Peter Mumby: It’s a good time to protect herbivorous fish in Australia

Prof Peter Mumby

ACRS Vice President
Marine Spatial Ecology Lab
The University of Queensland

November 2011

Reef managers world-wide are trying to take action to build the resilience of coral reefs to climate change, as well as local pressures such as pollution. Much is known about the resilience of reefs and large seaweeds can cause problems for corals throughout the world. Seaweeds can compete with corals by usurping space, overgrowing living coral, and leaking noxious chemicals. Not surprisingly, keeping seaweed under control has long been a priority for managing reef resilience.

In many areas, seaweed levels fluctuate naturally from season to season. However, outbreaks of seaweeds can occur if the flux of nutrients is unnaturally high or the level of grazing by fishes and urchins becomes unnaturally low. Great progress is being made to manage nutrient runoff in Australia’s coastal watersheds, but nothing is being done to manage herbivores.

It is often said that herbivorous fish, such as parrotfish, surgeonfish and rabbitfish, don’t need to be protected because they’re not threatened in Australia. This is certainly true today; there is no fishery for herbivorous fish in Australia. So why then should we bother?

There are several reasons we should consider protecting herbivorous fish in Australia. Some strategically benefit Australia. Others are more altruistic.

  1. While there is no fishery for herbivores today, experience elsewhere tells us that this may change in future. When I first began working in Belize (Central America, and host to the second-largest barrier reef), nobody ate parrotfish. People would look incredulous at the idea of consuming such a ‘trash fish’: Oh no, Belizeans only fished for prize groupers and snappers. Yet 13 years later, the grouper and snapper were heavily depleted and parrotfish had become the dominant catch. A similar story may unfold in the Bahamas. Here, one of the drivers of change is immigration of people into the islands who have a different set of values and quite a taste for parrotfish. So, taking action today will help future-proof this aspect of resilience for Australia’s reef. For example, who knows whether we’ll see a change in the species sought-after by recreational fisheries as tourism grows and continues to diversify?
  2. It is easy; hardly anyone is likely to object.
  3. Australia is a world leader in coral reef management. Taking action on this issue would signal the importance of conserving herbivores throughout the world.

The only likely objection to conserving herbivorous fishes in Australia is the cost of implementation (consultation, preparation of legal instruments, etc). This is clearly a judgement call for governments but as interventions go, it’s not that difficult.

Read more…

Mumby PJ, Steneck RS, Edwards AJ, Ferrari R, Harborne AR, Coleman R, Gibson JP (2012) Fishing down a Caribbean food web relaxes trophic cascades. Marine Ecology Progress Series 445: 13-24

Mumby PJ, Harborne AR (2010) Marine reserves enhance the recovery of corals on Caribbean reefs. PLoS One 5: e8657

Mumby PJ, Steneck RS (2008) Coral reef management and conservation in the light of rapidly-evolving ecological paradigms. Trends in Ecology and Evolution 23: 555-563

Laurence McCook: Good, adaptive ecosystem-based management can lead to good environmental and economic outcomes

Dr Laurence McCook

Science-based Management Applications
Pew Fellow in Marine Conservation
Manager, Ecosystem Health and Resilience,
Great Barrier Reef Marine Park Authority

August 2011

The need for urgent action to protect coral reefs is now beyond question, at least within the scientific community. A key aspect of success in conservation lies in our ability to get better as we go, and learn from our mistakes and our successes- that is to adaptively manage.  As we increase efforts, we need to ensure that we continually improve our effectiveness in slowing the global decline in reefs. This means accepting that we won’t get it right first time every time, and that we need to build on successful strategies and improve on unsuccessful ones. The scientific literature includes many critiques of marine conservation problems and mistakes, especially the literature on marine protected areas, but there’s a tendency to see the glass as half empty and throw up our hands. It’s really important to see the successes as well, the glass half full perspective, and to move onwards and upwards.

Around Australia, and internationally, efforts to improve the management of marine biodiversity are being hindered by perceptions that such efforts will have negative impacts on local communities, especially fishers. But available evidence suggests that well managed ecosystems can have far greater long-term economic and social benefits than over-exploited and unprotected systems.

The Great Barrier Reef provides a globally significant demonstration of the successes that can be achieved through carefully planned and implemented networks of marine reserves and ecosystem-based management.

