Restocking of the Blackwood River Estuary with black bream (Acanthopagrus butcheri)

Funded Activity Summary

There is an urgent need to rehabilitate the stock of black bream in the Blackwood River Estuary and enable the stock subsequently to be sustained at a higher level than present.

There is thus a need to culture black bream, using brood stock from the Blackwood River Estuary, for (i) restocking that estuary and (ii) to confirm subsequently that released black bream survive in the estuary and make a significant contribution to the fishable stock.

The collection of baseline data on the stock of black bream in the Blackwood River Estuary is required to make comparisons between the status and biological parameters of black bream prior to restocking the Blackwood River Estuary and (1) those in other estuaries where substantial stocks of this species are still present and (2) those of the entire population in the Blackwood River Estuary after restocking.

Management will need to ensure that the fishery is regulated in order that the enhanced stock is sustained. The production of management plans will require a sound understanding of the biological parameters of age, growth and reproductive biology prior to and after the restocking. Information is also required on the catch rates and size compositions of recreational and commercial catches prior to and after restocking.

Objectives:
1. To obtain baseline data on crucial biological parameters and catch statistics of black bream in the Blackwood River Estuary.
2. To obtain mature sized black bream from the Blackwood River Estuary to be used as brood stock for culturing juveniles on site.
3. To identify and determine the extent of habitats important to black bream in the Blackwood River Estuary.
4. To compare the densities of black bream in important habitats within the Blackwood River Estuary with those in similar habitats within other systems
5. To introduce cultured juveniles into the Blackwood River Estuary, all of which will be tagged.
6. To estimate the proportion of released black bream, which represent a known year class, amongst the total number of that age class and thereby estimate the extent to which restocking has enhanced the population.
7. To obtain data on the biological parameters and catch statistics of black bream in the Blackwood River Estuary following restocking.
8. To evaluate the success of the restocking program by comparing biological parameters and catch statistics prior to and after restocking.
9. To provide advice that can be used by management to develop plans to sustain the enhanced stock of black bream in the Blackwood River Estuary.
10. Compare the growth rates of restocked and "wild" fish during the first three and a half years of their life.
11. Estimate the proportion of restocked fish amongst all fish of a corresponding age.
12. Determine whether the length and age at maturity and age at maturity and the age at the minimum legal length of hatchery reared black bream are the same as those for the "wild" stock.
13. Estimate the average cost to produce each fish that will survive to the minimum legal length and this be available for exploitation.

Funded Activity Details

Start Date: 18-12-2000

End Date: 28-06-2007

Funding Scheme: Funding Scheme not available

Funding Amount: $325,813.00

Funder: Fisheries Research and Development Corporation

Research Topics

ANZSRC Field of Research (FoR)

There are no FoR codes available for this funding activity

ANZSRC Socio-Economic Objective (SEO)

There are no SEO codes available for this funding activity

Other Keywords

Ageing | Analytics | Aquaculture | Data | Estuarine | Fisheries Management | Habitat | Input costs | Restocking

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