n° 61 September-October 2011
p. 2 News p. 7 to 10 Research p. 1 News
M alaria is regressing. Progress in control made in 10 years has been spectacular. The annual report of the partnership Roll Back Malaria , published on 12 September 2011, has revealed that mortality across the world fell by almost 40%. In Africa, where the great majority of cases occur, “ at least 11 countries have recorded a decrease by over a half in the number of patients and associated deaths ”, states the study. A real success which the report attributes to the reinforcement since 2001 of worldscale action for preventive measures and health care.
Although scientists are unanimous about the record results obtained over the past ten years, several questions remain unresolved. One of them, concerning the contribution attributable to prevention measures, is still uncertain. In fact, some areas, where no vector control measures have been implemented, are nonetheless seeing a substantial fall in the number of patients. This is the case for Tanzania where the number of mosquito vectors –called Anopheles– decreased by more than 99% between 2003 and
2009. Apart from intervention programmes, the climate seems also to have a role to play. Other recent studies point to the main unknown factor for hoping one day to see the end of malaria: the vectors’ strong adaptability. Better knowledge of its physiology is necessary for developing secondgeneration arms against them. Mosaic mosquito nets, combining several types of insecticides, traps and odours, currently at prototype stage, or again hormonal confusion techniques, are promising possibilities being considered by researchers.
T he small dams installed in Sub-Saharan Africa have been indispensable elements in developers’ array of facilities for many decades. Are they living up to their promise? The answer is a highly mitigated one, suggests an
IRD researcher in a recent publication devoted to the subject. These facilities appear not to be meeting all the objectives intended for them when they were built, but they have acquired an irreplaceable role in the daily lives of rural African societies, particularly from the manifold uses they lend themselves to.
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T he results published this early autumn in the journal Nature
Climate Change by an international team are causing concern among specialists of the marine world. When two specific measured parameters of sea water –temperature and acidity– rise simultaneously, the calcareous parts of certain marine organisms are irreversibly destroyed. However, some of the conclusions put forward do bring hope.
The scientists showed that the two species of coral studied, but also mussels and limpets, have the ability to build their skeleton in spite of the acidification of sea water. This goes against most studies conducted in this sphere demonstrating that in acidic water, most calcifying organisms see their capacity for constructing their calcareous skeleton or shell diminish.
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I ncreasing uniformity of people’s ways of life, the rise in obesity, health policies, countries of the South…
Between preconceived ideas and real situations in the field, two studies made in the Mediterranean context have brought some qualified answers. From 2007 to 2011, the programme on obesity and nutritional changes ‘‘ Comprendre la transition nutritionnelle au Maghreb pour contribuer
à la prévention de l’obésité et des maladies non transmissibles associées ’’ (
OBE
-Maghreb) has been probing the question. Beside this, a recent study run by the
IRD and three Tunisian institutions among adolescents is giving a new insight on the modernization of diet.
p. 4 Partners p. 3 News
T he whereabouts of the cradle of the tropical rainforests is being called into question. Researchers have shown recently that the palms, characteristic of these ecosystems, began to diversify about
100 million years ago in the Northern Hemisphere.
T he “Black Atlantic”, the name given to the diaspora born of the slave trade from Africa to the New World, is at the centre of debate in Mexico and Central America. There are problems of social insertion and citizenship, issues concerning the definition of mixed national identities. In contrast to Brazil and Colombia, symbols of multiculturalism, the
«black question» in the countries of the Central American isthmus and Mexico has not up to now attracted much interest among politicians. The debates have long been dominated by problems concerning the Indian populations. In contrast, even just a few years ago the Afro-descendants had not had any real visibility.
The work forms part of the programme Afrodesc which will finish at the end of 2011. The activities of this international project, backed by
ANR and
AIRD
, have been conducted since 2008 in close conjunction with the European programme
EURESCL
.
L ake Chad, observed from the ground or from space, appears as a surprisingly fluctuating hydrological feature, a mosaic of fertile land and areas of shallow freshwater with manifold uses. Fishing, livestock rearing and agriculture intermingle to form one of the most productive natural environments of the African Sahel. It is also a lake whose water resources are vulnerable, both to the vagaries of climate but also to intensive agricultural practices developing on its catchment basin.
