Effects of suspended sediments on the development of eggs and larvae of striped bass and white perch

The possible ecological effects of suspended sediments are manifold. Briefly, suspended sediments may cause an increased surface for microorganism growth, fewer temperature fluctuations, chemical adsorption or absorption, blanketing, mechanical-abrasive actions, and light penetration reduction (Cairns, 1968). Sherk and Cronin (1970) have pointed out that the above effects have been little studied in the estuarine environment. The ecological effects of suspended sediments on fish eggs and larvae may be of prime importance t o the C and D Canal area, an important spawning and primary nursery area for a variety of estuary: e species (Johnson,1972). This section discusses the effects of suspended sediment on the eggs and larvae of striped bass and white perch.

Fundamental aspects of the feeding of the amphipod Gammarus (R.) balcanicus (Crustacea, Amphipoda). [Translation from: Nauchn.Dokl.vyssh.Shkoly (Biol.Nauk) 1970(7) 12-16, 1970]

The amphipods are major food items for many commercial fishes, and they are used as protein food for agricultural animals. In the present paper are presented the results of four-year observations on the feeding of Gammarus balcanicus in nature and in an aquarium. Among the studied aspects were the dependence of daily food ration on sex and physiological state (with and without eggs) and feeding on different kinds of plant food. The study concludes that Gammarus balcanicus willingly feed on soft half-decayed plant residues; into their ration also enters food of animal origin. In contrast to other amphipods, G. balcanicus eats representatives of its own species very rarely, and only dead or immobile ones.

Diurnal periodicity of activity in the spawning perch P. fluviatilis L. [Translation from: Kalamies 1972(7) 3, 1972]

Diurnal periodicity of spawning in the perch so far are rather meagre and found to be partly contrary to experiences of perch anglers. Therefore a study was made on the spawning during a 5-day period in the spring of 1971 in the Kuusamo area. Observations were made during the main spawning season, between 4- 9 June 1971. The perch were often measured, weighed and then released back into the water. The differences between spawning and non-spawning perch were studied as well as the time of roe discharge in a 24 hour period. Activity and environmental factors such as light intensity were also taken into consideration.

Studies on the mouth size of fish larvae. Method and conclusions only [Translation from: Bulletin of the Japanese Society of Scientific Fisheries 36, 353-368, 1970]

This study was conducted to look into the relationship between mouth size and the total length of larval fish, and the growth in total length of larval fish in one or within a one-year period. Study material was gathered in the South China Sea, the Bay of Bangkok and the Vietnamese coast. This translation focuses on methods and conclusions of the original (longer) paper.

A study of flow conditions near the substratum in an experimental channel [Translation from: Verhandlungen der Internationalen Vereinigung fur Theoretische und Angewandte Limnologie 18, 718-725, 1972]

In a slow flow, on a smooth uniform substratum, a limited bed allows the existence of currents slow enough for benthic invertebrates. These conditions rarely occur naturally. The investigations carried out in this work aimed, on an intermediary scale, to define the influence of irregularities in the substratum on flow near the bottom. The substrata used were made of glass marbles. The investigations were carried out in a transparent channel of 70 cm in length and a rectangular section 10 x 5 cm. The data was analysed to study the general evolution of flow in terms of average speeds and the appearance of the turbulence near the bottom.

Ecological significance of seasonal variation in clutch-size of Arctodiaptomus bacillifer in alpine lakes of high altitudes (Val Bognanco) [Translation from: Bollettino di Zoologia 37 491-492, 1970]

This brief paper describes the significance of seasonal variation in clutch-size of the copepod Arctodiaptomus bacillifer in alpine lakes of high altitudes (Val Bognanco). Seasonal dynamics of the zooplankton of these lakes was studied during summer and autumn of 1968 and 1969and results are summarised.

