Orange roughy stock assessment

Project: Orange roughy stock assessment
Project Code: ORH2004/02
Start Date: 1 October 2004
Completion Date: 30 September 2005
Vessel Use: None

Overall Objectives:

1. To carry out a stock assessment of orange roughy (Hoplostethus atlanticus), including estimating biomass and sustainable yields.

Specific Objectives:

1. To update the descriptive analysis of the commercial catch and effort data from selected orange roughy fisheries with the inclusion of data up to the end of the 2003/04 fishing year. These fisheries include ORH 1, ORH 2A (North and South), ORH 2B, ORH 3A, ORH 3B (Chatham Rise and other areas), and ORH 7B.
2. To update the unstandardised and standardised catch per unit effort analyses with the inclusion of data up to the end of the 2003/04 fishing year for the following area:
• Northeast Chatham Rise (ORH 3B)
3. To analyse length frequency, sex ratio, and reproductive data for orange roughy collected by the Observer Programme and from other sources during the 2003/04 fishing year for input into stock assessment models. The target number of samples that will be collected by the Observer Programme for each fishery in 2003/04 is specified below in the Rationale.
4. To review and summarise the historical biological data (including length frequency, sex ratio, otoliths, and reproductive condition data) for orange roughy collected by the MFish Observer Programme and other sources since the start of these programmes and the use of these data as inputs into stock assessments.
5. To update the stock assessment, including estimating biomass and sustainable yields for the following areas:
• Northeast Chatham Rise (ORH 3B)

Rationale:

General

There is a need to carry out regular monitoring programs and stock assessments to determine stock status and estimate sustainable yields for all orange roughy fisheries. The fisheries included in this project will be selected on the basis of having new information upon which to update the stock assessment. The results of this project will provide information that supports that objective.

In order to update the stock assessment for each fishery, commercial catch and effort data should be monitored and the descriptive analysis of the commercial catch and effort data should be updated on an annual basis.

In addition standardised CPUE analyses will be updated with the inclusion of data for the 2003/04 year for the following area:

• Northeast Chatham Rise (ORH 3B)

Objective 3

The current stock assessments for all fisheries incorporate information on fish length, sex ratios, length-weight data, and reproductive information of orange roughy from both commercial at-sea sampling and research surveys.

It is proposed to estimate biological parameters for input into the stock assessments by analysing length frequency and sex ratio data collected by the Observer Programme and from other sources during the 2003/04 fishing year.

A total of about 320 samples are expected from these fisheries as follows:

Objective 4

Biological data (including length frequency, sex ratio, otoliths, and reproductive condition data) have been collected for orange roughy by the MFish Observer Programme since its beginnings in the 1980s and more recently from other sources, i.e. the ORMC observer programme. Some of these data have been used as inputs into stock assessments for orange roughy, while much of it has not been incorporated into quantitative stock assessments. Thus far there has been no overall compilation and summary of the data collected or its use in stock assessments across all the orange roughy Fishstocks.

The purpose of this objective is to review and summarise the historical biological data (including length frequency, sex ratio, otoliths, and reproductive condition data) for orange roughy collected by the MFish Observer Programme and other sources since the start of these programmes and the use of these data as inputs into stock assessments. The outcome of the review and summary will be evaluated by the Deepwater Working Group and used to make recommendations concerning future observer data collection programmes and protocols.

It is proposed to estimate the abundance of orange roughy on the northeast Chatham Rise during winter 2004 within project ORH2003/01. In addition the relative abundance indices from the standardised CPUE analyses for this area will be updated with the inclusion of data from the 2003/04 fishing year in Objective 2 of this project. It is proposed to update the stock assessments for the fisheries for which abundance estimates become available, including estimating biomass and sustainable yields, using the available information.

Strategic Relevance

All the objectives in this project are consistent with Strategic Objectives iii and v of the Fisheries Resources goal in the Ministry of Fisheries Strategic Research Directions document.

Cost Recovery Information:

The percentage allocation for this project will be attributed to the following Fishstocks according to rule 9.2 of the Fisheries (Cost Recovery) Rules 2001:

• ORH 1
• ORH 2A
• ORH 2B
• ORH 3A
• ORH 3B
• ORH 7B

The project is estimated to cost between $100,000 - $150,000.