conservation of natural resources

Limnological Features of Some Northwestern Iowa Lakes

Quantitative information on the morphology, watershed characteristics, water transparency, water chemistry and algal crops of six Iowa lakes is summarized. Lake West Okoboji had less oxygen present in the hypolimnion in 1950-1973 than in 1919-1928, indicating an increase in eutrophication. On the basis of increasing plant-nutrient concentrations, increasing summer algal standing crops and decreasing water transparency, the lakes can be ranked thus: Lake West Okoboji, Big Spirit Lake, Lake East Okoboji (including Upper Gar and Minnewashta) and Lower Gar Lake. These differences among lakes are related to the ratio of watershed area to lake volume, which controls the impact of annual nutrient inputs from the watersheds

A Survey of Water Transparency in Iowa Lakes

Measurements of Secchi disk transparency were made in 50 Iowa lakes and reservoirs in the summer of 1975. Averages of July and August readings for individual lakes ranged from 0.1 to 2.7 m. The man-made lakes in the southern part of the state generally had greater transparencies than the natural lakes in the north. Reduced transparency was related more to algal density than to suspended inorganic matter

Potential Phytoplankton Productivity of Three Iowa Streams

A series of experiments were conducted to test the hypothesis that the concentrations of suspended algal populations in central Iowa streams are not limited by nutrient concentrations. River water samples with their natural plankton populations were collected from the Des Moines River, Skunk River, and Squaw Creek and were cultured under controlled conditions without the addition of nutrients. In 23 of 24 experiments significant increases in algal chlorophyll a were found with an average replication factor of 14 times. The data indicate that nutrients are not limiting suspended algal densities in the streams. A second series of experiments indicated that nitrate concentrations of up to 20 mg/I nitrate-nitrogen did not inhibit algal growth in these river waters