OpenUCT Home
→
Browsing by Author

Browsing by Author "de Moor, Carryn"

Now showing items 1-20 of 52

The 2018 Operational Management Procedure for the South African sardine and anchovy resources

Author: de Moor, Carryn Date: 2018 The Operational Management Procedure (OMP) to be used to recommend total allowable catches and bycatches for sardine and anchovy in South African waters has been updated and is detailed herein Read more
The acceptable level of risk for the South African sardine resource.

Author: de Moor, Carryn Date: 2019 An acceptable maximum level of risk for the South African sardine resource has been calculated by comparing the depletion of the effective west component spawner biomass from the recent Operating Model being used to develop OMP-18 with the ... Read more
Assessment of the South African sardine resource using data from 1984-2018: Initial results at the joint posterior mode for the two mixing-component hypothesis.

Author: de Moor, Carryn Date: 2019 The assessment of the South African sardine resource is in the process of being revised and updated using data available up to November 2018. While some data are yet to be finalised and robustness to some key model assumptions is still to be ... Read more
Calculating an informative prior distribution for the bias of hydro‐acoustic survey estimates of the biomass of the South African anchovy

Author: de Moor, Carryn ; Coetzee, Janet ; Butterworth, Doug Date: 2020 A prior distribution for the bias of the hydro‐acoustic survey estimates of the biomass of the South African anchovy is developed by considering the bias associated with the individual sources of error. Read more
A case for a higher critical biomass threshold in the anchovy‐only OMP‐ 18rev than in OMP‐18

Author: de Moor, Carryn Date: 2021 de Moor (2021a,b) has provided a number of results for alternative candidate Management Procedures for an anchovy‐only OMP‐18rev. The SWG‐PEL TTG has suggested that the shape of the anchovy HCR should remain the same as that for OMP‐18 (de ... Read more
Claim by Pichegru et al. that marine no-take zone benefits penguins remains premature

Author: Butterworth, Douglas ; Brandao, Anabela ; de Moor, Carryn ; Robinson, William Date: 2010 Pichegru et al. (2010), and a follow up comment by Ryan et al. (2010), make strongly stated claims that closures to pelagic fishing around islands with penguin breeding colonies lead to rapid improvements in those penguin populations. These ... Read more
Comparing the 2018 survey estimated sardine biomass to carrying capacity.

Author: de Moor, Carryn Date: 2019 This document details a calculation noted during the December 2018 Small Pelagic Scientific Working Group meeting which compared the recent survey estimate of sardine biomass to estimated carrying capacity, showing the survey biomass west of ... Read more
Comparisons between single area management and various forms of two area management for directed sardine TACs off South Africa

Author: de Moor, Carryn Date: 2017 Relatively simple Harvest Control Rules which recommend either a single directed sardine Total Allowable Catch (TAC) for the whole western and southern coastline of South Africa are compared with some alternatives which split the TAC between ... Read more
Considering alternative constraints to the anchovy Harvest Control Rule

Author: de Moor, Carryn Date: Apr 2018 As part of the development of OMP-18, alternative constraints in the anchovy Harvest Control Rule are investigated. Read more
Considering the variability in directed sardine catches for the current OMP-18 reference case HCR

Author: de Moor, Carryn Date: Mar 2018 As part of the development of OMP-18, alternative ‘stable’ TAC and minimum TAC thresholds for the sardine HCR are explored. Read more
The data used in the 2019 sardine assessment.

Author: de Moor, Carryn ; Merkle, Dagmar ; Coetzee, Janet ; van der Lingen, Carl Date: 2019 Data to which the 2019 assessment of the South African sardine resource is to be conditioned are listed Read more
Density dependent movement of South African sardine

Author: de Moor, Carryn ; Bergh, Mike ; Butterworth, Doug S ; Coetzee, Janet ; van der Lingen, Carl Date: Mar 2018 A hypothesis that the movement of South Africa sardine from the west to the south coast is dependent on west coast biomass is revisited and a relationship proposed for use in future projections. Read more
Developing informative prior distributions for the bias of hydro-acoustic survey estimates of the biomass of the South African round herring population

Author: de Moor, Carryn ; Coetzee, Janet ; Butterworth, Douglas Date: 2022 Prior distributions for the bias of the hydro‐acoustic survey estimates of the biomass of the South African round herring are developed by considering the bias associated with the individual sources of error Read more
Examination of redeye roundherring size and age data - towards developing a growth curve for the redeye stock assessment

Author: Durholtz, Deon ; de Moor, Carryn ; Geja, Yonela Date: 2010 Redeye roundherring (Etrumeus whiteheadi) in South African waters is exploited by the pelagic purse seine fishery, which primarily targets anchovy (Engraulis encrasicolus) and sardine (Sardinops sagax). In spite of a relatively large adult ... Read more
Final Anchovy TAC and small pelagic TABs for 2018

Author: de Moor, Carryn Date: Jul 2018 The final anchovy TAC and associated small sardine TAB quotas depend on outputs from the pre-agreed Harvest Control Rules. However, these require observations from a winter hydro-acoustic survey which did not take place during May/June 2018. ... Read more
Final anchovy TAC for 2019, using OMP-18.

Author: de Moor, Carryn Date: 2019 Following the recruit survey results, the anchovy TAC for 2019 is revised to a final value of 350 000t. Read more
Final baseline assessment of the South African sardine resource using data from 1984‐2018

Author: de Moor, Carryn Date: 2020 The quantitative assessment of the South African sardine resource, using data from 1984 to 2018 has been finalised. This two mixing‐component model assumed no stock recruitment relationship during conditioning. The west component abundance ... Read more
Further results towards finalising HCRs for OMP-18.

Author: de Moor, Carryn Date: Nov 2018 The baseline Operating Models to be used to tune a new Operational Management Procedure for South African sardine and anchovy have been updated, and the performance statistics from a Candidate Management Procedure (“CMP5”) assuming only ... Read more
Generating the future proportion of directed sardine catch taken west of Cape Agulhas in the absence of explicit spatial management

Author: de Moor, Carryn ; Butterworth, Doug S Date: Apr 2018 The relationship governing the proportion of directed sardine catch simulated to be taken west of Cape Agulhas during projections underlying the development of OMP-18 is updated. The relationship now differs for each draw from the posterior ... Read more
Initial Directed Anchovy TAC and Sardine and Anchovy TABs for 2019, Using OMP-18

Author: de Moor, Carryn Date: Dec 2018 OMP-18 is used to calculated a TAC for the anchovy fishery and an associated small sardine TAB. Read more