Adaptive management of the Great Barrier Reef: A globally significant demonstration of the benefits of networks of marine reserves

Abstract

The Great Barrier Reef (GBR) provides a globally significant demonstration of the effectiveness of large-scale networks of marine reserves in contributing to integrated, adaptive management. Comprehensive review of available evidence shows major, rapid benefits of no-take areas for targeted fish and sharks, in both reef and nonreef habitats, with potential benefits for fisheries as well as biodiversity conservation. Large, mobile species like sharks benefit less than smaller, site-attached fish. Critically, reserves also appear to benefit overall ecosystem health and resilience: outbreaks of coral-eating, crown-of-thorns starfish appear less frequent on no-take reefs, which consequently have higher abundance of coral, the very foundation of reef ecosystems. Effective marine reserves require regular review of compliance: fish abundances in no-entry zones suggest that even no-take zones may be significantly depleted due to poaching. Spatial analyses comparing zoning with seabed biodiversity or dugong distributions illustrate significant benefits from application of best-practice conservation principles in data-poor situations. Increases in the marine reserve network in 2004 affected fishers, but preliminary economic analysis suggests considerable net benefits, in terms of protecting environmental and tourism values. Relative to the revenue generated by reef tourism, current expenditure on protection is minor. Recent implementation of an Outlook Report provides regular, formal review of environmental condition and management and links to policy responses, key aspects of adaptive management. Given the major threat posed by climate change, the expanded network of marine reserves provides a critical and cost-effective contribution to enhancing the resilience of the Great Barrier Reef.biodiversity protection | spatial planning and zoning | social and ecological resilience | coral reefs | economic cost benefit analysis

Evolving science of marine reserves: New developments and emerging research frontiers

“…Additional networks are being implemented, planned, or discussed throughout the world. Although existing networks are still relatively new, early evidence has shown that fished species can exhibit relatively rapid increases in density and biomass inside reserve networks compared with fished areas outside (16,17). However, we have a poor understanding of the additive and/or synergistic effects of reserves in these or other networks.…”

“…In the Great Barrier Reef Marine Park, a review of the total area and habitat types that were protected in marine reserves illustrated that the network was likely inadequate to protect the full range of marine biodiversity found in the park (36). In one of the few global examples of adaptively managing marine reserves, the zoning of the park was subsequently modified to increase the total area protected in marine reserves from 4.5% to 33%, which encompassed a minimum of 20% of all identified bioregions in the park (17). Using only habitat representation analyses illustrated some of the inadequacies of management in the Marine Park, but more in-depth ecological and socioeconomic data are crucial for answering further questions about the adequacy of reserve size, maintenance of key ecological processes, protection of target species, costs and benefits to local communities, and enforcement success.…”

“…Hamilton et al (16) document significant increases in the density and biomass of targeted fish populations inside the Channel Islands reserve network after 5 y of protection, a finding that only emerged when the authors took into account the major environmental and biogeographic gradient across the islands. McCook et al (17) synthesize a vast amount of data and monitoring studies from the Great Barrier Reef, which show rapid effects of reserve protection for targeted fish and sharks, improvements to ecosystem health and resilience, and net economic benefits resulting from tourism revenues. These two studies provide an important starting point for our growing understanding of reserve networks and how to measure and assess whether a collection of reserves is truly functioning as a network along both ecological and socioeconomic dimensions.…”

“…Finally, whereas relatively sedentary species repeatedly show positive responses to reserve protection, the utility of marine reserves for highly mobile species, which may spend the majority of their time outside reserves, is often deemed negligible (30), although notable exceptions exist (17). Reserve protection of spawning grounds and other critical habitat could be beneficial, but it remains to be seen whether or not reserve protection of these key areas has demonstrable benefits to highly mobile stocks that are targeted by fisheries.…”

Coral Reef Resilience through Biodiversity

“…McCook et al [144] point out that the potential bene�ts for reef-building corals are even more important than those documented for �shes, because the whole ecosystem depends on these corals. e marine reserves they examined on the Great Barrier Reef had fewer outbreaks of the star�sh Acanthaster planci and, consequently, higher coral cover.…”