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Research Output

2017

Research Papers and Refereed Articles

Ansorge, I.J., Skelton, P., Bekker, A., de Bruyn, P.J.N, Butterworth, D.S., Cilliers, P., Cooper, J., Cowan, D.A., Dorrington, R., Fawcett, S., Fietz, S.F., Ken P., Froneman, P.W., Grantham, G.H., Greve, M., Hedding, D., Hofmeyr, G.J., Kosch, M., le Roux, P., Lucas, M., MacHutcho, K., Meiklejohn, I., Nel, W., Pistorius, P., Ryan, P., Stander, J., Swart, S., Treasure, A., Vichi, M., Jansen van Vuuren, B. Exploring South Africa’s southern frontier: A 20-year vision for Polar Research through the South African National Antarctic Programme. SA Journal of Science, 113 (5/6): 1-7.
Best, P., Tormosov, D., Brandão, A. and Mikhalev, Y. Geographical variation in the body size of adult female sperm whales (Physeter macrocephalus) – an example of McNab’s resource rule. Mammalia, 81(2) 189-196. 
de Moor, C.L., Butterworth, D.S. and van der Lingen, C.D. 2016. The quantitative use of parasite data in multistock modelling of South African sardine (Sardinops sagax). Canadian Journal of Fisheries and aquatic Sciences. dx.doi.org/10.1139/cjfas-2016-0280
Squires, D., Maunder, M., Allen, R., Andersen, P., Astorkiza, K., Butterworth, D.S., Caballero, G., Clarke, R., Ellefsen, H., Guillotreau, P.,Hampton, J., Hannesson, R., Havice, E., Helvey, M., Herrick, S., Hoydal, K., Maharaj, V., Metzner, R., Mosqueira, I., Parma, A., Prieto-Bowen, I., Restrepo, V., Sidique, S.F., Steinsham, S.I., Thunberg, E., del Valle, I. and Vestergaard, N. Effort rights-based management. Fish and Fisheries 18(3): 440-465.


Non-peer Reviewed Published Conference Proceedings

Butterworth, D.S. and Rademeyer, R.A. Statistical catch at length assessment methodology for Atlantic bluefin tuna. SCRS/2016/152: Collect. Vol. Sci. Pap. ICCAT, 73(6): 2202-2221: 20pp.
Kitakado, T. and Butterworth, D.S. On the role of age data in the performance of the modified CLA introduced in SC/66b/SP10. Annex T3. Journal of Cetacean Research and Management 18 (Suppl.): 442-444.


Unpublished Research/Technical/Policy Documents

Brandão, A.  Plots for baseline evaluation trials for the selected SLA for West Greenland bowhead whales based on 400 simulations. International Whaling Commission, SC/O17/AWMP/03Rev1: 14pp.
Brandão, A. Precision of 5th percentiles of West Greenland bowhead whales. International Whaling Commission, SC/67A/AWMP/04: 13pp.
Brandão, A. Potential SLAs for West Greenland fin whales testing against the agreed evaluation trials. International Whaling Commission, SC/67A/AWMP/12: 7pp.
Moosa, N. and Butterworth, D.S. Summary of an update of the Mori-Butterworth (2006) model of the krill-predator dynamics of the Antarctic ecosystem. International Whaling Commission, SC/67A/EM/14: 31pp.
Punt, A.E. and Brandão, A. Results of trials to evaluate the interim allowance strategy for West Greenland humpback whales, International Whaling Commission, SC/67A/AWMP/01: 23pp.

PowerPoint Presentations

Butterworth, D.S. On the benefits of harvest strategies. PEW video on MSE.
Butterworth, D.S. South African hake OMP revision. Presented to the Annual International Stock Assessment Review workshop. University of Cape Town, 27 November - 1 December 2017: 43pp.
de Moor, C.L. South African Fisheries management: World Leaders or World Followers. Presented to the SNAPP working group: Measuring the status of fisheries and factors leading to success, Seattle, USA, 1 June 2017: 19pp.
de Moor, C.L. A proposal for determining the final desirable maximum catch of directed sardine west of Cape Agulhas. Small Pelagic SWG Meeting, 27 June 2017: 11pp.
de Moor, C.L. Comparisons between single area management and various forms of two area management for directed sardine TACs off South Africa. Small Pelagic SWG Meeting, 12 October 2017: 36pp.
de Moor, C.L. Should OMP-14 be used to set South African sardine and anchovy catch limits for 2018? Small Pelagic SWG Meeting, 12 October 2017: 13pp.
de Moor, C.L. and Butterworth, D.S Letting the 'data' speak for themselves: The use of stock-recruit relationships to determine a biomass threshold above which management should aim to keep a resource. Presentation to the CAPAM workshop, Miami, USA. 2 November 2017: 28pp.
de Moor, C.L. Considering the short-term implications of the directed sardine catches during 2018. Presented to the Small Pelagic SWG meeting, 7 December 2017: 10pp.
de Moor, C.L. Introduction to South African sardine: Assessment and Management. Presented to the International Stock Assessment Workshop, Cape Town. 27 November 2017: 49pp.
Johnston, S.J. Development of a revised OMP for south coast rock lobster. Presented to the Annual International Stock Assessment Review Workshop, University of Cape Town. 27 November - 1 December 2017: 10pp.
Johnston, S.J. West coast rock lobster fishery: estimation of the extent and trends of poaching. Presented to the Annual International Stock Assessment Review Workshop, University of Cape Town. 27 November - 1 December 2017: 24pp.
Rademeyer, R.A. and Butterworth, D.S. A spatial box model of SA hake with explicit movement. Presentation to the BCC ECOFISH Synthesis Workshop, 29-31 May, DAFF, Cape Town: 8pp.
Rademeyer, R.A. and Butterworth, D.S. The SCAA assessment of SA hake. Presentation to the BCC ECOFISH Synthesis Workshop, 29-31 May, DAFF, Cape Town: 12pp.
Ross-Gillespie, A. and Butterworth, D.S. Modelling hake predation explicitly. Presentation to the BCC ECOFISH Synthesis Workshop, 29-31 May, DAFF, Cape Town: 10pp.

Southern Bluefin Tuna

Takahashi, N., Sakai, O., Kurota, H., Itoh, T. and Butterworth, D.S. A check of operating model predications from the viewpoint of the management procedure implementation in 2017. Southern bluefin tuna document: CCSBT-ESC/1708/27: 9pp.

Greenland Halibut

Rademeyer, R.A. and Butterworth, D.S. Initial applications of statistical catch-at-age assessment methodology to the Greenland halibut resource. NAFO SCR Doc 17/02REV: 26pp.
Rademeyer, R.A. and Butterworth, D.S. Management procedures for Greenland halibut. NAFO SCR Doc 17/003REV: 13pp.
Rademeyer, R.A. and Butterworth, D.S. Examples of management procedure outputs for Greenland halibut. NAFO WG-RBMS Working Group meeting, Falmouth, 25-27 April 2017: 11pp.
Rademeyer, R.A. and Butterworth, D.S. Results for initial candidate management procedure testing for Greenland halibut. NAFO SCR Doc 17-026REV: 41pp.
Rademeyer, R.A. and Butterworth, D.S. Statistical catch-at-age operating models for the Greenland halibut resource. NAFO SCR Doc 17-035REV: 46pp.
Rademeyer, R.A. and Butterworth, D.S. CMP projections under XSA in comparison to the SCAA baseline (OMO). NAFO SCR Doc 17-037REV: 13pp.
Rademeyer, R.A. and Butterworth, D.S. SCAA MSY evaluation methodology for Greenland halibut. NAFO SCR Doc 17-046: 2pp

Tristan

Butterworth, D.S. and Johnston, S.J. Recommendations on rock lobster TACs for the Tristan group of islands for the 2017/18 season. MARAM document: MARAM/TRISTAN/2017/AUG/09: 8pp.
Butterworth, D.S. and Johnston, S.J. Summary of recommendations on rock lobster TACs for the Tristan group of islands for the 2017/18 season. MARAM document: MARAM/TRISTAN/2017/AUG/10: 1pp.
Johnston, S.J. Workplan for 2017 w.r.t. Tristan rock lobster. MARAM document: MARAM/TRISTAN/2017/JAN/01: 1pp.
Johnston, S.J. Developing an OMP for Nightingale. MARAM document: MARAM/TRISTAN/FEB/02: 2pp.
Johnston, S.J. Tristan Group Biomass Survey (Leg1) results including data from the 2016 season. MARAM document: MARAM/TRISTAN/2017/FEB/03: 16pp.
Johnston, S.J. and Butterworth, D.S. Updated (and rescaled) Tristan GLM-standardised lobster CPUE to take account of data for the 2016 season. MARAM document: MARAM/TRISTAN/2017/MAY/04: 9pp.
Johnston, S.J. The amended Tristan OMP. MARAM document: MARAM/TRISTAN/2017/MAY/05: 1pp.
Johnston, S.J., Brandão, A. and Butterworth, D.S. Updated 2017 GLMM-standardised lobster CPUE from the Tristan da Cunha outer group of islands. MARAM document: MARAM/TRISTAN/2017/MAY/06: 14pp.
Johnston, S.J. and Butterworth, D.S. Updated 2017 Nightingale island rock lobster assessment. MARAM document: MARAM/TRISTAN/2017/MAY/07: 22pp.
Johnston, S.J. and Butterworth, D.S. Initial OMP candidates for the Nightingale rock lobster fishery. MARAM document: MARAM/TRISTAN/2017/JUL/08: 11pp.

Consultancy and Other Activities Based on Expertise Developed in Research

Brandão, A. Updated assessment of the South African kingklip resource that includes catch-at-length data for the one-stock and two-stock hypotheses. DAFF Branch Fisheries document: FISHERIES/2017/JUL/SWG-DEM/20: 29pp.
Brandão, A. and Butterworth, D.S. Updated trotline standardised CPUE series for toothfish (Dissostichus eleginoides) in the Prince Edward Islands EEZ over the period 2008-2016. DAFF Branch Fisheries document: FISHERIES/2017/SEP/SWG-DEM/26: 7pp.
Brandão, A. and Butterworth, D.S.  Assessment of the toothfish (Dissostichus eleginoides) resource in the Prince Edward Islands vicinity to include data from 1997 to 2016. DAFF Branch Fisheries document: FISHERIES/2017/SEP/SWG-DEM/27: 33pp.
Brandão, A. and Butterworth, D.S. Retrospective analysis of the toothfish (Dissostichus eleginoides) resource in the Prince Edward Islands vicinity, including stochastic projections. DAFF Branch Fisheries document: FISHERIES/2017/OCT/SWG-DEM/42: 10pp.
Butterworth, D.S. and Rademeyer, R.A. An initial list of issues for discussion at the international workshop regarding the 2018 hake OMP revision. DAFF Branch Fisheries document: FISHERIES/2017/OCT/SWG-DEM/52: 2pp.
Butterworth, D.S., de Moor, C.L. and Coetzee, J.C. At what biomass threshold should the directed sardine fishery be closed? MARAM/IWS/2017/Sardine/P5: 4pp.
Coetzee, J.C., de Moor, C.L. and Butterworth, D.S. A summary of the South African sardine (and anchovy) fishery. MARAM/IWS/2017/Sardine/BG1: 12pp.
Cox, S., Howell, D. and Punt, A.E. International review panel report for the 2017 International Fisheries Stock Assessment Workshop, 27 November – 1 December 2017, UCT, 14pp.
de Moor, C.L. The OMP-14 constraints, with straw-dog extrapolation to two-area candidate MPs. DAFF Branch Fisheries document: FISHERIES/2017/FEB/SWG-PEL/02: 6pp.
de Moor, C.L. and de Goede, J. TABs in OMP-17. DAFF Branch Fisheries document: FISHERIES/2017/FEB/SWG-PEL/03: 4pp.
de Moor, C.L. Draft simulation testing framework to be used during the development of OMP-17. DAFF Branch Fisheries document: FISHERIES/2017/FEB/SWG-PEL/04: 27pp.
de Moor, C.L. Sardine stock-recruit relationships. DAFF Branch Fisheries document: FISHERIES/2017/FEB/SWG-PEL/05: 4pp.
de Moor, C.L. Draft objectives for the management of the South African pelagic fishery for anchovy and sardine, using OMP-17. DAFF Branch Fisheries document: FISHERIES/2017/JUN/SWG-PEL/16: 5pp.
de Moor, C.L. A proposal for determining the final desirable maximum catch of directed sardine west of Cape Agulhas during 2017. DAFF Branch Fisheries document: FISHERIES/2017/JUN/SWG-PEL/18: 20pp.
de Moor, C.L. The agreed method to determine the maximum sardine catch west of Cape Agulhas during 2017. DAFF Branch Fisheries document: FISHERIES/2017/JUN/SWG-PEL/19: 3pp.
de Moor, C.L. Final anchovy and sardine TACs and TABs for 2017, using OMP-14. DAFF Branch Fisheries document: FISHERIES/2017/JUL/SWG-PEL/22: 5pp.
de Moor, C.L. Comparisons between single area management and various forms of two area management for directed sardine TACs off South Africa. DAFF Branch Fisheries document: FISHERIES/2017/OCT/SWG-PEL/24: 61pp.
de Moor, C.L. Should OMP-14 be used to set South African sardine and anchovy catch limits for 2018? DAFF Branch Fisheries document: FISHERIES/2017/OCT/SWG-PEL/25: 6pp.
de Moor, C.L. and Butterworth, D.S. Simple calibration of spawner biomass and survey biomass for South African sardine and anchovy. DAFF Branch Fisheries document: FISHERIES/2017/DEC/SWG-PEL/29: 6pp.
de Moor, C.L. Level at which the sardine directed fishery should be closed. DAFF Branch Fisheries document: FISHERIES/2017/DEC/SWG-PEL/30: 6pp.
de Moor, C.L. The simulated short term impact of using OMP-14 to set the initial directed sardine TAC. DAFF Branch Fisheries document: FISHERIES/2017/DEC/SWG-PEL/31: 7pp.
de Moor, C.L. Initial directed sardine and anchovy TACs and TABs for 2017. DAFF Branch Fisheries document: FISHERIES/2017/DEC/SWG-PEL/37: 4pp.
de Moor, C.L. Alternative risk thresholds for South African sardine and anchovy resources. MARAM/IWS/2017/Sardine/P2: 12pp.
de Moor, C.L. and Butterworth, D.S. Selection of acceptable levels of risk for South African small pelagics: the probability of dropping below pre-defined risk thresholds. MARAM/IWS/2017/Sardine/P3: 6pp.
de Moor, C.L. and Coetzee, J. Simulating single area management on two sardine components. MARAM/IWS/2017/Sardine/P4: 4pp.
de Moor, C.L. A summary of the operating models being used to simulation test OMP-18 for South African sardine and anchovy. MARAM/IWS/2017/Sardine/P6: 9pp.
de Moor, C.L. Results for sardine projections under alternative future management scenarios. MARAM/IWS/2017/Sardine/P7: 6pp.
de Moor, C.L., Butterworth, D.S. and van der Lingen, C.D. Progress on recommendations from the 2016 review panel report. MARAM/IWS/2017/Sardine/BG2: 6pp.
de Moor, C.L. Updated simulation testing framework to be used during the development of OMP-18. MARAM/IWS/2017/Sardine/BG7: 28pp.
Johnston, S.J. and Butterworth, D.S. West coast rock lobster projections to 2021 under the current TAC 2016 levels. DAFF Branch Fisheries document: FISHERES/2017/JAN/SWG-WCRL/01: 6pp.
Johnston, S.J. and Butterworth, D.S. Inshore versus offshore split of available quota. DAFF Branch Fisheries document: FISHERES/2017/JAN/SWG-WCRL/02: 18pp.
Johnston, S.J. Biomass trajectories under different future catch scenarios. DAFF Branch Fisheries document: FISHEREIS/2017/JUL/SWG-WCRL/06: 3pp. (Also MARAM/IWS/2017/WCRL/BG5).
Johnston, S.J. South coast rock lobster TAC for the 2017/18 season. DAFF Branch Fisheries document: FISHERIES/2017/AUG/SWG-SCRL/03: 2pp.
Johnston, S.J. and Butterworth, D.S. 2017 updated south coast rock lobster assessment results. DAFF Branch Fisheries document: FISHERIES/2017/AUG/SWG-SCRL/06: 16pp. (Also MARAM/IWS/2017/SCRL/P2).
Johnston, S.J. and Butterworth, D.S. Development of a new OMP for south coast rock lobster. MARAM/IWS/2017/P4: 1pp.
Johnston, S.J. and Butterworth, D.S. Summary of south coast rock lobster (Palinurus gilchristi) fishery. MARAM/IWS/2017/SCRL/BG1: 4pp.
Johnston, S.J. and Butterworth, D.S. The south coast rock lobster Reference Case Operating Model. MARAM/IWS/2017/SCRL/BG2: 26pp.
Johnston, S.J. and Butterworth, D.S. SCRL OMP-2014 simulation testing. MARAM/IWS/2017/SCRL/BG3: 7pp.
Johnston, S.J. and Butterworth, D.S. Summary of key issues for discussion at the international workshop regarding the estimation of the magnitude and trends of poaching of west coast rock lobster. MARAM/IWS/2017/WCRL/P2: 9pp.
Johnston, S.J. and Butterworth, D.S. A summary of the west coast rock lobster fishery. MARAM/IWS/2017/WCRL/BG1: 8pp.
Johnston, S.J. and Butterworth, D.S. The 2017 horse mackerel updated assessment. DAFF Branch Fisheries document: FISHERIES/2017/SEP/SWG-DEM/31: 12pp.
Johnston, S.J. and Butterworth, D.S. 2017 Horse mackerel projections. DAFF Branch Fisheries document: FISHERIES/2017/SEP/SWG-DEM/43: 14pp.
