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The greenest christmas tree is a real tree that you can replant and reuse. 
Jeffrey Coolidge/Getty Images
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Welcome to the Planet 100 for December 23, 2009. Here's what we're covering today:
WATCH VIDEO: Sustainable Seafood App and Alien Frogs
Sustainable Seafood App
With 70 percent of the world's fisheries either in decline or already fished at their capacity, eating fish from endangered fisheries is simply unsustainable.
California's Monterey Bay Aquarium's new iphone app can help seafood and sushi eaters make better choices. The app uses your phone's GPS to automatically determine the right seafood guide for your location, and lets you sort seafood by rank. The sushi guide lists fish by Japanese and common market name so you can say bye bye to blue-fin tuna, or maguro, for good.
Via: Monterey Bay Aquarium
Iphone ©Monterey Bay Aquarium
App ©Monterey Bay Aquarium
Alien Frogs
Residents of Anchorage may find some unexpected gifts hidden in Christmas trees imported from Washington State in the form of Pacific chorus frogs.
Although the non-native amphibians are not poisonous, authorities are concerned that the frogs maybe carrying deadly pathogens—which is why they are asking residents to kill them with an overdose of Oragel analgesic or by freezing them.
The reason why frogs are attached to Christmas trees in the first place? Alaska doesn't require its imported trees be mechanically shaken.
Via: Treehugger.com
Frog ©Maxi Millipede on Flickr
And Finally...
With Christmas around the corner you may be wondering what's greener—a fake tree or a real one. Turns out the fake trees produce relatively less carbon than buying a real one every year. But the best option is a real potted tree that can be reused.
