One-third of world's coral species at risk of extinction
Updated
The survey by an international team of scientists has been published in the prestigious journal, Science and announced at the International Coral Reef Symposium underway in Florida. The findings show coral reefs have joined the ranks of living creatures most likely to vanish permanently from the earth.
Presenter: Corinne Podger
Speakers: Dr Greta Aeby, Hawaii Institute of Marine Biology; Dr David Obura, Coral Reef Degradation agency; Roger McManus, vice-president, Marine Programs, Conservation International.
PODGER: The survey took in virtually every coral reef on the planet, from Indonesia to Kenya, Hawaii to eastern Australia. All over the world, coral reefs are dying off at a significant rate - the victims of a combination of climate change, ocean acidification, and pollution from run-off and human activity.
Some reefs are degrading more quickly than others. The area with the highest proportion of vulnerable species is the so-called "Coral Triangle", which covers waters off Indonesia, Malaysia, the Philippines, Papua New Guinea, the Solomon Islands and East Timor.
Conservation International, one of the agencies that commissioned the study, says the results have profound implications for millions of people who derive their food and income from reef systems.
Dr Greta Aeby, of the Hawaii Institute of Marine Biology in Honolulu, is one of the study's lead authors:
AEBY: Using information about population sizes, geographic range and also the susceptibility of these different coral species to bleaching, disease, or predation by crown of thorns, we wanted to determine how many species were at risk of being lost, and from our study we found that approximately one third of our coral species are at risk. This makes corals the most threatened group of animals on this earth, second only to the frogs and related amphibians for risk of extinction.
PODGER: The 39 researchers presenting their findings here in Florida say the progressive loss of coral reefs also threatens the survival of the 25 percent of all marine life that relies on reefs for food and shelter. Dr Greta Aeby again.
AEBY: Corals make up the very framework of the coral reef ecosystem. If these corals are lost, then the entire ecosystem is at risk of collapse, and so we can expect not only to lose coral species, but also the fish and crabs and other little critters that depend on these corals for food and shelter.
PODGER: Another lead author is Dr David Obura, from the agency Coral Reef Degradation in the Indian Ocean, who's based in Kenya. He says that while some of the factors damaging coral reefs are slow but steady, like carbon dioxide in the atmosphere, others - like El Nino and other severe weather events - do short, sharp bursts of damage, adding to the problem.
But Dr Obura says there's some evidence that coral reefs can recover to an extent, from events like these, if they live in reasonably healthy waters, and that this information's being used to help in the location, design and management of marine protected areas.
OBURA: We are finding that in some places, there are reefs that are recovering quite well. These generally tend to be in fairly remote areas, where water quality is very good, where there's low fishing impacts and things like that. Some species are more tolerant and resilient than others, it depends a lot on the quality of the environment, and the quality of different places, and so we try to find the places that have high resilience and maximise the benefits there.
PODGER: But in areas where coral recovery takes place, some species do better than others, so the way a reef will look, and the species it can support, may be very different to its original state. Given the importance of reef systems both to coastal communities around the world, and to science, the researchers involved in the study have urged governments to take urgent action to reduce greenhouse gas emissions. Roger McManus is the vice-president of Marine Programs at Conservation International.
MCMANUS: Clearly we've got an emerging conversation about the impacts of climate We all need to do our part institutionally and individually to reduce emissions but there is a consensus now that no matter what we do, we are going to see some impacts that are simply not reversible at this point. The results of the GMSA will help ensure that we highlight the urgency and need to improve stewardship of the ocean, but I think most importantly out of all of this is that we have to adjust to a new world in which we have to manage for change. We cannot manage to conserve or preserve the past or the present, we also have to be concerned about what's going to happen in the future, and how we're going manage and conserve biodiversity and productivity of the ocean in that light.
