Ecological Effects of Dredging and Dredge Spoil Disposal
Ecological Effects of Dredging and Dredge Spoil Disposal

Author: James Walter Morton

Publisher:

Published: 1977

Total Pages: 44

ISBN-13:

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The goal of this study was to prepare a comprehensive review of the literature on the physical, chemical, and biological effects of dredging and spoil disposal in estuaries and to identify alternative spoil disposal methods. Specific objectives were to identify the most critical problems relating to dredging and spoil disposal and to summarize the progress made to date in solving these problems. Using literature search facilities, bibliographies, and communications with experts throughout the United States, about 520 scientific and technical articles on dredging and spoil disposal were screened. Information extracted from selected articles is included in this review.

Lake Francis Case, a Missouri River Reservoir
Lake Francis Case, a Missouri River Reservoir

Author: Charles H. Walburg

Publisher:

Published: 1977

Total Pages: 20

ISBN-13:

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Studies conducted during the first 23 years of impoundment of Lake Francis Case indicated that fish abundance in the early 1970's was about half of that in the late 1950's. Of 39 species collected, 12 were abundant in the 1950's and 8 in the 1970's, but only 4 were abundant throughout the impoundment period.

Abundance, Composition, and Distribution of Crustacean Zooplankton in Relation to Hypolimnetic Oxygen Depletion in West-central Lake Erie
Abundance, Composition, and Distribution of Crustacean Zooplankton in Relation to Hypolimnetic Oxygen Depletion in West-central Lake Erie

Author: Roy F. Heberger

Publisher:

Published: 1977

Total Pages: 24

ISBN-13:

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Samples of crustacean zooplankton were collected monthly in west-central Lake Erie in April and June to October 1968, and in July and August 1970, before and during periods of hypolimnetic dissolved oxygen (DO) depletion. The water column at offshore stations was thermally stratified from June through September 1968, and the hypolimnion contained no DO in mid-August of 1968 or 1970. Composition, abundance, and vertical distribution of crustacean zooplankton changed coincidently with oxygen depletion. Zooplankton composition shifted from mainly cyclopoid copepods in July to mainly cladocerans and copepod nauplii in middle to late August. We believe that mortality of adults and dormancy of copepodites in response to anoxia was the probable reason for the late summer decline of planktonic C. b. thomasi.

Rainbow Trout Growth in Circular Tanks
Rainbow Trout Growth in Circular Tanks

Author: James L. Brauhn

Publisher:

Published: 1976

Total Pages: 24

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Prediction equations correlating density of fingerling rainbow trout with growth, yield, and food use efficiency indicated that ammonia nitrogen resulting from high fish densities wes responsible for reductions in all three factors. These predictable density-dependent responses present fish-culturists with alternatives of density selection for evaluation and attainment of specific goals. In examples, fish-culturists, by manipulating density, could achieve rapid growth, produce the maximum weight possible, balance yield with cost, optimize fish quality, or combine two or more of these goals.

Changes in Young-of-the-year Fish Stocks During and After Filling of Lake Oahe, an Upper Missouri River Storage Reservoir, 1966-74
Changes in Young-of-the-year Fish Stocks During and After Filling of Lake Oahe, an Upper Missouri River Storage Reservoir, 1966-74

Author: Fred C. June

Publisher:

Published: 1976

Total Pages: 32

ISBN-13:

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Abundance increased and was highest in the lower third of the reservoir while it was filling, whereas it decreased and was generally highest in the upper two-thirds of the reservoir after it was filled. Abundance of species produced in littoral areas was greater wwhile the reservoir was filling -- particularly in years when spring water levels covered vegetation, fluctuated little, and were maintained through May or longer -- than after the reservoir was filled.