1 / 71

Spiny dogfish characterisation of SPD 3, SPD 4 , & SPD 5

Spiny dogfish characterisation of SPD 3, SPD 4 , & SPD 5. Suze Baird and Sira Ballara Middle Depths WG meeting 26 August 2013. DRAFT — NOT TO BE CITED. Overview. Introduction Trawl survey Observer sampling Spiny dogfish fishery characterisation Catch-per-unit effort analyses

muriel
Télécharger la présentation

Spiny dogfish characterisation of SPD 3, SPD 4 , & SPD 5

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Spiny dogfish characterisation of SPD 3, SPD 4, & SPD 5 Suze Baird and Sira Ballara Middle Depths WG meeting 26 August 2013 DRAFT — NOT TO BE CITED

  2. Overview • Introduction • Trawl survey • Observer sampling • Spiny dogfish fishery characterisation • Catch-per-unit effort analyses • Stock structure • Overall summary DRAFT — NOT TO BE CITED

  3. Spiny dogfish characterisation DRAFT — NOT TO BE CITED SPECIFIC OBJECTIVES 2012/13: • To characterise the fisheries by analysis of commercial catch and effort data to 2010–11. • To carry out standardised CPUE analyses for the major fisheries (Fishstocks) where appropriate. • To review the indices from CPUE analyses, all relevant research trawl surveys and observer logbooks to determine any trends in biomass estimates, size frequency distributions or catch rates. • To review stock structure using data accessed above and any other relevant biological or fishery information. • To assess the availability and utility of developing a series of age frequency distributions from trawl survey and observer collected data. • To make recommendations on future data requirements (including recommendations for annual levels of observer sampling) and methods for monitoring the stocks.

  4. Spiny dogfish QMAs and analysis areas DRAFT — NOT TO BE CITED

  5. Introduction — distribution & biology • Generally south of 38° S in shelf and slope waters < 500 m • [juveniles shallower, mature dogfish shallow-deep] • Low fecundity; late maturity • Maturity: ♂ at 57.5 cm (6 y); ♀ at 73 cm (10 y) • 22 month gestation: females inshore then offshore • Pupping in 200–300 m off ECSI during March-September • Main Maximum size 69 cm; females larger than males • Mature at 3–4 y (~40 cm); maximum age 21 y • spawning time Aug–Oct Total length (TL) cm DRAFT — NOT TO BE CITED

  6. Introduction — length data distribution • 40-60 cm SPD on the shelf and inshore • > 60 cm on shelf edge and offshore • Observer data show similar distribution with > 80 cm SPD in deeper waters (~ 500 m) Trawl survey data Figs. A2,B3 DRAFT — NOT TO BE CITED

  7. Introduction — female reproductive stages Trawl survey data Fig. A13, A14 DRAFT — NOT TO BE CITED

  8. Introduction —female:male ratios • Chatham Rise trawl survey (200-800 m depths) • mostly 3.0-5.0 (range 2.5-11.0) • Sub-Antarctic trawl survey (300-800 m depths) • mostly 0.7-2.9 • Southland trawl survey (30-600 m depths) • 1.5 (2 surveys); 0.4 (2 surveys) • ECSI surveys (30-400 m) • summer survey range 0.6-0.9; winter mostly 0.5 (0.2-0.7) DRAFT — NOT TO BE CITED

  9. Introduction — feeding and trophic status • “Adaptive” – wide range invertebrates and fish • Dietary shift with growth from pelagic to more demersal prey to larger prey items and to more fish • Recent study (Dunn et al. 2013) ChatRise trawl surveys • single species trophic group – lowest of 4 shark groups • dietary variation: year, area, fish weight, bottom temp • importance: salps & euphausids most numerous • squids, uni fish, scavenged fish, HOK, OCT, by weight • fish(scavenged JMA, HOK, rattails) • Predators: young eaten by adult SPD and BWS; older by larger sharks (SCH, MAK, POS, WPS) DRAFT — NOT TO BE CITED

  10. Trawl survey summary • Information from inshore and offshore surveys • ECSI; Southland; Chatham Rise (CR); sub-Antarctic (SA) • No consistent trends in biomass from main series • Characterised by occasional large catches • CR (5500-8000 t) predominantly females • SA (3000-4000 t) change from female dominance to similar M/F estimates in 2006-09 • ♀ 55-100 cm; ♂ 50-80 cm;fewer >80 ♀ 2009-11 • CR modes: ♂,♀ at 60-64 cm; ♀ 82-84 cm • SA modes: ♂ at 64-68 cm; ♀ 60-64 cm DRAFT — NOT TO BE CITED

