Author: William Francis Thompson
Publisher:
ISBN:
Category : Halibut fisheries
Languages : en
Pages : 108

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Book Description

Author: International Fisheries Commission
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description

Author: William Francis Thompson
Publisher:
ISBN:
Category : Halibut fisheries
Languages : en
Pages : 108

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Book Description

Author: Bell, F. H. (Francis Hugh)
Publisher: Seattle, Wash. : International Fisheries Commission
ISBN:
Category : Halibut fisheries
Languages : en
Pages : 49

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Book Description

Author: William Francis Thompson
Publisher: Forgotten Books
ISBN: 9780265887936
Category :
Languages : en
Pages : 88

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Book Description
Excerpt from Statistics of the Halibut Fishery in the Pacific: Their Bearing on the Biology of the Species and the Condition of the Banks; A Note on a Sporozoan Parasite of the Halibut; The Problem of the Halibut Among the facts presented in the following pages. The one which stands forth most con apicuoualy is the great effect which the operations of the fishermen have bad on the character of the halibut populations of the various hanks. Not only have they been very extensively depleted. But the proportions of mature and immature. Of large and small ilsb have been radi cally changed. The presence of the greatest numbers of immature fish on those banks which have been exploited for the longest time and most intensely would be extremely misleading cairn the clicct of orertishlng were discounted. It is impossible in this connection to refrain from observing the striking parallelism between this condition and that prevailing in the North Sea in the case of the plaice. There. Although it is known that the Bight of Heiigoiand and the Dutch Coast are regions most intensely fished. The presence of great numbers of immature fish and the absence of mature has been urged in support of theories of migration from these nurseries to the deeper water spawningbanka. However this may be in regard to the plaice. It is evident that migration in the halibut must be shown by other means. It is not intended by this to deny the occurrence of migration. But simply to call attention to the obvious importance of the history of a bank in the consideration of its biological problems. It is a corollary of this that the distribution of large and small ilsb is not a criterion of fast and slow growth unless the depletion of the banks is taken into account. Throughout the attempt to correlate the average also of the fish on a bank and Its geographical position. The use of the terms fast and slow growing as synonyms of large and small has been avoided. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.

Author: Robert J. Trumble
Publisher: NRC Research Press
ISBN: 9780660151113
Category : Nature
Languages : en
Pages : 106

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Book Description
Atlantic halibut and Pacific halibut off the Atlantic and Pacific coasts of North America share many biological characteristics. The conventional separation of the halibut into separate species is not uniformly accepted. Reproduction and early life history are nearly identical, although the extensive drift of Pacific halibut eggs and larvae and countermigration as juveniles have not been demonstrated for the Atlantic halibut. Adult halibut undergo migration from winter spawning grounds along the upper continental slope to summer feeding grounds on the continental shelf. The two halibuts show the same pattern of age and growth. They exhibit different trophic selectivity, as small Atlantic halibut consume a higher proportion of invertebrates as samll fish and large Atlantic halibut consume a higher proportion of fish, compared to Pacific halibut. Halibut management in the Atlantic and Pacific varies dramatically. Atlantic halibut in Canada were managed with other groundfish until 1988 and are not managed in the United States. Pacific halibut have been managed by an international commission under treaty between the United States and Canada since 1923. Atlantic halibut have produced from 1000 to 5000 t annually, mainly off Canada, while Pacific halibut have produced 12,000 to 45,000 t, mainly off Alaska. Biological and fishery data are collected more extensively for the Pacific halibut, for which detailed stock assessment is conducted.

Author: William Edwin Ricker
Publisher:
ISBN: 9781932846232
Category : Technology & Engineering
Languages : en
Pages : 0

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Book Description
Computation and Interpretation of Biological Statistics of Fish Populations, first published in 1975, deals with the general field of biological statistics of fish populations. It is a compilation of the more important procedures used to estimate abundance, age composition, rate of growth, and mortality rates in fish populations, with working examples of all the computations. Computation and Interpretation of Biological Statistics of Fish Populations is one of the most highly cited scientific references in the field of fisheries.

Author: William F (William Francis) Thompson
Publisher: Legare Street Press
ISBN: 9781014455291
Category :
Languages : en
Pages : 92

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Book Description
This work has been selected by scholars as being culturally important and is part of the knowledge base of civilization as we know it. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. To ensure a quality reading experience, this work has been proofread and republished using a format that seamlessly blends the original graphical elements with text in an easy-to-read typeface. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 410

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Author: International Pacific Halibut Commission
Publisher: Seattle : The Commission
ISBN:
Category : Fishery management, International
Languages : en
Pages : 64

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Book Description