An Evaluation of Gill Nets of Various Mesh Sizes (Classic Reprint)
An Evaluation of Gill Nets of Various Mesh Sizes (Classic Reprint)

Author: Gerald Adkins

Publisher: Forgotten Books

Published: 2018-01-08

Total Pages: 140

ISBN-13: 9780428090388

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Excerpt from An Evaluation of Gill Nets of Various Mesh Sizes The nature of fishing conflicts have varied some what through history, but the method of taking fish was usually a central issue in any controversy. Nets and/or netting have always caused conflicts among factions fishing the same region or harvesting simi lar species. Nets are one of the oldest means of catch ing fish; the Bible documents their use by 11 of the 12 Apostles approximately years ago. 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.

Selectivity of Gill Nets on Spanish Mackerel, Scomberomorus Maculatus, King Mackerel, S. Cavalla, and Bluefish, Pomatomus Saltatrix
Selectivity of Gill Nets on Spanish Mackerel, Scomberomorus Maculatus, King Mackerel, S. Cavalla, and Bluefish, Pomatomus Saltatrix

Author: Lee Trent

Publisher:

Published: 1983

Total Pages: 40

ISBN-13:

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Information from experimental settings of gill nets reported in the literature and data taken from commercial fishermen in Florida from 1973 to 1981 were used to analyze gill net selection on Spanish mackerel, Scomberomorus maculatus, king mackerel, S. cavalla, and bluefish, Pomatomus saltatrix from Florida and Serra Spanish-mackerel, S. braziliensis, from Brazil. The information on Spanish mackerel and bluefish obtained from the commercial gillnet fishedes did not further our understanding of selectivity over that produced by experimental nettings except in defining girth-length relations. The commercial fisheries data appeared to reflect mostly the sizes of fish that were abundant at the time of capture ratner than the effects of selectivity. We did use commercial fisheries data for describing selectivity of king mackerel, however, because we had other estimates of the size compositions of the populations to adjust the gillnet distributions for unequal numbers of fish in the length intervals. Selectivity was evaluated under the assumptions that: (1) the selectivity curve would take the form of a normal frequency distribution; (2) the efficiencies of two nets with different mesh sizes would be similar for fish of their respective lengths; and (3) the standard deviations of the distributions for two different mesh sizes would be equal. Under these assumptions the computed mean selection lengths in relation to mesh size and species- were: Spanish mackerel - 6.3 cm stretched mesh, 30.8 cm fork length; 7.0 cm SM, 33.9 cm FL; 7.6 cm SM, 37.0 cm FL; 8.2 cm SM, 40.1 cm FL; 8.9 cm SM. 43.2 cm FL; and 9.5 cm SM, 46. 3 cm FL. Bluefish - 6.3 cm SM, 28.5 cm FL; 7.0 cm SM, 31.4 cm FL; 7.6 cm SM, 34.2 cm FL; 8.2 cm SM. 37.1 cm FL; and 8.9 cm SM, 40.0 cm FL. King mackerel - 12.1 cm 5M, 92.-1 cm FL. Serra Spanish mackerel - 6.0 cm SM. 42. 1 cm FL; 8.0 cm SM. 43.6 cm FL; and YO cm SM, 55.2 cm FL.

Microplastics in fisheries and aquaculture:
Microplastics in fisheries and aquaculture:

Author: Food and Agriculture Organization of the United Nations

Publisher: Food & Agriculture Org.

Published: 2018-11-09

Total Pages: 147

ISBN-13: 9251098824

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An overview of the occurrence and effects of microplastics on aquatic organisms, with recommendations regarding seafood safety and security, environmental risk assessment approaches and targeted monitoring of microplastics in the environment.

Fish Catching Methods of the World
Fish Catching Methods of the World

Author: Otto Gabriel

Publisher: John Wiley & Sons

Published: 2008-04-15

Total Pages: 536

ISBN-13: 0470995637

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In the sixteen years since the last edition of Von Brant’s classic work was published, fishing and fisheries have undergone vast changes. Not only has there been great progress in the development of new tools, materials and techniques, but the industry has seen an increasing need to address controversial issues such as declining fish stocks, enormous quantities of bycatch and discard and the impact of towed fishing gear on the environment. Fully revised and updated to reflect such changes, the fourth edition of this widely read and popular book offers: A unique, comprehensive survey of the evolution of fishing methods throughout the world Approximately 750 illustrations showing the extensive range of methods, techniques and equipment used in fishing across the globe Fishing gear classified according to the FAO system Additional chapters: Fishing Effects on Fish Stocks and Environment and Fishery and Gear Research All researchers, fisheries scientists, fisheries students, administrators and libraries in universities and research establishments where fish and fisheries are studied and taught will find this book a valuable addition to their shelves. Commercial and sports fishermen will also find Fish Catching Methods of the World a fascinating and vital reference.

Evaluation of Trawls for Monitoring and Harvesting Fish Populations in Lake Oahe, South Dakota
Evaluation of Trawls for Monitoring and Harvesting Fish Populations in Lake Oahe, South Dakota

Author: William Roland Nelson

Publisher:

Published: 1974

Total Pages: 16

ISBN-13:

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Trawls of various designs and sizes were compared to evaluate their use for monitoring and harvesting fish populations in Lake Oahe. Catches of a 20.7-m semiballoon trawl, selected to monitor changes in the fish populations from 1965 to 1970, showed a downward trend in the abundance of all species, except walleye; the decline was largest in the lower area of the reservoir with a slight increase in the upper area. Of two trawl designs tested, semiballoon trawls captured more fish per hour than high-rise trawls, and a 15.9-m semiballoon trawl with a 3.8-cm mesh cod end captured fish at the highest and most consistent rate. The size and species composition of the fish caught in small-mesh trawls differed from thos caught in trap nets. Trawl cataches were too small to recommend or warrant their use as a commercial fishing gear, but the use of both small mess trawls and trap nets should improve accuracy in monitoring fish populations in this reservoir.