Understanding of the impact of these uses on the sedimentary flows, better simulation of the lake’s response to climate, quantification of aquifer resources, are some of the scientific prerequisites essential for detailed assessments of the consequences of large international projects devoted to ensuring the development of areas neighbouring the lake. This feature presents some of the research projects the
IRD and its partners are running around this lake which has become symbolic of the rapid environmental changes taking place in Sub-Saharan Africa.
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H ow can high quality fish be produced by drawing on local resources? A Senegalese entrepreneur is taking up knowledge and know-how developed at the
IRD and is rising to the challenge. Guy Gohier and research scientists from the
IRD have thus worked in concert towards the progressive adaptation of a variety of Tilapia: the “ marquis argenté du Sénégal ”. This fish tolerates the salinity rates of sea water while conserving flesh with high eating quality much appreciated by consumers. The technology of the scheme is based on the Integrated Recycling Aquaculture System for treating organic and mineral components.
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H ow can a small volcanic island be shown to its best advantage? Equatorial Guinea has found a solution original. Horacio, a small 5 hectare patch of land 200 m from the coast is now doted with a "nature-culture" trail, inaugurated in summer 2011 in the presence of the major partners. The project is founded on the working plan devised by a specialist mission from the
IRD which is project supervisor. The visitor follows a pathway between land and sea arranged with alternating basalt stones and wooden footbridges marked with sculptures created by a local artist. Eight interpretation points highlight the different trades of the region, the culture, vegetation and the fauna. The site is intended to become a place where the biodiversity and cultural richness of Equatorial Guinea can be promoted, to reach school and academic publics, national researchers but also tourists. This aim is doubled with a scientific objective.
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O rganized by the
E n v i r o n m e n t a l
Research Observatory
(
HYBAM
), the meeting
"Hydrology and Present
Geodynamic of South American Basins" was held recently in
Lima, Peru. Universities and services in charge of water resources in South America took part, in particular those from the
Amazonian Basin. The data gathered by the Observatory go beyond the bounds of hydrology and geodynamics, feeding into a wide range of disciplines. These go from geophysics, to environmental geochemistry, and climatology to ecology and the study of coastal processes. This represents an overall approach essential for an understanding of the pnemonena at work at the scale of an entire basin.
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T he plant biodiversity of Laos is especially rich, but still poorly known. Only half of the 8000 to 11000 species of plants the country harbours have been described. The National Herbarium, inaugurated in summer 2011 in Vientiane, will change the situation. The National Herbarium of Laos will come as support for the conservation policy of the recently created Ministry of the Environment. This new realization was born thanks to the initiative Sud Expert Plantes . The new facility will allow the recording and assessment of the number of species, their distribution and their protection status.
I n the Red Sea, the Seychelles and more recently off
Réunion Island, a spectacular series of shark attacks, killing or injuring bathers and surfers, has received intense media coverage. A total of 83 accidents have been counted in the world for the first nine months of 2011 alone, 12 of them fatal. Does this mean the phenomenon is on the increase? The question is on everyone’s lips. In terms of the absolute figure it is indeed the case, the world inventory of attacks by sharks showing a regular progression of their number. Does it show a change in sharks’ behaviour?
Nothing is less certain, as they are predators long adapted for their function and their environment. Humans, however, are increasingly present in maritime areas and the probability of fatal encounters inevitably increases. Humans are much more dangerous for sharks than the other way round! The cartilaginous fish in general (sharks and rays) are subject to intense fishing. In 2009, production registered by
FAO reached 720 000 tonnes, regressing since 2003 when it attained 900 000 tonnes. To this must be added undeclared catches and individuals thrown back, estimated at 700 000 tonnes. In all, these extractions could reach 1.5 million tonnes per year. Sharks represent a considerable economic interest. The market for fins, for example, reaps an annual 37 billion dollars, according to 2003 estimates, as high a yield as drugs! The price per kilogram of dried fin is thus higher than 500 euros and a bowl of soup will cost 100 euros!