Glycocalyx production in teleosts [Translation from: Verhandlungen der Deutschen Zoologischen Gesellschaft, p.286, 1970]

Shielding the organism against harmful effects from the environment is one of the most important tasks of the outer covering of all animals. The epidermis of primarily aquatic organisms and the epithelia of organs which are exposed to water, such as the digestive or the urinary system, possess a film of glycoproteins and mucopolysaccharides, the glycocalyx. This short paper examines the relationship of the mucus cells with the glycocalyx.

Individual growth and seasonal cycle of Daphnia middendorffiana in an Alpine lake [Translation from: Memorie dell'Istituto Italiano di Idrobiologia Dott.Marco de Marchi 26 41-83, 1970]

The problem of the peculiar reproductive biology of the cladoceran Daphnia middendorffiana is investigated from a cytological viewpoint, and by direct observation the meiotic phenomena of the eggs both subitaneous and resting is studied. and during maturation, the true mechanism of the succession of reproductive phases of different ecological significance. Samples were collected in the Italian Alpine Lake of Campo 4°.

Ecological study of the River Lambourn. Report for the period October 1970 to September 1973

Few detailed studies have been made on the ecology of the chalk streams. A complex community of plants and animals is present and much more information is required to achieve an understanding of the requirements and interactions of all the species. It is important that the rivers affected by this scheme should be studied and kept under continued observation so that any effects produced by the scheme can be detected. This need has been recognised by the Thames Conservancy and the Water Resources Board who jointly sponsored this investigation on one of the chalk streams involved in the scheme. The present investigation has two main objectives both of which depend on obtaining a detailed picture of the ecology of the river at the present time. First, it will provide basic information on the state of the river prior to the development of the pumping scheme which will be available for comparison at any later date. Secondly, it may be possible to use some of the data to predict the ecological changes which may occur if the flow of the river is altered by the pumping scheme. The study covers suspended solids, invertebrates, fish.This report is part of a series of fives studies on the River Lambourn which were undertaken between 1970 and 1979. [PDF contains 24 pages]

Concentrations of major ions in the stream water of the River Duddon, England, 1970-1974 [Dataset]

This dataset provides raw data of chemical analyses made during studies on seasonal variations of some major ions in the stream water of the River Duddon in Cumbria. Measurements of sodium, calcium, potassium, magnesium and chloride ions and pH were taken at 5 stations in the River Duddon between January 1970 and August 1974.

Concentrations of major ions in the stream water of the upper basin of the River Duddon, England, 1972-1974 [Dataset]

This dataset provides raw data of chemical analyses made during studies on seasonal variations of some major ions in the stream water of the upper basin of the River Duddon in Cumbria. Measurements of sodium, calcium, potassium, magnesium and chloride ions and pH were taken at 26 stations in the River Duddon basin between 1972 and 1974.

An indexed bibliography of papers on tagging of tunas and billfishes

Two working parties, the Working Party on Tuna Tagging in the Pacific and Indian Oceans and the Working Party on Tuna Tagging in the Atlantic and Adjacent Seas, were formed by the Food and Agriculture Organization (FAD) of the United Nations in 1966 (Anonymous, 1966c). The conveners of these working parties were Dr. James Joseph of the Inter-American Tropical Tuna Commission (IATTC) and Mr. FrankJ. Mather, III, of the Woods Hole Oceanographic Institution (WHOI). In 1969 it was recommended that the working parties direct their attention toward billfishes, as well as tunas (Anonymous, 1969h: 5). One report (Joseph and working party, 1969) was published by the Pacific and Indian Oceans group and two (Mather and working party, 1969 and 1972) were published by the Atlantic Ocean and adjacent seas group. Each of the three working party reports included a bibliography of tuna and billfish tagging. The compiler of this bibliography, beginning in 1970, prepared numerous memoranda to the members of the working party, most of which included lists of papers on tuna and billfish tagging which had come to his attention, either directly or through members of the working party. The bibliographies in the three working party reports and the lists of references in the memoranda form the basis for the present bibliography.