Sustainable trawl fishing and sampling methodology
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Sustainable trawl fishing and sampling methodology_Online Workshop 23-10-2020 ICAR-CIFT, MSSRF Trials
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Sustainable trawl fishing and sampling methodology
- 1. SUSTAINABLE TRAWL FISHING AND SAMPLING METHODOLOGY - ONLINE WORKSHOP 23.10.2020
- 2. WHY BYCATCH REDUCTION DEVICES • Big issue in world fisheries and trawling sector in particular • Recent estimates by FAO reveal that out of 9.61 mt of discards, 4.56 mt are contributed by trawling (47.5%) • Discards mostly consists of non-edible faction and juveniles of commercially important species • Growth overfishing – we are not allowing fishes to grow to optimal size • Huge loss to the industry – an estimate by CMFRI calculates loss as US$ 19,445 million per year from mechanized and motorized sector (Ten years ago!!) 14 crore lakh!! INR • Using technical devices and mgt. measures, can significantly reduce the quantity of juveniles being caught
- 3. WHY BYCATCH REDUCTION DEVICES • There are issues with protected species – Turtles, sharks etc. • Trade barriers • Some losses are expected, but this is insignificant when calculating the gains in the long run. • Some BRDs like the Square mesh codends are found to reduce drag and hence savings in fuel • Overall it’s always good to go green
- 4. MLS - TN Sivadas et al., 2017
- 5. MOVIE ON BYCATCH REDUCTION DEVICE BY ICAR-CIFT https://youtu.be/ReSkatOvxUw https://www.youtube.com/watch?v=ReSkatOvxUw&feature=youtu.be
- 9. SAMPLE COLLECTION DETAILS Total catch The entire catch from the codend that is emptied to the deck Targeted catch The catch that is kept in ice after sorting – often called the valuable catch Other catch Other species like Crab/bivalves etc. that are kept live – either on the deck or tied suspended in water Discarded catch The portion of the catch that is discarded, due to its low value or other reasons like poisonous snakes, etc. Illegal species Illegal species unintentionally caught and needs to be recorded and released back into water like Turtles, sharks etc.
- 10. TOTAL CATCH
- 11. UNSORTED CATCH
- 12. TARGET CATCH
- 13. DISCARDS
- 14. OTHER CATCHES Crabs – kept live Other species of high value in any , kept separately • To be recorded in the observation book • Length • Weight • Total numbers These species would not appear in the normal sampling process. Thus record it separately
- 15. ILLEGAL SPECIES Sharks Turtles Other species that are illegal to be caught and retained Take note of it in the observation book • Length (approx.) • Weight (approx.) • Photograph
- 16. CODES TO BE USED SQU_MAN_01, SQU_MAN_02 JFE_MAN_01, JFE_MAN_02, CON_MAN_01, CON_MAN_02, CON_MAN_03, TED_MAN_01, TED_MAN_02, TED_MAN_03 Square mesh codend, JFE-SSD, CONTROL & TED rigged Trawl net Use the same book (intended for a BRD) for the entire experiment at all locations MAN – Mandapam RAM – Rameswaram KOT – Kotaipattanam
- 17. JUVENILE FISH EXCLUDER CUM SHRIMP SORTING DEVICE [JFE-SSD] JFE_MAN_UP_01 JFE_MAN_LO_01 JFE_MAN_UP_01 JFE_MAN_LO_01 JFE_MAN_UP_01_TAR JFE_MAN_UP_01_DIS JFE_MAN_LO_01_TAR JFE_MAN_LO_01_DIS
- 18. TURTLE EXCLUDE DEVICE [TED] TED_MAN_COD_01 TED_MAN_EX_01 TED_MAN_COD_01_TA R TED_MAN_COD_01_DI S
- 19. SAMPLING METHODOLOGY After landing the catches on the deck Sorting Target catch Discard Take weight Mix well Sample Approx. 2 kg Take weight Mix well Sample Approx. 2 kg
- 20. FUEL CONSUMPTION • Can we make an estimate? To be decided by the skipper • Noting down the RPM values and speed every 15 minutes if possible • Indicate if wind is favourable or otherwise • Crude estimation possible using the above • Any other means : suggestions
- 21. DATA ENTRY SHEET DATE Start time from shore The type of BRD used Add other specifications if required Time out Time in Depth – m or fathom (specify) Warp length Speed in knots Direction Add if sample taken – Yes / No Information about other species – crabs, sharks, turtles etc. Target catch sample – YES/ No Discard sample – Yes / No BRD TYPE SQU_MAN_01 Time - reaching shore Total weight of catch – Total target catch weight Total discards weight
- 22. THANK YOU Contacts Dr. Raghu Prakash – 9440608980; 6302896746 – Sampling design Dr. Madhu V R – 8089439629 – Sampling design, Sample collection, Gear rigging Dr. Renjith R K – 9895538835; 7738961901 – Sample collection, Species identification Mr. Nobi P S – 944601652; 8075770887 – Gear rigging