Butterworth, D.S. and Rademeyer, R.A. A possible approach to address the poor performance of CMPs under some R3 Oms. SCRS/2020/164. Collect. Vol. Sci. Pap. Vol 77(2): 1006-1014 (2021). Also available at: https://www.iccat.int/en/pubs_CVSP.html.
PowerPoint Presentations
Brandão, A. and Butterworth, D.S. Standardised CPUE series for the Alfonsino resource in the SIOFA area of the Indian Ocean. Virtual presentation to the Second Meeting of the Southern Indian Ocean Fisheries Agreement (SIOFA) Stock and Ecological Risk Assessment Working Group (SERA-WG2), 23 June 2020: 15pp.
Brandão, A., Butterworth, D.S. and Johnston, S.J. ASPM assessments of the Alfonsino resource in the SIOFA area of the Indian Ocean. Virtual presentation to the Second Meeting of the Southern Indian Ocean Fisheries Agreement (SIOFA) Stock and Ecological Risk Assessment Working Group (SERA-WG2), 23 June 2020: 22pp.
Brandão, A., Butterworth, D.S. and Johnston, S.J. ASPM assessments of the Alfonsino resource in the SIOFA area of the Indian Ocean. Additional Virtual presentation to the Second Meeting of the Southern Indian Ocean Fisheries Agreement (SIOFA) Stock and Ecological Risk Assessment Working Group (SERA-WG2), 25 June 2020: 7pp.
de Moor, C.L. Experiences with MSE implementation in South Africa. Presented to Management strategy evaluation in Chilean small pelagic resources, Viña de Mar, Chile, 9 March 2020: 44pp.
de Moor, C.L. Some comments relating to the proposal by FISHERIES/2020/JUN/SWG-PEL/38rev. Presentation to the Small Pelagic Scientific Working Group, Cape Town, 5 June 2020: 11pp.
de Moor, C.L., Coetzee, J.C. and Butterworth, D.S. Calculating and informative prior distribution for anchovy survey bias and an update of the anchovy assessment using this prior. Presentation to the Small Pelagic Scientific Working Group, Cape Town, 5 June 2020: 9pp.
de Moor, C.L., van der Lingen, C. and Butterworth, D.S. The assumptions associated with the indices of South African anchovy abundance provided by the Daily Egg Production Method. Presentation to the Small Pelagic Scientific Working Group, Cape Town, 14 July 2020: 6pp.
de Moor, C.L. and Butterworth, D.S. Does the ratio of juvenile sardine:anchovy observed in the fishery and the recruit surveys correlate with that predicted by models? Presentation to the Small Pelagic Scientific Working Group, Cape Town, 14 July 2020: 6pp.
de Moor, C.L. The South African anchovy assessment with annual maturity ogives. Presentation to the Small Pelagic Scientific Working Group, Cape Town, 14 July 2020: 10pp.
de Moor, C.L. A method to recommend the final anchovy TAC for 2020 based on short-term projections of the anchovy resource. Presentation to the Small Pelagic Scientific Working Group, Cape Town, 14 July 2020: 18pp.
de Moor, C.L. Using the ratio of juvenile sardine:anchovy estimated by the June 2020 recruit survey to predict the 2020 sardine bycatch. Presentation to the Small Pelagic Scientific Working Group, Cape Town, 14 July 2020: 4pp.
de Moor, C.L. Consideration of a revision to the 2020 directed sardine TAC. Virtual presentation to the Small Pelagic Scientific Working Group, Cape Town, 20 August, 2020: 15pp.
de Moor, C.L. A proposal for future penguin island closures. Virtual presentation to the Small Pelagic Scientific Working Group, Cape Town, 26 October 2020: 10pp.
de Moor, C.L. Some initial results in the development. Virtual presentation to the Small Pelagic Scientific Working Group, Cape Town, 11 December 2020: 32pp.
