World's Mangroves Retreating At Alarming Rate: Study

Reuters 15 Jul 10;

The world's mangroves are being destroyed up to four times faster than other forests, costing millions of dollars in losses in areas such as fisheries and storm protection, a report said Wednesday.

The study commissioned by the United Nations Environment Program (UNEP) and The Nature Conservancy said a fifth of mangroves had been lost since 1980 and that they continued to be destroyed at a rate of around 0.7 percent a year by activities such as coastal construction and shrimp farming.
The 'World Mangrove Atlas' report noted that mangrove forests provide huge economic services, acting as nurseries for sea fish, storing carbon and providing robust defenses against floods and cyclones at a time of rising sea levels.

The trees and shrubs, which grow in saline coastal habitats, also provide excellent rot-resistant wood.

"Given their value, there can be no justification for further mangrove loss," said Emmanuel Ze Meka, head of the International Tropical Timber Organization, which helped fund the report.

The report cited evidence that mangroves reduced the impact of the 2004 Indian Ocean tsunami in some places.

It urged nations, especially those with the largest mangroves like Brazil, Indonesia and Australia, to do more to halt the retreat of an estimated 150,000 square kilometers of global mangrove forest cover. "The greatest drivers for mangrove forest loss are direct conversion to aquaculture, agriculture and urban land uses. Coastal zones are often densely populated and pressure for land intense. Where mangroves remain, they have often been degraded through overharvesting," it found.

It cited Malaysia as a country that uses state-ownership of mangroves to better manage them and stem their decline.

Taking stock of mangroves, thin frontlines of diversity
NatGeo News Watch 14 Jul 10;

Mark Spalding, a marine scientist with The Nature Conservancy, has spent decades researching mangroves, the rare and critically important forests that grow at the intersection of land and sea. He is also lead author of the World Atlas of Mangroves, the first in-depth look in over a decade of mangroves.

According to the Atlas, which was released today, about one fifth of all mangroves are thought to have been lost since 1980. Mangroves are lost at a rate three to four times higher than land-based global forests, despite positive restoration efforts by some countries, Spalding and the other Atlas authors note. "Any further destruction due to unsustainable activities such as, shrimp farming and coastal development, will cause significant economic and ecological decline," they warn.

"While mangroves are rare compared to other forest types, the waters all around them foster some of the greatest productivity of fish and shellfish in any coastal waters. Mangrove forests help prevent erosion and mitigate natural hazards--they are natural coastal defenses whose importance will only grow as sea level rise becomes a reality around the world," the authors noted in a news release.

David Braun interviewed Mark Spalding about the new atlas:

While the rate of loss of mangroves may be slowing, some species of mangroves are disappearing much more rapidly than others. What are the hottest spots for loss of mangroves and associated biodiversity on the planet?

The most dramatic, rapid losses at large scales almost always link to conversion to aquaculture. It is incredible to zoom in on satellite imagery and suddenly find mile after mile of rectangular "fields" of water, separated by embankments, where once there were mangroves--in Ecuador, Honduras, Thailand, China, the Philippines and elsewhere.

But this front line of destruction is constantly moving. China has lost most of its mangroves, but Indonesia is still the largest mangrove country in the world (and with the greatest diversity of species). Here the front line of is moving eastwards--the densely populated island of Java barely has any mangroves left. Southern Borneo has also lost vast areas, but here the pressure remains for more conversion. Further east some of the most extensive mangroves in the world are threatened by logging and by oil and gas extraction.

Another front line, which of course doesn't do much to the statistics, is the loss of small patches in countries where mangroves were never abundant. Coastal development, including tourism, has decimated mangroves in many small island nations, particularly in the Caribbean. Here mangrove forests are precious packets of diversity, rich in fish and crabs, sheltering resident and migratory birds. But to some eyes they are prime development land, quickly replaced by hotels or golf courses.

But loss is just the extreme end of degradation. Look at the mangroves of the Niger Delta, one of the world's largest mangrove forests. Still standing, these forests have been choked by oil pollution on a scale close to that of the Deepwater oil spill in the Gulf of Mexico for some 50 years.

