Fishery biology and management of black jewfish Proteonibea diacanthus (Sciaenidae) aggregations near Injinoo community, far northern Cape York

Project number: 1998-135
Project Status:
Completed
Budget expenditure: $179,445.00
Principal Investigator: Michael Phelan
Organisation: Balkanu Cape York Development Corporation
Project start/end date: 28 Jun 1998 - 14 Sep 2006
Contact:
FRDC

Need

Populations of black jewfish in northern Australian waters are increasingly a focus of fishery attention, especially where aggregations appear at certain times each year. Indigenous, recreational and commercial fishers all derive benefit from the exploitation of the species, yet surprisingly little information is available about the current condition of the resource and on how to use it sustainably. This unsatisfactory situation is exacerbated by the limitations of the fishery database, which is restricted to almost exclusively the details of the commercial harvest.

The initiative introduced in this document addresses two important issues: how to deal with indigenous fisheries issues; and how to establish resource status in and management needs of black jewfish in tropical coastal waters. While the geographic setting is Queensland, the results of the studies proposed will have significant application to fisheries for this and other species in mainland States and Territories.

Australian fisheries have a long history of being managed, researched and monitored in cooperation with non-indigenous commercial and recreational fishing groups, a process which has neglected the high social and cultural value of fishing to indigenous communities. Indigenous fisheries monitoring and management within Australia is a new concept for most natural resource management agencies. Inclusion of indigenous groups in a broad-based fisheries management network will provide these agencies with a truly comprehensive basis for future management decisions and strategic directions which should enjoy the widest possible public support. Because the Injinoo Community have actively sought participation in the ecologically sustainable use by all stakeholders of a fishery resource for which they claim customary title, the prospects for successful outcomes in this project are excellent.

The biological relationship between black jewfish aggregations at Injinoo and those populations exploited in commercial netfisheries in the Gulf of Carpentaria and along the east Queensland coast is unknown. Establishing the associated fishery impacts and deriving suitable sustainability indicators for resource monitoring programmes are key issues for responsible fishery stewardship, as well as for resolving a developing problem in the allocation of the harvest. Target fishing occurs on aggregations of other inshore fish species in tropical Australian waters, so the approach generated here should suggest a tool to address management issues of concern with these activities.

Objectives

1. To undertake a preliminary survey of the fishery for black jewfish in Injinoo Community waters, far northern Cape York. To characterise the black jewfish fishery of the NPA in terms of catch and effort by the various user groups through on-ground surveys.
2. To characterise the annual black jewfish aggregation events in terms of the time of formation and dispersal, reproductive status and resource condition.
3. To determine the level of genetic relatedness among individuals, identification of population differentiation and gene flow in black jewfish in the waters adjacent to the NPA, Gulf of Carpentaria and northern East Coast of Queensland.
4. To collate available historical data on the fishery to establish trends over time.
5. To advise the Injinoo Community and the Queensland Fisheries Management Authority on current resource condition, sustainability indicators for long term monitoring in the fishery, and options for management on a sustainable basis.

Final report

ISBN: 0-9580542-0-7
Author: Michael Phelan
Final Report • 2005-09-30 • 4.27 MB
1998-135-DLD.pdf

Summary

The comprehensive consultation process conducted throughout the lifetime of this project ensured the implications of the research have been recognised by the fisheries management authorities and the communities of the Northern Peninsula Area (NPA). In response to the findings of the present project, the Injinoo Land Trust (representing the Traditional Land Owner Groups of the Anggamuthi, Atambaya, Gudang and Yadhaykenu Aboriginal people), in cooperation with the Injinoo Community Council, have self-­imposed a two-year ban on the taking of Black Jewfish (Protonibea diacanthus). The area of closure incorporates the inshore waters of the NPA north of the southern boundaries of Crab Island (on the West Coast) and Albany Island (on the East Coast).

The aim of the two-year ban is to allow local stocks of Black Jewfish to reach a mature size with an objective of improving the reproductive capacity.

 

Related research

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Communities
Environment

Coastal stocks of fish: from which estuaries are most adults derived?

Project number: 1998-139
Project Status:
Completed
Budget expenditure: $142,684.00
Principal Investigator: Bronwyn M. Gillanders
Organisation: University of Sydney (USYD)
Project start/end date: 20 Jun 1998 - 12 Jun 2002
Contact:
FRDC
SPECIES

Need

The origins of many stocks of fish are unknown. As juveniles, many fish are found in estuarine regions. After a period in these habitats they may leave estuaries for coastal reefs and shelf waters. Degradation of habitats within estuaries (from pollution, land reclamation, marinas etc) and death of fish as by-catch in commercial and recreational fishing may affect abundances of adults on coastal reefs. The contribution of each estuary to total stock size in coastal waters is unknown. It is difficult to determine which estuary adult fish may have come from using conventional tagging methods, because of the small size of fish in estuaries. Alternative methods for determining the origins of adult fish are needed.

Molecular genetics provides one possibility, but these methods are in their infancy. An alternative method may utilise chemical elements in bones to show origins of fish. Chemical analyses have proven useful in distinguishing between periods of freshwater and marine residence within individual fish (e.g. Kalish 1990) and have also been used to distinguish stocks or sub-populations within marine species (e.g. Edmonds et al. 1989, 1991, 1992, 1995). Recently, we (Gillanders and Kingsford 1996) have used chemical analyses of ear bones to distinguish recruits that settled to seagrass from those that settled to reef habitats. We then analysed the centre region of adult ear bones to determine the origin (estuary or reef) of adult fish showing that this approach is possible.

Many studies have documented important estuarine "nursery" areas in terms of numbers of fish, but if few fishes from these areas reach coastal reefs, such habitats may be relatively unimportant to sustaining populations of adults. The research will focus on snapper (Pagrus auratus) because it is the most important species (in terms of production) that has individuals leaving estuaries for coastal reefs or shelf waters (Bell and Worthington 1993).

Objectives

1. To solve a pressing problem for the fishery by determining what proportion of the commercial catch is from different estuaries.
2. To use methods being developed on juvenile fish to establish a chemical "fingerprint" for each estuary so that in future years the proportion of adults from each estuary can be determined.

Final report

ISBN: 0-86396-690-X
Author: Bronwyn Gillanders
Final Report • 2002-04-12 • 265.80 KB
1998-139-DLD.pdf

Summary

The origins of many stocks of fish are unknown.  As juveniles, many fish are found in estuarine regions.  After a period in these habitats they may leave estuaries for coastal reefs and shelf waters where they may be commercially fished.  Currently, we do not know the proportion of individuals in harvested populations that may have spent time in different estuaries as juveniles and whether one or a few estuaries are making substantial contributions to maintaining local stocks.  This study used elemental chemistry of ear bones (otoliths) of fish to determine natal or nursery estuaries of adult fish.