ii BOBLME-2015-Ecology-53 The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of Food and Agriculture Organization of the United Nations concerning the legal and development status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. The BOBLME Project encourages the use of this report for study, research, news reporting, criticism or review. Selected passages, tables or diagrams may be reproduced for such purposes provided acknowledgment of the source is included. Major extracts or the entire document may not be reproduced by any process without the written permission of the BOBLME Project Regional Coordinator. BOBLME contract: LOA/RAP/2013/29 For bibliographic purposes, please reference this publication as: BOBLME (2015) Procedures and methods for continuing assessment of the status of Hilsa resources in India. BOBLME-2015-Ecology-53 ii iii Procedures and methods for continuing assessment of the status of Hilsa resources in India Suggested citation CIFRI, 2015. Final project report on "Procedures and methods for continuing assessment of the status of Hilsa resources in India". Report to FAO for the Bay of Bengal Large Marine Ecosystem Project. ICAR-Central Inland Fisheries Research Institute, Kolkata, India. 64p. Funding agency Bay of Bengal Large Marine Ecosystem Project (Food and Agriculture Organization, Rome) Executing agency ICAR-Central Inland Fisheries Research Institute Barrackpore, Kolkata-700 120, India. Project team D. Panda M. Naskar R. K. Raman Subrata Das Yousuf Ali Field assistant (02) Cover credit Sujit Choudhury Published by Director ICAR-Central Inland Fisheries Research Institute Barrackpore, Kolkata-700 120, India. iv Procedures and methods for continuing assessment of the status of Hilsa resources in India Acknowledgements We express our deepest sense of gratitude and indebtedness to Dr S. Ayyappan, Director General, Indian Council of Agricultural Research (ICAR), and New Delhi for giving us the opportunity to carry out this research work at CIFRI, Kolkata, India. We are extremely thankful to Dr (Mrs) Meenakumari, Deputy Director General and Dr S. D. Singh, Assistant Director General (Inland Fisheries), Fisheries Science Division, ICAR, New Delhi for their kind support and cooperation for smoothly conducting the research work. We profess our heartfelt gratefulness and sincere regard to Prof. A. P. Sharma, Director, ICAR-Central Inland Fisheries Research Institute, Kolkata, India for his timely, unconditional support and guidance during the project period for the successful completion of this work. We are extremely thankful to Director, Department of Fisheries, Government of West Bengal and Director, ICAR-Central Marine Fisheries Research Institute, Kochi for providing requisite information. We are at loss of words to express our special thanks to Mr Subrata Das, Mr Y. Ali, all field staff and all the staff of CIFRI, Barrackpore for their kind helps in successful completion of the project. The financial assistance provided by the Bay of Bengal Large Marine Ecosystem Project (FAO) is gratefully acknowledged. Place: Kolkata, India Date: (Debabrata Panda) v Procedures and methods for continuing assessment of the status of Hilsa resources in India Table of contents 1. Project outline ................................................................................................................................. 1 1.1. Background ............................................................................................................................. 1 1.2. Objective ................................................................................................................................. 1 1.3. Expected output ...................................................................................................................... 2 1.4. Expected outcome .................................................................................................................. 2 1.5. Implementation and arrangements ........................................................................................ 2 1.6. Technical activity ..................................................................................................................... 2 1.7. Timeframe ............................................................................................................................... 3 2. Review of status of Hilsa ................................................................................................................. 5 2.1. Analysis of historical data ....................................................................................................... 6 2.1.1. Department of Fisheries, West Bengal ........................................................................... 6 2.1.2. CMFRI .............................................................................................................................. 9 2.2. Time series analysis ............................................................................................................... 10 3. Procedures and methods .............................................................................................................. 12 3.1. Sampling and data collection ................................................................................................ 12 3.2. Catch assessment .................................................................................................................. 16 3.3. Spawning profile ................................................................................................................... 16 3.4. Size distribution .................................................................................................................... 17 3.5. Water quality assessment ..................................................................................................... 17 4. Taxonomy ...................................................................................................................................... 18 4.1. Systematic position: Nelson (2006) ...................................................................................... 18 4.1.1. Diagnostic features: (Whitehead, 1985) ....................................................................... 19 4.1.2. Differentiation: (Whitehead, 1985 and Froese & Pauly, 2015) .................................... 19 5. Catch and effort/CPUE assessment .............................................................................................. 21 5.1. Inland Hilsa landings ............................................................................................................. 21 5.2. Marine Hilsa landings ............................................................................................................ 21 5.3. Total Hilsa landings ............................................................................................................... 22 5.4. Effort/CPUE ........................................................................................................................... 24 5.4.1. Inland sector ................................................................................................................. 24 5.4.2. Marine sector ................................................................................................................ 25 6. Length based analysis ................................................................................................................... 27 6.1. Length-weight relationship ................................................................................................... 27 6.2. Condition factor .................................................................................................................... 27 6.3. Length frequency analysis ..................................................................................................... 29 6.4. Growth parameter ................................................................................................................ 30 6.5. Mortality parameter ............................................................................................................. 31 vi Procedures and methods for continuing assessment of the status of Hilsa resources in India 6.6. Recruitment .......................................................................................................................... 31 6.7. Length at first capture (Lc) .................................................................................................... 32 6.8. Gill net selectivity .................................................................................................................. 33 6.9. Relative yield per recruit (Y’/R) and biomass per recruit (B’/R) ........................................... 36 7. Maturity and spawning profile ..................................................................................................... 37 7.1. Maturity and spawning season ............................................................................................. 37 7.2. Spawning frequency .............................................................................................................. 39 7.3. Fecundity ............................................................................................................................... 39 7.4. Length at first maturity