Sturgeons can live for up to 100 years, and grow to 5 meters in length. The majestic fish have been around for 250 million years, and are one of the oldest inhabitants of our rivers and lakes. Because sturgeons migrate, dams cut them off from much of their spawning grounds. After they have lived through dramatic upheavals through the ages, sturgeons are now driven to extinction by a few decades of human intervention. The Chinese Paddlefish has, for example, most likely been extinct by dam building in the last few years. Overall, sturgeons are the most threatened group of animals on IUCN's Red List of Threatened Species. Eighty-five percent of them are at risk of extinction, with 63 percent of species listed as critically endangered.
The new Global Biodiversity Outlook, an in-depth review of the planet's biodiversity, shows that sturgeons stand for a global trend. We continue to lose biodiversity at a rate which is up to 1000 times higher than historical rates. "Natural systems that support economies, lives and livelihoods across the planet are at risk of rapid degradation and collapse," the new report finds.
According to the IUCN's Red List, 17,291 out of the 47,677 assessed species are threatened with extinction. Seventy percent of plants, 37 percent of freshwater fishes, 30 percent of all known amphibians, 28 percent of reptiles, 21 percent of all known mammals, and 12 percent of all known birds are under threat.
The five principle pressures driving the loss of biodiversity are habitat change (for example through dam building), overexploitation (through over-fishing), pollution (such as pesticide run-off), invasive alien species and climate change. The report warns that if these factors are not addressed immediately, ecosystems will reach "tipping points" with massive, irreversible loss of biodiversity and their related services to human society.
"The arrogance of humanity is that somehow we imagine that we can get by without biodiversity," says Achim Steiner, the Executive Director of the United Nations Environment Programme (UNEP). Yet biodiversity is the foundation of our agriculture, our health, our safety and our economy. Losses due to deforestation alone may already amount to $4.5 trillion per year.
Rivers and lakes are close to my heart. The new report finds that "rivers and their floodplains, lakes and wetlands have undergone more dramatic changes than any other type of ecosystem, due to a combination of human activities." The reasons include pollution, drainage of wetlands and water abstraction for agriculture and industrial development, and dam construction.
Two thirds of the world's large river systems have become fragmented by reservoirs and dams. The new biodiversity report warns:
"A single freshwater ecosystem can often provide multiple benefits such as purification of water, protection from natural disasters, food and materials for local livelihoods and income from tourism. (...) More than 40% of the global river discharge is now intercepted by large dams and one-third of sediment destined for the coastal zones no longer arrives. These large-scale disruptions have had a major impact on fish migration, freshwater biodiversity more generally and the services it provides. They also have a significant influence on biodiversity in terrestrial, coastal and marine ecosystems."
The Global Biodiversity Outlook was prepared by the Convention on Biological Diversity and UNEP, as one of the milestones of the International Year of Biodiversity. The report includes a strategic plan, which will be discussed by the UN General Assembly in September and the annual meeting of the Biodiversity Convention in October 2010. The plan proposes measures such as expanding and strengthening protected areas, preventing pollution, restoring ecosystems, and improving the efficiency in the use of land, energy, freshwater and materials.
The new report argues that for a fraction of the money mobilized immediately by governments to avoid an economic meltdown, we can avoid a much more serious and fundamental breakdown in the Earth's life support system. Will governments muster the political will to take the necessary actions? We owe it to the majestic sturgeon - and quite possibly to ourselves.
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