Or take the mangroves in the deltas of great rivers such as the Zambezi in Mozambique or the Indus in Pakistan. Upstream water use has shrunk these mighty rivers to mere trickles, barely reaching the sea for parts of the year. Without the enriching waters of the deltas, and the resupply of sediments, erosion sets in, and the rich diversity is lost as only the hardiest species can survive.

Some countries are making big efforts to restore mangrove forests. Which examples are the most encouraging in terms of showing others the right path?

The Philippines is a fascinating place--we don't have a good handle on how many mangroves there were originally, but it seems likely that they have lost half, perhaps more of the original cover. This was largely to aquaculture, aided by some large-scale government policies and subsidies.

Recently, however the value of mangroves has risen right to the fore and there have been massive efforts to restore mangroves in many areas. And these efforts give us the whole spectrum--good news and bad.

Some of the least successful efforts have come from big money, top-down approaches: remarkable failures involving planting the wrong species in the wrong places.

But wonderful successes too. Of course some of these were also the big schemes, but many of the more successful efforts came from local initiatives. Here there was perhaps a greater effort to get around the problems of land ownership, so the mangroves were planted in the right place (a little above the mid-tide line, all the way to the high tide).

And of course local leadership gives a sense of ownership, and a sense of pride. And in the Philippines has also led to some very healthy copycat restoration as neighboring towns and villages see the benefits--fisheries, timber and coastal protection--set against the unproductive dead no-man's land of abandoned or unproductive aquaculture--and want the same.

How is technology, such as satellite-monitoring, helping mangrove restoration and conservation?

Mangroves have often lost out in large-scale satellite mapping. Even where they are extensive there are challenges for expert mappers to determine what's what due to the complex reflections from a habitat that is sometimes waterlogged, sometimes just wet, and sometimes hyper arid.

Meanwhile in many areas this problem is compounded by the fact that mangroves are narrow strips tracing the shore, with bright reflective water on one side and often completely different land use on the other. From a satellite that makes them very difficult to make out.

But with good resolution data, and with expert interpretation and verification we can make them out very well indeed. That's what this new atlas has done for the first time at a global scale. We've used mapping expertise from the Food and Agriculture Organization of the United Nations and from the UNEP World Conservation Monitoring Centre, but such maps have benefitted immensely from expert review, verification, and quite often correction. We had a network of over 100 experts feeding into this project and that has made a huge difference.

And its only when you've got the images that you can start to measure extent and change. All too often its numbers and statistics that start to turn heads and change policies, so we need reliable mapping in the first instance to make the case for management. And with that we can also start to use the same imagery for other purposes--for the design of protected areas systems, for planning for restoration, and, importantly now, planning for the proposed changes arising from sea level rise.

How does this atlas help land developers make more sensible decisions about land use? How can conservation groups use it to assist their efforts in shoring up protection of habitats?

The Atlas is a very high altitude overflight--you wouldn't use it for navigation on the ground, but it's a critical stock-take at a global and a regional scale.

Some of the most fascinating stories come from comparisons. The contrasts between countries can be shocking, with different government policies showing up quite clearly on the maps. Some countries such as Malaysia and Tanzania have state ownership of mangroves and have attempted to manage them sustainably. Others, such as the Philippines effectively privatized their mangroves, selling or leasing vast areas to aquaculture development.

The detailed descriptions which fill this Atlas give a wealth of examples, not just stand-alone, one-off stories. Such facts, backed up by repetition, and by good solid numbers and reliable science, should lie at the heart of coastal development decisions--do you want to make money fast, for a few years, from aquaculture, or have a regular good income, with employment for hundreds of people, from sustainable use? Can aquaculture be done differently? (Yes!).

And of course the conservationists need these lessons too. We need to learn from experiences round the world.

Mangroves can be restored, quite easily in fact. Mangrove plantations, using native species, can be good for wildlife as well as for timber production. How can ecotourism be developed in mangroves?