  11. Chatham Rise trawl survey Figure A3 DRAFT — NOT TO BE CITED

  12. Chatham Rise trawl survey Figure A4 DRAFT — NOT TO BE CITED

  13. Sub-Antarctic trawl survey Figure A5 DRAFT — NOT TO BE CITED

  14. Sub-Antarctic trawl survey Figure A6 DRAFT — NOT TO BE CITED

  15. Other survey data – Southland autumn Figure A7 & A8 DRAFT — NOT TO BE CITED

  16. Other survey data – ECSI autumn-winter Figure A11 DRAFT — NOT TO BE CITED

  17. Other survey data – ECSI autumn-winter Figure A12 DRAFT — NOT TO BE CITED

  18. Observer coverage DRAFT — NOT TO BE CITED Largest proportions of annual and observed catch from SUBA, ECSI, & CHAT [Figure B1] Monthly coverage by area more uneven – determined by main target fisheries [Figure B2]

  19. Observed SPD catch (t) DRAFT — NOT TO BE CITED

  20. Observer biological data sampling CHAT 7% sampled tows SUBA 44% sampled tows Table B1 DRAFT — NOT TO BE CITED

  21. Chatham Rise observer data Figure B4 DRAFT — NOT TO BE CITED Very few males Similar to CR survey for ♂, but more variable for ♀ Low numbers

  22. Sub-Antarctic observer data ♀ ♂ Figure B6 DRAFT — NOT TO BE CITED

  23. Main fisheries catch distribution All data 1990 to 2011 • Trawl and bottom longline (BLL) catch distribution by statistical area – all forms • Managed under 5 stocks: • SPD 1, 3, 4, 5,and 7 • Focus here: SPD 3-5 Figure C9c DRAFT — NOT TO BE CITED

  24. Catch distribution All data 1990 to 2011 • Main fisheries: • “CHAT” = SPD 4 + eastern SPD 3 • trawl October-June • BLL July-September • “SUBA” = SPD 5 • trawl October-May • BLL • setnet CHAT SUBA DRAFT — NOT TO BE CITED

  25. Trawl catch distribution Catch (t) Catch (t) SQU HOK HOK BAR,LIN,SWA,SQU FLA TCEPR data 1990 to 2011 TCER data 2008 to 2011 Figures C9a+b DRAFT — NOT TO BE CITED

  26. Spiny dogfish catches and TACC Total reported landings by QMA 1992-93 competitive quotas in SPD 3 and SPD 5; trawl ban SPD 4 Introduced into QMS on 1 October 2004 Fig. 2 DRAFT — NOT TO BE CITED

  27. Spiny dogfish landings, MHR, and TACC Annual landings since QMS SPD 3 2000-3000 t SPD 4 800-1400 t SPD 5 1500-2500 t QMR/MHR landings (grey bars), un-groomed landings (blue lines), TACC (dotted line) Fig. C1 DRAFT — NOT TO BE CITED

  28. Descriptive analysis • Catch effort data up to 2010–11 • Data groomed and processed by roll-up method (Starr 2007) • stratified data with greenweight landings allocated to trip-stratum (a unique combination of trip, vessel, target species, stat area, and month) • unstratified data with catch effort at ordinal scale of reporting. • Descriptive analysis of catch by area • Fisheries confined within each area CHAT and SUBA DRAFT — NOT TO BE CITED

  29. All SPD catch data • All year round • Most by bottom trawl • Increase pre- and post- QMS • Mainly Chatham Rise (includes ECSI) • Recent increase from Sub-Antarctic • Mix of targets: most from HOK • Most from NZ and Korean vessels Figure C10 DRAFT — NOT TO BE CITED

  30. DRAFT ONLY – Not to be quoted CHAT BLL: takes most SPD catch west+sthChat Is. CHAT BT hoki: Mernoo Bank, Sth CR, Chat Is. SUBA BT hoki and squid: Stewart-Snares shelf, Auck Is. Shelf, Puysegur Analysis presented by area: CHAT, SUBA

  31. DRAFT ONLY – Not to be quoted Model: Lognormal CPUE models on non-zero tows - dependent variable, Log(catch/tow) Variables offered in tow-by-tow analysis: Categorical variables: year, vessel, statistical area, month, twin trawl vessel, target species Third order polynomials: fishing duration, fishing distance (position-based), distance2 (speed x duration), day of year, depth of bottom, effort depth, effort height, effort speed, latitude, longitude, start time, time mid, vessel experience Fourth order polynomial: fishing duration Final CPUE analyses

