The world’s coral reefs are being degraded, and the need to reduce local pressures to offset the effects of increasing global pressures is now widely recognized. This study investigates the spatial and temporal dynamics of coral cover, identifies the main drivers of coral mortality, and quantifies the rates of potential recovery of the Great Barrier Reef. Based on the world’s most extensive time series data on reef condition (2,258 surveys of 214 reefs over 1985–2012), we show a major decline in coral cover from 28.0% to 13.8% (0.53% y−1), a loss of 50.7% of initial coral cover. Tropical cyclones, coral predation by crown-of-thorns starfish (COTS), and coral bleaching accounted for 48%, 42%, and 10% of the respective estimated losses, amounting to 3.38% y−1 mortality rate. Importantly, the relatively pristine northern region showed no overall decline. The estimated rate of increase in coral cover in the absence of cyclones, COTS, and bleaching was 2.85% y−1, demonstrating substantial capacity for recovery of reefs. In the absence of COTS, coral cover would increase at 0.89% y−1, despite ongoing losses due to cyclones and bleaching. Thus, reducing COTS populations, by improving water quality and developing alternative control measures, could prevent further coral decline and improve the outlook for the Great Barrier Reef. Such strategies can, however, only be successful if climatic conditions are stabilized, as losses due to bleaching and cyclones will otherwise increase.

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The 27–year decline of coral cover on the Great Barrier Reef and its causes

Originally conceived to conserve iconic landscapes and wildlife, protected areas are now expected to achieve an increasingly diverse set of conservation, social and economic objectives. The amount of land and sea designated as formally protected has markedly increased over the past century, but there is still a major shortfall in political commitments to enhance the coverage and effectiveness of protected areas. Financial support for protected areas is dwarfed by the benefits that they provide, but these returns depend on effective management. A step change involving increased recognition, funding, planning and enforcement is urgently needed if protected areas are going to fulfil their potential.

The performance and potential of protected areas

Coral reefs support immense biodiversity and provide important ecosystem services to many millions of people Yet reefs are degrading rapidly in response to numerous anthropogenic drivers In the coming centuries, reefs will run the gauntlet of climate change, and rising temperatures will transform them into new configurations, unlike anything observed previously by humans Returning reefs to past configurations is no longer an option Instead, the global challenge is to steer reefs through the Anthropocene era in a way that maintains their biological functions Successful navigation of this transition will require radical changes in the science, management and governance of coral reefs

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Coral reefs in the Anthropocene

Many definitions of food security exist, and these have been the subject of much debate. As early as 1992, Maxwell and Smith (1992) reviewed more than 180 items discussing concepts and definitions, and more definitions have been formulated since (DEFRA, 2006). Whereas many earlier definitions centered on food production, more recent definitions highlight access to food, in keeping with the 1996 World Food Summit definition (FAO, 1996) that food security is met when “all people, at all times, have physical and economic access to sufficient, safe, and nutritious food to meet their dietary needs and food preferences for an active and healthy life.” Worldwide attention on food access was given impetus by the food “price spike” in 2007–2008, triggered by a complex set of long- and short-term factors (FAO, 2009b; von Braun and Torero, 2009). FAO concluded, “provisional estimates show that, in 2007, 75 million more people were added to the total number of undernourished relative to 2003–05” (FAO, 2008); this is arguably a low-end estimate (Headey and Fan, 2010). More than enough food is currently produced per capita to feed the global population, yet about 870 million people remained hungry in the period from 2010 to 2012 (FAO et al., 2012). The questions for this chapter are how far climate and its change affect current food production systems and food security and the extent to which they will do so in the future (Figure 7-1).

Food security and food production systems

Corals of the world

aLLiSon perry Reefs at Risk Revisited ContriButing inStitutionS Reefs at Risk Revisited is a project of the World Resources Institute (WRI), developed and implemented in close collaboration with The Nature Conservancy (TNC), the WorldFish Center, the International Coral Reef Action Network (ICRAN), the United Nations Environment Programme World Conservation Monitoring Centre (UNEP-WCMC), and the Global Coral Reef Monitoring Network (GCRMN). Many other government agencies, international organizations, research institutions, universities, nongovernmental organizations, and initiatives provided scientific guidance, contributed data, and reviewed results, including:

Reefs at Risk Revisited

aLLiSon perry Reefs at Risk Revisited in the Coral Triangle ContriButing inStitutionS Reefs at Risk Revisited in the Coral Triangle was developed by the World Resources Institute (WRI) in close collaboration with the USAID-funded Coral Triangle Support Partnership (CTSP). This report was adapted from WRI’s 2011 global analysis of threats to coral reefs, Reefs at Risk Revisited, produced in partnership with The Nature Conservancy (TNC), the WorldFish Center, the International Coral Reef Action Network (ICRAN), the United Nations Environment Programme-World Conservation Monitoring Centre (UNEP-WCMC), and the Global Coral Reef Monitoring Network (GCRMN). Many other government agencies, international organizations, research institutions, universities, non-governmental organizations and initiatives provided scientific guidance, contributed data, and reviewed results for these reports, including:

Reefs at Risk Revisited in the Coral Triangle

This report is based on the information collected by hard working scientists, managers, conservation organisations and non-governmental organisations working tirelessly across the Pacific. It shows that the coral reefs of the Pacific are in better condition than those in other reef regions in the world, and remain the less stressed compared to reefs elsewhere. This is encouraging considering that recent global reports paint a gloomy picture of the status (and likely future prospects) of large areas of the world’s coral reefs. However, the longer term outlook for Pacific reefs is not encouraging with increasing human-induced threats and global climate change predicted to result in considerable damage in coming decades. This constitutes our conclusion, while many of the reefs in the Pacific appear healthy and resilient now, the outlook is poor.

Most Pacific reefs are in reasonable to good condition with either healthy or recovering coral communities and reasonably intact coral reef fish and invertebrate populations. There are large numbers of coral reefs spread over vast areas of the Pacific that are remote from human pressures; these remain among the best preserved reefs in the world. Many of these reefs grow around low lying and uninhabited atolls with few human pressures and no runoff from the land. Recently, there have been active processes to declare many of these reefs as protected areas with considerable success

Katie Reytar

Papers

Reefs at Risk Revisited

Reefs at Risk Revisited in the Coral Triangle

Status of Coral Reefs of the Pacific and Outlook: 2011

Reefs at Risk Revisited (preliminary results)

Tackling the challenges of assessing socioeconomic impacts of farmland restoration: The case of Malawi