The vast majority of debris in the ocean — about 75 percent of it — is made of plastic. It can consist of anything from plastic bottles to packaging materials, but whatever form it takes, it doesn't go away easily.
While plastic may break down into smaller and smaller pieces, some as small as grains of sand, these pieces are never truly biodegradable. The plastic bits, some small enough that they're called microplastics, threaten marine life like fish and birds, explains Richard Thompson, a professor of marine biology at Plymouth University in the U.K.
MELISSA BLOCK, BYLINE: This is ALL THINGS CONSIDERED from NPR News. I'm Melissa Block.
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And I'm Robert Siegel. President Obama is once again exercising his executive authority for an environmental cause. Today he announced plans to create the world's largest marine preserve. His proposal came in a video shown at the State Department's "Our Ocean" conference. The White House says it will seek input from fisherman, scientists, and other experts before setting boundaries for the preserve. NPR's Michele Kelemen has our story.
Government officials, scientists and business leaders from more than 80 countries are gathering at the State Department today and tomorrow. They're there to figure out ways to protect the world's oceans and commercial fisheries. Secretary of State John Kerry says this is an issue he's been working on for a long time, as NPR's Michele Kelemen reports.
MICHELE KELEMEN, BYLINE: When Secretary Kerry talks about his hopes for this conference he reaches back deep into his childhood in Massachusetts.
And from food to fuel, corn is a major pillar of the U.S. economy. It's the country's biggest crop. One-third of all U.S. cropland is dedicated to corn. A new study says climate change and unsustainable irrigation practices are a long-term threat to U.S. corn production. The study calls on farmers, governments and businesses to cooperate to head off those negative effects. NPR's John Ydstie has more.
Drive just an hour and a half north of San Francisco, and you're in Drakes Estero, named for the first English explorer to lay claim to California.
This near-pristine, wind-whipped marine wilderness is a federally protected home for large beds of eelgrass, the base of the marine food chain. The estuary hosts the largest colony of harbor seals on the West Coast, and tens of thousands of resident and migratory birds.