Download or read book Proposed Vessel Calibration Studies for NOAA Ship Henry B Bigelow written by NEFSC Vessel Calibration Working Group and published by . This book was released on 2007 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Standardized bottom trawl surveys have been an integral component of Northeast Fisheries Science Center ecosystem monitoring activities since the autumn of 1963 (Azarovitz et al. 1997). The autumn survey was supplemented by a spring survey starting in 1968 and a winter series was initiated in 1992. These surveys are designed to characterize spatial and temporal changes in the abundance of fish and macroinvertebrate species vulnerable to the sampling gear, demographic attributes of these species, and ecological interactions based on food habits studies and other observations. A stratified random sampling design has been employed for all surveys and biological samples are collected using a multi-stage cluster sampling design. Observations on lower trophic levels and oceanographic properties are also collected in conjunction with these surveys and in complementary ecosystem monitoring cruises. The NOAA Ship Albatross IV (Albatross) has been the principal research vessel employed throughout the series although the NOAA Ship Delaware II (Delaware) has also been used in selected bottom trawl surveys. An extensive series of calibration experiments has been undertaken to test for vessel differences and permit conversion of Delaware catches to Albatross catch units to account for these changes (Byrne and Fogarty 1985; Byrne and Forrester 1991). For general overviews of the design and analysis of comparative fishing trials, see Bergh et al. (1990) and Pelletier (1998). The Albatross is scheduled to be replaced by the NOAA Ship Henry B. Bigelow (Bigelow) in 2008, necessitating a new series of vessel calibration studies. The objective of the proposed experiments is to develop Bigelow-Albatross conversion coefficients to maintain consistent time series for the purpose of meeting stock assessment and ecosystem monitoring requirements. In addition to the vessel replacement, a change in the trawl gear used in standardized surveys from a Yankee No. 36 to a four-seam bottom trawl will be made at the recommendation of the MAFMC/NEFMC Trawl Advisory Panel (Brown 2007). Changes in selected sampling protocols, including tow speed and duration for the Bigelow are also recommended by the panel in conjunction with the gear change"--Introduction.
Download or read book Calibration of Bottom Trawl Survey Vessels written by G. Mark Fowler and published by . This book was released on 2009 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Adjustments to calibrate fish and invertebrate abundance estimates between two research survey vessels were determined using mixed-effects and fixed-effects modelling. The fixed-effects model assumes equal probability of a fish being available for capture between the two vessels for a given paired tow set, while the mixed-effects model assumes equal probability over the population of sets, including an estimate of within-set variability as random error. The mixed-effects approach appeared superior to the fixed-effects approach, being better able to resolve the high variability between sets characteristic of the stratified-random survey design in which the calibrartion experiment was conducted. Differences in catchability with length of animals was pervasive, the greatest differences in catchability between vessels being associated with the smallest animals. The influence of length on catchability was best portrayed as a curilinear relationship, as catchability tended to plateau for animals over about 26cm. For some species catchabilities between vessles differed according to the time of day and depth of a tow, though in most cases the differences were of fairly small magnitude.
Download or read book Northeast Fisheries Science Center Bottom Trawl Survey Protocols for the NOAA Ship Henry B Bigelow written by Philip J. Politis and published by . This book was released on 2014 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This document describes the standard operational protocols for conducting the Northeast Fisheries Science Center spring and autumn Multispecies Bottom Trawl Survey aboard the NOAA Ship Henry B. Bigelow. This manual documents current survey protocols and standard sampling gear implemented in spring 2009 after the 2008 survey calibration with the NOAA Ship Albatross IV and the NOAA Ship Henry B. Bigelow. It is intended to serve as a reference manual to ensure survey standardization and aid in the training of new personnel"--Executive summary.
Download or read book Albatross Bigelow Survey Data Calibration for American Lobsters written by Lawrence D. Jacobson and published by . This book was released on 2012 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The Research Vessel Henry B. Bigelow (including a new survey bottom trawl and survey protocols) replaced the NOAA Research Vessel Albatross IV during 2009 for use in conducting Northeast Fisheries Science Center (NEFSC) spring and fall bottom trawl surveys. Paired tow calibration studies were carried out using both vessels during 2008. The vessel calibration experiment data and a beta-binomial model were used to estimate length based calibration factors that convert American lobster catches by the Bigelow into equivalent catches by the Albatross. Calibration factors for lobster were estimated so that the Bigelow catch for a particular size and station divided by the calibration factor estimates the equivalent catch by the Albatross. A total of 2,314 lobsters were taken by one or both research vessels at 201 out of 636 experimental stations. The Bigelow caught 64% more (N=1,481) lobsters than the Albatross (N= 833). Lobsters were taken by both vessels at 87 stations lobsters, the Albatross caught lobsters but the Bigelow did not at 36 stations, and the Bigelow caught lobsters but the Albatross did not at 78 stations. The Bigelow consistently caught higher numbers of lobsters 10 cm carapace length (CL) and higher proportions of total catch for lobsters
Download or read book Bottom Trawl Surveys written by W. G. Doubleday and published by Department of Fisheries and Oceans = Ministère des pêches et des océans. This book was released on 1981 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Commerce Justice Science and Related Agencies Appropriations for Fiscal Year 2007 written by United States. Congress. Senate. Committee on Appropriations. Subcommittee on Commerce, Justice, Science, and Related Agencies and published by . This book was released on 2006 with total page 2068 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Science the Departments of State Justice and Commerce and Related Agencies Appropriations for 2007 written by United States. Congress. House. Committee on Appropriations. Subcommittee on Science, State, Justice, and Commerce, and Related Agencies and published by . This book was released on 2006 with total page 2066 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Federal Register written by and published by . This book was released on 2013-08 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Surveys of Fisheries Resources written by Donald R. Gunderson and published by John Wiley & Sons. This book was released on 1993-05-06 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: Commences with a discussion of biological and statistical considerations involved in designing an effective survey. Examines sampling equipment and techniques used in conducting direct surveys with equal attention to trawl, acoustic, ichthyoplankton and sighting studies. Alternative approaches used in each type of survey are reviewed and numerous case histories illustrate successful applications.