Greenland Halibut
Rademeyer, R.A. and Butterworth, D.S. Updated SCAA Base Case assessment for Greenland halibut. NAFO SCR Working paper: 20/030REV: 22pp.
SIOFA
Brandão, A., Butterworth, D.S. and Johnston, S.J. Age-Structured Production Model (ASPM) assessments of the Alfonsino (Beryx splendens) resource in the SIOFA area of the Southern Indian Ocean. 2nd Meeting of the Stock and Ecological Risk Assessment Working Group (SERAWG2). SERAWG2-02-14: 39pp.
Tristan
Johnston, S.J. Tristan Group Biomass Survey (Leg 1) results including data from the 2019 season. MARAM document: MARAM/TRISTAN/2020/JAN/01: 15pp.
Johnston, S.J. MARAM work schedule for 2020. MARAM document: MARAM/TRISTAN/2020/JAN/02: 1pp.
Johnston, S.J. and Nelson, J. Catches taken by the Powerboats, the Edinburgh and for the annual biomass surveys at Tristan da Cunha island since 1990. MARAM document: MARAM/TRISTAN/2020/FEB/03: 2pp. (DATA)
Johnston, S.J. and Butterworth, D.S. Updated 2020 Tristan da Cunha rock lobster assessment. MARAM document: MARAM/TRISTAN/2020/FEB/04: 14pp.
Johnston, S.J. and Butterworth, D.S. Nightingale island rock lobster assessment updated for 2020. MARAM document: MARAM/TRISTAN/2020/MAR/05: 26pp.
Johnston, S.J. Nominal CPUE for the catches taken by the Edinburgh/Geo Searcher off Tristan da Cunha island. MARAM document: MARAM/TRISTAN/2020/MAY/06: 2pp.
Johnston, S.J. and Butterworth, D.S. Initial results from the development of a new OMP 2020 for Tristan da Cunha island rock lobster resource. MARAM document: MARAM/TRISTAN/2020/MAY/07: 16pp.
Johnston, S.J. and Butterworth, D.S. Initial results from the development of a new OMP 2020 for Tristan da Cunha island rock lobster resource. MARAM document: MARAM/TRISTAN/2020/MAY/07/Add: 2pp.
Johnston, S.J. and Butterworth, D.S. Updated (and rescaled) Tristan GLM-standardised lobster CPUE to take account of data for the 2019 season. MARAM document: MARAM/TRISTAN/2020/MAY/08: 10pp.
Johnston, S.J. and Butterworth, D.S. Updated 2020 GLMM-standardised lobster CPUE from the Tristan da Cunha outer group of islands. MARAM document: MARAM/TRISTAN/2020/MAY/09: 16pp.
Johnston, S.J. and Butterworth, D.S. OMP 2020 candidates for the Nightingale rock lobster fishery. MARAM document: MARAM/TRISTAN/2020/MAY/10: 13pp.
Johnston, S.J. New OMPs for the rock lobster fisheries at Nightingale and Tristan islands. MARAM document: MARAM/TRISTAN/2020/JUL/11: 5pp.
Johnston, S.J. and Butterworth, D.S. Recommendations on rock lobster TACs for the Tristan group of islands for the 2020/21 season. MARAM document: MARAM/TRISTAN/2020/JUL/12: 6pp.
Johnston, S.J. and Butterworth, D.S. Summary of recommendations on rock lobster TACs for the Tristan group of islands for the 2020/21 season. MARAM document: MARAM/TRISTAN/2020/JUL/13: 1pp.
Johnston, S.J. Updated observer catch-at-length data from the commercial fisheries at the Tristan da Cunha group of islands with comparisons to biomass survey catch-at-length data. MARAM document: MARAM/TRISTAN/2020/JUL/14: 20pp.
Johnston, S.J. Further GLM analyses of Nightingale, Inaccessible and Gough CPUE data to incorporate trip length data. MARAM document: MARAM/TRISTAN/2020/NOV/15: 8pp.