Does the atlas show any global connectivity between the last patches of mangrove forests? I was thinking specifically if certain animal species (birds, fish) need mangroves for way stations or as crucial places for their life cycles?

Mangroves are disappearing relatively fast, and some authors have talked about the end of mangroves, but I think this book shows that we're not yet dealing with "the last mangroves"--we don't know how much we've lost, but there are still many. And about a quarter are in protected areas, which is higher than for most other habitat types. That said the connectivity story is a great story to tell.

First off we need to think about how mangroves connect with adjacent areas. The big, obvious connection is fish and shellfish. Many, many offshore fisheries rely on mangroves which are critical spawning and nursery areas.

Quite a few governments and fishers don't even realize this connection. Australia benefits tens of millions of dollars annually from its prawn capture fisheries in northern waters which are almost entirely mangrove dependent--and the same can be said for Malaysia, the Guianas and many other areas.

Many coral reef fish too, utilize mangroves and adjacent salt marshes moving between the three like a connected whole. But in this case mangroves are also functionally critical--holding back sediments and stripping nutrients from the waters, enabling reefs to flourish in adjacent waters.

But there are global connections too. The most striking of course are the migratory birds--the Coppename Monding Nature Reserve in Suriname extends along just 50 km [35 miles] of coast, but is host to 1.2 million migratory shorebirds each year. These are the same birds familiar as summer arrivals in temperate countries to the north and south of the equator--that nest in vast numbers in the coasts and marshes of northern Europe, the USA, Canada and Russia.

Mangrove loss outpacing destruction of land-based forests, UN reports
UN News Centre 14 Jul 10;

14 July 2010 – Despite restoration efforts by some countries, mangroves are being lost at a rate three to four times higher than land-based forests, with one fifth of all of the world’s mangroves thought to have been lost in the past three decades, according to a new United Nations report.

Mangrove losses have slowed to 0.7 per cent annually, but the authors of the new atlas – the first global assessment of mangroves in more than a decade – warn that any further destruction due to shrimp farming and coastal development will result in significant economic and ecological declines.

Mangroves – forests straddling land and sea – are believed to generate up to $9,000 per hectare, a strong argument in favour of mangrove management, protection and restoration.

The global area of mangroves, some 150,000 square kilometers, is equivalent to the area of Suriname or half of the Philippines.

“Together, the science and the economics can drive policy shifts,” said Achim Steiner, Executive Director of the UN Environment Programme (UNEP).

He noted that 1,200 protected areas are safeguarding one quarter of the world’s remaining mangroves while many countries are embarking on major restorations, “a positive signal upon which to build and to accelerate a definitive response in 2010, the UN’s International Year of Biodiversity.”

More than 100 top mangrove researchers and organizations provided data, reviews and other input for the World Mangrove Atlas, a joint effort of UNEP, the UN Food and Agriculture Organization (FAO), and other groups.

“Mangrove forests are the ultimate illustration of why humans need nature,” said Mark Spalding, lead author of the publication, which he noted illustrates the “extraordinary synergies” between people and forests.

Mangrove forests endangered
Aaron Cook The Sydney Morning Herald 15 Jul 10;

Global mangrove forests are being lost up to four times faster than land forests, the first international assessment in more than a decade has shown.

The World Atlas of Mangroves is the outcome of a five-year research collaboration headed by the United Nations Environment Program.

It says about one-fifth of global mangroves have vanished since 1980; the present rate of loss is 0.7 per cent a year. The assessment estimates that close to 50,000 square kilometres, one-quarter of original mangrove cover, has been lost as a result of human intervention.

Mangroves, which inhabit fringe areas between fresh water and salt water systems, are mainly lost due to urban development or to make way for agriculture or aquaculture, such as shrimp farms.

Australia has the world’s third largest mangrove coverage at 7 per cent of the global total. Only Indonesia and Brazil have more.

But Professor Richard Kingsford, director of the Australian Wetlands and Rivers Centre at the University of NSW, says Australia enjoys a rate of mangrove loss below the global average.

According to the most recent study, Australia had lost about 14 per cent of its mangroves up to 2001.

