Scientists highlight the resurrection of extinct animals as both a strong possibility and a major potential conservation issue

sj387 — Mon, 23 Dec 2013 09:54:30 +0000

Resurrection of several extinct species, the increasingly accelerated loss of wild rhinoceroses and a disastrous financial response to unburnable carbon are just some future global conservation issues flagged up in this year’s Horizon Scan, recently published in Trends in Ecology and Evolution.

Professor William Sutherland and Dr Mark Spalding are amongst the 18 scientists who took part in this year’s Horizon Scan, seeking to identify potential future conservation issues in order to reduce the “probability of sudden confrontation with major social or environmental changes”.

One such plausible issue is the resurrection or re-construction of extinct species, such as the woolly mammoth, passenger pigeon or the thylacine (a carnivorous marsupial). However, though there may be many benefits to the restoration of these animals, such a high-profile project could lead to attention and resources being diverted from attempts to thwart current threats to non-extinct species’ survival.

Professor Sutherland said ‘There has been discussion of this idea for some time but it is now looking more practical and the idea is being taken seriously. A key issues is whether this is really a conservation priority’.

Though the last woolly mammoth died around 4000 years ago, methods such as back-breeding, cloning and genetic engineering may lead to their resurrection. Not only could these extinct animals, and others such as the thylacine and the passenger pigeon, be re-constructed and returned to their native environments, they could potentially be used to “provide tools for outreach and education”.

However, though this would be a conservational triumph, it could also hamper efforts to protect animals that are currently facing extinction, as both attention and resources would be diverted from preserving existing species and their habitats. Furthermore, there has not been any investigation into the “viability, ethics and safety of releasing resurrected species”, nor the effect their presence may have on indigenous flora and fauna.

Another potential conservational issue identified by the Horizon Scan further highlights the problems facing species today. ̽��ֱ��loss of wild rhinoceroses and elephants is set to reaccelerate within the next few years, partially stimulated by a growing desire for ivory and horn.

In 2013, it is estimated that over 600 rhinoceroses were poached for their horn in South Africa alone, out of a total global population of less than 26,000. Though an increased human population and proximity to growing infrastructure is partially responsible, organised crime syndicates and intensive hunting carry the weight of the blame. In the Asian countries that use it, rhinoceros horn is more expensive than gold. Demand for the precious horn is ever increasing, resulting in elevated levels of poaching. If attention and resources are diverted from the protection of these majestic animals, we may have yet more candidates for resurrection in the future.

Altogether, this group of scientists identified the top 15 potential conservation issues (out of an initial group of 81 issues). In addition to the above topics, extensive land loss in southeast Asia from subsidence of peatlands, carbon solar cells as an alternative source of renewable energy, and an emerging fungal disease amongst snakes, have also been voted as plausible threats that need to be stopped before they can be realised.

Scientists from across the world have “scanned the horizon” in order to identify potentially significant medium and long-term threats to conservation efforts.

There has been discussion of this idea for some time but it is now looking more practical and the idea is being taken seriously

Professor William Sutherland

E.J. Keller Baker

Thylacine, or Tasmanian tiger

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Mangroves could survive sea-level rise if protected

tdk25 — Wed, 31 Jul 2013 07:44:32 +0000

Mangroves, which provide a natural coastal defence to communities around the world, may be able to withstand a future rise in sea levels far more than previously thought, scientists have found.

Their report should serve to allay fears that many mangrove areas could be lost in the coming decades as sea levels go up because of global warming.

It comes, however, with a cautionary note: ̽��ֱ��authors, who have carried out a rare and detailed survey of how mangroves adapt to their environment, also argue that it is vital that they are managed and conserved so that they can continue to provide this protection.

̽��ֱ��survey warns that human activity on land – such as the damming up of rivers or the felling of trees to create shrimp ponds – is currently a far greater threat to many mangrove habitats than the effects of climate change on sea level.

Mangroves – trees and shrubs which grow in saltwater, coastal environments – play a critical role in protecting thousands of shoreline communities in tropical and subtropical regions from floods, storms, and other hazards.

