Friday, July 24, 2009

Riders of the Storm: Do dragonflies really make epic journeys across the Indian Ocean like sailors of old?

“They come in by their hundreds, like fighter planes in an old war movie” says Terence Vel, referring to the swarming of dragonflies, cigal in Creole, towards the end of each year on Mahe island. Terence runs Dragonfly Watch, an educational program set up by Nature Seychelles at the Sanctuary at Roche Caiman.

Terence and I have noticed that for some species, particularly the Wandering Glider also known as the Globe Skimmer (Pantala flavescens), the breeding is obscure but large numbers suddenly appear at the Sanctuary at Roche Caiman especially in the Northwest monsoon.

Thursday, July 23, 2009

Remembering George. G. Shor

George G. Shor Jr, Professor Emeritus of geophysics at the Scripps Institution of Oceanography in California, USA died on the 3r of July . My father is probably the only person in Seychelles who remembers George Shor and gave me some details of his trip to our waters.

Shor's distinguished career included helping develop the United State’s consortium of oceanographic research ships and the creation of the California Sea Grant program. But for the countries of the Western Indian Ocean it is worthy to note that his studies included pioneering research in our region and helped lay the foundation for the theory of tectonic plates, one of the most important concepts in earth sciences.

Tuesday, July 21, 2009

Killer mosquitoes on mission to save mankind

Mad scientists load blood-sucking flying insects with toxic chemical bombs which are then dropped killing millions of their own kind. Science fiction? Think again. Not-so-mad researchers working in the Amazon city of Iquitos in Peru, have turned normal adult mosquitoes, the Dengue (and Yellow Fever) carrier Aedes aegypti, into infanticidal beasts by making them carry an insecticide to their breeding sites thus killing most of the eggs and larvae living there.

The insecticide, placed in resting areas of the mosquitoes, will stick to the insects’ bodies when they fly off to aquatic habitat to lay eggs. There, the insecticide will destroy immature mosquitoes at that site and wherever else they fly to deposit more eggs.

This is a huge breakthrough in mosquito control, say experts. It replaces costly and not very effective spraying of habitats, many of them hidden and cryptic, where mosquitoes lay their eggs and larvae develop. The method is also relevant to small island states where human settlements are clustered in coastal areas because it involves the control of mosquitoes that develop in small, protected aquatic habitats in urban areas

The senior author Gregor J. Devine and his colleagues from the UK, Peru, Tanzania and the US have published this work entitled “Using adult mosquitoes to transfer insecticides to Aedes aegypti larval habitats” in the Proceedings of the National Academy of Sciences (PNAS) of June 29

The insecticide used is called pyriproxyfen which is an equivalent of an insect juvenile hormone. In the study it was placed at dissemination stations in a known resting area of mosquitoes in a cemetery in Iquitos. The pyriproxyfen was placed in only 3 to 5 percent of the total resting area, but it destroyed 42 to 98 percent of mosquitoes about to emerge at each breeding site.

Pyriproxyfen does not interfere with the fundamental behaviors of mosquitoes because it is neither lethal nor repellent to adults. "It is the act of oviposition (egg-laying) that contaminates the aquatic habitat, so the technique explicitly and precisely targets the mosquitoes' preferred breeding sites." the paper says.

Pyriproxyfen is also harmless to humans It is registered for public health use and the World Health Organization states that it is safe for drinking at 300 parts per billion, which is 1000 times the dose used by the researchers in the study.

Globally, 50 million dengue infections annually result in 500,000 cases of dengue hemorrhagic fever and 22,000 deaths. The most severe form of the disease, dengue haemorrhagic fever (DHF), strikes a half million people a year. Dengue is spread by Aedes aegypti as well as the Asian Tiger Mosquito Aedes albopictus, a widely occurring mosquito in Seychelles

The results of this study have now raised hopes that not just Dengue but other mosquito borne diseases can finally be controlled in our lifetime.

Dengue - Island Fever or Urban Disease?

