摘要:

Controlled experiments on the variables affecting the pre-treatment of fresh fillets for smoking show that the preliminary ice storage of the fish should be for longer than two days and the fillets should be treated with 80 per cent saturated brine at a temperature of between 1 and 7 °C. for approximately 15 minutes. Drying should be with air at a velocity of between 125 and 400 centimetres per second, a wet-bulb temperature between 15 and 23 °C. and a relatively humidity below 70 per cent. These conditions must be adjusted so that the drying time is at least from 35 to 40 minutes.

ISSN:0706-652X    

DOI:10.1139/f37-001

出版商:NRC Research Press    

年代:1937

数据来源: NRC

摘要:

An investigation to determine what species of diatoms are used as food by different species of copepods:Calanus tonsus,Euchaeta japonica,Metridia lucens,Harpacticus uniremis, andDiosaccus spinatus. Also to determine the food chains between diatoms, copepods, and the following fish: Pacific herring,Clupea pallasii; chum salmon,Oncorhynchus keta; spring salmon,O.tschawytscha; dogfish,Squalus suckleyi; ling cod,Ophiodon elongatus; rockfish,Sebastodes caurinus; starry flounder,Platichthys stellatus; lemon sole,Parophrys vetulus; yellow-finned surffish,Damalichthys vacca; blue perch,Taeniotoca lateralis, and yellow shiner,Cymatogaster aggregatus. Stomach, intestines, and excreta were examined for the presence of diatoms. Almost all the common diatoms were found to be used as food by the copepods. The copepods and herring were found to be important links in the food chains between diatoms and the larger fishes.

ISSN:0706-652X    

DOI:10.1139/f37-002

出版商:NRC Research Press    

年代:1937

数据来源: NRC

摘要:

Examination of 167 specimens shows that immature fish feed upon planktonic forms while mature fish feed upon larger bottom organisms and bottom detritus. The diet varies with habitat and season, depending upon what is available. Since it eats the spawn of salmonids and takes much the same food organisms as they do, its presence in waters containing important salmonids is undesirable.

ISSN:0706-652X    

DOI:10.1139/f37-003

出版商:NRC Research Press    

年代:1937

数据来源: NRC

摘要:

From the marking of 104,061 seaward-migrating sockeye at Cultus lake, B.C., in 1930 and 365,265 in 1931, recoveries of 3,821 and 12,803 adults, respectively, were obtained, or 3.67 per cent and 3.5 per cent. Consideration of errors of 10 per cent and 5 per cent respectively, for marked adults missed and a differential mortality among marked fish ranging from 58 per cent to 65 per cent, probable value—62 per cent, indicate a normal survival in the ocean of between 3.5 per cent and 11.7 per cent, probable value, 9.9 per cent. Of eggs deposited naturally a mortality of 97.5 per cent to the seaward migrant stage occurs. The total loss during the life cycle thus amounts to approximately 99.75 per cent. On the basis of 4,500 eggs per sockeye female the ratio of spawning parents to returning mature offspring ranges from 1:2 to 1:6.5, most probable ratio −1:5.5. Females predominate in trap and seine catches and males in gill nets but the paucity of males in the spawning escapement is not clearly explained. Marked sockeye recoveries in the fishing areas indicate no regular geographic progression in the run except at the estuary of the Fraser river. Catches were made in all areas over the same periods but a lag at the river mouth was noted. Migration to the Fraser occurred through both Juan de Fuca and Johnstone straits. A particular spawning population does not necessarily, therefore, travel in a compact school nor follow the same route.

ISSN:0706-652X    

DOI:10.1139/f37-004

出版商:NRC Research Press    

年代:1937

数据来源: NRC

摘要:

Characteristic tidal circulation in a canal, a fiard and a fiord is shown and it is indicated that the depth of tidal circulation in those inlets having a threshold probably varies inversely as the temperature of the circulating waters. A series of tidal observations indicated the presence of a semi-daily tide cycle in the surface waters and a daily tide cycle in the deep waters of the sea adjacent to the sound. Evidence of the upwelling of deep ocean water along the coast is shown by the oxygen content. A zone of photo-synthetic activity between 3 and 6 metres depth is outlined by the occurrence of chemical anomalies.

ISSN:0706-652X    

DOI:10.1139/f37-005

出版商:NRC Research Press    

年代:1937

数据来源: NRC

摘要:

A study has been made of thirty strains of red halophilic organisms from reddened fish, salt and the timbers of salt fish plants. Eleven were cocci and belong to the speciesSarcina litoralisandSarcina sp. of Lochhead. The rod forms are of five types. Three resembleBact.trapanicumPetter,Serratia salinariaandSerratia cutirubraLochhead. The others do not resemble any of the described species. Of thirty samples of salt, reddening organisms were found in twenty, seven of which were mined or evaporated salts.

ISSN:0706-652X    

DOI:10.1139/f37-006

出版商:NRC Research Press    

年代:1937

数据来源: NRC

摘要:

The increase in volatile nitrogenous bases in codfish muscle between the pre-rigor period and the first appearance of odour is approximately 6 mg. per 100 grams of tissue, and is due almost entirely to the action of bacteria. It can be used to follow the course of spoilage only if the original value of the fish in question is known, as the range in variation of the original values is as great as the increase to the appearance of odour.A method for the rapid determination of "trimethylamine" in cod muscle has been devised. Its increase parallels the increase in bacterial population. Odours always appear at approximately the same level of "trimethylamine". The increase resulting from autolysis is negligible. The increase during the development of spoilage is fifteen to twenty times the original value. Spoilage can be followed in fish preserved with borates as well as in untreated fish.

ISSN:0706-652X    

DOI:10.1139/f37-007

出版商:NRC Research Press    

年代:1937

数据来源: NRC