Their densely-packed, overground root systems can absorb wave energy and reduce the velocity of a sudden surge of water. In the 2004 tsunami, for example, mangroves were sometimes the difference between life and death for people whose homes lay in the path of the giant waves which crashed into shorelines around South Asia.

For some time, scientists have been concerned that if sea levels rise as predicted, they will kill off mangroves – removing these natural coastal defences at the very time they are expected to be needed most.

̽��ֱ��new study suggests that this is far less likely than previously thought, however. Dr Anna McIvor, from the ̽��ֱ�� of Cambridge, and the report’s lead author, said: “Although we can expect some mangrove areas to be lost as sea levels rise, many of them appear to be able to withstand it.”

“In fact, changes to mangrove habitats through human activity are likely to pose a bigger threat to these coastal defences than sea level rise as it stands. Our research has enabled us to find out more about how mangroves continue to flourish in spite of a rise in sea levels – but that information should be used as the basis for better management of these important ecosystems.”

̽��ֱ��study was carried out by a team from ̽��ֱ��Nature Conservancy, Wetlands International, and the Cambridge Coastal Research Unit (based in the ̽��ֱ��’s Department of Geography). ̽��ֱ��researchers examined both recent reports looking at surface elevation in mangrove areas, and the historical reasons why mangroves have, in some places, persisted for thousands of years.

They found that the height of the soil surface in mangrove areas is often “surprisingly dynamic”, and in some cases appears to be building up at rates of between one and 10 millimetres every year. ̽��ֱ��global mean sea level rise is currently 3mm per year, meaning that many mangrove areas build up soil at a rate which keeps pace with the sea.

There are several reasons for this, but chief among them appear to be the ability of mangroves to trap sediment as it is carried down to them by rivers, and the work of their roots beneath the surface. “Mangroves provide much of the organic sediment matter that makes up the soil, their complex roots help to bind and trap the sediments on the soil surface, while the unseen growth of roots beneath helps to build up the soil from below,” McIvor said.

Despite this resistance to changes in sea level, however, the report cautions that the future stability of mangroves is by no means guaranteed. “Threshold rates of sea level rise are likely to exist, beyond which mangrove surfaces are no longer able to keep up,” the authors point out.

Perhaps more urgently, in some regions human activities like agriculture and construction are being authorised regardless of their impact on the ecosystems which enable mangroves to thrive.

In some countries, for example, rivers which play a vital role by carrying sediment to the mangrove areas so that the soil can be built up are being dammed or diverted. Another common threat is aquaculture: in Indonesia, and other South Asian countries, mangroves are often cut down without restriction to make way for shrimp ponds.

̽��ֱ��report also warns that mangroves may need room to expand landward, especially where conditions are such that sea level rise may still be a threat to their growth. Communities which rely on them for coastal defence need to leave space to ensure that this can happen, the authors advise.

Dr Mark Spalding, from ̽��ֱ��Nature Conservancy and the Department of Zoology, ̽��ֱ�� of Cambridge, said: “This report shows that well-managed mangroves in many places will continue to support and safeguard many vulnerable communities as sea levels rise. We still have lots to learn about them, but the sensible, precautionary approach is to look after them and restore them as a critical first line of defence.”

̽��ֱ��full report can be downloaded at: http://coastalresilience.org/science/mangroves/surface-elevation-and-sea...

For more information about this story, please contact Tom Kirk, Tel: 01223 332300, thomas.kirk@admin.cam.ac.uk

Human activity is currently a bigger threat to mangroves, and the natural defences they provide against storm surges and other coastal disasters, than rising sea levels, according to a new study.

Although we can expect some mangrove areas to be lost as sea levels rise, many of them appear to be able to withstand it.

Anna McIvor

Wikimedia Commons.

Mangrove trees along a coastline, Everglades National Park.

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̽��ֱ�� of Cambridge - Mark Spalding

Scientists highlight the resurrection of extinct animals as both a strong possibility and a major potential conservation issue

Mangroves could survive sea-level rise if protected