摘要:

Physical oceanographic data from the international NorPac survey of August 1955, in the area north of Lat. 45°N and east of Long. 161°W, were examined. The temperature, salinity, and density distribution and structure from the surface to 2000 m are discussed.The temperature structure showed an isothermal layer to about 30 m depth, a marked thermocline to about 100 m depth, a temperature inversion in most of the area, and below this a gradual temperature decrease into the abyss. At all depths the water was coldest in a "cold core" centered about 100 miles south of Kodiak and the Shumagin Islands. From there the temperature increased at each level in all directions.The salinity structure showed an isohaline layer to about 100 m depth, a marked halocline to about 200 m depth, and below this the salinity increased slightly into the abyss. The salinity structure did not coincide with the temperature structure.The density structure showed an isopycnal layer to about 30 m depth, a pycnocline associated with the thermocline, a second isopycnal layer, a second pycnocline associated with the halocline, and below this the density increased slightly into the abyss.Variations in these structures throughout the region are discussed in some detail.There is no horizontal isosteric level in the 2000 m of depth. It is concluded that there is no level of "no net motion" in this range, but a reference level of 2000 decibars (db) for dynamic calculations is more acceptable than the usual 1000-db level. A new procedure is introduced to extend the reference level into the bottom in near coastal areas.The geostrophic currents were calculated. There was a major latitudinal drift from the west into the central part of the area. It veered northward and continued around the Gulf of Alaska, forming the Alaska Gyral, and left the area to the westward, as an intensified current (Alaskan Stream) close along the Alaskan Peninsula. This intensification is probably due to conservation of absolute vorticity through changing latitude.The circulation pattern extended to at least 2000 m depth, and probably to the bottom. It transported about 17 million m3of water per second. There were a number of eddies in the system, some of which were observed on earlier surveys.The major flow pattern was not wind-generated within the region. The influence of local winds was limited to the upper 200 m of depth. In some areas it aided the flow, and in others retarded it.There is evidence to show that two chains of seamounts influenced the current pattern according to the Sverdrup concept. Since the major portion of these is below 2000 m depth it is concluded that currents exist in the abyss, in essentially the same direction as at the upper levels.

ISSN:0706-652X    

DOI:10.1139/f59-047

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

One of the features of the circulation in an estuary is the net outflow in the surface layer of the fresh water discharged into the estuary together with an appreciable volume of salt water entrained. Continuity considerations require that there be an inflow of salt water to compensate for that taken out in the surface. In a shallow estuary, such as Chesapeake Bay, this results in a two-layer flow, out at the surface and in below it.In a deep estuary, the questions arise whether or not it also possesses this simple two-layer flow and what is the depth and extent of the inflow. Measurements have been made in several inlets in the British Columbia coast to obtain information about the circulation in a deep estuary. Preliminary experiments were made in Toba, Bute and Knight Inlets, the series made in Knight Inlet in July 1956 being the most complete. The techniques employed and the results obtained are described and discussed.In a shallow section (75 m), in-and-out (flood-and-ebb) flow occurred in phase from surface to bottom, with a net outflow in the upper half and inflow below this. In the presence of an up-inlet wind, the flow in the surface few metres reversed and became up-inlet, with an increased outflow below it.In a deep section, both oscillatory (tidal period) as well as net currents occurred at all depths from the surface to 300 m (relevant bottom depth was 350 m). In this deeper section, the oscillatory components were not in phase from surface to bottom, and the net flow showed a three- or four-layer pattern, rather than the simple two-layer pattern which has previously been assumed to exist. The wind had a marked direct effect on the upper layers to a depth of about 10 m and possibly deeper.The movement of the ship while at anchor was monitored and found to be considerable. Most of the current observations were corrected for ship motion before analysis.Calculations of the net fresh water transport (in the upper layer) give reasonable values but similar calculations for the deep water show a net transport which is not to be expected. This apparent net transport may be a consequence of assuming that the current profile across the entire inlet is the same as that in the centre where measurements were made. Other possible sources of error are suggested. In addition, several recommendations are made for future work.