"The main cause of mangrove loss in Australia remains urban development," Professor Kingsford said. "But because a large amount of Australia’s mangroves are found in undeveloped areas along the north and east coast, the loss has been less than in other countries."

Professor Kingsford said mangroves were disappearing much more rapidly in neighbouring South-East Asia, where rampant shrimp farming was the primary culprit.

Achim Steiner, executive director of the UNEP, highlighted the "immense costs those losses have had for people as well as nature", while pointing to the importance of conservation policies.

"Together, science and economics can drive policy shifts," he said. "Protected areas are now safeguarding around a quarter of remaining mangroves and many countries are now embarking on major restorations."

Professor Kingsford said Australia’s restoration efforts were limited.

"Rehabilitation is happening a little bit, but it’s not a major rehabilitation effort," he said. "It’s much easier to prevent than restore mangrove loss, and much cheaper."

But he also highlighted the potential for increasing losses in line with rising sea levels. Mangroves follow sea water inland, posing a problem when urban areas get in the way.

He said protected mangrove forests near urban areas, such as those around Sydney Olympic Park, could be lost with rising sea levels.

Mangroves Report Reveals Threats & Opportunities to Global Economy & the Planet
UNEP 14 Jul 10;

'World Mangrove Atlas' highlights the importance of and threats to mangroves

July 14, 2010, London/Nairobi - The first global assessment of mangroves in over a decade reveals that rare and critically important mangrove forests continue to be lost at a rate three to four times higher than land-based global forests, despite positive restoration efforts by some countries.

About one fifth of all mangroves are thought to have been lost since 1980. Although losses are slowing at 0.7 per cent a year, the authors warn that any further destruction due to shrimp farming and coastal development will cause significant economic and ecological decline.

Economic assessments provide some of the most powerful arguments in favour of mangrove management, protection or restoration. Studies estimate that mangroves generate between US$2000-9000 per hectare annually, considerably more than alternative uses such as aquaculture, agriculture or insensitive tourism.

The new atlas also underscores positive trends. Restoration efforts now cover some 400,000 hectares, as foresighted countries make the link between these coastal forests and economically-important services from flood defenses and fish nurseries to carbon storage to combat climate change.

Achim Steiner, UN Under-Secretary General and Executive Director, UN Environment Programme (UNEP), said: "The Economics of Ecosystems and Biodiversity, which is hosted by UNEP is bringing to the fore the multi-trillion dollar value of the world's nature-based assets. This atlas brings our attention onto mangroves and puts them up front and central, plotting where they are, describing where they have been lost, and underlining the immense costs those loses have had for people as well as nature".

"Together, the science and the economics can drive policy shifts. Some 1,200 protected areas are now safeguarding around a quarter of remaining mangroves and many countries are now embarking on major restorations-a positive signal upon which to build and to accelerate a definitive response in 2010, the UN's International Year of Biodiversity," he added.

"Mangrove forests are the ultimate illustration of why humans need nature," says Dr. Mark Spalding, lead author of the World Mangrove Atlas and senior marine scientist with The Nature Conservancy. "In place after place the book details the extraordinary synergies between people and forests. The trees provide hard, rot-resistant timber and make some of the best charcoal in the world. The waters all around foster some of the greatest productivity of fish and shellfish in any coastal waters. What's more, mangrove forests help prevent erosion and mitigate natural hazards from cyclones to tsunamis - these are natural coastal defenses whose importance will only grow as sea level rise becomes a reality around the world."

"Given their value, there can be no justification for further mangrove loss. What's urgently needed is for all those working in fields of forestry, fisheries and the environment to work together and communicate their worth, both to the public and to those with the capacity to make a difference", said Emmanuel Ze Meka, Executive Director of the International Tropical Timber Organization (ITTO) which provided the bulk of funding for the Atlas. This book goes a considerable way to communicating that message."