Local health authorities are worried about a new Dengue outbreak in neighboring countires and have warned travelers to be on their guard and to avoid certain places. Dengue is spread by the Asian Tiger Mosquito (ATM) Aedes albopictus , and another mosquito Aedes aegypti These mosquitoes are also responsible for spreading Chikungunya.

In 1977 about 75% of the Seychelles population suffered from a Dengue epidemic. Another epidemic occurred in 1978 and 1979. Environmental health authorities speculate that the next epidemic will originate from an infected person arriving from overseas and will affect a large proportion of the population.

Some Dengue infections can lead to hemorrhagic fever. This is where blood vessels start to leak and cause bleeding from the nose, mouth, and gums. Without treatment, the blood vessels can collapse, causing shock and sometimes death.

Persons who have been infected with one or more forms of Dengue virus are at greater risk for the more severe hemorrhagic fever. There are 4 viruses that cause the disease and there are no vaccines yet to immunize people against them. With the increase in all types of virus, the occurrence of Dengue hemorrhagic fever becomes more likely, say physicians

Every year about 50 million people become infected with Dengue worldwide. The return of Dengue and the proliferation of mosquitos like the ATM are making the disease a global health threat on the same level as malaria.

The spread of Dengue reflects the ability of diseases to spread in an increasingly globalized and modern world. As with alien and pest species, the constant movement of goods and people create efficient pathways for diseases and their vectors.

Climate change, especially changes in temperature which the mosquito vectors are sensitive to, and increased precipitation (and thus more aquatic habitats being made available) can lead to increase in numbers and in their range. Global warming is definitely a factor in the spread of the disease.

The prevalence of the disease has also increased with the expansion of urban and suburban areas. Seychelles is one of the most urbanized countries in Africa and there are high densities of ATMs in our urban areas. The population of this mosquito has doubled since the 1960’s. Investigators found that flower pots and discarded containers are the main sources of breeding in and around houses in Seychelles.

Changes in lifestyles in Seychelles have resulted in more and more containers being made available for mosquito breeding. Health officials have suggested that a law on mosquito control should be established and strongly enforced. This and other measures become more urgent as other changes may also result in the growth of mosquito populations.

Thursday, July 16, 2009

Climate Change increases Cyclones

For someone living on a small tropical island it’s scary to think that tropical storms may be getting worse over the years. Indeed, more evidence is piling up that global warming is increasing the intensity and number of cyclones and hurricanes. In 2005, two papers created quite a stir in the scientific community. One by Kerry Emmanuel demonstrated that in the last 50 years there had been a substantial increase in the power of cyclones in the West Pacific and Atlantic and, the other by P.J Webster and colleagues, portrayed a substantial global increase of almost 100%) in the proportion of the most severe tropical cyclones from the period from 1975 to 2004. (

Now a study published in the journal Marine Environmental Research shows that, incredibly, there has been a 5 fold increase in cyclones in the Arabian Sea since 1995. In fact the increase has been in what is described as “most intense cyclones”. The 1995-2007 periods has seen five times the number of these cyclones than in the previous 25 years from 1970 to 1995

The paper entitled “Response of the Arabian Sea to global warming and associated regional climate shift” by Prasanna S. Kumar and colleagues states that it’s not just the number but also intensity of these cyclones which has increased. Cyclones with a wind speed greater than 100 km per hour are termed as ‘most intense cyclones’.

The authors say that “The response of the Arabian Sea to global warming is the major disturbance in the natural decadal cycle in the sea surface temperature (SST) after 1995, followed by a secular warming”.

The “signatures of this climate-shift are also perceptible over the adjacent landmass of India as progressively warmer winters, and decreased decadal monsoon rainfall.” The climatic changes have “possible impact on frequency and intensity of cyclones, summer monsoon rainfall, wheat production, land vegetation cover and frequency of heat spells.” Since more than 80 per cent of the rainfall over India occurs during summer monsoon, it is expected to have a major influence on the vegetation cover.

