摘要:

not available

ISSN:0706-652X    

DOI:10.1139/f58-060

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

In addition to the usual tidal currents in the Strait of Belle Isle, there is, at times, a tendency for the current to set in one direction more than in the other. This over-balance of water movement in one direction is termed the element of dominant flow. The possible causes of this flow are attributed to meteorological factors and to others effecting long-period fluctuations in sea level.Very few extended oceanographic observations have been available to illustrate this phenomenon on a grand scale, particularly for a westerly flow. Observations taken in September 1955 illustrate a dominant westerly flow in considerable detail. This dominant flow was associated with the passage of an intense low pressure area (Hurricane Ione) from the Gulf of St. Lawrence to the Labrador Sea between September 21–23, 1955.

ISSN:0706-652X    

DOI:10.1139/f58-061

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

The discoloured appearance of Foxe Basin ice has been a continuous subject of controversy since Baffin described the condition of this ice in 1615. A number of explanations are reviewed and discussed in view of the recent findings of H.M.C.S.Labradorin Foxe Basin.A study of the problem was undertaken in relation to the oceanographic features of Foxe Basin. The results of these surveys have led to a theory of suspension-freezing of bottom sediments during the winter. Analyses of ice and bottom sediments support the theory that the dirt embedded in the ice is a marine sediment as opposed to wind-blown terrestrial particles.

ISSN:0706-652X    

DOI:10.1139/f58-062

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

Upper lethal temperatures of scallops are raised 1 °C. by each increase of 5 °C. in acclimation temperature. Acclimation upwards is fairly rapid (average 1.7 °C. per day over part of the range). Loss of acclimation to high temperature is slow, and appears to take as long as 3 months. There is a winter-to-summerdeclinein lethal temperature. It appears that naturally occurring water temperatures over 23.5 °C. will be lethal to scallops and directly responsible for mortalities. Temperatures over 21 °C. may also be a direct cause of mortalities but only in special circumstances could mortalities occur as a direct result of temperatures below this. In the "sub-lethal" temperature range, sudden temperature changes upward or downward may so reduce scallop mobility as to make them easier prey to enemies. In this way sudden temperature change could be an indirect cause of increased mortality.

ISSN:0706-652X    

DOI:10.1139/f58-063

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

Salmon from the fishery in the brackish outflow of the Shubenacadie River through its estuary and Cobequid Bay consist mainly of 3-year-old grilse that are much larger than comparable fish taken in Grand Lake at the head of the River, and somewhat larger than comparable fish taken in Minas Channel through which these waters are connected with the Bay of Fundy. These salmon are found to be peculiar also in age composition and thus to form a separate population. That they are large for their age is attributed to exceptionally good estuarial conditions for production of zooplankton and for feeding.With low rainfall these fish are caught mainly far in the outflow and with high rainfall far out. Their numbers fluctuate greatly for unknown reasons except that utter failure of the grilse in 1951 has been found related to lack of rain when they should have been spawned.

ISSN:0706-652X    

DOI:10.1139/f58-064

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

The inner Bay of Fundy and Minas Channel are practically devoid of locally produced zooplankton. The few plankters present are either estuarine species from Minas Basin and Chignecto Bay or immigrants from the Gulf of Maine. The former (Acartia tonsa,Eurytemora herdmani,Centropages hamatus,Pseudodiaptomus coronatusandCanuella canadensis) are abundant inland with shallowing and heavy river discharge. The latter (Calanus finmarchicus,Sagitta elegans,Pseudocalanus minutus,Oithona similisandParafavella gigantea) all show a similar distribution, being abundant in the mouth of the Bay, but declining greatly going inward. Also,Calanusspecimens from the inner Bay have little or no fat, which indicates a lack of food there.The extreme paucity of all zooplankton in Minas Channel is apparently caused by heavy and deep turbulence, which prevents development of phytoplankton on which the animals depend for food.

ISSN:0706-652X    

DOI:10.1139/f58-065

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

An analysis of otolith edge types, age compositions, length distributions, and an examination of growth from age–length data as compared to growth from tagging data are presented as evidence for the validity of the otolith method of age determination for Lockeport haddock.

ISSN:0706-652X    

DOI:10.1139/f58-066

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

Comparisons of scale and otolith age readings have been made for haddock from Subareas 4 and 5 of the ICNAF Convention Area. Percentage of disagreeing readings increases with increasing average age of the fish. In cases of disagreement, scale ages are consistently lower than otolith ages for fish above about 7 years of age in Subarea 5, and for practically all ages in Subarea 4. Variation in results from the 2 methods produces differences in relative strengths of year-classes but has little effect on growth rates.

ISSN:0706-652X    

DOI:10.1139/f58-067

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

Data pertinent to the deep warm waters of a three-layer system in the Cabot Strait area of the Laurentian Channel have been collected since 1915. Typical temperature–depth curves indicate that the temperature of the deep layer reaches a maximum at about 250 m. which shows little or no seasonal variations. Observations show warming of the deep layer from the 1920's to the 1950's. This upward trend of temperatures is accompanied by an increase in volume of the deep layer. The deep layer consists of a mixture of "Labrador" and "Slope" waters in which the mixing ratio of the components remains fairly constant from year to year. Fluctuations in temperature of "Labrador" water are reflected by a corresponding change in temperature of the deep layer in the Laurentian Channel. The vertical structure of the waters in the lower Laurentian Channel and the transport of the waters in Cabot Strait suggest that in the deep layers, there is a continuing supply of oceanic waters to the Gulf of St. Lawrence.

ISSN:0706-652X    

DOI:10.1139/f58-068

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

Fat determinations, by ether extraction, were made on 205 samples of "sardine" herring (Clupea harengusL.) from the Quoddy region of the Bay of Fundy on the east coast of Canada. The period covered was from 1942 to 1952. The fat content was lowest in April to June and highest from August to November, with few exceptions. It varied between 1.2% and 27.5% of the wet weight of the fish. There was marked variation from year to year. Until sexual maturity was reached, the fatness increased with size. The herring were extremely fat in the winter of 1942–43 and quite poor in the next winter; a remote connection with plankton abundance is discussed. Certain regions are noted for very high fatness. A fungus disease did not greatly affect the fatness of recovering fish.

ISSN:0706-652X    

DOI:10.1139/f58-069

出版商:NRC Research Press    

年代:1958

数据来源: NRC