5. The Future. Estimating the Value of Coral Reefs. 130 NINGALOO: Australia s Untamed Reef

Transcription

1 130 NINGALOO: Australia s Untamed Reef 5. The Future The future of coral reefs is uncertain. Decades of overexploitation, sedimentation and nutrient enrichment have left a great number of reefs seriously degraded, in poor and rich nations alike. Half the problem is that ecosystems do not appear to be visible in economic projections, leaving their services undervalued and their health ignored. But chronic anthropogenic stress is no longer the only threat After 200 years of burning billions of tons of fossil fuels and clearing countless forests, we have caused the global climate to heat up rapidly. So rapidly, in fact, that many organisms are facing decimation or extinction. Corals are among the creatures at the frontline and there is no evidence to suggest that they are able to keep up with the rate of change. Already, numerous species are reported to have suffered local extinctions as mass coral bleaching events have become a regular occurrence in some regions. With our current rate of greenhouse gas emissions, unsustainable resource use and high degree of global apathy, the accepted estimate is that only 30% of the world s reefs are likely to survive the first half of this century. But it doesn t have to be this way. If we have learned something positive in the last few decades it is that corals are inherently resilient and do respond well to management Estimating the Value of Coral Reefs The biosphere consists of a series of biomes (i.e. sets of ecosystems with specific characteristics), each of which provides a range of services absolutely crucial to the functioning of the Earth s life-support system and human welfare. Yet, in the majority of policy decisions, these services are given little weight, presumably because only a few allow conventional economical evaluations within the framework of existing commercial markets leaving the remainder unassessed and practically invisible from an economic viewpoint 104. Whilst we can easily count the tourist dollars spent in a National Park, how, indeed, do we determine the economic value of the primary production of a hectare of bushland; the aesthetic beauty of a kilometre of reef; or the medicinal potential of a rare and undescribed worm? As a result, we find that unsustainable exploitation is often allowed to continue indefinitely under the spectacularly short sighted miscomprehension that it somehow benefits the community, e.g. by preserving jobs or state/national income. Time and time again, unsustainable harvesting causes real economic losses that typically eclipse the gains from the unsustainable practices themselves and not just in the long term 105. Estimating the value of ecosystems can help to ensure that they are taken into account in decisionmaking processes and that financial resources are made available for their management and conservation. So what do coral reefs really do for us? And what are they worth in dollars? Answers to these questions are of course very difficult to determine and will always depend on a long list of assumptions, making any evaluation attempt highly conjectural. Yet the first important rough estimates are out ever since a landmark report published in Nature provided global estimates of the economical values for each of a series of the biosphere s biomes and its services 104. And although these estimates are not likely to be accurate by any standard, they do give us some indication of the size of the ballpark. The following values are those as estimated by this report in 1997 (not adjusted for inflation), unless otherwise specified. One of the more obvious services of coral reefs is food production. Rich in marine life, reefs have always been popular fishing grounds. For traditional coastal cultures in tropical regions they commonly provide a substantial proportion of the diet. Today, about 30 million of the world s poorest people rely on coral reefs for food, with numerous Pacific Ocean island communities deriving between 80 and 98% of their animal protein intake from coral reefs. But the idea that these ecosystems are able to support major fisheries is false. Coral reefs depend on the efficient recycling of nutrients, as the nutrient inflow from the surrounding environment is very limited. This subsequently leads to very low net production rates and, ultimately, low sustainable yields reflected in a food production value estimate of only ~US$ 22,000 /km 2 /yr 104. Coral reefs are also often quoted to be a source of raw materials, such as limestone and sand for the building industry, but sustainable extraction of anything, let alone reef structures that may take centuries to build, is extremely limited. The potential value for sustainable extraction of raw materials is therefore low, i.e. ~US$ 2,700 /km 2 /yr 104. Much more important is the value of coral reefs associated with protecting coastlines and coastal ecosystems (such as mangroves, seagrass meadows and beaches) from erosion and storm damage. Part of the value of this protection can be estimated based on the cost of losses likely to be incurred and/or

