Blue-eye trevalla is an important species in the South East Fishery. Blue-eye trevalla is taken in large quantities by the trawl and non-trawl sectors in south eastern coastal waters and around offshore seamounts. Despite the high value of this species in the trawl and non-trawl fisheries, however, there is limited information on the stock structure and appropriate management units. Bolch et al. (1993) concluded there was sufficient gene flow to prevent genetic differentiation between blue-eye trevalla off Tasmania, South Australia and NSW, but the sample sizes were small, there are limitations to allozyme electrophoresis (the method they used), and they did not sample fish from NZ. Ward and Last (1993) suggested that, given the known limitations of allozyme electrophoresis, further genetic studies based on mitochondrial DNA analyses and larger samples be undertaken. As a consequence, the relationship between fish caught off the south eastern Australian coast and those taken from offshore seamounts is unknown. The need to identify the stock structure of Blue-eye trevalla has also been identified as a high priority by the blue-eye working group and SEFAG.

In recent years, developmental trawl fishing has been occurring in the East Coast Deep Water (ECDW) fishery. Significant amounts of blue-eye trevalla have been caught in this fishery from grounds well to the east of 157ºE, and currently these fish are under the same quota restrictions that apply to the rest of the SEF trawl fishery. The large distances between the ECDW fishing grounds and grounds where most of the east coast blue-eye are caught has led fishers to question whether the ECDW fish can be considered part of the stock upon which the TAC was based. There is an urgent need to assess the stock structure of blue-eye trevalla caught throughout the SEF, the ECDW fisheries and New Zealand. The results from a study assessing the stock structure of this species will provide managers with information on potential management units.

A proposal to investigate the relationships between blue-eye trevalla caught in the ECDW zone and the SEF was submitted to AFMA in 2001, and although supported, it was not funded at this time for a number of reasons. In response to suggestions from AFMA, the MACs and SEFAG, it was decided that the proposal should be re-submitted in 2002. To address suggestions from industry and management groups that the stock structure of blue-eye needed to be evaluated over a much larger area, the extent of the project was expanded to include blue-eye samples from across south eastern Australia, including offshore seamounts (such as those off Tasmania, Norfolk and Lord Howe Islands) and New Zealand.