Title

Improving the knowledge of dugong distribution in the Great Barrier Reef World Heritage Area through analysis of historic catch and effort information

Objectives

1. To assess the availability and quality of catch information for dugongs in Queensland waters.
2. To evaluate the use of such catch information for broad-scale monitoring of dugong distribution.
3. To collate the available historic catch and effort information for dugongs to identify trends in distribution.

Relevance

The project is likely to result in information which will directly assist in maintaining or enhancing dugong numbers outside the DPAs. Involvement of the fishing and indigenous communities in the assessment of the status of dugongs, using their own catch data, will give ownership of such assessments and a greater degree of cooperation with future management policies. Furthermore, incorporating diverse sources of information gathered over a wide geographic range will provide feedback on dugong status over the whole World Heritage Area. Assessments drawn from this information can be validated against fishery independent aerial surveys that have been carried out or are planned in future projects.

Feasibility

The key to this project is access to catch and effort data for dugong bycatch. Over thirty years a level of trust has been built up between commercial fishers and staff of the Northern Fisheries Centre (NFC) hence there is a good chance to obtain the cooperation required, particularly if the fishers are directly involved in the project. Similarly NFC, in conjunction with Balkanu Aboriginal Development Corporation and the Queensland Parks and Wildlife Service, have developed a culturally appropriate fisheries survey for Indigenous communities. NFC staff are also currently involved with Balkanu and James Cook University, Tropical Environmental Studies and Geography (TESAG), in a proposed fisheries resource study of the black jew fish at Injinoo. Again, the personal contacts and trust built up with Indigenous community representatives should ensure cooperation with the collection of dugong catch data. The final source of bycatch data is the Queensland Shark Safety Program (QSSP) which has already been made available to NFC Stock Assessment and Modelling staff.

The proposal is a complement to two current FRDC funded research projects involving NFC staff: the Tropical Resource Assessment Program, which is developing stock assessment and population dynamics models for the inshore set net fisheries, and The effects of net fishing on coastal biodiversity and bycatch, which is assessing the effects of mesh nets on inshore biodiversity.

Methodology

To collate catch and effort information from:

1. Commercial fisher records (private logbooks and diaries);
2. Indigenous fisher records (oral history);
3. Shark control bycatch (QSCP records).

A meta-analysis is proposed using triangulation of sources to assign reliability to the data (Gribble and Robertson,1998). The most reliable catch and effort data will be used to estimate biomass time-series (biomass-dynamic fisheries production models) at locations along the Queensland East Coast. More complex models are possible if 'fishery' independent biological parameters such as population age structure and age at length (growth) are available. It is essential that local fishing communities and Indigenous communities be involved with the assessments to facilitate the gathering of data and to ensure the widest possible community cooperation.

Reference

Gribble, N.A. and Robertson, J. 1998, Fishing effort in the Far Northern cross-shelf closure of the Great Barrier Reef Marine Park: the effectiveness of area closures, Journal Environmental Management, January 1998 edition in press.

Approximate cost

$20 000

• Salary for part-time facilitation officer
• Travel and allowances
• Computer sundries and site license contributions.
• Corporate services charge and operating expenses.

Time required

One year