Technical Information Sheet #23

Published 2002

This page contains background and history of the Representative Areas Program.

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Marine sanctuaries: A sustainable future for our fisheries

While the aim of the Representative Areas Program is to protect biodiversity, creating a network of marine sanctuaries will result in benefits for commercial and recreational fisheries.

Globally, where marine sanctuaries have been established, not only have they achieved their conservation goals but they have also bought about social and economic benefits. Some of the most convincing success stories are from places where marine sanctuaries have protected 10 –35% of the total area fished (Gell and Roberts 2002). A common trend is that fishers who once opposed marine sanctuaries have turned into their avid supporters.  Some fishers have described the implementation of marine sanctuaries as ‘short term pain for long term gain’ (Roberts and Hawkins, 2000).

Marine sanctuaries provide benefits to fisheries through:

• Protecting a wide variety of species, including those of commercial value, eg fish, crustaceans (crabs, crayfish), molluscs (oysters, trochus) and sea cucumber;
• Providing for increases in number and size of animals within the sanctuary. Larger fish produce more eggs and there is increasing evidence that marine sanctuaries replenish populations regionally via larval export;
• Migration of adult animals from marine sanctuaries to enhance fisheries outside the sanctuary, commonly known as ‘spill over’;
• In the studies that have examined ‘spill over’ effects, the size and abundance of exploited species increase in areas adjacent to marine sanctuaries;
• Providing a refuge for commercial and non-commercial species;
• Acting to maintain genetic diversity;
• Protecting important fisheries habitat and spawning areas;
• Aiding protection of migratory species through protection of habitat, aggregation sites and nursery grounds;
• Acting as an insurance policy against the failures of fisheries management and environmental uncertainty (e.g. global warming).

Marine sanctuaries will benefit fisheries within the Great Barrier Reef Marine Park

Research carried out by Associate Professor Gary Russ and his colleagues at James Cook University have shown that marine sanctuaries in the Palm and Whitsunday Islands can increase numbers of coral trout by up to 3 times, and increase biomass by up to 5 times. This means there can be up to 5 times more breeding stock within the marine sanctuaries than in fished areas.

Protecting 25% of the GBRMP effectively would increase the biomass of spawning coral trout in the water by 200% compared to having no marine sanctuaries.  Similar benefits could be expected for other fished species with similar lifecycles to coral trout.

The eggs and larvae of most fish species on the Great Barrier Reef can be moved by currents, 10s or even 100s of kilometres from where they were spawned. This means that most new potential recruits (coral trout) are very likely to move from the protected marine sanctuaries to the fished areas. Marine sanctuaries in the GBRMP can, in the medium- to long-term, maintain or even enhance recruitment and thus, fisheries.

   Associate Professor Russ and his colleagues believe that without some level of protection of spawning stocks beyond traditional size catch and fishing effort limits, catches of species like coral trout, red emperor and nannygai will decline in the next 10-20 years. They believe that a network of marine sanctuaries will help ensure the long-term sustainability of fisheries, and all of the recreational and economic benefits the fisheries provide (Russ, 2002).

Marine sanctuaries offer benefits to recreational fisheries: an example

In 1962, two estuarine areas around Merritt Island at Cape Canaveral in Florida were closed to all types of fishing.  The reason for closure was to protect the security of the nearby Kennedy Space Centre. Some time after the areas were closed, studies had shown that protecting the area within a marine sanctuary had allowed fish numbers and sizes to increase.

Researchers then examined the evidence for ‘spill over’ of fish from the marine sanctuary to areas available to fishing.  Using data collected by the International Game Fishing Association, researchers found that since the closure of the Merritt Island marine sanctuaries in 1962 the numbers of fish caught outside the sanctuary areas had increased.  Also, since 1985 all new Florida records for the popular game fish, the black drum, have been for fish caught adjacent to the Merritt Island marine sanctuaries.

While this is not the first time that scientists have shown that fish catches increase when permanent marine sanctuaries are established, it does show a very direct benefit to fishers (Roberts et al, 2001)

Local fishers support the Leigh Marine Sanctuary, New Zealand

When the Leigh Marine Sanctuary was first proposed in the 1960s, commercial fishers, local landowners and public opinion was divided over the benefits of closing off such an area. After a few years, researchers started recording changes in populations of commercially-important species, including rock lobster. Local fishers began setting their traps along the boundary of the marine sanctuary feeling this was the place they would get the best catches.

After a decade of operation, the marine sanctuary is supported strongly by the community. Local fishermen say they now catch more fish outside the sanctuary and are in favour of the establishment of more sanctuaries. Tourism in the area has grown steadily as people are attracted by stories of abundant marine life. (Ballantine 1989, Roberts & Hawkins 2000).

References

Ballantine, W.J. (1989). Marine Reserves: Lessons from New Zealand. Progress in Underwater Science 13: 1-14.

Gell, F.R. and C.M. Roberts (2002). The Fishery Effects of Marine Reserves and Fishery Closures. WWF-US, 1250 24^th Street, NW, Washington, DC 20037,USA. Available at: http://www.worldwildlife.org.oceans/fishery_effects.pdf

Roberts, C., Bohnsack, J., Gell, F., Hawkins, J.P., and R Goodridge (2001).  Effects of Marine Reserves on Adjacent Fisheries. Science, Vol 294: 1920-1923.

Roberts, CM. and Hawkins, JP. (2000). Fully protected marine reserves: a guide.

WWF Endangered Seas Campaign, 1250 24^th Street, NW, Washington, DC 20037, USA and Environment Department, University of York, YO10 5DD, UK.

Russ, G (2002). Great Barrier Reef Green Zones Help Not Harm Line Fisheries. Media Release 7/8/2002