Fishing vessel execution of acoustic surveys for deep-sea species : main issues and way forward

• Record Nr.: UNINA9910464602703321
• Pubbl/distr/stampa: Rome : , : Food and Agriculture Organization of the United Nations, , 2012
• Descrizione fisica: 1 online resource (105 p.)
• Collana: FAO fisheries and aquaculture circular, , 2070-6065 ; ; no. 1059
• Soggetti: Underwater acoustics; Fishing surveys; Fishery resources; Fish stock assessment; Electronic books.
• Lingua di pubblicazione: Inglese
• Formato: Materiale a stampa
• Livello bibliografico: Monografia
• Note generali: "FIRF/C1059 (En)".
• Nota di bibliografia: Includes bibliographical references.
• Nota di contenuto: ""PREPARATION OF THIS DOCUMENT""; ""ABSTRACT""; ""CONTENTS""; ""1. INTRODUCTION AND BACKGROUND""; ""1.1 Introduction""; ""1.2 Background""; ""2. INSTITUTIONAL AND ORGANIZATIONAL ISSUES""; ""2.1 Who this report is intended for""; ""2.2 Why there is an issue""; ""2.3 Strategic and tactical considerations""; ""2.4 Requirements that must be met for stock assessment""; ""3. APPLICATIONS AT SEA AND OPERATIONAL CHALLENGES""; ""3.1 Operational characteristics""; ""3.2 Role of incentives/disincentives""; ""3.3 Integrating surveys with commercial fishing activities""; ""3.4 Echo mark identification""; ""4. VESSELS AND EQUIPMENT""""4.1 Introduction""; ""4.2 The echosounder""; ""4.3 Frequency considerations""; ""4.4 Choice of vessel""; ""4.5 Location of transducers""; ""4.6 Calibration""; ""4.7 Opportunities for introduction of new technologies""; ""5. SURVEY METHODS""; ""5.1 Strategic considerations""; ""5.3 Area-based surveys""; ""5.4 Multiple surveys""; ""5.5 Deciding which data to use for estimation of abundance""; ""6. ACOUSTIC DATA PROCESSING""; ""7. ACOUSTIC BACKSCATTERING CROSS-SECTION VALUES""; ""7.1 Importance of proper specification""; ""7.2 Problems associated with use of Ï?b and sv values""""8. ESTIMATION OF ABUNDANCE""; ""8.1 Introduction""; ""8.2 Area-based surveys""; ""8.3 Aggregation-based surveys""; ""8.4 Comparison of estimators""; ""9. UNCERTAINTY OF RESULTS""; ""9.1 Sources of uncertainty""; ""9.2 Sampling error""; ""9.3 Determination of species composition""; ""9.4 Backscattering cross-section""; ""9.5 Fish distribution and behaviour""; ""9.6 Weather""; ""9.7 Seafloor acoustic “dead zoneâ€?""; ""9.8 Calibration error""; ""9.9 Other errors""; ""10. IMPORTANCE OF COLLECTION OF BIOLOGICAL DATA""; ""10.1 Data to be collected""""10.2 Species composition of the catch""; ""10.3 Length and weight frequency data""; ""10.4 Records of bycatch""; ""10.5 Sex composition and status of gonads""; ""10.6 Otoliths""; ""11. INCORPORATING INDUSTRY SURVEY RESULTS INTO THE ASSESSMENT AND MANAGEMENT PROCESS""; ""11.1 Stock assessment""; ""11.2 Indices of abundance""; ""11.3 Fishing vessel data and stock assessments""; ""12. FUNDING OF ACOUSTIC SURVEYS""; ""12.1 Funding considerations""; ""12.2 Cost items""; ""12.3 National applications""; ""13. DISCUSSION""; ""13.1 Common views""; ""13.2 Communication with vessel crews""""13.3 Research strategies""; ""14. WORKSHOP RECOMMENDATIONS""; ""14.1 General recommendations""; ""14.2 Applications at sea and operational challenges""; ""14.3 Vessels and equipment""; ""14.4 Operational protocols""; ""14.5 Collection of biological data""; ""14.6 Acoustic data processing""; ""14.7 Estimating and estimates of acoustic backscattering values of deepwater species""; ""14.8 Estimation of abundance""; ""14.9 Uncertainty (error in estimates)""; ""14.10 Costs involved in commercial vessel stock assessment and funding issues""; ""15. REFERENCES""