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Page 1 : Results 1 to 5 on 8
404 - Marine protected areas : what is their impact on fishing?
May 2012
In 2005, there were more than 5,000 marine protected areas across the globe. These reserves assist in preserving biodiversity. And yet, the impact on fishing has not yet been demonstrated. The Amphore( 1) programme, coordinated by the IRD and involving French and West African laboratories, provides a detailed economic and biological survey. Four reserves of varying size and age were studied in closer detail, including two in West Africa: one in Senegal, the other in Mauritania. A ban on fishing operations within protected areas only gives rise to a small increase in the total fish biomass, although there is an improvement in population diversity. The observations and models carried out by researchers show that halieutic resources are greater outside of protected areas, in zones that can be exploited by fishermen. The larger the area of the reserve, the more positive the effect. However, the creation of vast protected areas can cause problems, particularly in heavily anthropized areas, and requires participatory management.
389 - Cards reshuffled in Saharan geopolitics
November 2011
Since the early 2000s the Sahara has come back strongly into the international political and media arena. The whole region is going through a period of turbulence stemming from its growing economic and strategic importance and a highly confused geopolitical environment. This situation stems from the “Arab spring” events, the fall of Colonel Gaddafi and the installation of Al Qaeda Organization in the Islamic Maghreb (AQIM) in Mali.
A special issue of the journal Hérodote has published review articles on these upheavals by IRD geographers and economists and their and their research partners. Beyond the geopolitical and security aspects, they describe the economic changes, the development of the trans-Saharan migrations and the race for raw materials pursued by the world’s great powers. All these powers seek the underground wealth the region conceals (such as oil, uranium, iron). Simultaneously coveted and feared, the Sahara never ceases to arouse concern in the international community.
373 - Increasing rice production using genes from the African species
May 2011
Rice is the world’s most commonly used cereal food, feeding half of humanity. However, rice production will have to double within 20 years from now to meet the needs of a growing population.
Two species are used for cultivation, one Asian and the other African. The Asian species gives much stronger agronomic performances, but the African one is more rustic, more resistant to pathogens, more tolerant to drought and soil salinity.
With the aim of transferring these properties to Asian rice, IRD scientists and their research partners( 1) are seeking to overcome the sterility between the two species( 2). They used genome sequencing to compare the structure of a portion of chromosome, identified as the factor behind the reproductive barrier. These investigations, the first results of which were published recently in the journal PLoS One , have led to the definition of genetic markers allowing more rapid development of fertile lineages of improved Asian rice.
369 - Africa at a population turning point
March 2011
In the coming decades, the West African countries could benefit from a demographic window of opportunity to reduce their poverty. The arrival of 160 million young people on the labour market between 2010 and 2030 could accelerate economic growth. These countries could take advantage of this “demographic dividend”, which the emerging countries have been doing for 40 years. On condition that they lower their fertility rates, are still the highest in the world, with an average of five children per woman. That would enable them to reduce the number of economically non-active people being supported for each active individual..
An IRD researcher asserts this in a review published recently by the Agence française de développement (AFD), concerning a far-reaching survey( 1) conducted in 12 West African countries( 2): family planning and promotion of contraception are some of the main keys to sustainable economic growth. Yet to arrive at such a situation, these countries must assign 3 to 5 times the means currently given over to such a policy. Will they be able to manage this population turning point successfully?
353 - The Great Green Wall: how to check the advancing desert
June 2010
The desert has been nibbling away at the Sahel’s fertile land for several decades. To halt this advancing desertification, 11 African countries( 1) have come together to build a “Great Green Wall”. This immense project, initiated in 2005, aims to replant with trees a 15 km wide strip stretching 7000 km across the Africa, from Dakar to Djibouti.
A community of international specialists, including IRD researchers, has been mobilized to ensure that this wall of greenery will be as effective as possible. Their objectives are to choose the revegetation techniques and the best adapted species. These experts( 2) are focusing on a natural process which functions in most plant species: symbiosis between the plant and a fungus. Favouring this process would improve plant growth in degraded soils and increase their drought resistance. A tree with remarkable properties( 3) is one of the various recommended species that will be used: the filao tree, which can fix nitrogen from the air and hence colonize impoverished land.
It remains to be determined how the project can be integrated into an environment which is already used and how to enable the local communities to benefit from it.
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