These climate changes have led to a rainfall deficiency of 71 mm during 1995-2005 compared to deficiency of 8 mm during 1985-1995. The rainfall deficiency could also lead to a drinking water crisis.

Increases in intensity and number of cyclones, hurricanes and other storm events do not bode well for the Indian Ocean region. It may mean that countries in our region which at present are not directly affected by cyclones will feel the full impact of these changes in the near future.

Cyclone experts say that in recent years the world has experienced an increase in economic damage and disturbance by tropical cyclones. Large loss of human life will continue in developing countries, they say. Projected sea level rises should also be of concern in the context of society’s vulnerability to cyclone-induced storm surges. This is because the main cause of death in the major cyclone disasters in history has been salt-water flooding associated with storm surges.

In a Statement on Tropical Cyclones and Climate Change authored by participants of the WMO International Workshop on Tropical Cyclones in 2006, it is stated that "Despite the diversity of research opinions on this issue it is agreed that if there has been a recent increase in tropical cyclone activity that is largely anthropogenic in origin, then humanity is faced with a substantial and unanticipated threat." (

Friday, July 10, 2009

Sorghum Superhero and the divide between African mainland and island states

The 2009 World Food Prize, worth USD 250,000 has been awarded to Dr. Gebisa Ejeta an Ethiopian who is professor of agronomy at Purdue University in the US. ( Ironically, the prize flags up the divide between mainland Africa and at least one of its island states.

Known as the Sorghum Superhero, Ejeta has been honored for developing Africa's first hybrid and high-yielding sorghum varieties tolerant to drought and the devastating Striga seed. This in turn accelerated crop productivity and gave rise to the first commercial sorghum seed industry in Sudan. By 1999, one million acres of the hybrid had been harvested in Sudan, says the Science and Development Network (

But Ejeta’s work is seemingly irrelevant to us here in Seychelles. Sorghum is so little know in this African island nation that it has no local name. I have tried in vain to quiz experienced agronomists and farmers in Seychelles for a Creol name for Sorgum. Whilst sorghum is one of the most essential grain crops in Africa (made into breads, porridges, and beverages), its importance in Seychelles has been supplemented by rice and wheat and others such as maize.

Yet, sorghum grows well in Seychelles. At the award winning Heritage Gardens at Roche Caiman, Nature Seychelles has grown three harvests of sorghum with little effort. But because this grain is not utilized by the local population, the birds have befitted from nutritious feed.

My father, coming from an Indian tradition, gave me the seeds to plant at the Heritage Garden. He himself had grown the plant many years before on a property by the sea so he knew that it would do well here. He even tried to mill the seeds and make bread out of it.

Rice and wheat are not grown in Seychelles but are imported. On the other hand Sorghum grows very well. So why is it we are not growing this important food plant? Is it simply out of tradition and “what came first”? Whatever the case, should we not be eating foods that we can grow locally instead of relying on imports to satisfy some of our basic nutritional needs?

After last year's global food crisis, national food security strategies in many countries have taken on board a very important element of self suficency, abandoned by so called modern economies some time ago in favour of focusing on competitive advantages. We should start doing the same right here in Seychelles.

Tuesday, July 7, 2009

Resilient Ecosystems- a comment on the economic crisis

I flew into Mumbai, India last year on December 21, the same day the modern wing of the Taj Mahal Hotel was re-opened after being damaged during the Mumbai terror attacks. Yes, the heritage wing of the hotel which had almost been gutted was still closed but the official re-opening in the presence of a packed crowd of India’s glitterati proved to many the resilience of the people of Mumbai.

Resilience is a word that is bandied around nowadays. Much of what we know about resilience as a science comes from a relatively new discipline in ecology which has generated many papers and books. To some, especially those working on issues to do with small island developing states (SIDS), resilience is the other face of vulnerability. Many vulnerable human and natural ecosystems display resilience, or not, when hit by shocks.

