The SIOFA Scientific Committee (SC) provides scientific advice to the Meeting of Parties (MoP) on the
status of stocks and sustainable yields of deep‐sea fisheries resources. In 2018, the SIOFA Scientific
Committee (SC3) conducted the first orange roughy stock assessments in the SIOFA region and
provided advice to the Meeting of Parties on the stock status and sustainable yields for orange roughy.
An updated orange roughy stock assessment was conducted and presented to SC7 in 2022.
As required under SIOFA CMM 15, orange roughy stock assessments are conducted every 3‐5 years,
and the next Scientific Committee (SC10) (March 2025) will consider the new orange roughy stock
assessments to provide its advice to the MoP.
Project objectives
1. During the project, present the work to the SIOFA orange roughy assessment Advisory Panel to
discuss data inputs, the assessment approach, and preliminary results.
2. Develop standardised CPUE indices for each stock. Note this should standardise, to the extent
possible, using factors such as location (e.g., area and seamount), season, gear parameters,
alfonsino bycatch, prevailing weather, etc. As the fishery has been undertaken by 1‐3 vessels only,
standardisation by vessel may not be possible.
3. Review the previous stock assessments, and use all new information (including updated growth,
maturity, and local area acoustic abundance data), and other relevant information to undertake a
statistical catch‐at‐age stock assessment to determine the stock status of orange roughy for
Walters Shoal and the Southwest Indian Rise. The outcomes of the assessment should include the
following:
a. Evaluation of the stock against the SIOFA interim reference points (Target = 40%B0 and
Limit = 20%B0). A range of other reference points should also be considered and estimates
of stock status, fishing mortality, and biomass should be provided in the terminal year of
the assessment and over time including, at least but not limited to status in relationship
to B40% and B20%, MSY, SBMSY, SB0, SBF=0, SB/SBMSY, SB/SBF=0, SB/SB0, F, FMSY, F/FMSY,
F40%B0.
b. Appropriate sensitivities to model structural assumptions, choices of biological
parameters, acoustic and CPUE abundance indices, and age composition data.
c. Estimates of 20‐year projected status (at 5‐year intervals) under a range of future catch
scenarios and appropriate estimates of future productivity (i.e., year class strengths).
Analysis should include projections using constant catch and constant fishing mortality
strategies with both annual and 5‐year changes in catch limits.
d. Kobe I (stock status trajectories) and appropriate Kobe II (strategy risk matrix) summaries
of the stock assessment results. Refer to Table 1 below as an example of the Kobe II risk
strategy matrix from Indian Ocean Tuna Commission (IOTC), showing risk probabilities
violating target and limit reference levels for F and B (biomass) next 3 and 10 years in 9
different catch levels (0%, ±10%, ±20%, ±30% and ±40% of the current level).
4. Provide relevant text to update Section 6 of the SIOFA Fisheries Summary: orange roughy.