SEA CHANGE: Marine maladies have garnered a lot of recent news coverage, punctuated today with a study reporting that the world's oceans may face "imminent" changes due to warming and acidification. A research team led by Dr. Glenn De'ath — no, not that Dr. Death — found coral growth on the Great Barrier Reef has slowed more than 14 percent since 1990, a steep plunge unprecedented in the last 400 years. Carbon dioxide and rising sea temperatures are leading suspects in the plight of coral and many similar species, whose demise would cripple oceanic food chains. The Christian Science Monitor explains how climate change actually hinders the construction of these animals' shells and skeletons. (Sources: The EconomistAgence France-PresseScience, Scientific AmericanCS Monitor)

CAREFUL WHAT YOU FISH FOR: Not only are oceans increasingly warm and acidic, but rampant overfishing has reduced many wild fish species near or past the point of no return. The Economist has a sobering special report this week surveying the devastation wrought by fishermen gone wild. Among the grim standouts: Cod haven't been spotted in Canada's Grand Banks in 16 years, 90 percent of large predatory fish are gone and so are 85 percent of large whales. Overfishing has gotten so bad, in fact, a University of Michigan scientist reported today that increased fish farming, despite its own environmental dangers, could be necessary to save wild stocks. (Sources: The Economist, CBC)

COAL CASE: Famed NASA climatologist James Hansen wrote a long-winded but clear-headed open letter to both Barack and Michelle Obama today, calling for a carbon tax, a phase-out of all coal plants that don't capture CO2 and "urgent R&D" on fourth-generation nuclear power. (Source: Grist

AIR ABERRANT: Hong Kong's street-level air quality was worse in 2008 than any year since 2000, when official roadside pollution measurements began there. A local think tank says at least 10,000 deaths in Hong Kong, Macau and Southern China are caused by the area's runaway air pollution each year. (Source: AFP

JET-SET OFFSETS: A new kiosk opening at San Francisco International Airport this spring will let travelers buy carbon offsets, which in theory cancel out some of their carbon footprint by preventing CO2 emissions elsewhere. It'll be the first time an airport has gotten into the offsetting business; consumer experts often criticize the fuzziness of the math involved, and suggest calculating your own emissions footprint before shopping for offsets. (Sources: The New York Times, The Guardian)

OLD AND IN THE WAY: America's few remaining old-growth forests — full of huge trees that can be thousands of years old and have complex canopies — are scattered and difficult to protect, according to a recent report (PDF), which partially blames the vagueness in classifying a forest as "old-growth." The phrase was thrown around a lot in late November, when President Bush pushed to allow logging on nearly 1.8 million acres of Oregon old-growth forest that's also the northern spotted owl's last refuge. (Sources: The Christian Science Monitor, National Council for Science and the EnvironmentThe Los Angeles Times

Russell McLendon

Russell McLendon ( @russmclendon ) writes about humans and other wildlife.

Last Call: 01/02
Oceans face a sea change — from coral and krill to killer whales. Can fish farming save fish? Also: James Hansen's open letter to Obama, Hong Kong's bad air, Sa