Download or read book Improving the Collection Management and Use of Marine Fisheries Data written by National Research Council and published by National Academies Press. This book was released on 2000-12-10 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt: Congress has promoted fisheries science for over a century and its involvement in fisheries management took a great leap forward with passage of the Fisheries Conservation and Management Act of 1976. In the past decade, Congress has requested advice from the National Research Council (NRC) on both national issues (e.g., individual fishing quotas and community development quotas) and the assessments related to specific fisheries (Northeast groundfish). This report was produced, in part, in response to another congressional request, this time related to the assessments of the summer flounder stocks along the East Coast of the United States. Following the initial request, the NRC, National Marine Fisheries Service (NMFS), and congressional staff agreed to broaden the study into a more comprehensive review of marine fisheries data collection, management, and use.
Download or read book A Calibration Function for Correcting Mean Net Spread Values Obtained from Marport Spread Sensors Used in Conjunction with the Marport MK II Receiver written by Robert Russell Lauth and published by . This book was released on 2014 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Acoustic net mensuration is used on chartered Alaska Fisheries Science Center (AFSC) bottom trawl (BT) survey vessels to monitor and record net spread during standard survey operations. Net spread measurements are a critical component for calculating area swept by the survey BT at each station (Alverson and Pereyra 1969). Area swept estimates are used to extrapolate catch sample weights and numbers to estimate survey abundance and biomass of commercially important bottom fishes and crabs to monitor their population trends (BSAI Groundfish Plan Team 2013). By the late 2000s, the existing inventory of the AFSC's acoustic net mensuration sensors and receivers, produced by either Scanmar or Netmind, Northstar Technical, Inc., were aging and becoming increasingly unreliable and costly to maintain and repair; hence, replacements had to be found. In 2009, the AFSC committed to replacing its inventory with sensors and receivers produced by a new and different manufacturer, Marport Deep Sea Technologies, Inc.. By 2013, the AFSC had purchased a sufficient quantity of Marport MK II acoustic receivers and net mensuration sensors to completely outfit its primary bottom trawl surveys"--Introduction.
Download or read book Calibration of Electronic Measurement Boards and Length Values Recorded in the Fisheries Scientific Computing System FSCS written by Victoria Price and published by . This book was released on 2015 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measured length distributions of Atlantic herring (Clupea harengus) were not identical between midwater trawl catches from the fall systematic herring survey and bottom trawl catches from the fall stratified-random survey conducted by the Northeast Fisheries Science Center (NEFSC) from 1998 to 2012. The Scantrol FishMeter fish measurement board was used during the stratified-random bottom trawl survey, while the Ichthystick II Electronic Fish Measuring Board was used during the systematic herring survey. Both sets of measurements were recorded by the Fisheries Scientific Computing System (FSCS). We investigated whether differences in length-measurement systems caused discrepancies in length distributions between the 2 surveys. Our initial concern was that the Scantrol board may have rounded up to the nearest 0.5 centimeter on measurement and that on recording into FSCS the measurement was again rounded up to the nearest whole centimeter. In the first set of measurements, dowels were cut to known lengths, randomized, measured with each board, and recorded into FSCS. Three different measurement boards of each type were compared to assess variability within each board type. The actual board measurements and the recorded FSCS values were compared against the known values. Systematic biases were observed in 2 of the Scantrol boards, prompting a series of systematic measurements on all Scantrol boards. All fish lengths stored in FSCS from Scantrol boards were positively biased by 0.25 cm, and some boards appear to have a mechanical offset that can increase the bias up to 0.50 cm when compared to true lengths. We cannot completely rule out instrument error as the cause of discrepancies in mean Atlantic herring lengths between surveys, but the effects of rounding by the Scantrol boards and FSCS do not appear to explain the magnitude of the differences. Biological and sampling factors should be investigated as the cause of length distribution discrepancies between surveys. [doi:10.7289/V5QZ27X1 (http://dx.doi.org/10.7289/V5QZ27X1)]
Download or read book NOAA Technical Report NMFS written by and published by . This book was released on 1984 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Canadian Journal of Fisheries and Aquatic Sciences written by and published by . This book was released on 2013 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fishery Bulletin written by and published by . This book was released on 2000 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Programmatic Supplemental EIS for Alaska Groundfish Fisheries Implemented Under the Authority of the Fishery Management Plans for the Groundfish Fishery of the Gulf of Alaska and the Groundfish of the Bering Sea and Aleutian Islands Area written by and published by . This book was released on 2004 with total page 810 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Habitat and Distribution Models of Marine and Estuarine Species Advances for a Sustainable Future written by Mary C. Fabrizio and published by Frontiers Media SA. This book was released on 2022-11-23 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:
