Butterworth, D.S. and Rademeyer, R.A. Outline of a Simple Approach to Develop a MSE for 3LN Redfish – Now Modified to Incorporate Density Dependent Productivity and to Fit to a Longer Time Series of Historical Data. Scientific Council Research Document, SCR Doc. 25/010ADD: 1-8 pp.
Gulf Menhaden
Tristan
Johnston, S.J. Tristan Group Biomass Survey results of Jasus tristani including data from the 2024 season. MARAM document, MARAM/TRISTAN/2025/MAR/01: 15pp.
Johnston, S.J. Updated 2024 GLMM -standardised lobster CPUE from Inaccessible, Nightingale and Gough islands from the Jasus tristani fishery. MARAM document, MARAM/TRISTAN/2025/APR/02: 17pp.
Johnston, S.J. Updated (and rescaled) Tristan island GLM-standardised Jasus tristani lobster Powerboat CPUE to take account of data for the 2024 season. MARAM document, MARAM/TRISTAN/2025/APR/03: 10pp.
Johnston, S.J. GLM-standardised rock lobster (Jasus tristani) vessel CPUE at Tristan. MARAM document, MARAM/TRISTAN/2025/APR/07: 7pp.
Johnston, S.J. Recommendations on rock lobster TACs for Tristan rock lobster Jasus tristani, at Tristan, Nightingale, Inaccessible and Gough islands for the 2025/26 season. MARAM document, MARAM/TRISTAN/2025/APR/05: 10pp.
Johnston, S.J. Summary of recommendations on Jasus tristani rock lobster TACs for the Tristan group of islands for the 2025/26 season. MARAM document, MARAM/TRISTAN/2025/APR/06: 2pp.
Johnston, S.J. Summary of rock lobster somatic growth rate data and analyses available for the Tristan da Cunha group of islands including recent data from tagging studies. MARAM document, MARAM/TRISTAN/2025/JUN/08: 19pp.
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/2025/JUN/07: 19pp.
Research for DFFE
Brandao, A. and Butterworth, D.S. The way forward to model pack data for the chokka squid (Loligo reynaudii) resource of South Africa. DFFE Branch Fisheries document, FISHERIES/2025/MARCH/SWG-SQ/05: 5 pp.
Brandao, A. and Butterworth, D.S. Modelling the “old” and the “new” databases simultaneously to estimate poaching trends for abalone in Zones A to D. DFFE Branch Fisheries document, FISHERIES/2025/SWG-AB/06: 10pp
Brandao, A. and Butterworth, D.S. Modelling the “old” and the “new” databases simultaneously to estimate poaching trends for abalone in Zones A to G and Zones E to G. DFFE Branch Fisheries document, FISHERIES/2025/SWG-AB/07: 8pp
Brandao, A. and Butterworth, D.S. Updated poaching trends until 2024 for West Coast rock lobster. DFFE Branch Fisheries document, FISHERIES/2025/JUL/SWG/WCRL06: 14pp.
Brandao, A. and Butterworth, D.S. Updated “Replacement Yield” model fit to catch and survey data for the South coast and for the West coast kingklip resources off South Africa to include data up to 2024. DFFE Branch Fisheries document, FISHERIES/2025/OCT/SWG-DEM/08: XX pp.
Brandao, A. and Butterworth, D.S. Longline and trotline GLMM standardised CPUE series for the toothfish (Dissostichus eleginoides) resource in the Prince Edward Islands EEZ updated to include data to the 2024 season. DFFE Branch Fisheries document, FISHERIES/2025/OCT/SWG-DEM/12: XX pp.
Brandao, A. and Butterworth, D.S. Reference case assessment of the toothfish (Dissostichus eleginoides) resource in the Prince Edward Islands vicinity updated to include 2024 data. DFFE Branch Fisheries document, FISHERIES/2025/OCT/SWG-DEM/13: XX pp.
Butterworth, D.S. On the possible implementation of recommendations of the Lenfest report. DFFE Branch Fisheries document, FISHERIES/2025/SEP/EIMTG/09: XX pp.
Butterworth, D.S. and Ross-Gillespie, A. An Application of the Schaefer Model to Sardine. DFFE Branch fisheries document, FISHERIES/2025/MAY/SWG-PEL/20: 7 pp.
Butterworth, D.S., Coetzee, J.C. and Ross-Gillespie, A. Extending the Aggregated Biomass Model for Sardine to provide MP-Like Projections. DFFE Branch Fisheries document, FISHERIES/2025/MAR/SWG-PEL/11rev: 20 pp.
Butterworth, D.S. and Ross-Gillespie, A. Towards a simple MP for round herring. DFFE Branch Fisheries document, FISHERIES/2025/JUN/SWG-PEL/30: XX pp.
Butterworth, D.S. Some brief comments on the results reported in “Further initial results of the scoping MSE for South African sardine. DFFE Branch Fisheries document, FISHERIES/2025/JULY/SWG-PEL/36: XX pp.
de Moor, C.L. A Proposal for Possible Updates to the Interim TAC/Bs for 2025. DFFE Branch Fisheries document, FISHERIES/2025/FEB/SWG-PEL/02: 2 pp
de Moor, C.L. and Coetzee, J.C. Sensitivity of the prior distribution for hydro-acoustic survey bias of the South African round herring population to errors associated with target strength dependence on depth. DFFE Branch Fisheries document, FISHERIES/2025/MAR/SWG-PEL/10: 3 pp
de Moor, C.L., Coetzee, J.C. and de Goede, J. Recent targeting of round herring. DFFE Branch Fisheries document, FISHERIES/2025/MAR/SWG-PEL/12: 4 pp.
de Moor, C.L. A method to convert the hydroacoustic survey estimates of small pelagic biomass from a March/April 2025 survey to equivalent biomasses that might have been surveyed in November 2024, for use in 2025 fisheries management advice. DFFE Branch Fisheries document, FISHERIES/2025/APR/SWG-PEL/16: 6 pp.
de Moor, C.L. The updated assessment model for the revised sardine stock structure hypothesis. DFFE Branch Fisheries document, FISHERIES/2025/APR/SWG-PEL/17rev: 18 pp.
de Moor, C.L. Results from the updated stock assessment model of the revised South African sardine stock structure hypothesis, with alternative weightings of catch by stock off the west coast. DFFE Branch Fisheries document, FISHERIES/2025/APR/SWG-PEL/18rev: 59 pp.
de Moor, C.L. OMP‐18rev recommended initial anchovy TAC for 2025. DFFE Branch Fisheries document, FISHERIES/2025/MAY/SWG-PEL/22: 3 pp.
de Moor, C.L. An update to the sardine assessment using data from 1984‐2024, with associated implications for 2025 management recommendations. DFFE Branch Fisheries document, FISHERIES/2025/MAY/SWG‐PEL/26: XX pp.
de Moor, C.L. Investigating the impact on the South African sardine assessment of estimating Beverton Holt stock recruitment relationships during conditioning. DFFE Branch Fisheries document, FISHERIES/2025/MAY/SWG-PEL/28: 7 pp.
de Moor, C.L. Posterior distributions of key model parameters from the sardine assessments to be used as input for the Operating Models for the Scoping MSE. DFFE Branch Fisheries document, FISHERIES/2025/JUN/SWG‐PEL/31: XX pp.
de Moor, C.L. Initial testing of the Scoping MSE for South African sardine. DFFE Branch Fisheries document, FISHERIES/2025/JUNE/SWG-PEL/32: 24 pp.
de Moor, C.L. Management Objectives for the South African Small Pelagic Fishery of Sardine and Anchovy. DFFE Branch Fisheries document, FISHERIES/2025/JUNE/SWG-PEL/33: 8 pp.
de Moor, C.L. Further initial results of the scoping MSE for South African sardine. DFFE Branch Fisheries document, FISHERIES/2025/JUL/SWG-PEL/35: 25 pp.
de Moor, C.L. Comparing an initial set of candidate Management Procedures for the Scoping MP for South African sardine. DFFE Branch Fisheries document, FISHERIES/2025/JUL/SWG-PEL/41: XX pp.
de Moor, C.L. Further candidate Management Procedures towards a Scoping MP for South African sardine. DFFE Branch Fisheries document, FISHERIES/2025/JUL/SWG‐PEL/43: XX pp.
de Moor, C.L. Exploring natural mortality assumptions for the sardine assessment. DFFE Branch Fisheries document, FISHERIES/2025/AUG/SWG-PEL/45: XX pp.
de Moor, C.L. OMP-18rev calculated final anchovy TAC for 2025. DFFE Branch Fisheries document, FISHERIES/2025/AUG/SWG-PEL/47: XX pp.
de Moor, C.L. Exploring further key uncertainties about the sardine assessment. DFFE Branch Fisheries document, FISHERIES/2025/SEP/SWG-PEL/49: XX pp.
