Unified Interior Regions

Region 4: Mississippi Basin

Regions L2 Landing Page Tabs

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Year Published: 1966

Contamination of the freshwater ecosystem by pesticides

A large part of our disquieting present-day pesticide problem is intimately tied to the freshwater ecosystem. Economic poisons are used in so many types of terrain to control so many kinds of organisms that almost all lakes and streams are likely to be contaminated. In addition to accidental contamination many pesticides are deliberately applied...

Cope, Oliver B.

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Year Published: 1966

Dechlorination of DDT by Aerobacter aerogenes

Dechlorination of DDT to DDD in higher animals requires the presence of molecular oxygen, but in microorganisms the presence of oxygen hinders dechlorination. In cell-free preparations of Aerobacter aerogenes, the use of selected metabolic inhibitors indicated that reduced Fe(II) cytochrome oxidase was responsible for DDT dechlorination. This...

Wedemeyer, Gary

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Year Published: 1966

Persistence of 2,6-Dichlorobenzonitrile in aquatic environments

In two experiments 2,6-dichlorobenzonitrile was added to aquatic systems, and the residue levels were followed for about 6 months. A granular formulation applied to a farm pond at 0.6 p.p.m. produced highest residues in water and fish about 2 weeks following treatment whereas vegetation and soil samples had the highest levels within 1 or 2 days....

Van Valin, C.C.

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Year Published: 1966

Some effects of Heptachlor on bluegills (Lepomis macrochirus)

In complementary studies of the chronic effects of heptachlor on bluegills, four similar earthen ponds were treated once with different concentrations of heptachlor, and the fish in six plastic pools were routinely fed different levels of heptachlor. A fifth pond and two plastic pools were used as controls. Higher dosages resulted in higher...

Andrews, Austin K.; Stebbings, Bruce E.; Van Valin, Charles C.

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Year Published: 1966

Toxicities of several pesticides to two species of Cladocerans

Laboratory bioassays were conducted with some chlorinated hydrocarbon insecticides, organophosphate insecticides, other insecticides and acaricides, and with herbicides to determine their relative toxicities and immobilization values for two species of daphnids, Daphnia pulex and Simocephalus serrulatus. Both species are satisfactory bioassay...

Sanders, Herman O.; Cope, Oliver B.

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Year Published: 1966

Uptake of 2,4-dichlorophenoxyacetic acid by Pseudomonas fluorescens

Factors influencing the uptake of the sodium salt of 2,4-dichlorophenoxyacetic acid (2,4-D), under conditions in which no net metabolism occurred, were investigated in an effort to determine both the significance of “non-metabolic” uptake as a potential agent in reducing pesticide levels and the mechanisms involved. Uptake of 2,4-D was affected by...

Wedemeyer, Gary

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Year Published: 1965

The 1965 Mississippi River flood in Iowa

The great flood of 1965 on the Mississippi River, along the eastern border if the State, exceeded any flood known in 139 years. It cause damages probably in excess of ten millions of dollars in the State of Iowa. Studied now in progress will more thoroughly cover this and other phases of the flood. The underlying cause of the flood was an...

Schwob, Harlan H.; Myers, Richard E.
The 1965 Mississippi River flood in Iowa; 1965; OFR; 65-145; Schwob, Harian H.; Myers, Richard E.

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Year Published: 1965

Relative toxicities of similar formulations of pyrethrum and rotenone to fish and immature stoneflies

The insecticidal properties of rotenone and pyrethrum have been known for many years. Both toxicants have long histories of extensive use for control of a variety of insect pests. Rotenone has been also employed as a management tool by fishery biologists to rehabilitate fishing waters, and its toxicity to fish in a number of ecological situations...

Bridges, W.R.; Cope, O.B.