In simplistic terms a resilient ecosystem, be it human or natural, is one that can withstand shocks and rebuild itself when necessary. Just as the people of Mumbai seemingly bounced back after the horrific attacks, so it is that resilient ecosystems have the ability to absorb blows and come back to some state of “normality” without much delay. But, it’s never that simple. The state that emerges after shocks may be somewhat different. The raucous, easy, free-wheeling democracy that was previously evident in Mumbai has now given way to a police regulated city with heavy security installed at hotels, cinemas and historical sites and police check points set up everywhere.

Inevitably, we see resilience now being used in the context of the global economic crisis. Pundits, journalists and pop-economists are debating which country will be more resilient in managing the crisis. For us in Seychelles we have a double whammy to cope with; the national debt servicing plus the economic woes of the developed world which provides us with tourists, investment and development assistance.

I believe Seychelles as a nation displays many aspects of resilience necessary to rebuild its system. But not all parts of the system will end up the same as before, meaning not all parts of society will be able to withstand the blows as well. There are similar situations in natural ecosystem. Studies of impacts of cyclones and hurricanes show that water quality and phytoplankton productivity in the sea for example– a measure of the health of the food web – are impacted by winds and heavy rainfall, but return to normal within months. Not all components of the marine system are equally resilient. After hurricanes, many coral reefs suffer massive damage and the ecosystem can shift to a different regime, one that may not be as productive or diverse.

Monday, July 6, 2009

Chagos-The most pristine marine environment on earth?

Diego Garcia, in the Chagos archipelago, is back in the international news with the release of a new book in the United States entitled Island of Shame: The Secret History of the U.S. Military base on Diego Garcia, by David Vine. It is what the publishers call a “groundbreaking work that dares to expose the other Guantánamo”. The book was officially launched in Seychelles and Mauritius in June this year. The author will donate all the book royalties to the Chagossians.

Seychellois, especially those of a certain generation, have a good knowledge of the Chagos. The coconut plantation on Diego Garcia was managed from Seychelles. My father's company on Mahe provided fuel and supplies once upon a time to the Chagos and also exported the copra from there. The Chagossians who returned to Seychelles integrated into our society, with their Association still very active.Many other people around the world, through the international media, know about the Chagossians and their fight to return to "Diego "

What is less well known is that many scientists believe that the Chagos - a UK Overseas Territory - is probably the most pristine tropical marine environment on Earth. The archipelago has the world's largest coral atoll, its healthiest reefs and its cleanest seas, they say

A booklet was launched in March this year called The Chagos Archipelago: Its Nature and the Future, to start a discussion on a programme “to create one of the world's greatest conservation areas”. The archipelago is described as comparable with the Galapagos Islands or the Great Barrier Reef in environmental and scientific importance.

The publication flags up the Chagos as the United Kingdom's greatest area of marine biodiversity by far. The area is a crucial refuge, staging post and breeding ground for marine life, it says. The Chagos also provides a scientific benchmark for an environment without degradation; this is important for helping to deal with problems such as pollution, climate change and loss of biodiversity. It calls for people to support these ideas and encourage the British Government to make the conservation area a reality. This is a great start, in my opinion, as it sets aside a very important area of the planet and defers benefits to future generation - hopefully generations of Chagossians whose fate is currently a political hot potato.

Drawing on best practice from other sites, the aims of the conservation area would be: to protect nature, including fish stocks (benefiting countries such as Seychelles in the region); to benefit science, and support action against damaging climate change; and to be compatible with security and be financially sustainable. In my view, one of the major aims should be to provide livelyhood opportunities and environmental services for Chagossians upon their return.

Pollution, overfishing and climate change are affecting the oceans worldwide, but the creation of a conservation area around the Chagos will help preserve this pristine marine environment and secure rich natural heritage that many people say the Chagossians are actually the stewards of.

Wednesday, July 1, 2009

Tsunami predictions are plain wrong

"I just wanted to let you know to stay away from the beaches all around in the month of July. There is a prediction that there will be another tsunami or earthquake hitting on 22 July 2009. It is also when there will be a sun eclipse,"

This is a typical "Tsunami Warning" email message that has been filling my inbox over the last month. The message goes on to say that an earthquake is predicted to hit Japan on July 22nd, which would trigger a Tsunami traveling as far as Seychelles Mauritius and the East African coast.

