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  IUCN 31 Oct 06
New strategy to help corals and mangroves survive climate change

BBC 1 Nov 06
Corals get climate survival guide

Yahoo News 31 Oct 06
Coral reefs can be saved from climate change: conservation body

GENEVA (AFP) - Measures to control overfishing and pollution and to protect mangroves would counter the destruction of coral reefs by climate change, the World Conservation Union (IUCN) said.

About a fifth of the colourful marine reefs have already been destroyed and half are threatened with destruction because of the impact of climate change, including increased sea temperatures, according to the IUCN.

New reports by the organisation on coral bleaching and on mangroves showed that attempts to fight other problem areas improve the health of reefs, which are home to about one quarter of known marine species, and make them more resilient to climate change.

"The two reports give a clear positive message: while we cannot stop climate change in the short term, we can help tropical marine ecosystems survive," Carl Gustaf Lundin, head of the IUCN's Global Marine Programme said.

Greater acidity of the oceans, caused by higher levels of dissolved carbon dioxide from emissions, is adding to mass coral bleaching caused by higher sea surface temperatures as well as other forms of pollution, the reports said.

Overfishing also undermines the complex balance of marine life that creates and sustains the reefs, said Gabriel Grimsditch, one of the authors.

Mangroves, which are often directly next to reefs, are part of the same ecosystem, providing a protective nursery for juvenile fish, nutrients for corals and trapping damaging sediments from land, he explained.

Mangroves are threatened by rising sea-levels, more violent tropical storms caused by climate change, as well as clearance during coastal development for tourism or expanding urban areas, the IUCN said.

"We need to minimize human impacts such as pollution, overfishing or unsustainable coastal development," Grimsditch said. "Then the coral reefs have a bigger chance of coming back after bleaching and of adapting to rising sea temperatures or more acid waters," he added.

Coral reefs provide livelihoods for 100 million people and form the basis for industries such as tourism and fishing, worth 30 billion dollars a year, according to the IUCN.

One hectare of mangroves can deliver products and services worth up to 900,000 dollars in products, including timber and wood chips, and as an environment for fish spawning, it added.

BBC 1 Nov 06
Corals get climate survival guide

Strategies to help vulnerable marine ecosystems survive the impact of climate change have been published by conservationists.

Coral reefs and mangroves are being degraded by global warming, pollution and coastal developments, they said. The authors say limiting the human impact on the habitats will allow them to be more resilient to climate shifts.

The reports have been produced by the World Conservation Union (IUCN) and The Nature Conservancy (TNC). "Coral Reef Resilience and Resistance to Bleaching" and "Managing mangroves for Resilience to Climate Change" list the range of human threats to the ecology, and the risks posed by climate change.

"The two reports give a clear message," says Carl Gustaf Lundin, head of the IUCN Global Marine Programme. "While we cannot stop climate change in the short term, we can help tropical marine ecosystems survive," he adds. "If reef managers and politicians follow the measures proposed in these publications, we may be able to reverse the trends."

Warming seas

Reefs are particularly sensitive to climate change because they bleach easily if there are changes to sea surface temperatures (SSTs), the groups warn.

Corals get their colour from tiny single-cell plants - zooxanthellae - which provide for the reef-building creatures, the polyps. If there is an increase in SST for a prolonged period, the zooxanthellae are driven away, the coral loses its colour, the polyps lose their food and the reef is weakened.

The reefs then become more vulnerable to other threats, such as: overfishing; pollution; creatures that eat them; sedimentation from storm surges and snorkellers; and coastal developments.

Sometimes called "the tropical rainforests of the ocean", reefs only cover 0.2% of the world's sea-floor, but contain an estimated 25% of marine species. They also provide a source of income and food for millions of people, the authors say, delivering about $30bn (£16bn) worth of benefits in goods and services.

To mitigate the damage to coral weakened by warming waters, the report calls for the adoption of a range of measures, such as: improved reef monitoring marine protection areas transplanting healthy coral to degraded reefs coastal and fishing management schemes

"We need to minimise human impacts such as pollution, overfishing or unsustainable coastal developments," says Gabriel Grimsditch, one of the authors of the coral report. "The coral reefs then have a bigger chance of coming back after bleaching and of adapting to rising sea temperatures or more acid waters," he explains.

Managing mangroves

Although mangroves are well suited for harsh conditions, rising sea levels and deforestation threatens to undermine some of the plants' long-term survival, the authors warn.

Writing in the report, they add: "But the good news is that not all coastlines with mangrove forests are projected to experience a rise in relative sea level. "At sites that are projected to experience rising seas, mangrove ecosystems on low relief islands and those deprived of sediment are especially vulnerable.