de Moor, C.L. Considering only variability in annual recruitments in the sardine assessment. DFFE Branch Fisheries document, FISHERIES/2025/SEP/SWG-PEL/50: XX pp.
de Moor, C.L. Responses to Requests from the Technical Task Group, DFFE Branch Fisheries Document. FISHERIES/2025/OCT/SWG‐PEL/53: XX pp
de Moor, C.L. Revisions to the updated assessment model for the revised sardine stock structure hypothesis. DFFE Branch Fisheries Document FISHERIES/2025/OCT/SWG‐PEL/54rev (IWS/2025/Sardine/BG3): 19 pp
de Moor, C.L. Assessment of the South African anchovy resource using data up to 2024. DFFE Branch Fisheries Document FISHERIES/2025/OCT/SWG‐PEL/55 (IWS/2025/Sardine/BG7): 46 pp
de Moor, C.L. Variability about Density Dependent Natural Mortality. DFFE Branch Fisheries Document FISHERIES/2025/NOV/SWG-PEL/69 (IWS/2025/EBFM/P4): 4 pp
de Moor, C.L. Stock recruitment relationships for South African anchovy. IWS/2025/Sardine/P2. 8 pp.
de Moor, C.L. Projections of the sardine population using an operating model which does not estimate stock-recruitment relationships during conditioning. IWS/2025/Sardine/P3. 15 pp.
de Moor, C.L. Projections of the sardine population using an operating model with parametric stock-recruitment relationships estimated during conditioning. IWS/2025/Sardine/P4. 13 pp.
de Moor, C.L. Projections of the sardine population using an operating model which does not estimate stock-recruitment relationships during conditioning and uses a ‘binning’ approach for generating future recruitment. IWS/2025/Sardine/P7. 9 pp.
Johnston, S.J. Updated 2025 south coast rock lobster assessment and projections. DFFE Branch Fisheries document, FISHERIES/2025/AUG/SWG/SCRL/06: XX pp.
Johnston, S.J. Overall poaching time series for west coast rock lobster as evaluated in 2025, resulting from combining estimates of illegally exported and locally sold lobsters with compliance time series. DFFE Branch Fisheries document, FISHERIES/2025/AUG/SWG/WCRL/09: XX pp.
Johnston, S.J. and Butterworth, D.S. Updated assessments of the west coast rock lobster resource for 2025. DFFE Branch Fisheries document, FISHERIES/2024/AUG/SWG/WCRL/10: XX pp.
Johnston, S.J. and Butterworth, D.S. Projections of the west coast rock lobster resource using the 2025 stock assessments. DFFE Branch Fisheries document, FISHERIES/2025/AUG/SWG/WCRL/11: XX pp.
Johnston, S.J. and Butterworth, D.S. Initial Updated 2025 horse mackerel assessments and projections. DFFE Branch Fisheries document, FISHERIES/2025/OCT/SWG-DEM/11: XX pp.
Johnston, S.J. and Singh, L. Calculation of the horse mackerel demersal by-catch reserve for 2025. DFFE Branch Fisheries document, FISHERIES/2025/OCT/SWG-DEM/23rev: XX pp.
Ross-Gillespie, A, Butterworth, D.S. and Maphumalo, T. Update to the hake Reference Case Operating Model with inclusion of the 2024 commercial data. DFFE Branch Fisheries document, FISHERIES/2025/OCT/SWG-DEM/17: 14 pp.
Ross-Gillespie, A, Butterworth, D.S. and Maphumalo, T. MP formula output for the 2026 hake TAC, and the inclusion of the 2024 commercial data in the OMP projection plots. DFFE Branch Fisheries document, FISHERIES/2025/OCT/SWG-DEM/18: XX pp.
Ross-Gillespie, A. and Butterworth, D.S. Further CMPs and robustness tests for round herring. DFFE Branch Fisheries document, FISHERIES/2025/OCT/SWG-PEL/52rev: XX pp.
Media articles
Butterworth, D.S. Understanding the decline of African penguins, a call for evidence-based action. Cape Argus, 3 January 2025: 3pp.
Butterworth, D.S. The African Penguin Debate. A Response to SANCCOB/Birdlife. Fishing Industry News and Agriculture. 25 February 2025: 3pp.
Butterworth, D.S. Open Letter on How to Improve Media Marine Scientist Interactions. Fishing Industry News and Agriculture. 18 August 2025: XX pp