The Qualitative and Quantitative Distribution of Plankton in the Strait of Georgia in Relation to Certain Oceanographic Factors

1957 ◽  
Vol 14 (4) ◽  
pp. 521-552 ◽  
Author(s):  
Joseph Eugène Henri Légaré
Keyword(s):  
Salinity Gradient ◽  
General Distribution ◽  
Fraser River ◽  
Strait Of Georgia ◽  
Quantitative Distribution ◽  
Qualitative And Quantitative ◽  
Chemical Factors ◽  
Physical And Chemical ◽  
Plankton Communities ◽  
Made In

In order to gain some picture of the seasonal variations in the plankton communities two cruises were made in the Strait of Georgia, one in June 1955, and the other in November 1955; 165 plankton collections were taken, also surface temperatures.The correlation of these data have resulted in a number of conclusions concerning the distribution of plankton in the Strait of Georgia. The chief factor affecting the general distribution of plankton is the salinity gradient. The inflow of fresh water from the Fraser River forms zones of varying properties, and leads to the development of different plankton communities. The extent to which physical and chemical factors may determine the presence or absence of certain organisms from the zones described is discussed.

Offshore Characteristics in the Deep Waters of the Strait of Georgia as Indicated by Bathypelagic Fish

1954 ◽  
Vol 11 (5) ◽  
pp. 501-506
Author(s):  
W. E. Barraclough ◽  
M. Waldichuk
Keyword(s):  
Deep Water ◽  
Fraser River ◽  
Strait Of Georgia ◽  
Deep Waters ◽  
Juan De Fuca ◽  
Bottom Waters ◽  
Chemical Conditions ◽  
Physical And Chemical ◽  
Juan De Fuca Strait ◽  
Inflowing Water

An attempt is made from oceanographical observations to explain the occurrence of certain bathypelagic species of fish which have been captured in the bottom waters of the southern Strait of Georgia. It is noted that there is a considerable seaward surface Sow of water from the Fraser River. The water from intermediate depths over the continental shelf forms the inflowing deep water of Juan de Fuca Strait mixing with the Fraser River water in the turbulent channels of the San Juan Archipelago. This mixture forms the deep inflowing water of southern Strait of Georgia and the outflowing surface water of the Juan de Fuca Strait as shown by salinity distribution and current measurements. The net inward movement of deep water is suggested as an agent of transport or a directive factor for the occurrence of these fish in this region. Physical and chemical conditions of the deep water in the Strait of Georgia are shown to be only slightly different from those found in the intermediate offshore water. It is probable that a combination of factors provides conditions suitable for survival of these species in the deep water of the southern Strait of Georgia.

scholarly journals A Quantitative Study of the Fauna of the Sandy Beach at Port Erin

1932 ◽  
Vol 18 (1) ◽  
pp. 279-296 ◽  
Author(s):  
Marjorie E. Pirrie ◽  
J. R. Bruce ◽  
H. B. Moore
Keyword(s):  
Quantitative Study ◽  
Dominant Species ◽  
Sandy Beach ◽  
Interstitial Water ◽  
Tidal Level ◽  
Isle Of Man ◽  
Chemical Factors ◽  
Physical And Chemical ◽  
Made In

A survey of the sandy beach at Port Erin, Isle of Man, was made in. September, 1931. Observations were made, at a number of stations, involving simultaneous records of the macro-fauna and its density, and certain physical and chemical factors of the sand and interstitial water, as well as tidal level on the beach. The results enable certain general conclusions to be drawn as to the causes of the observed distribution of species, and of the differences between the faunas of this and some Scottish beaches. Plans are given, indicating tidal contours, salinity, and grade composition, in situ on the beach, together with frequency diagrams for five dominant species.

Evaluation of Hilla River Water by Measuring some Physical and Chemical Factors

2020 ◽  
Vol 51 (3) ◽  
pp. 203-210
Author(s):  
MOHAMMED ALI SHALAB ◽  
DR. NUHA FALIH KADHIM
Keyword(s):  
River Water ◽  
Chemical Factors ◽  
Physical And Chemical

Further Studies upon Chemical Factors Affecting the Breeding of Anopheles in Trinidad

1934 ◽  
Vol 25 (4) ◽  
pp. 491-494 ◽  
Author(s):  
P. A. Buxton
Keyword(s):  
Analytical Study ◽  
Chemical Constituents ◽  
Physical Factors ◽  
Factors Affecting ◽  
Early Stages ◽  
Freshwater Biology ◽  
Chemical Technique ◽  
Chemical Factors ◽  
Physical And Chemical

During the last decade, entomologists have made progress in understanding the environment in which certain insects live; in particular, we begin to understand the effect of certain physical and chemical factors, which make up a part of the environment. With this gain in knowledge, it is sometimes possible to forecast outbreaks of insects and of diseases conveyed by them, and one can sometimes say that a particular alteration of the environment will result in loss or gain. But so far as mosquitos are concerned, one must admit that though much work has been devoted to the analytical study of the water in which the early stages are passed, the results are disappointing. A consideration of the published work suggests several reasons for this. Investigation into the ecology of the mosquito has had a vogue, and much of it has been done by workers who were isolated and whose knowledge of chemical technique and freshwater biology was limited. Apart from that, the inherent difficulties are great, for the worker must hunt for the limiting chemical and physical factors among a host of others which are doubtless unimportant, and there are few clues to indicate which of the chemical constituents of the water affects the mosquito. The data are therefore voluminous and it is difficult to reduce them to order and present them so that they can be readily understood.