"In contrast, mangrove ecosystems with ample sediment supplies [or with] room to move inland are likely to survive projected rates of sea-level rise." As well as sea-level rises, another climate-related risk is changing rainfall patterns, which can affect the forests' growth and development.

Over the past 50 years, an estimated one-third of the world's mangrove forests have been cleared for fuel, coastal developments or farming. The main reason behind the clearance has been the emergence of shrimp farms in Indonesia and Thailand to meet global demand for the shellfish.

The report's authors, from the IUCN and TNC, highlight 10 strategies that could help protect the forests, including: identify and protect areas naturally positioned to survive climate change manage human demands on the plantations establish green belts and buffer zones to allow mangrove migration restore degraded areas that have displayed resilience to climate shifts

The reports are the first publications in a series by the IUCN on the impacts of climate change on the natural world.

IUCN 31 Oct 06
New strategy to help corals and mangroves survive climate change

With climate change threatening tropical marine ecosystems, scientists of the World Conservation Union (IUCN) and The Nature Conservancy are spelling out the survival strategy for coral reefs and mangroves in new publications launched today.

Geneva, Switzerland, 31 October 2006 (IUCN) -- Climate change is destroying tropical marine ecosystems through sea temperature increase and ocean acidification. 20% of coral reefs have already been wrecked and a further 50% are facing immediate or long term danger of collapse.

Last week, the media reported that climate change is likely to kill over half of all coral reefs within the next 25 years.

A new report "Coral Reef Resilience and Resistance to Bleaching" published today by the World Conservation Union (IUCN) and The Nature Conservancy (TNC) shows that the fate of corals may not yet be sealed. By fighting other stress factors such as pollution or overfishing impacting on coral reefs, reefs will be able to better adapt to climate change impacts.

The report "Managing mangroves for Resilience to Climate Change" follows a similar strategy. To help mangroves, especially threatened by sea-level rise, and corals survive in the face of climate change, the two reports publish a series of strategies and tools to fight the other stress factors impacting on them. Both publications are part of a new IUCN series on climate change and coral reefs.

"The two reports give a clear positive message: while we cannot stop climate change in the short term, we can help tropical marine ecosystems survive. If reef managers and politicians follow the measures proposed in these publications, we may be able to reverse the trend," said Carl Gustaf Lundin, Head of the IUCN Global Marine Programme.

Increased sea surface temperatures and ocean acidification--due to higher levels of dissolved CO2--lead to increased mass coral bleaching and mortality, reduced growth of corals and weakened animal skeletons.

Rapid sea level rise, more violent tropical storms and changes in rainfall and salinity are also affecting coral reefs and mangroves.

The idea behind these measures is to keep other disturbances and threats off the reef, to make it healthier and thus more resilient to climate change impacts.

"We need to minimize human impacts such as pollution, overfishing or unsustainable coastal development. Then the coral reefs have a bigger chance of coming back after bleaching and of adapting to rising sea temperatures or more acid waters," says Gabriel Grimsditch of the IUCN Global Marine Programme, one of the authors of the publication on coral reefs.

Other measures include protecting so-called 'refuges' of particularly healthy and climate-change-resilient sites that may be able to help regenerate degraded coral reefs and mangroves in the future; and monitoring of coral reefs before, during and after a bleaching event to raise awareness amongst managers and politicians.

Coral reefs only cover 0.2% of the ocean floor, but contain an incredible 25% of marine species globally. Coral reefs provide livelihoods to 100 million people and provide the basis for industries such as tourism and fishing, worth an annual net benefit of US$ 30 billion.

One hectare of mangroves is estimated to deliver products and services worth up to $900,000. Examples of these products and services include timber and wood chips, an environment for fish spawning, and habitat for economically important species.

However, climate change is compromising these ecosystems--ability to deliver benefits to plants, animals and humans into the future.

At the recently concluded 3rd International Tropical Marine Ecosystems Management Symposium (ITMEMS3, 15-20 October 2006), scientists therefore concluded that sea temperature increase must be limited to 2°C above pre-industrial levels if major damages to tropical ecosystems are to be avoided.

"Rising temperatures and sea-levels challenge reef managers to be flexible and adapt their approaches to make the reefs and mangroves under their care more resilient to climate change as new science and understanding emerges," says Rodney Salm, Director of the Transforming Coastal Marine Conservation Program at The Nature Conservancy, and the other co-author of the coral reef resilience publication.

"It is high time for action--that is the clear message expressed by scientists at this Symposium and around the world. IUCN therefore works to identify the best science and offer practical solutions to policy-makers and conservation managers, which is the goal of these manuals, says Lundin.

Download the reports (PDF files)
Coral Reef Resilience and Resistance to Bleaching
Gabriel D. Grimsditch and Rodney V. Salm

Managing Mangroves for Resilience to Climate Change
Elizabeth Mcleod and Rodney V. Salm
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