2 resultados para 3D vision
em Aquatic Commons
Resumo:
Ce rapport présente les activités et les résultats de l’atelier Vision 2050: Changement climatique, pêche et aquaculture en Afrique de l’Ouest. Les objectifs de l’atelier étaient de discuter les questions critiques et les incertitudes auxquelles est confronté le secteur de la pêche et de l’aquaculture au Ghana, au Sénégal et en Mauritanie, d’élaborer des scénarios sectoriels pour 2050 et de discuter de l’implication de ces scénarios dans le contexte du changement climatique pour ces pays et la région ouest africaine.
Resumo:
Shallow coral reefs in the IndoPacific contain the highest diversity of marine organisms in the world, with approximately 1500 described species of fish, over 500 species of scleractinian corals, and an estimated 1-10 million organisms yet to be characterized (Reaka-Kudla et al. 1994). These centers of marine biodiversity are facing significant, multiple threats to reef community and habitat structure and function, resulting in local to wide-scale regional damage. Wilkinson (2004) characterized the major pressures as including (1) global climate change, (2) diseases, plagues and invasive species, (3) direct human pressures, (4) poor governance and lack of political will, and (5) international action or inaction. Signs that the natural plasticity of reef ecosystems has been exceeded in many areas from the effects of environmental (e.g., global climate change) and anthropogenic (e.g., land use, pollution) stressors is evidenced by the loss of 20% of the world’s coral reefs (Wilkinson 2004). Predictions are that another 24% (Wilkinson 2006) are under imminent risk of collapse and an additional 26% are under a longer term threat from reduced fitness, disease outbreaks, and increased mortality. These predictions indicate that the current list of approximately 30-40 fatal diseases impacting corals will expand as will the frequency and extent of “coral bleaching” (Waddell 2005; Wilkinson 2004). Disease and corallivore outbreaks, in combination with multiple, concomitant human disturbances are compromising corals and coral reef communities to the point where their ability to rebound from natural disturbances is being lost.