  32. DRAFT ONLY – Not to be quoted lognormal, binomial, and delta-lognormal for the CHAT TCEPR hoki bottom trawl fishery during 1999–2011 (on estimated catch); lognormal CHAT ling bottom longline fishery during 1997–2011; lognormal, binomial, and delta-lognormal for the SUBA TCEPR main bottom trawl fisheries during 2000–2011; lognormal SUBA bottom trawl fisheries for main targets, based on the merged data from TCEPR, CELR, and TCER forms for 2000–2011. CPUE analyses

  33. DRAFT ONLY – Not to be quoted CHATHAM RISE CPUE analyses

  34. 2006-07 Chatham Rise Trawl TCEPR Bottom longline 2010-11 Figs. C21, C22 DRAFT — NOT TO BE CITED

  35. CHAT fishery area • Trawl fisheries: • BT, Oct-Mar, TCEPR • HOK • 023,… • Bottom longline: • Jul-Sep • Ling • 049,… • Increasing catch from BLL Figure C23 DRAFT — NOT TO BE CITED

  36. CHAT CPUE analyses: TCEPR HOK BT estimated catch CPUE datasets: TCEPR tow-by-tow, 1999-2011 fishing years Core vessels (≥ 3 years vessel participation, 80% catch, &≥ 20 tows per vessel-year) Method: BT Target: HOK Catch: < 10 t Other: east of 174° E, 300-900 m, 0.2-12 h duration Annual catch (core) 123-297 t Proportion of zero catches 73-88% per fishing year Table D3 DRAFT — NOT TO BE CITED

  37. CHAT CPUE analyses:TCEPRcore vessels = 13 DRAFT — NOT TO BE CITED

  38. CHAT CPUE analyses: TCEPR estimated Key terms Year 5.3% Vessel 15.9% Duration 20.0% Mid time 25.0% Month 26.2% Bot. depth 27.6% • Increasing trend from 2001, followed by a decrease from 2009 • Standardised and unstandardised CPUE indices similar to the catch, especially after QMS Figure D2b DRAFT — NOT TO BE CITED

  39. CHAT CPUE analyses: TCEPR estimated Key terms Year 5.3% Vessel 15.9% Duration 20.0% Mid time 25.0% Month 26.2% Bot. depth 27.6% Very small changes in variable influence plots Figure D3a DRAFT — NOT TO BE CITED

  40. CHAT CPUE analyses: TCEPR estimated Standardised residuals and qqplot Figure D3a DRAFT — NOT TO BE CITED

  41. CHAT CPUE analysesTCEPR estimated v daily processed core DRAFT — NOT TO BE CITED

  42. CHAT TCEPR BT hoki comparison Index appears to increase to 2009 then decrease Chatham Rise survey biomass increased from early 1990s to 2001, then relatively flat at a slightly lower level 2011 1999 DRAFT — NOT TO BE CITED

  43. Summary CHAT BT hoki • Bycatch species and < 300 t annual catch (core) • Catch mainly females • LFs show no obvious length class progressions. Fewer larger females in recent surveys • Trawl survey may be useful in monitoring SPD relative abundance in absence of anything else – samples only part of the full distribution DRAFT — NOT TO BE CITED

  44. CHAT CPUE analyses: BLL target ling CPUE dataset: CELR, LCER, LTCER merged to vessel-day-statistical area 1996-2011 fishing years Core vessels (≥ 2 years vessel participation, &≥ 50 sets per vessel) Catch: < 10 t Other: east of 174° E, total hooks 1000-50000, CPUE>1 Annual catch (core) 128-716 t. Post QMS = 128-463 t. Table D3 DRAFT — NOT TO BE CITED

  45. CHAT BLL ling Effort max. = 251 vessel-days Catch max. = 350 t Figure D7a DRAFT — NOT TO BE CITED

  46. CHAT BLL ling Key terms Year 16.5% Total hook 29.7% Month 36.9% Vessel 40.8% Stat. area 42.6% Figure D7b DRAFT — NOT TO BE CITED

  47. CHAT BLL ling Figure D7c DRAFT — NOT TO BE CITED

  48. CHAT BLL ling Figure D9 DRAFT — NOT TO BE CITED

  49. CHAT BLL ling Figure D9 DRAFT — NOT TO BE CITED

  50. CHAT BLL ling Figure D9 DRAFT — NOT TO BE CITED

More Related