2 results

Stock delineation of the pink ling (Genypterus blacodes) in Australian waters using genetic and morphometric techniques

Project number: 1997-117
Project Status:
Completed
Budget expenditure: $219,149.63
Principal Investigator: Peter Last
Organisation: CSIRO Oceans and Atmosphere Hobart
Project start/end date: 21 Jun 1997 - 29 Nov 2000
Contact:
FRDC
SPECIES

Need

There are two basic needs for the ling fishery that are addressed by this proposal:

1) It is important to determine whether pink ling from WA, the GAB, the SEF Eastern sector, and the SEF Western sector represent separate stocks, with the implied need for a separate management plan for each, or are simply components of a single large stock best managed as a single entity. Industry has noted the potential for development of the fishery in the west. It is particularly important to establish whether or not the developing western fishery is distinct from the more fully exploited eastern fishery. Stock delineation work needs to be carried out before reliable biomass and yield estimates of stocks can be derived, and before new management plans are put into operation.

2) It is necessary to know for certain whether the orange form is the juvenile pink ling or whether it is a distinct species. This is necessary to integrate non-trawl components of the fishery with the trawl component. If the orange form is the juvenile of the pink form, then it will be important to manage gear types, such as set-netting, that most affect the smaller orange ling. The lack of such protection may otherwise impact on recruitment to the deepwater part of the fishery, which represents almost all of the economic value of ling. Whilst preliminary allozyme analysis indicates that the two colour forms of ling are the same species, there is a need to confirm this using more powerful genetic techniques.

Objectives

1. Delineate stock structure of pink ling in Australian waters so that separate management plans for each stock can be developed if required.
2. Examine the nature and relationship of orange and pink forms of ling so that management plans for the deepwater and inshore components of the fishery can be properly integrated.
3. To collect biological information, particularly in regards to life history and reproduction, that can be used together with stock delineation results and other information to develop yield estimates so that TACs can be reviewed.

Final report

Modelling the population dynamics of high priority SEF species

Project number: 1997-115
Project Status:
Completed
Budget expenditure: $380,485.77
Principal Investigator: Robin Thomson
Organisation: CSIRO Oceans and Atmosphere Hobart
Project start/end date: 26 Jun 1997 - 30 Jul 2002
Contact:
FRDC

Need

The need for special research projects and individual stock assessments is detailed by the South East Fishery Assessment Group (SEFAG) and endorsed by SETMAC. The development of stock assessments for blue grenadier, and ling are high priority. Other species with high priority for quality stock assessment include blue warehou, redfish, blue-eye trevalla, and (following SETMAC 55) tiger flathead.

Blue grenadier is a species for which new data have become (or are becoming) available and for which there is a conflict between the relatively optimistic scientific advice (based primarily on an acoustic and an egg production estimate) and the more pessimistic view of several industry representatives. The stock assessment for this species will be accorded first priority. The other two species to be assessed wil be determined based on discussions with SETMAC, its research sub-committee and AFMA.

Objectives

1. Provide high quality population dynamics models and stock assessment advice for three SEF quota species for which there is immediate concern of stock status.
2. Work with industry and managers in developing population dynamics models in a manner that will improve the stock assessment in the SEF and its perception by industry.
3. Use the stock assessments to evaluate stock status against current management performance indicators and to provide advice on alternative performance indicators if necessary.
4. Evaluate the value (in terms of improved assessement) of future data collections and research studies for the assessed species.

Final report

ISBN: 1-876996-13-7
Author: Robin Thomson