摘要:

not available

ISSN:0706-652X    

DOI:10.1139/f55-011

出版商:NRC Research Press    

年代:1955

数据来源: NRC

摘要:

The smallmouth bass (Micropterus dolomieui) population of South Bay, Lake Huron and the sport fishery imposed on it have been studied by means of marking and creel census carried out during the years 1947 to 1952 inclusive. Population estimates of legal-sized bass (over 10 inches–fork length), based on the recovery of marked fish, show a decrease from 5,900 fish in 1947 to 2,900 in 1949 with an increase again to 5,700 in 1952. The number of bass caught per 100 rod-hours in these years was 89, 51 and 87, respectively. The recovery of the population from its low in 1949 was due solely to the 1947 year-class which dominated the fishery in 1950, 1951 and 1952, contributing 34%, 71% and 67%, respectively, of the anglers' catch in these years. Analysis of scale samples of the anglers' catch shows considerable variation in year-class strength. In contrast to the 3,500 fish contributed to the anglers' creel by the 1947 year-class, the 1945 year-class contributed only 400 fish.South Bay bass enter the sport fishery in small numbers at age III and 70% of the anglers' catch consisted of age-III to age-V fish. Sixty per cent of the legal-sized population of bass present in South Bay in one year are taken by anglers in the succeeding 4–5 years at the present exploitation.A large percentage of the bass population is located in the Inner Basin of South Bay where they are dispersed in varying concentrations along the shoreline. During the five-year study 3,331 bass were tagged and, although the loss of tags was high, 692 were recaptured by trap nets in the same season they were released. Eighty-five per cent of these were taken within two miles of their release point. Of 60 bass recaptured a year after tagging, 43 (72%) were taken within two miles of their release point. Only five per cent of all recorded recaptures were caught over five miles from their release point. Larger bass tended to range farther than small bass.

ISSN:0706-652X    

DOI:10.1139/f55-012

出版商:NRC Research Press    

年代:1955

数据来源: NRC

摘要:

Light sensitivity of the sockeye salmon smolt (Oncorhynchus nerka) is dependent upon the pineal organ as well as the eyes. Destruction of the pineal area of the brain affects the distribution of pigment in the chromatophores and the phototactic response of the fish.

ISSN:0706-652X    

DOI:10.1139/f55-013

出版商:NRC Research Press    

年代:1955

数据来源: NRC