Johnston, S.J. and Butterworth, D.S. GLM-standardised lobster vessel CPUE at Tristan. MARAM document: MARAM/TRISTAN/2020/NOV/16: 7pp.
Consultancy and Other Activities Based on Expertise Developed in Research
Brandão, A. and Butterworth, D.S. Results for a potential Candidate Management Procedure for the toothfish (Dissostichus eleginoides) resource in the Prince Edward Islands vicinity. DEFF Fisheries document: FISHERIES/2020/MAR/SWG-DEM/06: 22pp.
Brandão, A. and Butterworth, D.S. Results of the progression towards a proposed Management Procedure for the toothfish (Dissostichus eleginoides) resource in the Prince Edward Islands vicinity. DEFF Fisheries document: FISHERIES/2020/OCT/SWG-DEM/22/Rev: 79pp.
Brandão, A. and Butterworth, D.S. Key aspects of the proposed Management Procedure for the toothfish (Dissostichus eleginoides) resource in the Prince Edward Islands vicinity. DEFF Fisheries document: FISHERIES/2020/0CT/SWG-DEM/24/Rev: 11pp.
Brandão, A. and Butterworth, D.S. Application of the proposed Management Procedure for the toothfish (Dissostichus eleginoides) resource in the Prince Edward Islands vicinity to provide a TAC recommendation for the 2021 “fishing” year. DEFF Fisheries document: FISHERIES/2020/OCT/SWG-DEM/29: 3pp.
Butterworth, D.S. On estimates of the impact of fishing from analyses of the island closure experiment which model individual penguin responses directly. DEFF Fisheries document: FISHERIES/2020/JAN/SWG-PEL/08: 2pp.
Butterworth, D.S. A rationale for the initial anchovy TAC recommendation. DEFF Fisheries document: FISHERIES/2020/MAR/SWG-PEL/25: 1pp.
Butterworth, D.S. A possible straightforward approach to TAC update given a survey estimate of recruitment. DEFF Fisheries document: FISHERIES/2020/JUL/SWG-PEL/57: 4pp.
Butterworth, D.S., Ross-Gillespie, A. and Glazer, J. Can CPUE inform on sardine and anchovy recruitment strength? DEFF Fisheries document: FISHERIES/2020/JUL/SWG-PEL/59: 5pp.
Butterworth, D.S. and Ross-Gillespie, A. Continuous approach applied to sardine recruitment survey estimate to advise on juvenile sardine TAB estimates for 2020 and the corresponding recruitment strength. DEFF Fisheries document: FISHERIES/2020/JUL/SWG-PEL/60: 10pp.
Butterworth, D.S. and Ross-Gillespie, A. Some investigations of the regression approach of FISHEREIES/2020/JUL/SWG-PEL/60 to use the 2020 recruitment survey result to provide an estimate for the strength of the most recent west coast sardine recruitment. DEFF Fisheries document: FISHERIES/2020/AUG/SWG-PEL/71: 6pp.
Butterworth, D.S. and Ross-Gillespie, A. Directed sardine TAC updates using the 2020 recruit survey estimate. DEFF Fisheries document: FISHERIES/2020/AUG/SWG-PEL/72: 3pp.
Butterworth, D.S. and Ross-Gillespie, A. Addendum to FISHERIES/2020/AUG/SWG-PEL/72. Update of the TAC estimates using consequence tables with one additional significant figure. DEFF Fisheries document: FISHERIES/2020/AUG/SWG-PEL/72/Add: 2pp.
Butterworth, D.S. and Ross-Gillespie, A. Refining the November 2019 sardine west component recruitment estimate. DEFF Fisheries document: FISHERIES/2020/AUG/SWG-PEL/73: 6pp.
Butterworth, D.S. A response to Sherley: FISHERIES/2020/JUL/SWG-PEL/53rev. DEFF Fisheries document: FISHERIES/2020/AUG/SWG-PEL/82: 38pp.