The prediction is based on one fact: a solar eclipse will take place on July 22nd 2009 directly to the south west of Japan. This eclipse according to the prediction circulating on the World Wide Web means that the gravitational pull of the Sun and Moon pulling together will 1. Lift the earth’s tectonic plates in that region of Asia; 2. Cause the tide to rise more than usual and 3. Cause an underground molten magma tide to dip and raise the plates following the water tide.

On July 22nd 2009, according to this prediction, a 6+ Magnitude Quake will take place at 3:00PM Local Japanese time. This will be followed by two level 5+ Earthquakes and a Tsunami between 5:00PM and 7:00PM. The Tsunami will start out in the Pacific Ocean and hit all the islands to the south west of Japan , Indonesia and New Zealand and also the Western Indian Ocean to Seychelles Mauritius and East Africa.

The prediction, outlined by a computer games developer called Britton La Roche in the US, is based on the following theory. A solar eclipse means that the moon is blocking the sun. The moon has enough gravitational pull to cause the tides and other natural phenomena on earth. The sun has enough gravitational pull to keep the earth in orbit. The theory is that during a solar eclipse, the moon has the Sun's added pull on the Earth's tectonic plates. When the Sun and Moon are together on one side of the planet, they can supposedly pull together and lift up the tectonic plate, just beneath the eclipse. This causes the plate to shift upward, and then an earthquake is generated when the lifted plate gets the little extra push (lift) it needed to move over its neighboring plate.

But this has been pooh poohed by the scientific community. The first to react was the Earth Observatory of Singapore (EOS). Dr. Kerry Sieh of EOS affirms on the EOS website that to date, scientists have not found any significant correlation between solar eclipses and earthquakes. Since 1900, for example, of 82 earthquakes greater than magnitude 8 worldwide, only two occurred close to the time of a solar eclipse. However, these were not only partial eclipses but also far from the locations of the earthquakes. Dr Sieh is visiting from the California Institute of Technology (Caltech) in the US. His principal research interest is earthquake geology. He, students and colleagues are studying the megathrust that produced the devastating giant Sumatran earthquakes and Indian Ocean Tsunamis of 2004 and 2005.

“Earthquakes are not caused by gravitational pull”, says Dr. Kate Hutton, a seismologist also at Caltech, reported by Earthquakes are caused by the accumulation of strain in the Earth's crust, she adds. The U.S. Geological Survey has also stated: "Neither the USGS nor Caltech nor any other scientists have ever predicted a major earthquake. They do not know how, and they do not expect to know how any time in the foreseeable future."

Professor Ian Main of the University of Edinburgh, UK writing in the journal Nature about earthquakes says that in the USA, the emphasis has long been shifted to a better understanding of the earthquake process, and on an improved calculation of the seismic hazard. In Japan, particularly in the aftermath of the Kobe earthquake in 1995, there is a growing realization that successful earthquake prediction might not be realistic. In China, thirty false alarms have brought power lines and business operations to a standstill in the past three years, leading to recent government plans to clamp down on unofficial predictions, he says.

Dr. Chris Rowan a geologist specializing in paleomagnetism, also at the University of Edinburgh writes in his blog that “Any geologist would be celebrating a genuine, proven, method of earthquake prediction: but we're clearly not there yet. Right now, the best we can get is a hazy view of tectonic storm clouds building on the horizon, and we lack even the equivalent of a barometer, let alone advanced tools like weather satellites, to give us a more specific forecast. It would be irresponsible to claim otherwise.”

Poor old Britton La Roche has been dropped in it because he was simply theorizing so that he or others could think about building a Game Simulator. In fact on his blog he says “This is a theory and I have no background in earth science or seismology. In short, I have no valid qualification to back this prediction.” But the media and the internet community have reacted as if this was a scientific fact and have managed to stir panic throughout Asia and the Indian Ocean region