EBookClubs

Read Books & Download eBooks Full Online

EBookClubs

Read Books & Download eBooks Full Online

Book Effects of Gear Modifications on the Trawl Performance and Catching Efficiency of the West Coast Upper Continental Slope Groundfish Survey Trawl

Download or read book Effects of Gear Modifications on the Trawl Performance and Catching Efficiency of the West Coast Upper Continental Slope Groundfish Survey Trawl written by Alaska Fisheries Science Center Nationa and published by BiblioGov. This book was released on 2013-06 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the 1970's the National Oceanic and Atmospheric Administration (NOAA) was made to manage our oceanic and atmospheric resources. The Alaska Fisheries Science Center is the research branch for marine life and coastal oceans off parts of the U.S. west coast and Alaska. This includes the Eastern Bering Sea where some the worlds most important commercial fishing takes place. Their mission is to develop and maintain scientific exploration to help understand and manage that region's environment. Over the years there have been many reports published which discuss their findings; this is one of them.

Book Effects of Gear Modifications on the Trawl Performance and Catching Efficiency of the West Coast Upper Continental Slope Groundfish Survey Trawl

Download or read book Effects of Gear Modifications on the Trawl Performance and Catching Efficiency of the West Coast Upper Continental Slope Groundfish Survey Trawl written by Robert Russell Lauth and published by . This book was released on 1998 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Marine Fisheries Review

Download or read book Marine Fisheries Review written by and published by . This book was released on 1998 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Pacific Coast Groundfish Fishery Management Plan Bycatch Mitigation Program

Download or read book Pacific Coast Groundfish Fishery Management Plan Bycatch Mitigation Program written by and published by . This book was released on 2004 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Report of the Workshop on Trawl Warp Effects on Fishing Gear Performance Marine Biological Laboratory Woods Hole Massachusetts October 2 3 2002

Download or read book Report of the Workshop on Trawl Warp Effects on Fishing Gear Performance Marine Biological Laboratory Woods Hole Massachusetts October 2 3 2002 written by and published by . This book was released on 2002 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: "On 3 September 2002, in response to a concern raised by a member of the fishing industry, the trawl cables ('warps') on the NOAA Ship ALBATROSS IV were inspected and found to have inaccurate 50-meter markings. That is, the marks were not exactly at true 50-meter intervals over the first 1,000 meters of the warps. The difference in marks from the true values ranged between less than 1 inch to 38.4 inches. Also, some of the marks were not evenly matched between the port and starboard cables. The cables were mismarked by the vendor upon installation in February 2000 and were used in eight bottom trawl surveys beginning with Winter 2000 and ending with Spring 2002. Thus, at times during these surveys, more cable may have been deployed on one side of the bottom trawl than on the other. The difference between the two warps is a matter of inches at shallower fishing depths but increases as more cable is set out. For example, when 100 meters (328 feet) of cable are deployed, the warp lengths differ by about 1 inch; when 300 meters (984 feet) are let out, the warp lengths differ by about 6 feet. Approximately 75% of the sampling tows accomplished in the bottom trawl surveys use 300 meters or less of cable. Due to the warp offsets, the survey trawl gear may have fished differently during the eight bottom surveys than during previous surveys, and this may have affected survey catch rates and related survey data used in stock assessments. To evaluate the possible impacts of the warp offsets, data from the last two year's of surveys are being reanalyzed by species, geographic area and depth to detect any changes in catchability that may have occurred . Additionally, the survey results are being compared to the results from other trawl surveys (e.g., Canadian Georges Bank bottom trawl surveys; NMFS sea scallop surveys) conducted during the winter 2000-spring 2002 time period. The sensitivity of groundfish stock assessment results to possible changes in survey catch per tow indices that may have been induced by the warp offsets is also being examined by arbitrarily increasing the catches in the eight surveys by 10%, 25% and 100%, redoing the assessments and then determining the improvement, if any, in the fits of the assessment models. All of the above analyses will be summarized in the Report of the Groundfish Assessment Review Meeting (GARM) that will be available and distributed at the end of October 2002."--Introduction.

Book Options to Mitigate Bottom Habitat Impact of Dragged Gears

Download or read book Options to Mitigate Bottom Habitat Impact of Dragged Gears written by John Willy Valdemarsen and published by Food & Agriculture Org.. This book was released on 2007 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes the basic principles that can be used to reduce the impact of trawling, some of which are already developed as practical solutions and implemented in commercial fisheries. These basic mitigation measures aim at reducing pressure on the bottom of various trawl components and minimising the impacted area while trawling.