Butterworth, D.S. A reply to: Some comments on FISHERIES/2020/JAN/SWG-PEL/08. DEFF Fisheries document: FISHERIES/2020/SEP/SWG-PEL/91: 7pp.
Butterworth, D.S. Summary comments on analyses of the island closure experiment. DEFF Fisheries document: FISHERIES/2020/SEP/SWG-PEL/96rev: 5pp.
Butterworth, D.S. An initial proposal for future island closures based on the closure experiment results. DEFF Fisheries document: FISHERIES/2020/SEP/SEG-PEL/97rev: 3pp.
Butterworth, D.S. Initial comments on two documents contributed to inform APBMP discussions. DEFF Fisheries document: FISHERIES/2020/SEP/SWG-PEL/98: 2pp.
Butterworth, D.S. A proposal for a basis to consider future island closures, taking account especially of the current results from the island closure experiment. DEFF Fisheries document: FISHERIES/2020/OCT/SWG-PEL/103: 5pp.
Butterworth, D.S. A response to FISHERIES/2020/JUL/SWG-PEL/102. DEFF Fisheries document: FISHERIES/2020/OCT/SWG-PEL/110: 1pp.
Butterworth, D.S. Response to FISHERIES/2020/JUL/SWG-PEL/105. DEFF Fisheries document: FISHERIES/2020/OCT/SWG-PEL/111: 13pp.
Butterworth, D.S. A brief initial response to FISHERIES/2020/JUL/SWG-PEL/128 re the Precautionary Principle. DEFF Fisheries document: FISHERIES/2020/DEC/SWG-PEL/135: 1pp.
Butterworth, D.S. and Ross-Gillespie, A. On the robustness of the SA hake OMP2018 to an increased Namibian catch of M. paradoxus. DEFF Fisheries document: FISHERIES/2020/MAR/SWG-DEM/02: 11pp.
Butterworth, D.S. and Ross-Gillespie, A. Simple variants of the SA hake Reference Case Operating Model (assessment) to take account of Namibian catches of M. paradoxus. DEFF Fisheries document: FISHERIES/2020/MAR/SWG-DEM/03: 11pp.
Butterworth, D.S. and Ross-Gillespie, A. A further variant of the South African hake 2019 Reference Case assessment model that includes the Namibian M. paradoxus survey abundance series as well as historical Namibian catches. Fisheries Branch document FISHERIES/2020/AUG/SWG-DEM/11. 4pp.
de Moor, C.L., Merkle, D. and Coetzee, J. The data used in the 2020 anchovy assessment. DEFF Fisheries document: FISHERIES/2020/JAN/SWG-PEL/02: 17pp.
de Moor, C.L. Assessment of the South African anchovy resource using data from 1984 – 2019: initial results. DEFF Fisheries document: FISHERIES/2020/JAN/SWG-PEL/03: 21pp.
de Moor, C.L. Should Exceptional Circumstances be declared for anchovy? DEFF Fisheries document: FISHERIES/2020/FEB/SWG-PEL/14: 6pp.
de Moor, C.L. Further results pertaining to the South African anchovy assessment. DEFF Fisheries document: FISHERIES/2020/MAR/SWG-PEL/15: 10pp.
de Moor, C.L. Short-term projections of the South African anchovy resource using constant catch scenarios. DEFF Fisheries document: FISHERIES/2020/MAR/SWG-PEL/16: 65pp.
de Moor, C.L. A recommendation for the initial anchovy Total Allowable Catch for 2020. DEFF Fisheries document: FISHERIES/2020/MAR/SWG-PEL/20: 3pp.
de Moor, C.L. Final baseline assessment of the South African sardine resource using data from 1984-2018. DEFF Fisheries document: FISHERIES/2020/MAR/SWG-PEL/28: 36pp.
