Disturbing news continues to emerge from beneath the waves. In December, science journals reported that disappearing deep-sea species could trigger an ocean-wide collapse of sea life, that global warming is destroying coral — and that loss of top predators is knocking ocean ecosystems out of whack.

That’s just some of the bad news. The oceans are in peril, and therefore, so are we.

Oceans are a key driver of the climate processes that make Earth inhabitable. Fish are an important protein source for people everywhere. About 100 million people who live along coastlines of tropical developing countries earn their livelihood from the sea. Caribbean coral reefs alone generate over $4 billion in services from fisheries, tourism and coastal protection.

We’re killing our oceans through consumption and pollution. Oceanographer Sylvia Earle estimates about 100 million tons of wildlife are pulled from the sea annually. Commercial fishing boats catch virtually everything that swims by in gill nets that act as invisible underwater fences or on 60-mile longlines. Some are unintended victims: young or low-value fish, seabirds, marine mammals and sea turtles are tossed overboard, dead or dying — about 30 million tons of wasted life.

High-impact fishing methods are rapidly emptying the sea, disrupting food chains fine-tuned over millions of years. They have essentially eliminated the easy-to-catch dinner table fish, pushing fishing operations farther out into the deep ocean where species are more fragile.

Heavy nets used by industrial bottom trawlers ravage crucial habitat, ripping up sea grasses and coral forests that are up to 2,000 years old. Water quality grows ever poorer, fouled by a witch’s brew of pollutants running off the land or dumped at sea. Nutrients, mostly fertilizers and sewage, have created 146 “dead zones” in the world’s oceans, with oxygen levels so low that marine life cannot survive.

Research by marine biologist Boris Worm projects that all commercial seafood species could collapse within 40 years due to overfishing, loss of habitat, and pollution.

Scientists are just beginning to calculate the impact of another pollutant: carbon dioxide. Oceans absorb almost a million tons of carbon from the atmosphere per hour, roughly 10 times the pre-Industrial Revolution rate. This massive influx of carbon dioxide is changing water chemistry, making oceans more acidic than they’ve been in 650,000 years.

Acidic seawater is toxic to eggs and developing fish, and inhibits the ability of corals, certain plankton and other animals to build shells — and corrodes them. Coral reefs, already dying from warming waters, could develop symptoms similar to osteoporosis. These “rainforests of the sea” are home to a quarter of all ocean species during some portion of their lives — and since 1980, about 20 percent have disappeared.

That’s the bad news. There’s good news, too. Last January, the revised U.S. Magnuson-Stevens Act adopted an ecosystem approach to ocean protection, mandating an end to overfishing and bycatch of protected species — and protection for deep-sea corals. Other nations, including the UK, Australia and New Zealand, are also changing fishing practices.

About $30 billion dollars in global subsidies support the rapacious fishing practices that threaten the world’s fish stocks. In 2001, the U.S. spent $867 million on subsidies, second behind Japan’s $3 billion. In November, the World Trade Organization proposed to eliminate most fishing subsidies.

Some are calling for an international scientific council to assess the oceans similar to the Intergovernmental Panel on Climate Change that studies global warming — and for a UN political process addressing ocean issues.

Research has shown that reefs rebound when completely protected. We need to conserve critical ocean areas, while sustainably managing fishing and tightening pollution controls. For the health of the planet, we must address climate change now — but need to brace ocean ecosystems for what lies ahead by reducing other pressures.

We have turned things around before. After World War II, about 120 whale species were on the brink. Conservation efforts saved the whales — at a time when people were much less environmentally conscious than today.

We’re all participating in the oceans’ demise. We can also be part of the solution by making informed choices in restaurants or at the fish counter. We don’t have to eat swordfish or tuna, the apex predators that are the lions of the sea. Our survival is not dependent on eating orange roughy that lives 1,500 feet down and is devastated by fishing because it doesn’t reproduce until it’s 30 years old.

If you need inspiration, take your child or grandchild to the aquarium or the beach. Vote for candidates that understand we’re facing an environmental crisis — individuals who will fight to put the health of our planet above corporate profits.

We can secure an enduring future for life on Earth and maintain a home where we can prosper — or not. The next 10 years may be the most important in the next thousand. This should excite, inspire and motivate us.

Sharon Guynup’s first book is titled “State of the Wild 2006: A Global Portrait of Wildlife, Wildlands, and Oceans.” She writes on science and the environment for national magazines and websites. © 2007 Blue Ridge Press.