Tuesday, May 15, 2012

The Sixth Great Extinction

There is a recent report, "The Living Planet Index", from World Wildlife Fund and the London Zoological Society that spells out the bad news for other life on Earth. Species are becoming extinct at a rate 10,000 times faster than natural {08.05.07}. Biodiversity, especially in the tropics, has declined by about 30% since 1970. We as a species consume resources at a rate of 1.5 times Earth every year. The scientific teams tracked nearly 4,000 species, and conclude the causes of the increased extinctions are all aspects of human activity on the planet: climate change, pollution, destruction of habitat, spread of invasive species, and overexploitation. The ultimate impact of biodiversity loss on human life cannot be denied. Food supplies will become more vulnerable to pests and disease, and water will be in irregular or short supply. International pledges to reduce loss of biodiversity are already moot given the current rate of resource exploitation. Nations attending the Convention on Biological Diversity in Bonn will have to confront an embarrassing failure to take effective action.

critically endangered Goliath grouper
A case in point are the sub-family of groupers (Epiphelinae). Groupers are large fish related to sea bass often inhabiting coral reefs. Their meat is highly regarded; consequently they are being fished to near extinction by man. A team from the International Union for Conservation of Nature (IUCN) has studied 163 grouper species worldwide for ten years. They report that 20 species are at risk of extinction if human predation continues at current levels. An additional 22 species are near threatened. The study results are published in the journal, Fish and Fisheries. The animals suffer from a human perception that the world's ocean resources are infinite, which cannot be farther from the truth. The scientists estimate that 90,000,000 groupers were caught in 2009. Often they are sold in markets still dying and are the highest priced. But groupers are top reef predators and play a large role in their ecosystems. They are also very slow breeders, taking 5-10 years to mature which makes them vulnerable to population collapse when they are overfished. Grouper farming has not mitigated the depletion of wild stocks. It is up to humans to make better culinary choices and avoid species whose existence hangs in the balance. US Person simplifies the equation for the math challenged: healthy wildlife = healthy humans.