de Moor, C.L., Merkle, D., Coetzee, J. and van der Lingen, C.D. The data used in the 2020 sardine assessment. DEFF Fisheries document: FISHERIES/2020/MAR/SWG-PEL/29: 24pp.
de Moor, C.L. Baseline assessment of the South African sardine resource using data from 1984-2019. DEFF Fisheries document: FISHERIES/2020/APR/SWG-PEL/30: 30pp.
de Moor, C.L. Sardine projections based on constant catch scenarios. DEFF Fisheries document: FISHERIES/2020/APR/SWG-PEL/33: 36pp.
de Moor, C.L., Coetzee, J.C. and Butterworth, D.S. Calculating an informative prior distribution for the bias of hydro-acoustic survey estimates of the biomass of the South African anchovy. DEFF Fisheries document: FISHERIES/2020/MAY/SWG-PEL/39: 9pp.
de Moor, C.L. The South African anchovy assessment with an informative prior distribution on the bias in hydro-acoustic survey estimates of abundance. DEFF Fisheries document: FISHERIES/2020/JUN/SWG-PEL/40: 4pp.
de Moor, C.L. Some comments relating to the proposal by FISHERIES/2020/JUN/SWG-PEL/38rev. DEFF Fisheries document: FISHERIES/2020/JUN/SWG-PEL/41: 4pp.
de Moor, C.L. Some further comments relating to the proposal to base anchovy TACs on expected exploitation rates. DEFF Fisheries document: FISHERIES/2020/JUN/SWG-PEL/46: 2pp.
de Moor, C.L., van der Lingen, C.D. and Butterworth, D.S. The assumptions associated with the indices of South African anchovy abundance provided by the Daily Egg Production Method. DEFF Fisheries document: FISHERIES/2020/JUN/SWG-PEL/48: 3pp.
de Moor, C.L. and Butterworth, D.S. Does the ratio of juvenile sardine:anchovy observed in the fishery and the recruit surveys correlate with that predicted by models? DEFF Fisheries document: FISHERIES/2020/JUN/SWG-PEL/49: 5pp.
de Moor, C.L. The South African anchovy assessment with annual maturity ogives. DEFF Fisheries document: FISHERIES/2020/JUL/SWG-PEL/51: 14pp.
de Moor, C.L. Updated short-term projections of the South African anchovy resource using constant catch scenarios. DEFF Fisheries document: FISHERIES/2020/JUL/SWG-PEL/52: 15pp.
de Moor, C.L. A method to recommend the final anchovy Total Allowable Catch for 2020 based on short-term projections of the anchovy resource. DEFF Fisheries document: FISHERIES/2020/JUL/SWG-PEL/54: 6pp.
de Moor, C.L. Using the June 2020 survey estimate of anchovy recruitment to recommend a final anchovy TAC for 2020 based on the method of Butterworth (2020). DEFF Fisheries document: FISHERIES/2020/JUL/SWG-PEL/55: 6pp.
de Moor, C.L. Using the ratio of juvenile sardine:anchovy estimated by the June 2020 recruit survey to predict the 2020 sardine bycatch. DEFF Fisheries document: FISHERIES/2020/JUL/SWG-PEL/62: 2pp.
de Moor, C.L. Sardine projections based on constant catch scenarios separated by recruitment scenarios. DEFF Fisheries document: FISHERIES/2020/JUL/SWG-PEL/63: 4pp.
de Moor, C.L. Considering the historical sardine bycatch with anchovy directed fishing. DEFF Fisheries document: FISHERIES/2020/JUL/SWG-PEL/65: 3pp.
de Moor, C.L. Additional sardine projections based on constant catch scenarios assuming alternative November 2019 recruitment levels. DEFF Fisheries document: FISHERIES/2020/AUG/SWG-PEL/70rev: 29pp.
de Moor, C.L. Consideration of a revision to the 2020 directed sardine TAC. DEFF Fisheries document: FISHERIES/2020/AUG/SWG-PEL/74: 8pp.