ISSN:0706-652X    

DOI:10.1139/f59-048

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

Samples of Pacific herring (Clupea pallasii) were obtained from commercial catches made at approximately monthly intervals for a period of a year. These samples were analysed for their water, oil, protein and ash content. The seasonal variations obtained in the analytical values in general confirmed those observed previously for this species of fish.When Tester's "fat factor" determined by dividing the weight of the fish by its weight in water was used to calculate the oil content of herring, the average deviation of the calculated oil content from that determined experimentally was 15% and the range of deviation was 2 to 49%. Use of the "fat factor" as a practical means of determining the oil content of herring is not recommended.

ISSN:0706-652X    

DOI:10.1139/f59-049

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

The chief methods of preparing condensed solubles are by concentrating stickwater after first treating it with acid or enzymes to remove or destroy interfering proteins. When acid treatment of the stickwater is used prior to its centrifugation and concentration, there is a change in the viscosity of solubles with season, which can be attributed to changes in its gelatin content. The effect of the gelatin can be overcome by the use of enzymes.Stickwater can be preserved with acid, sodium acid pyrophosphate or penicillin prior to its conversion to solubles.The amino acid and vitamin content of condensed solubles is discussed with particular reference to factors such as freshness of the fish, degree of spoilage of the stickwater and methods of processing the solubles which cause variations in the levels of these nutrients.The composition of the solubles is also determined by the species of fish used, the age and extent of maturation of the fish, and by the type of material (whether whole fish or fish scraps) from which the solubles is prepared.The use of condensed fish solubles as a feed supplement is discussed. The need for using fish solubles of known history both in practical rations and in nutrition studies is stressed.

ISSN:0706-652X    

DOI:10.1139/f59-050

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

A four year field study was conducted on rainbow trout (Salmo gairdneri) spawning in the inlet and outlet of Loon Lake. Young and adult trout were trapped and marked in both streams. About 5000 fish spawn in the outlet between mid-March and June; about 22,000 spawn in the inlet between late April and July. Outlet young either enter the lake by late summer or overwinter in the stream and enter the lake next spring or summer. Most inlet young enter the lake in their first year. Return as adults, of fish which had been clipped while entering the lake as young, indicated that about 94% of fish originating from each end homed to their parent stream. Because of the large number of inlet spawners, about a quarter of the outlet spawners are strays which had hatched in the inlet. Recovery of marked fish, movement of adults within the lake, and experimental transfer of adults and young between streams, all indicate that inlet and outlet spawners do not differ genetically in their responses to current. The biological and applied significance of homing, and its possible mechanisms, are discussed.

ISSN:0706-652X    

DOI:10.1139/f59-051

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

The use of size as a basic determinant of growth rate is discussed and compared to analogous situations described in literature on other physiological rates.Ecologicalopportunity andphysiologicalopportunity are visualized as the two interacting components that determine growth, both of which are entered at "threshold" sizes. The parabolic function,is developed into a growth equation for linear dimensions and its application explored and discussed using steelhead trout and chinook salmon as an example. Significant differences in growth rate are found between life history types and sexes. The chinook data are then treated on alt+1,ltplot and it is shown how an apparent fit of the von Bertalanffy type growth equation can result from selectivity of fishing for the larger fish of any brood year. Two lines of research are indicated. (1) The independent measurement of the exponentxthrough study of size-specific metabolic rates, and (2) the relationship between total mortality rate and growth rate. Without this knowledge a satisfactory synthesis of growth rate into a yield equation cannot be achieved.

ISSN:0706-652X    

DOI:10.1139/f59-052

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

The rate of proteolysis and the deamination of free amino acids in cod muscle treated with 4, 8, 12 and 16% sodium chloride varies with the sodium chloride content and temperature. Proteolysis of the fish muscle protein is completely inhibited at concentrations of 16 and 12% sodium chloride. Trimethylamine formation is inhibited by 16% sodium chloride for at least 15 days. Both inhibitions take place at either 15 or 25 °C. In salted muscle deamination can occur in the absence of trimethylamine formation. The reaction appears to be hardly influenced by salt. Indole formation is completely inhibited by 8% salt at either 15 or 25 °C.

ISSN:0706-652X    

DOI:10.1139/f59-053

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

not available

ISSN:0706-652X    

DOI:10.1139/f59-054

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

not available

ISSN:0706-652X    

DOI:10.1139/f59-055

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

not available

ISSN:0706-652X    

DOI:10.1139/f59-056

出版商:NRC Research Press    

年代:1959

数据来源: NRC