Starting in late 1992, two initiatives combined to give scientists opportunities to become more responsive to the needs of users and managers of the Great Barrier Reef. the development of the Twenty-five Year Strategic Plan for the GBR World Heritage Area (published in 1994), and the establishment of the Co-operative Research Centre for the Ecologically Sustainable Development of the Great Barrier Reef (the CRC Reef Research Centre, July 1993).

The strategic planning process regularly brought representatives of the science and management communities together with leaders of all major interest groups: conservationists; recreational and commercial fishers; Aboriginal Australians and Torres Strait Islanders; tourism representatives; local government; and state government departments. Divergent issues and perspectives were brought to the table by different groups:

• Fishers (recreational and commercial) expressed concerns about continued reasonable access to a reliable resource;
• Indigenous people wanted to be involved in policy setting and management, and have their traditional uses of the sea respected;
• Conservation groups stressed the need to preserve opportunities for wilderness experiences;
  
  and

• Tourism operators felt concerned about a shortage of suitable 'sites' for development of visiting and viewing facilities at coral reefs, and for the security and amenity of these sites in the context of destructive acts of nature.

The completed Plan¹¹ includes a shared vision, principles, objectives and strategies based on the cumulative insights coming from all parties.

There are fifty-seven, five-year objectives grouped under eight broad headings: conservation; resource management; education, communication, consultation and commitment; research and monitoring; integrated planning; recognition of Aboriginal and Torres Strait Islander interests; management processes; and legislation. Three of the five-year (1995-2000) objectives (with the lead agency for implementation) are as follows:

• To develop, implement and evaluate management plans for harvestable resources, ie. sustainable fishing (Queensland Fisheries Management Authority)
• To have catchment management strategies planned and their implementation commenced in those priority river catchments that will adversely impact on the GBR World Heritage Area (Queensland Department of Primary Industry)
• To protect representative biological communities throughout the Area to act as source areas, reference areas and reservoirs of biodiversity and species abundance (Great Barrier Reef Marine Park Authority).

The remainder of this article provides a glimpse of some of the scientific activities currently under way in support of these three objectives.

GBRMPA works through the Queensland Fisheries Management Authority (QFMA) which has responsibility for management of all the diverse fisheries of the GBR Region (trawl, reef line, net and harvest and collection). Their legislation stipulates regard for principles of an ecologically sustainable development, specifically conservation of biodiversity and ecosystem processes as can be illustrated by reference to two fisheries: trawl and reef.

In prawn-trawling areas, previously undisturbed sea-bed habitats are now disturbed on a regular basis by trawling, leading to particular concerns about the amount of by-catch, the fate of biodiversity and ecosystem processes, and the grounds' continued capacity to support the fishery (Figure 3). Research by CSIRO and the Queensland Department of Primary Industry (QDPI) reports that each trawl across the sea-bed removes 5-20% of the sponge, sea-whip, sea-fan, and coral biomass in its path, not to mention the abundant epifauna and flora which live on these animals¹². Because of a scarcity of taxonomic experts world-wide, complete inventories of sea-bed biodiversity do not exist, and it is, therefore, a case of not knowing exactly what is being placed at risk. The risk itself is also very hard to quantify, because statistics are lacking on the average time between sweeps of the same patch of sea floor, and the extent and amount of undisturbed areas. This will soon be rectified by the fitting of accurate position-fixing transponders to trawlers, but in the meantime, the trawling activity is widely considered to be urgently in need of better information and management.

The pressure can be taken off sea-bed biodiversity by switching more to mariculture prawns reared and fed in artificial ponds, though this approach brings its own issues of habitat destruction, pollution, and environmental best practice.

Fishing on coral reefs using a hand-line or rod and reel is a major recreational and commercial use of the Reef. The CRC is currently running an 'Effects of Line Fishing Experiments'¹³ to provide data on both the effort (distribution, frequency, intensity) and the response (in target and non-target species, and in the broader ecosystem). This project, which involves fishing on eight out of 486 reefs previously zoned as 'no fishing' zones, was commissioned by the GBRMPA and QFMA, which need more information to set safe future levels. The researchers gained wide support for the experiment from commercial and recreational fishing groups, but the opening of the no-fishing zones was opposed by some local conservation groups, sections of the media, and political parties.

The potential benefits in gaining a quantitative understanding on both effort and response sides of the sustainable fishing story applicable to the wider GBR were seen by managers, industry and the broader community to outweigh the temporary and localised depletion of fish numbers that the experiment will promote.

There are many other propositions about the ways the GBR fishing scene could unfold which still need to be assessed scientifically. Two important questions which have been highlighted by QFMA and elsewhere in this article are:

• How can 'source-sink' concepts be best incorporated in the management of sustainable fisheries?
• Are there vulnerable keystone species (for example: those that control nuisance-seaweed increases or even crown-of-thorns starfish numbers) whose populations are intentionally or inadvertently reduced by fishing to levels at which there are flow-on effects to other aspects of the ecosystem structure or function?