"The Nature Conservancy is an organization with its feet firmly on the ground in 30 countries," said Mark Terceck, CEO of the Conservancy. "Already we have teams working to protect and restore mangroves from Florida to Indonesia, Palau to Grenada. This book raises the stakes and engenders urgency, but it also offers hope. These are robust and resilient ecosystems. Get things right for them and the payback will be immense: security for rich biodiversity and a lifeline to many of the world's most vulnerable people."

Key Findings from the Atlas

Loss and restoration

* The global area of mangroves - 150 000 square kilometers - is equivalent to the area of Suriname, or the state of Illinois, or half the area of the Philippines. Mangrove forests straddle land and sea and are found in 123 countries in tropical and subtropical regions.

* The nations with the largest mangrove areas include Indonesia with 21 per cent of global mangroves, Brazil with 9 per cent, Australia 7 per cent, Mexico 5 per cent and Nigeria with 5 per cent.

* The greatest drivers for mangrove forest loss are direct conversion to aquaculture, agriculture and urban land uses. Coastal zones are often densely populated and pressure for land intense. Where mangroves remain, they have often been degraded through overharvesting.

* Where vast tracts of mangroves have been cleared for shrimp aquaculture, fast profits often left a legacy of long-term debts and poverty, which are hard to reverse.

* According to the FAO (Food and Agricultural Organization) mangrove losses have been considerable and are continuing. Some 35,600 square kilometers were lost between 1980 and 2005.

* While there are no accurate estimates of the original cover, there is a general consensus that it would have been over 200,000 square kilometers and that considerably more than 50,000 square kilometers or one-quarter of original mangrove cover has been lost as a result of human intervention.

* Mangroves have now been actively planted or encouraged to grow through activities such as site clearance and the removal of waste. Examples include Australia, Bangladesh, Benin, Brazil, Cuba, India, Indonesia, Pakistan, Philippines, Thailand and Vietnam.

Use and ecological niche

* Mangroves contribute to livelihoods locally and globally by providing forest resources such as timber, firewood and thatching materials as well as non-timber products.

* They are also recognized as an important greenbelt and carbon sink that protects coastal areas from natural disasters such as tsunamis, cyclones and erosion resulting from sea-level rise especially in small island countries.

* There is good evidence that mangroves even reduced the impact of the 2004 Indian Ocean tsunami in a number of locations.

* There is also considerable storage of organic carbon in mangrove soils, meaning they may have an important role to play in the process of mitigating climate change. Preliminary estimates indicate that the total above-ground biomass for the world's mangrove forests may be over 3700Tg of carbon, and that carbon sequestration directly into mangrove sediments is likely to be in the range of 14-17Tg of carbon per year.

* Mangroves are also among the most important intertidal habitats for marine and coastal fisheries. Mangrove related species have been estimated to support 30 per cent of fish catch and almost 100 per cent of shrimp catch in South-East Asian countries, while mangroves and associated habitats in Queensland, Australia support 75 per cent of commercial fisheries species

Policy and solutions

* The destruction of mangroves is often prompted by local decisions, market forces, industrial demand, population expansion or poverty. However, in many countries, the fate of mangroves is also determined by high level policy decisions.

* In the Philippines, as an example, state-wide encouragement of aquaculture dating back to the 1950s led to massive losses. In Malaysia, by contrast, state ownership of mangroves prevails. While there have still been losses, large areas remain in forest reserves, managed for timber and charcoal production, with concomitant benefits for fisheries.

* Trends of mangrove gain or loss can be rapidly and quite dramatically reversed. Laws addressing the placement of aquaculture standards or water quality pollution minimization have greatly altered the shape of new aquaculture developments in many countries.

* New policies and projects have led to widespread mangrove plantation across the Philippines. Policies have led to the offsetting of mangrove loss by replanting or restoration with examples in Florida (US) and Australia.

* Many countries, such as Mexico, Belize, Tanzania and Mozambique, have also established general legal protection for mangroves, controlling destructive activities through strict licensing systems.

The Atlas

* The atlas brings together an unprecedented partnership of organizations - from forestry and conservation sectors and from across the United Nations - and includes a new and comprehensive map and account of mangrove forests.