Publications & Reports
Statements of Intent
Statement of Intent 2004 - 2008
Research Services
Pelagic Fisheries
Stock monitoring of blue mackerel
Stock monitoring of jack mackerels
Stock assessment of JMA 1
Characterisation of the kahawai fisheries
Developing kingfish stock monitoring and assessment
Movements of southern bluefin tuna
Stock assessment of swordfish
Stock assessment of TRE 1
Stock assessment of TRE 7
Estimation of non-target fish catches in the tuna longline fishery
Research Observer Days - Pelagic Fisheries

Stock monitoring of jack mackerels


Project: Stock monitoring of jack mackerels
Project Code: JMA2004/01
Start Date: 1 October 2004
Completion Date: 30 January 2007
Vessel Use: None

Overall Objectives:

  1. To determine the seasonality and species composition of the commercial catches of Trachurus declivis, T. symmetricus murphyi, and T. novaezelandiae in JMA 1, 3, and 7.

Specific Objectives:

  1. To collect samples from fish processing sheds to determine the seasonality and species composition of the commercial catches of T. declivis, T. s. murphyi, and T. novaezelandiae in JMA 1 in the 2004/2005 fishing year.
  2. To collect samples from fish processing sheds to determine the seasonality and species composition of the commercial catches of T. declivis, T. s. murphyi, and T. novaezelandiae in JMA 1 in the 2005/2006 fishing year.
  3. To collect samples from fish processing sheds to determine the seasonality and species composition of the commercial catches of T. declivis, T. s. murphyi, and T. novaezelandiae in JMA 3 in the 2004/2005 fishing year.
  4. To collect samples from fish processing sheds to determine the seasonality and species composition of the commercial catches of T. declivis, T. s. murphyi, and T. novaezelandiae in JMA 3 in the 2005/2006 fishing year.
  5. To collect samples from fish processing sheds to determine the seasonality and species composition of the commercial catches of T. declivis, T. s. murphyi, and T. novaezelandiae in JMA 7 in the 2004/2005 fishing year.
  6. To collect samples from fish processing sheds to determine the seasonality and species composition of the commercial catches of T. declivis, T. s. murphyi, and T. novaezelandiae in JMA 7 in the 2005/2006 fishing year.
  7. To determine from the catch at sea, the seasonality and species composition of the commercial catches of T. declivis, T. s. murphyi, and T. novaezelandiae in JMA 3 in the 2004/2005 fishing year.
  8. To determine from the catch at sea, the seasonality and species composition of the commercial catches of T. declivis, T. s. murphyi, and T. novaezelandiae in JMA 3 in the 2005/2006 fishing year.
  9. To determine from the catch at sea, the seasonality and species composition of the commercial catches of T. declivis, T. s. murphyi, and T. novaezelandiae in JMA 7 in the 2004/2005 fishing year.
  10. To determine from the catch at sea, the seasonality and species composition of the commercial catches of T. declivis, T. s. murphyi, and T. novaezelandiae in JMA 7 in the 2005/2006 fishing year.
  11. To document relevant market variables for the JMA 1, 3 & 7 fisheries in the 2004/05 fishing year.
  12. To document relevant market variables for JMA 1, 3 & 7 fisheries in the 2005/06 fishing year.

Note:

The successful tenderer will be expected to liase with the fishing industry to ensure the successful outcome of this project.

Rationale:

General

What is the status of the jack mackerel stocks in relation to the maximum sustainable yield? A stock assessment and subsequent determination of the status of the stock in relation to the maximum sustainable yield is not possible at this time (generally confounded by clear distinction of the proportions of each of the species in the catch).

Steps to allow stock assessment in future are underway, and data on seasonality and species composition of the jack mackerel catch will be important for this. The jack mackerel fisheries catch three species, the two New Zealand species, Trachurus declivis and T. novaezelandiae, and the more recently arrived T. symmetricus murphyi (the Peruvian jack mackerel). T. s. murphyi spread into New Zealand waters in the early 1980s and is now the dominant species in some areas.

The three species of jack mackerel support substantial commercial trawl and purse seine fisheries, with landings from 1991/92 to 1994/95 ranging between 38,000 t and 48,000 t. In 2001/2002 landings totalled 32,585 t with JMA 3 accounting for 5,000 t, JMA 7 for 22,338 t and JMA 1 for 5,247 t. JMA 1 is the major recreational fishery for jack mackerels with around 100 t being taken annually.

For JMA 7, the current TACC (32,536 t) and recent landings are considered to be sustainable. In JMA 1 and JMA 3 landings have generally increased since the 1980s, probably caused by the increased availability of T. s. murphyi. The size of the jack mackerel resource in JMA 1 is unknown, although aerial sighting data from 1976 to 1993 suggest no change in abundance until the early 1990s when an increase may have occurred. The resource in JMA 3 has increased in recent years but few stock assessment data are available. However, for JMA 1 and 3 it is not known whether catches at the level of the current TACCs (10,000 t and 18,000 t, respectively) or recent catch levels are sustainable in the long term.

Increased availability of jack mackerels caused by the invading T. s. murphyi resulted in increased quotas in JMA 1 and JMA 3 under the proviso that they be accounted for by increased catches of T. s. murphyi only. Industry agreed to these limits and voluntarily introduced monitoring programmes to provide the information necessary for them to be met. However, this information pertains to the two New Zealand species (T. declivis and T. novaezelandiae) combined and T. s. murphyi i.e. the two New Zealand species are not separated.

Jack mackerel catches are significant and knowing the total catch of each species accurately is basic biological information required for management. This research will provide the detail on species proportions in the catch not otherwise available (vital input data for any future stock assessment). As this research is an essential building block for future stock assessment and fundamental to management of this multi-species complex, this research project is considered a high priority.

Objectives 1, 2, 3, 4, 5, 6, 7, 8, 9 & 10

Because the three species of jack mackerel are not individually distinguished in catch records, there is a need to continue to determine the species composition of jack mackerel landings to monitor the species catch limits. Such information is also essential to derive catch histories and abundance indices before stock assessments can be attempted.

In JMA 1 over 90 % of the catch is taken by purse seiners that land into Tauranga and Nelson. The current fish shed sampling program provides reliable species composition information. However, in JMA 3 and JMA 7 the situation is more problematic as most of the jack mackerel catch is processed at sea. In the past, species compositions for JMA 3 and 7 have been determined from observer information, however, research in 2000 revealed that species composition information from this source was highly uncertain.

To improve the species composition information from JMA 3 and JMA 7, project JMA2001/01 will include a catch sampling program on-board the large factory vessels that process their catch at sea, and an observer sampling regime will be continued.

This project continues the time series of species composition data for jack mackerels. Tenderers should consider the results from JMA2001/01 while fine-tuning a sampling regime for the 2004/2005 fishing year.

Objective 11 & 12

The market has a large influence of the size range, species and quantum of jack mackerels targeted in any year. Without a summary of these market variables, interpretations of catch data are difficult. This analysis should document relevant market variables for the JMA 1, JMA 3 and JMA 7 fisheries in the 2004/05 and 2005/06 fishing years.

Strategic Relevance

This project forms a part of the programme to provide the information on sustainable yields and stock status required for the sustainable utilisation of New Zealand’s fisheries resources, a part of the jack mackerel medium-term research plan and a part of the pelagic fisheries medium term research plan. This project is consistent with 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:

  • JMA 1
  • JMA 3
  • JMA 7

The project is estimated to cost between $200,000 - $250,000.

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Updated : 16 November 2007