de Moor, C.L. Comments on FISHERIES/2020/AUG/SWG-PEL/75 and FISHERIES/2020/AUG/SWG-PEL/76. DEFF Fisheries document: FISHERIES/2020/AUG/SWG-PEL/77rev: 7pp.
de Moor, C.L. South African anchovy assessment sensitivity tests. DEFF Fisheries document: FISHERIES/2020/SEP/SWG-PEL/90: 27pp.
de Moor, C.L. A simple summary of the penguin island closure analyses. DEFF Fisheries document: FISHERIES/2020/SEP/SWG-PEL/95rev: 7pp.
de Moor, C.L. A proposal for future penguin island closures. DEFF Fisheries document: FISHERIES/2020/0CT/SWG-PEL/102: 3pp.
de Moor, C.L. A proposal for penguin island closures in 2021. DEFF Fisheries document: FISHERIES/2020/NOV/SWG-PEL/121: 1pp.
de Moor, C.L. The simulation testing framework for OMP-18rev. DEFF Fisheries document: FISHERIES/2020/DEC/SWG-PEL/122: 24pp.
de Moor, C.L. Some initial results in the development of OMP-18rev. DEFF Fisheries document: FISHERIES/2020/DEC/SWG-PEL/123: 29pp.
de Moor, C.L. Some comments on FISHERIES/2020/DEC/SWG-PEL/129: DEFF Fisheries document: FISHERIES/2020/DEC/SWG-PEL/136: 2pp.
de Moor, C.L. South African sardine assessment posterior distributions and sensitivity tests. DEFF Fisheries document: FISHERIES/2020/DEC/SWG-PEL/138: 30pp.
Glazer, J.P. and Butterworth, D.S. 2020 sole dynamic Schaefer production model results. DEFF Fisheries document: FISHERIES/2020/OCT/SWG-DEM/26: 11pp.
Haddon, M., Parma, A., Punt, A.E. and Wilberg, M.J. Report of the International Review of some aspects of the Island Closure Experiment for the 2020 International Fisheries Stock Assessment workshop. MARAM/IWS/2020: 7pp.
Johnston, S.J. South coast rock lobster TAC for the 2020 season. DEFF Fisheries document: FISHERIES/2020/JUL/SWG-SCRL/03: 2pp.
Johnston, S.J. and Butterworth, D.S. Updated 2020 horse mackerel data and assessment model description. DEFF Fisheries document: FISHERIES/2020/OCT/SWG-DEM/18: 21pp.
Johnston, S.J. and Butterworth, D.S. Updated 2020 horse mackerel assessments and projections. DEFF Fisheries document: FISHERIES/2020/OCT/SWG-DEM/19: 23pp.
Johnston, S.J. and Butterworth, D.S. Recommendation of a TAE for the directed midwater trawl horse mackerel fishery for 2021. DEFF Fisheries document: FISHERIES/2020/OCT/SWG-DEM/30: 6pp.
Ross-Gillespie, A. and Butterworth, D.S. Updated implementation of the Algorithm recommended by the Panel for the 2016 International Stock Assessment Workshop for assessing whether or not to continue with the penguin island closure experiment. DEFF Fisheries document: FISHERIES/2020/JAN/SWG-PEL/09rev. 18pp.
Ross-Gillespie, A. and Butterworth, D.S. Application of the power analysis algorithm to chick condition data standardised by month. DEFF Fisheries document: FISHERIES/2020/FEB/SWG-PEL/12rev: 8pp.
Ross-Gillespie, A. and Butterworth, D.S. Output from the South African Hake OMP-2018 for the 2021 TAC recommendation. DEFF Fisheries document: FISHERIES/2020/OCT/SWG-DEM/23: 6pp.
Theses
Jacobs, M.R.A. 2020.The implementation of a management procedure approach to set catch limits for the Southern Bluefin Tuna and the Atlantic Bluefin Tuna. MSc Thesis, University of Cape Town. 121pp.