In a recent paper, we reviewed the available evidence on the effects of the network of marine reserves on the Great Barrier Reef, a network which set the bar for spatial management in marine ecosystems. Key conclusions include:

  1. “Overall, zoning of the GBR marine reserve network appears to be making major contributions to the protection of biodiversity, ecosystem resilience and social and economic values of the GBR Marine Park.” Importantly, there are likely benefits for fisheries, as well as biodiversity conservation.
  2. “The breadth and extent of benefits reflect very well on the scientific and engagement processes involved in the development and implementation of the 2004 Zoning Plan, especially the value of larger reserve size and high proportion of overall area in reserves to provide margins of error.”
  3. “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.”
  • A key new result is the demonstration that protected zones suffer less damage to corals from crown-of-thorns starfish. This is especially important since corals provide the very foundation of the reef, and are critical to the tourism industry. 
  • The paper shows significant benefits for fish populations within reserves, and probably for GBR-wide fish populations. There are benefits to sharks, dugong and turtles, although these groups remain at serious risk, and require complementary protection measures.
  • Although there have been some effects on fishers, these have been less than suggested in some media, there appear to have been some benefits, and there remains strong support amongst fishers for the need to protect biodiversity. Economic effects have been the focus of a structural adjustment program by the Australian Government.
  • A healthy GBR generates enormous economic value, approximately $5.5 billion per year, which is far greater than the cost of protecting it. 

Emerging evidence suggests that the Great Barrier Reef is suffering long-term declines. In that context, it is even more important that we recognize our wins, as well as our losses.

Read more…

Journal article:

McCook LJ, Ayling T, Cappo M, Choat JH, Evans RD, Freitas DM De, Heupel M, Hughes TP, Jones GP, Mapstone B, Marsh H, Mills M, Molloy F, Pitcher CR, Pressey RL, Russ GR, Sutton S, Sweatman H, Tobin R,Wachenfeld DR, Williamson DH (2010) Adaptive management of the Great Barrier Reef: a globally significant demonstration of the benefits of networks of marine reserves. Proceedings of the National Academy of Sciences USA 107: 18278-18285.

ABSTRACT: The Great Barrier Reef 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 non-reef 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.

Other recent articles:

Gunn J, Fraser G, Kimball B (2010) Review of the Great Barrier Reef Marine Park Structural Adjustment Package. Report prepared for the Department of Environment, Heritage and the Arts.

Macintosh A, Bonyhady T, Wilkinson D (2010) Dealing with interests displaced by marine protected areas: A case study on the Great Barrier Reef Marine Park Structural Adjustment Package. Ocean and Coastal Management 53: 581-588.

Peter Sale: The Elephant in the Room

Prof Peter F. Sale

Coral Reef Ecologist

Assistant Director, Institute for Water, Environment and Health, United Nations University,
Hamilton, Ontario, Canada

February 2011

There are now three times as many people on earth as when I was born. Some of these live in developed countries and consume far more than individuals consumed when I was born. Many more live in rapidly developing countries such as India and China and their combined use of resources is rising rapidly. The world population is expected to reach 9.2 billion by 2050, and the majority of these people will live in coastal communities in developing countries. Yet policy discussions rarely admit that this elephant is at the center of our problem with coral reefs. In addition to over-fishing, our growing coastal populations degrade coral reefs through inappropriate coastal development and pollution, and all of us contribute through climate change effects. The major problem for coral reefs is that our growing demands exceed what can be supplied.

Let’s acknowledge this elephant exists, and set about taming it. A future with fewer people and with higher quality of life is attainable, but not if we never discuss it. That future could include coral reefs.

Read more…


Sale PF (2011) Our dying planet: an ecologist’s view of the crisis we face. University of California Press, Berkeley.

ABSTRACT: Coral reefs are on track to become the first ecosystem actually eliminated from the planet. So says leading ecologist Peter F. Sale in this crash course on the state of the planet today. Sale draws from his own extensive work on coral reefs, and from recent research by other ecologists, to explore the many ways we are changing the earth and to explain why it matters. Weaving his own firsthand field experiences around the world into the narrative, Sale brings ecology alive while giving a solid understanding of the science at work behind today’s pressing environmental issues. He delves into topics including overfishing, deforestation, biodiversity loss, use of fossil fuels, population growth, and climate change while discussing the real consequences of our growing ecological footprint. Most importantly, this passionately written book emphasizes that a gloom and doom scenario is not inevitable, and as Sale explores alternative paths, he considers the ways in which science can help us realize a better future.

Click here for the flyer

Click here to purchase “Our Dying Planet: An Ecologist’s View of the Crisis We Face”

Journal article:

Sale PF (2008) Management of coral reefs: Where we have gone wrong and what we can do about it. Marine Pollution Bulletin 56: 805-809.

ABSTRACT: Globally, our current management of coral reefs is inadequate and becoming more so as we place new and greater stresses on these ecosystems. The future looks very dim, and yet we have the capacity to do a far more effective job of reef management if we want to. Making substantial improvements to the condition of these enormously valuable coastal marine ecosystems does not require new scientific discoveries, but a new commitment to apply the knowledge we already possess to manage our impacts so that sustainability becomes possible.