After centuries of over-harvesting and bouts of disease, oyster populations in the Chesapeake Bay plummeted along with profits for the oyster industry and the health of the Bay. In some areas, native oysters are becoming more abundant. But culture and ecology clash as watermen, who depend on harvesting oysters for income, are at odds with scientists and conservationists who want to restore oyster populations. Filmmaker Sandy Cannon-Brown looks at oysters and the people behind them in her documentary "Spat! Bringing Oysters Back to the Bay."

Wood is found in countless products consumers use every day. In fact, lumber is closely connected to the world’s economy – a country’ s importation of lumber tends to rise in correlation with its gross domestic product. Following groups like “Guardians of the Forest,” we explore illegal lumber poaching in the forests of Brazil and Oregon, where citizens and scientists are working together to combat the illegal lumber trade.

Every twenty minutes an elephant is killed to feed an insatiable demand for ivory. African elephants may be gone in as little as ten years. Behind the slaughter are the most dangerous groups in the world – organized crime syndicates, insurgents and terrorists. Ivory buys guns and ammunition for Uganda's Lord’s Resistance Army and Sudan's Janjaweed, both linked to mass atrocities and supports al Shabaab, the al Qaeda affiliate behind the attacks on Kenya’s Westgate Mall and Garissa University.

The ocean is a sponge for all the greenhouse gas emissions we produce, and entire aquatic ecosystems are beginning to collapse. Off the coast of California, the disappearing abalone population is raising flags about ocean health and the lasting impact of rising sea temperatures, acidification and pollution. Various teams of scientists, volunteers and businesspeople are collaborating to protect underwater species threatened by the invasion of sea urchins.

The global demand for oil and gas has long-lasting impacts on the communities that supply it. In Alaska’s Arctic National Wildlife Refuge, powerful native communities are at odds over an oil exploration and drilling plan that will boost their economy but have long-term consequences on native species and their environment. In California’s Kern County, the mayors of two neighboring towns face off on the economic benefits and health risks of oil production and their vastly different visions for the most sustainable path to the future.

The realities of milk production are forcing dairy communities across the globe to rethink the dairy production process. In this episode, we travel to a village in Kenya where the commercialization of camel milk is proving a sustainable solution in the face of drought. In Northern California, the heart of the U.S. dairy industry is finding innovative alternatives to limit the use of water and manure emissions.

Led by Buddhist monks, Cambodia's indigenous Chong people protest the construction of a hydroelectric dam. The dam, to be built by the Chinese company Sinohydro, would displace the Chong and destroy their ancestral forest home. Kalyanne Mam documents their plight in her film "Fight For Areng Valley." China is beginning to draw on its religious traditions — Tibetan Buddhism, Daoism and Confucianism — to help address serious environmental challenges as profiled in Gary Marcuse and Shi Lihong's film "Searching for Sacred Mountain." 

Solar power is changing lives in unexpected places. At the Barefoot College in Zanzibar, Muslim women who have traditionally been marginalized in the workforce are learning solar installation and bringing it back to their villages, which are primarily powered by candles and paraffin lamps. In East Los Angeles, formerly incarcerated individuals are finding green job opportunities as they transition underserved communities into solar power.

This episode features author and illustrator Lynne Cherry's film series "Young Voices for the Planet" about young adults making positive environmental change.

“Vanishing Coral” presents the personal story of scientists and naturalists who are working with local communities to protect coral reefs that are being destroyed by warming seas, pollution, and destructive fishing practices. Featured in the documentary is the President of the Biosphere 2 Foundation Abigail Alling, marine biologist and coral expert Phil Dustan, captain of the Mir research sailing vessel Mark Van Thillo, and Nono Suparno, a leading conservationist in Bali.

Neonicotinoids are the most widely used insecticides in the world. But they've been linked to the decline of honeybees, which pollinate many food crops. And scientists now say neonicotinoids also harm many terrestrial, aquatic, and marine invertebrates. These pervasive insecticides damage sea urchin DNA, suppress the immune systems of crabs, and affect the tunneling and reproductive behavior of earthworms. They kill off insects that many birds, amphibians, and reptiles rely on for food.

Desert tortoises are a threatened species. Habitat destruction, diseases and other factors have reduced their numbers by up to 90 percent. Now flocks of ravens, that often live off human trash, are eating baby tortoises, reducing the odds of tortoise survival as a species. This documentary explores that impact, pointing out how people can change the environment through seemingly innocent actions.

The popular demand for avocados, once considered an “exotic” item, is having a devastating impact on a drought-stricken community in Chile. Lying within one of the largest avocado producing regions in the country, Petorca avocado plantations are in a battle over water rights, where claims of illegal water diversion are creating civil unrest.

Honey bees, the essential pollinators of many major U.S. crops, have been dying off in massive numbers since 2006. This threatens the American agricultural system and the one in 12 jobs that depends on it. There is growing evidence that a new class of pesticides -- nerve toxins called neonicotinoids, which are used on many U.S. crops like corn -- may be toxic to bees.

(Earth Focus: Episode 52) U.S. domestic gas production is on the rise because of hydraulic fracturing, or fracking, a controversial method of extracting natural gas from shale rock by pumping millions of gallons of water mixed with sand and chemicals underground at high pressure. Environmentalists say this gas boon threatens water supplies and pollutes air. Now, as fracking expands around the world, so does growing resistance. "Earth Focus" looks at three countries on the new fracking frontline: South Africa, Poland, and the UK.