摘要:

Following developments of Taylor, Allard and Redfield, the rates at which energy is dissipated in the Bay of Fundy in various ways are calculated. A total of 30.9 × 106 kw. is transmitted into the bay of which 1.26 × 106 kw. is transmitted into Passamaquoddy Bay. Work is done on the moon at the rate of 2.48 × 106 kw. and 0.03 × 106 kw. is used to maintain the mixed state in the waters of the Bay of Fundy. The remaining 27.1 × 106 kw. must be dissipated by tidal friction. This value is compatible with the usual concepts of turbulent flow over a rough surface if the "roughness length" (Z0) is equal to 0.4 cm. or the average size of the roughness elements (E) is about 11 cm.The effect which the extraction of additional power from the system would have on tidal ranges is evaluated. The range at the head of the Bay of Fundy would decrease at the rate of 0.84 foot (26 cm.) for each million kilowatts. The proposed Passamaquoddy Project would probably increase the mean tidal range at Hopewell Cape by 0.6 foot (18 cm.)

ISSN:0706-652X    

DOI:10.1139/f58-008

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

An attempt has been made to extract myosin from cod muscle using potassium iodide solution as extractant. The product resembled in several respects myosins made from other cold-blooded animals by other methods, and like them, differed from rabbit myosin in solubility and sedimentation behaviour. Comparison was also made with cod actomyosin with respect to electrophoresis, sedimentation, viscosity, and solubility.

ISSN:0706-652X    

DOI:10.1139/f58-009

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

Results of the physical oceanographic work of the "Calanus" expeditions of 1949–55 are presented in summary. Bathymetric maps are given for Ungava Bay, Frobisher Bay and northeast Hudson Bay. Temperature, salinity and density profiles are used to show the direction of flow of water, without dynamic calculations. Temperature–salinity correlation diagrams show the presence of Atlantic water below 100 metres, well developed in Cumberland Sound, less so in Ungava Bay and Hudson Strait (but still present), and very slight in northern Hudson Bay. In Frobisher Bay the entry of Atlantic water, if it occurs, is masked by tidal turbulence. Inversions of density, giving temporary negative stabilities, are recorded at a number of stations, concentrated in the regions of large tidal ranges; association of these inversions with the state of the tide is indicated. Stability conditions of the water in general are presented; the winter régime in northern Hudson Bay offers no reason to doubt that a normal vertical exchange of water occurs. Special hydrographic conditions in certain inlets are described. The dominance of the whole hydrodynamic pattern by the tides, especially in the eastern part of the area under study, is emphasized.

ISSN:0706-652X    

DOI:10.1139/f58-010

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

Heming, Home and Wapun Lakes are small, eutrophic lakes on the Precambrian Shield. They are at the headwaters of the Nelson River in northern Manitoba at approximately 55°N. longitude, 101°W. latitude. The lakes are each about one square mile in area and are all under 30 feet in depth. For four years physical and chemical studies have been conducted as part of theTriaenophorusinvestigation. During six months of the year the lake is ice-covered. No summer thermal or oxygen stratification is evident. Oxygen concentrations remain at a high level throughout the year. Summer water temperatures follow very closely changes in air temperature. The pH remains close to neutrality and the dissolved mineral content is about 60 p.p.m. The mineral content of these three soft water lakes is similar. Flora and fauna identified from Heming Lake include 41 genera of phytoplankton, 35 species of zooplankton, 17 genera of bottom organisms, 13 species of fish and 9 species of fish parasites.

ISSN:0706-652X    

DOI:10.1139/f58-011

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

This preliminary study is based on material from 113 specimens from the eastern Canadian Arctic. Animals may be aged from the claws up to 9 to 16 years. The male matures at 7 and the female at 6 years. The pup is produced around May 1 and the males are probably in full rut in mid-May. Females which have produced a pup forego ovulation until after the male rut, thus establishing a two-year cycle of pup production. The embryo implants during a 11/2-month period around early August, after 21/2 months of delay in development. The animal grows from 120 cm. in nose–tail length at birth to about 235 cm. The female increases her length by about 33% in the first year and reaches about 91% of her final length at puberty, at 6 years; these figures are somewhat larger than expected from the growth patterns of other Pinnipedia.

ISSN:0706-652X    

DOI:10.1139/f58-012

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

Eggs of the chum salmon (Oncorhynchus keta) were exposed to various constant levels of dissolved oxygen for a period of seven days. The procedure was repeated with fresh egg samples at various developmental stages. Temperatures were constant at 10 °C. from fertilization to hatching. Estimates of oxygen consumption uninhibited by low dissolved oxygen levels were obtained at various stages of egg development for whole eggs and also on the basis of the weight of larvae, excluding the yolk. Eggs were most sensitive to hypoxia between 100–200 Centigrade degree-days and compensated for reduced oxygen availability by reducing the oxygen demand and rate of development. Very low oxygen levels at early incubation stages resulted in the production of monstrosities. At about the time the circulatory system becomes functional the compensatory reduction in rate of growth under hypoxial conditions is reduced, but eggs no longer survive extreme hypoxial conditions. Eggs subjected to low dissolved oxygen levels just prior to hatching hatch prematurely at a rate dependent on the degree of hypoxia. The maximum premature hatching rate corresponded approximately with the median lethal oxygen level. Estimated median lethal levels rose slowly from fertilization to hatching. Oxygen consumption per egg rose from fertilization to hatching while the consumption per gram of larval tissue declined from a high to a low level at about the time of blastopore closure. Subsequently, a slight rise in the rate occurred up to a level which was more or less constant to hatching. "Critical" dissolved oxygen levels were calculated and they appear to define the oxygen level above which respiratory rate is unmodified by oxygen availability. Critical levels ranged from about 1 p.p.m. in early stages to over 7 p.p.m. shortly before hatching.

ISSN:0706-652X    

DOI:10.1139/f58-013

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

Either individuals or schools of downstream-migrating chum, sockeye and pink salmon quickly establish a constant course in a circular channel. This clockwise or counter-clockwise course, once established, is not altered by a variety of disturbances including transfer to a channel of different size and shape or, in the case of the chum, removal from the apparatus for almost two days. The schools travel much more frequently in some particular area of a simple maze although, from time to time, they swim through all parts of it. The tendency to swim steadily forward in a winding maze seems to decline as the season of migration comes to an end. Fish trained to swim along one compass direction show no bias for this direction when given a choice of this or an alternate direction at right angles. Fish trained to reverse direction after a definite distance show a tendency to do this when given an opportunity to swim in a channel twice as long. The findings are discussed in relation to simple types of learning such as habituation, insight learning, latent learning and imprinting. The biological significance of the learning is considered in relation to the problem of migration.

ISSN:0706-652X    

DOI:10.1139/f58-014

出版商:NRC Research Press    

年代:1958

数据来源: NRC