Our Daily Planet: More Dolphin Deaths and Severe Southern Weather

Each weekday morning, OurAmazingPlanet takes the pulse of the Earth, reporting on natural phenomena and exploration news from around the globe.

Grand Canyon Rock Slide: Two hikers were injured by a human-caused rock fall on a trail below the South Rim of Grand Canyon National Park.

Stormy South: A line of severe thunderstorms swept across the southeast yesterday. A tornado was reported in central Florida and strong winds ripped a cruise ship from its dock in Cape Canaveral. Forty homes were damaged in Mississippi by a possible tornado. [Related: Deadly Dixie: Tornado Alley's Lethal Neighbor .]

More Dolphin Deaths: A new study suggests that as many as 50 times more whales and dolphins may have been killed in the Gulf of Mexico by the BP oil spill than reported, though the exact cause is still under investigation.

Shakey Forest Deal: The single biggest forest-protection deal ever, in Canada's Boreal Forest, is at risk. Timber companies, environmental groups and Canadian aboriginal groups are butting heads over the conservation plan.

Cesium in the Seawater: Radioactive cesium has made its way into seawater near the damaged Fukushima nuclear reactors, raising fears that radiation could enter the food chain.

Previously on Our Daily Planet: April Fool's Snow and a Greener Antarctica

Reach OurAmazingPlanet staff writer Brett Israel at bisrael@techmedianetwork.com. Follow him on Twitter @btisrael.