Download or read book Abundance Composition and Distribution of Crustacean Zooplankton in Relation to Hypolimnetic Oxygen Depletion in West central Lake Erie written by Roy F. Heberger and published by . This book was released on 1977 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 1978 with total page 1090 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Technical Papers of the U S Fish and Wildlife Service written by and published by . This book was released on 1980 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Toxicity of Three Herbicides butyl Isooctyl and Propylene Glycol Butyl Ether Esters of 2 4 D to Cutthroat Trout and Lake Trout written by D. F. Woodward and published by . This book was released on 1978 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two formulations of the herbicide 2,4-D (2,4-dichlorophenoxyacetic acid) - the butyl ester (BE) and the propylene glycol butyl ether ester (PGBEE) -- had 96-h LC50's to cutthroat trout and lake trout ranging from 490 to 1,200 microgram/liter in static tests. A third formulation -- the isooctyl ester (IE) -- was not toxic to cutthroat trout or lake trout at concentrations below 60.000 microgram/liter. The butyl ester (2,4-D BE) was slightly more toxic than 2,4-D PGBEE, and the toxicity of both esters increased as water temperature decreased.

Download or read book Great Lakes Fishery Laboratory Progress in Fishery Research written by U.S. Fish and Wildlife Service and published by . This book was released on with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Abate Effects of the Organophosphate Insecticide on Bluegills and Invertebrates in Ponds written by Herman O. Sanders and published by . This book was released on 1981 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Application of the organophosphate insecticide Abate three times (at about monthly intervals) to duplicate 0.04 ha earthen ponds at 18 g/ha (4 micrograms/liter) -- the recommended application rate -- and 180 g/ha (40 micrograms/liter) caused no mortality on blugills. In ponds treated with 18 g/ha fewer bluegill fry were produced than in control ponds, brain acetylcholinesterase (AChE) activity was not affected, and accelerated growth of both fry and adults appeared to result from heavy feeding on dead or moribund Diptera larvae that resulted from the first two applications of Abate. The routine use of Abate at the recommended rate should have little adverse effect on fishery resources.

Download or read book Progress in Fishery Research written by Great Lakes Fishery Laboratory and published by . This book was released on 1976 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sport Fishery Abstracts written by and published by . This book was released on 1978 with total page 1150 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fish and Wildlife Service Publications written by U.S. Fish and Wildlife Service and published by . This book was released on 1990 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bibliography of Copepoda Up to and Including 1980 written by Vervoort and published by BRILL. This book was released on 2023-10-09 with total page 479 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Monthly Catalogue United States Public Documents written by and published by . This book was released on 1978 with total page 832 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Technical Papers of the U S Fish and Wildlife Service written by and published by . This book was released on 1974 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Neuroendocrine Mediation of Photoperiod and Other Environmental Influences on Physiological Responses of Salmonids written by Hugh A. Poston and published by . This book was released on 1978 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Manipulation of photoperiods, combined with modifications by other environmental conditions such as temperature and salinity, can alter growth, smoltification, and sexual maturation of salmonid fishes by way of a neuroendocrine pathway. The extent of responses of salmonids to environmental changes, however, is restricted by circadian endogenous metabolic rhythms that cannot be completely overcome by external factors. The success of the manipulation of photoperiod depends primarily on four factors: the daily length and the duration of the light treatment; the season and time of day during which fish are exposed to light; the age, sex, size and species of fish; and the type of physiological response under consideration. Although gaps remain in the available information, salmonids apparently need systematically changing, intermittent periods of darkness for optimum long-term stimulation of growth, reproduction, and migration.

Download or read book Ecological Effects of Dredging and Dredge Spoil Disposal written by James Walter Morton and published by . This book was released on 1977 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Annual Report written by U. S. Fish and Wildlife Service and published by . This book was released on 1972 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sport Fishery and Wildlife Research written by and published by . This book was released on 1974 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Lake Francis Case a Missouri River Reservoir written by Charles H. Walburg and published by . This book was released on 1977 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.