Paul Watson

Paul Watson doesn't stay on dry land very much. Last year the tireless eco-warrior was at sea for 50 weeks, and this year he has spent just one week at his home in Washington State. As he puts it: "There's no rest when you're on planetary duty."

Nancy Knowlton

Nancy Knowlton was the founding director of the Center for Marine Biodiversity and Conservation at the Scripps Institution of Oceanography before being hired in 2007 to lead the Smithsonian's Ocean Initiative. As part of this initiative, Knowlton will oversee a new research program and will help develop an ocean Web portal. Knowlton tells Smithsonian.com the problems facing the ocean today—and what we can do to save it.

Ariel Schwartz

Could cyanobacteria eventually become a more popular biofuel than corn, sugarcane, or even algae? Quite possibly. According to Science Daily, cyanobacteria can convert up to 10 percent of the sun’s energy into biomass. This is a drastic improvement over the 1 percent rate of crops like corn and sugarcane, as well as the 5 percent rate of algae. With such a high conversion rate, cyanobacteria could replace a hefty amount of fossil fuels without taking up too much land.

Sylvia Earle

Sylvia Earle is a renowned deep sea diver, National Geographic explorer-in-residence, and former Chief Scientist for the National Oceanic and Atmospheric Administration. When Earle spoke with EarthSky, she spoke on behalf of grasslands, streams, rivers — and especially for the sea. - This is the time, as never before, that the systems that do safeguard and give us life are in trouble. And that means we’re in trouble.