Rademeyer, R.A. and Butterworth, D.S. Specifications of the South African hake 2016 Reference Case assessment. DAFF Branch Fisheries document: FISHERIES/2017/FEB/SWG-DEM/07: 43pp.
Rademeyer, R.A. and Butterworth, D.S. A spatially structured stock assessment for the South African hake resource with movement based on a gravity model, and including fitting to outputs from the GeoPop Model. DAFF Branch Fisheries document: FISHERIES/2017/JUL/SWG-DEM/15: 56pp. (Also MARAM/IWS/2017/Hake/BG9).
Rademeyer, R.A. Data needed for the baseline stock assessment update, the 2018 TAC recommendation, and for OMP revision for the South African hake resource. DAFF Branch Fisheries document: FISHERIES/2017/SEP/SWG-DEM/33: 2pp.
Rademeyer, R.A. Output from the South African hake OMP-2014 for the 2018 TAC recommendation. DAFF Branch Fisheries document: FISHERIES/2017/OCT/SWG-DEM/41: 4pp.
Rademeyer, R.A. and Butterworth, D.S. Routine update of the South African hake reference case assessment. DAFF Branch Fisheries document: FISHERIES/2017/OCT/SWF-DEM/51: 26pp.
Rademeyer, R.A. and Butterworth, D.S. Comparison of results for the South African hake 2017 reference case assessment before and after the correction of some minor coding errors. DAFF Branch Fisheries document: FISHERIES/2017/NOV/SWG-DEM/55: 4pp.
Rademeyer, R.A. and Butterworth, D.S. Specifications of the South African hake 2017 reference case assessment. DAFF Branch Fisheries document: FISHERIES/2017/NOV/SWG-DEM/56: 40pp. (Also MARAM/IWS/2017/Hake/P2rev).
Rademeyer, R.A. and Butterworth, D.S. Retrospective analysis for the South African hake resource Reference Case Assessment. MARAM/IWS/2017/Hake/P3: 3pp.
Rademeyer, R.A. Updated Reference Set Operating Model results for South African hake. MARAM/IWS/2017/Hake/P4: 8pp.
Rademeyer, R.A. and Butterworth, D.S. An example contrasting TAC behaviour under target- and slope-based empirical management procedures. MARAM/IWS/2017/Hake/P10: 4pp.
Ross-Gillespie, A., Fourie, A., Butterworth, D.S. and Bergh, M. Modelling hake cannibalism and inter-species predation: Comments from the 2016 International Stock Assessment Workshop, progress to date, and pending work. DAFF Branch Fisheries document: FISHERIES/2017/FEB/SWG-DEM/08: 2pp.
Ross-Gillespie, A. and Butterworth, D.S. Updated and extended GLM results for the South Coast penguin colony foraging data. DAFF Branch Fisheries document: FISHERIES/2017/DEC/SWG-PEL/38: 7pp.
Ross-Gillespie, A. and Butterworth, D.S. Hake predation model mortality rates. MARAM/IWS/2017/Hake/P6: 11pp.
Ross-Gillespie, A. and Butterworth, D.S. Progress on recommendations from 2016 review panel report regarding hake. MARAM/IWS/2017/Hake/BG14: 4pp.
van Zyl, D. and Butterworth, D.S. A comparison of west coast rock lobster TACs and catches over recent seasons. DAFF Branch Fisheries document: FISHERIES/2017/JUL/SWG-WCRL/05: 2pp.
van Zyl, D., Glazer, J.P. and Butterworth, D.S. Analyses of trends in west coast rock lobster poaching and policing effort data. DAFF Branch Fisheries document: FISHERIES/2017/AUG/SWG-WCRL/12: 2pp. (Also MARAM/IWS/2017/WCRL/BG4).
Vrancken, C. and Butterworth, D.S. An approach to weighting the various Operating Models in a Reference Set in inverse relation to the similarity of their results. MARAM/IWS/2017/Hake/P9: 15pp.

Theses

Moosa, N. An updated model of the krill-predator dynamics of the Antarctic ecosystem. MSc thesis. University of Cape Town: 251pp.