2 The Future 131 Coral reefs protect coastlines & coastal ecosystems; harbour a large proportion of the Earth s genetic diversity; and support important tourism industries, yet their health is routinely overlooked in policy decisions in favour of short-term gains. Here, the reef front provides some protection for a resting humpback mother & calf. (Photo: Craig Kitson) One of WA s delicious fish, the spangled emperor (Lethrinus nebulosus, Family Lethrinidae) is a prize catch for commercial and recreational anglers alike. (Photo: Craig Kitson)

3 132 NINGALOO: Australia s Untamed Reef Top: Corals meeting the beach: illustrating both Ningaloo Reef s remarkable beauty and its vulnerability. (Photo: Ian Anderson) Left: The retracted polyps of a star coral (Favites sp., Family Faviidae). (Photo: Blue Office / MIRG Australia)

4 The Future Staghorn corals covering every inch of a steep slope at the Abrolhos Islands. (Photo: Blue Office / MIRG Australia) A green turtle looking up towards the surface. (Photo: Blue Office / MIRG Australia) 133

5 134 NINGALOO: Australia s Untamed Reef maintenance needed without the presence of these reefs. In Indonesia, for instance, Cesar (1996) 106 estimated the local value of coral reefs over 25 years at: US$ 820 /km at sparsely populated regions where they protect agricultural activity; US$ 50,000 /km in areas of some coastal urban development; and US$ 1 million /km where they protect and maintain sandy beaches at major tourism destinations, but note that in other parts of the world where prices are higher these values would increase dramatically. Grouping all coral reefs of the world and all disturbance regulation services Costanza et al arrived at a mean value of ~US$ 275,000 /km 2 /yr. Also of enormous value is the recreational potential (i.e. estimated at ~US$ 300,000 /km 2 /yr) as many millions of people annually spend time diving, fishing and surfing at or near coral reefs, supporting tourism and retail industries. Ecotourism, growing at an incredible 10-30% per year and accounting for 20% of world-wide tourism, provides poor nations that are currently degrading their reefs to earn a quick dollar in food and aquarium trade exports with a prosperous alternative whilst ensuring a stable and healthy future 68. In addition to the above, coral reefs provide gas regulation services, nutrient cycling services, climate regulation services, pollution control/detoxification services, biological control services, nursery/habitat services, cultural services and the potentially gigantic but unvalued service of storing a particularly significant proportion of the Earth s genetic diversity (Topic Box 10) 104. Only a fraction of coral reef organisms have been tested for bio-active components to combat current diseases and viruses and every time a useful component is found a new value is created both in real economic markets (e.g. the pharmaceutical industry) and in terms of quality-of-life for patients. Consider the compounds discovered in a Caribbean Sponge that now form the base of a treatment for people with HIV infections; the coral compounds that are leading to new sunblock products; or the natural algal compounds preventing bacteria to form biofilms (responsible for 65% of all human infections) 107 Is there a limit to the potential life-saving products that await discovery at coral reefs? And what is carried within the bodies of those yet unknown, undescribed and unnamed species that are silently slipping away from existence? The universal truth that we don t realise what something is worth until it s gone does also appear to apply to coral reefs. Now, more than a decade after the mass coral bleaching event of , the net value of its direct losses over the next 50 years (not including those associated with intrinsic value or those that relate to services that are more difficult to ascertain in economic terms) are estimated at between US$ billion 107. If we take into account future events these losses are beginning to add up. In the Caribbean alone losses of global climate change are estimated to reach US$ 110 billion in the foreseeable future equal to about 14% of the total Gross Domestic Product of the region 107. Can we really afford to make policy decisions without taking these real economic consequences into account? So what is the value of our coral reefs? Is it in the vicinity of US$ 30 billion /yr 107 in net benefits (i.e. goods and services that we directly can trace through existing accounts) or closer to the US$ 375 billion /yr counting also those components that do not directly translate into tangible economic benefits as suggested by Costanza et al. (1997) 104? We still can t answer the question, but we are beginning to realise that coral reefs require conservation not just for their aesthetics, recreational value and biodiversity, but also to ensure our own well being and a healthy economy. It is certainly becoming clear that, besides being a provider of a number of crucial services that are literally irreplaceable, coral reefs provide their services cheaper than any other manufactured alternative. Healthy coral reef systems tend to have a good proportion of large mound-building corals each with an age of many decades or even several centuries. (Photo: Blue Office / MIRG Australia)