Book Estimating Confidence in Trawl Efficiency and Catch Quantification for the Eastern Bering Sea Shelf Survey

Download or read book Estimating Confidence in Trawl Efficiency and Catch Quantification for the Eastern Bering Sea Shelf Survey written by Duane E. Stevenson and published by . This book was released on 2016 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Alaska Fisheries Science Center’s Resource Assessment and Conservation Engineering (RACE) Division has been conducting annual multispecies bottom trawl surveys of the eastern Bering Sea continental shelf using the same standardized gear and trawling procedures since 1982. The data and results from these surveys are available to the general public. However, because the use of these data and results by researchers outside RACE is not monitored, users should be aware of the limitations of this information and design their analyses accordingly. In particular, there are multiple sources of variability in the sampling efficiency of the trawl gear used for the survey, both species- and size-specific, that may affect inferences about the nature of the overall catches and relative animal densities. Furthermore, the quality and specificity of catch quantification (weighing and counting) at sea of many taxa can vary depending on the overall size of the catch and the species composition of the sample, particularly for non-commercial taxa of small size. This document is an assessment of the relative reliability of survey catch weights, numbers, and catch per unit effort estimates derived from the eastern Bering Sea shelf bottom trawl survey and is intended to serve as a guideline for researchers interested in using the survey data and results. Included within is a confidence matrix of sampling efficiency and catch quantification for all fishes and invertebrates identified during the shelf survey. [doi:10.7289/V5/TM-AFSC-335 (http://dx.doi.org/10.7289/V5/TM-AFSC-335)]

Book Oceanic Abstracts

Download or read book Oceanic Abstracts written by and published by . This book was released on 1997-10 with total page 1070 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Trawl Rationalization Trailing Actions Chafing Gear

Download or read book Trawl Rationalization Trailing Actions Chafing Gear written by L.B. Boydstun and published by . This book was released on 2014 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The action modifies chafing gear regulations that apply to all midwater trawl gear used in the Pacific Coast groundfish fishery. Chafing gear is webbing or other material attached to the codend to minimize damage from rubbing against the stern ramp and from contact with the ocean floor. The proposed action is neither expected to compromise the sustainability of any target or non-target species, nor is it expected to result in significant social or economic impacts interrelated with significant natural or physical environmental effects. Increased chafing gear coverage may result in fewer small fish escaping from the codend by reducing the effective mesh size or creating the effect of a double-walled codend. Small fish include juvenile Pacific whiting and non-groundfish species such as coastal pelagic species, eulachon, and small forage fish. Eulachon is listed as threatened under the Endangered Species Act. Because vessels targeting Pacific whiting have less market opportunity for small fish, they are expected to take measures to reduce the catch of small unmarketable Pacific whiting. The catch of small non-target species, including eulachon is not expected to increase substantially. Eulachon will continue to be monitored and managed to stay within thresholds identified in the current Endangered Species Act Section 7 biological opinion for the groundfish fishery. Increased chafing gear coverage may result in midwater trawl gear being used to fish in a manner that results in more contact with ocean floor than is currently occurring. Historical data indicate that the midwater trawl gear used to target Pacific whiting does occasionally make contact with the ocean floor (approximately 8 percent of the hauls). The vulnerability of the net to damage from bottom contact means that increases in chafing gear are not likely to result in substantial increases in bottom contact. The expected impact to EFH and bottom habitat is minor"--Cover letter summary.

Book Trawl Fishery of the Washington Oregon California Region

Download or read book Trawl Fishery of the Washington Oregon California Region written by and published by . This book was released on 1977 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Calculations for Fishing Gear Designs

Download or read book Calculations for Fishing Gear Designs written by A. L. Fridman and published by Pierides Press. This book was released on 2008-10 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many of the earliest books, particularly those dating back to the 1900s and before, are now extremely scarce and increasingly expensive. We are republishing these classic works in affordable, high quality, modern editions, using the original text and artwork.

Book Effects of Trawling and Dredging on Seafloor Habitat

Download or read book Effects of Trawling and Dredging on Seafloor Habitat written by National Research Council and published by National Academies Press. This book was released on 2002-08-09 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concerns over the potential ecological effects of fishing have increased with the expansion of fisheries throughout the marine waters of the United States. Effects of Trawling and Dredging on Seafloor Habitat describes how assessment of fishing impacts depends on gear type, number and location of bottom tows, and the physical and biological characteristics of seafloor habitats. Many experimental studies have documented acute, gear-specific effects of trawling and dredging on various types of habitat. These studies indicate that low mobility, long-lived species are more vulnerable to towed fishing gear than short-lived species in areas where the seabed is often disturbed by natural phenomena. Trawling and dredging may also change the composition and productivity of fish communities dependent on seafloor habitats for food and refuge. The scale of these impacts depends on the level of fishing effort. This volume presents color maps of fishing effort for all regions with significant bottom trawl or dredge fisheries-the first time that such data has been assembled and analyzed for the entire nation.