Inducible processes in human cells by low doses of genotoxic physical and chemical factors

1992 ◽  
Vol 13 (4) ◽  
pp. 383-390
Author(s):  
H. Altmann ◽  
H. Tuschl
Keyword(s):  
Human Cells ◽  
Low Doses ◽  
Chemical Factors ◽  
Physical And Chemical

Menadione nicotinamide bisulphite as a source of vitamin K and niacin activities for the growing pig

2000 ◽  
Vol 71 (1) ◽  
pp. 111-117 ◽  
Author(s):  
M. Marchetti ◽  
M. Tassinari ◽  
S. Marchetti
Keyword(s):  
Vitamin K ◽  
Control Diet ◽  
Live Weight ◽  
Organic Salt ◽  
Free Form ◽  
Food Supplementation ◽  
Sodium Bisulphite ◽  
Chemical Factors ◽  
And Control ◽  
Physical And Chemical

AbstractWhen compared with other menadione derivatives such as menadione sodium bisulphite (MSB), menadione nicotinamide bisulphite (MNB), an organic salt combining menadione and nicotinamide, shows better stability towards physical and chemical factors once it is added to pre-mixes or foods. The present work evaluates the bioavailability of the two vitamins present in this compound and toxicity in the pig. To assess vitamin bioavailability, pigs were given small amounts of food containing MNB or equivalent amounts of MSB and nicotinamide in the free form. Menadione and nicotinamide concentrations in blood samples drawn at set times after the diets were given did not reveal any significant differences between the two modes of administration. Haematic levels of both vitamins in animals receiving MNB, or MSB and nicotinamide, were after 2, 4, 8 and 12 h higher (P < 0·001) than those of untreated animals. The tolerance level to MNB was evaluated in pigs given diets containing graded amounts of MNB (100, 500, 2500 mg/kg) for 28 days. No significant (P > 0·05) differences were recorded in live weight, food intake and gain/food ratio in pigs given these diets when compared with those given an unsupplemented diet. Haemoglobin and bilirubin levels did not differ between animals given various amounts of MNB and control animals. Plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities in pigs given 100 mg/kg of MNB did not show significant differences when compared with those observed in pigs given an unsupplemented control diet. In pigs on the diets supplemented with 500 and 2500 mg/kg of MNB there was a significant increase in the two enzymatic activities as compared with controls (P < 0·001 and P < 0·01). In the case of ALT this had disappeared by 28 weeks. MNB is a good source of vitamin K for the pig and does not appear to have any adverse effects, even when administered at levels higher than those normally used in pig food supplementation.

Comparative Assessment of Neurochemical Indices in Patients with Occupational Pathology Caused by Physical and Chemical Factors

2021 ◽  
Vol 15 (4) ◽  
pp. 482-486
Author(s):  
G. M. Bodienkova ◽  
E. V. Boklazhenko
Keyword(s):  
Comparative Assessment ◽  
Chemical Factors ◽  
Physical And Chemical

A global review of the downstream effects of small impoundments on stream habitat conditions and macroinvertebrates

2015 ◽  
Vol 23 (3) ◽  
pp. 257-262 ◽  
Author(s):  
John Gichimu Mbaka ◽  
Mercy Wanjiru Mwaniki
Keyword(s):  
Ecological Effects ◽  
Stream Habitat ◽  
Habitat Conditions ◽  
Qualitative And Quantitative ◽  
Downstream Effects ◽  
Physico Chemical ◽  
Low Head ◽  
Quantitative Analyses ◽  
Physical And Chemical ◽  
Run Of River

The downstream ecological effects of large impoundments have previously been reviewed; however, little is known about the downstream ecological effects of small man-made impoundments. In this review, we examine 94 papers focusing on the effects of small impoundments on stream habitat conditions and macroinvertebrates. Most studies (89.3%) address the effects of small impoundments on physical and chemical habitat conditions, while fewer studies (48.9%) address the effects on macroinvertebrates. In general, most studies report no significant downstream effects of small impoundments on physico-chemical variables, whereas macroinvertebrates richness and abundance increased or decreased. Mean effect sizes (as Cohen’s d) for physico-chemical variables range from −0.82 to 0.68 (small weir: −0.21 to 0.35; run-of-river dam: −0.82 to 0.64; low head dam: −0.49 to 0.68), and from −0.03 to 0.63 for macroinvertebrates abundance and richness. Our assessment of the published literature demonstrates the advantage of combining qualitative and quantitative analyses, and that, while small impoundments may have minimal significant effects on most physico-chemical variables, macroinvertebrates’ richness and density may be affected. This review is relevant for management and scientific communities to identify potential alterations of stream habitats and biota by small impoundments.

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