Out Thierry Perez's office window, past the crumbling 16th century island prison where Alexandre Dumas set the "Count of Monte Cristo," roils a Mediterranean Sea that didn't exist just a few decades ago.

Major disease outbreaks worsened by warming waters now strike sea life five times more than when Perez, a marine ecologist with the French government, began studying the Mediterranean in the 1990s. Water temperatures have risen two to three times faster than across the world’s oceans at large. Half of the Mediterranean's fish are pushing north, with wrasses and barracuda once native to North Africa now common off southern France.

View Images Populations of bream fish, like these off Marseille in southern France, are expected to decline due to global warming. Warmer and less-oxygenated oceans make it difficult for bigger fish to get enough oxygen to grow. photograph by Boris Horvat

Yet just four hours away by train, international climate negotiators in Paris have been reluctant to even mention oceans in their formal blueprints outlining an action plan for combating global warming. With so much division over how to curb greenhouse gas emissions from deforestation and the burning of coal oil and gas, few global leaders were willing to add something else for 195 battle-weary countries to squabble about.

Ocean scientists streamed into France anyway, coming from around the world to insist the seas get more attention in the United Nations climate strategy. The marine world is too important to overlook, they say, both as a victim of climate change but also as place that can be part of the fix.

"We need to put oceans on the agenda," Vladimir Ryabinin, a Russian marine scientist and executive secretary of UNESCO's Intergovernmental Oceanographic Commission, told a panel of researchers in Paris. "Oceans are the common heritage of all mankind."

From the outside, this battle may seem academic: Negotiators aren't suggesting the seascape that covers 70 percent of earth is unimportant. But many advocates say so much is happening so quickly in these watery environments that oceans need a higher profile that would elevate discussion of their problems and create momentum to solve them.

Already a new proposal to protect the Indian Ocean off the Republic of Seychelles is being highlighted as a model to protect against climate change. Conservationists are turning to complicated financial instruments to raise money for ocean protection in developing island nations.

View Images Fishermen lift bluefin tunas onto their boat off Barbate in Spain. In this traditional technique, nets are used to catch tuna as they migrate from the Atlantic to the Mediterranean. Because of warming waters, bluefin tuna now stick around longer in the sea's western regions. photography by Pablo Blazquez Dominguez

But scientists say policymakers and the public first need to understand how fast changes are coming. For that, says Perez, there's no place quite like the Mediterranean. "It's like its own miniature ocean," he says.

Sponges Die, Flatfish Increase

Stretching from Spain to the Balkans and from Libya to France, the Mediterranean occupies nearly a million square miles. It’s connected to the world’s oceans through the Strait of Gibraltar to the west and the Suez Canal to the southeast.

It's proximity to the climate talks–and that unusual geography that keeps it mostly isolated from other oceans–makes it a microcosm of many problems affecting the seas. Neither a tropical nor polar environment where scientists expected to see problems appearing first, the Mediterranean is, even for Perez, sometimes hard to grasp because it’s experiencing so many changes.

It's here that a colleague stumbled on one of the earliest signs that climate appeared to be altering marine waters. In the late 1980s a disease started killing off marine sponges, some of which had been harvested for 4,000 years. By the 1990s scientists began linking the virulence of the pathogen to the unusual warmth of the water. "It was a very impressive syndrome," Perez says. That was just the beginning.

Before 1995, it was unusual to see 10 major marine-life epidemics in five years. Today, one five-year span might include 50 disease outbreaks, causing die-offs of everything from corals to bryozoans. Some pathogens even drove localized extinctions of some creatures, including a species of sea fan in Italy and a sponge in Monaco.

View Images A long-snouted wrasse swims in seaweed off Costa Brava, Spain. photograph by Reinhard Dirschert, ullstein bild

Temperatures now let invasive species, such as algae-grazing rabbitfish, introduced through the Suez Canal from the Red Sea, explode. Some invertebrates are dwindling because the season for males to mate has changed even though females are still ready to reproduce at the same time they always have been.

And as species move, the entire system is reorganizing. Bluefin tuna now stick around longer in the sea's western regions. In the northernmost stretches of southern France and the Adriatic, where the sea is bounded by land, some animals have no place left to go to find cold water. When that happens, Perez says with a shrug, "Sometimes they die."

Herring-like sprat between Italy and the Balkans have all but disappeared, even though they were barely fished. Sardine populations, on the other hand, are bigger in the north than they've ever been.

Perez acknowledges that it can be hard to tease out the role of fishing and land pollution as partial culprits, but he says warming waters are compounding everything else, often in unpredictable ways.

The fishing industry recently started catching more sole and other flatfish up north. Eventually scientists determined that increased precipitation was filling rivers and giving them more power. As they spilled into the sea, they churned up the ocean bottom, causing more mixing and more production of food for the things flatfish eat.

It's too soon to say where all this is leading, Perez says, but it's clear more attention is needed. He's met fisherman who have given up and switched jobs, and others who are finding new species to catch.

"When we start talking about this to a wider audience, people are very concerned," Perez says. "What's clear is we have a marine population that is just more and more sensitive."

Swapping Debt to Save Oceans

Trying to cushion ocean environments for this kind of havoc is what drove The Nature Conservancy to experiment in the Seychelles. Now other countries may replicate those efforts.

In the tiny archipelago of just over 100 islands, where half the land is already protected, rising seas, storms, pollution, and fishing were harming the coast and nearby reefs. Fishermen using hand-held lines to snag grouper and snapper began noticing that fish they caught for their families and sold to tourists were getting smaller. The commercial fishing industry, facing troubled reefs, started heading out to sea to catch more and bigger species. Some ran into pirates, which drove them back toward land, increasing the fishing pressure near shore.

"Coral reefs are our first physical protection from the ocean," says Ronald Jumeau, Seychelles ambassador to the United Nations. And in Seychelles, now, "they're under strain."

With about 1,000 species of marine fish, 400 of them around their reefs, the government wanted a solution but it had no money to address the rising threats. In fact the government was deep in debt.

That's when Rob Weary stepped in. The Nature Conservancy financial guru has been finding ways to use the creative wizardry of Wall Street–where debt is bought and sold like other commodities–to champion nature. He asked Jumeau if he could investigate a "debt-swap."

That complicated financial transaction would allow The Nature Conservancy to work with the holders of the country's debt to restructure payments on about $30 million. Through loans and grants, The Nature Conservancy would create a fund that the Seychelles government could use for conservation. A governing trust would manage the account.

Similar deals have been done on land, but not for marine conservation. Seychelles said yes, and the organizations spent several years negotiating.

Now the deal is final and plans are underway in the Indian Ocean. The country plans to protect up to 30 percent of the 1.4 million square kilometers of ocean within its exclusive economic zone.

The deal is expected to protect mangrove lagoons home to 11 seabird species and six types of sharks. It will likely set aside some vulnerable coral reefs so they can continue to help block storm surges. Scientists are studying the ocean waters trying to figure out which areas could be protected for use by fishermen and which should be off limits. Some of these areas might even change over time as fish stock rebuild or others warrant protection.

While none of these efforts will forestall climate change, it will help make the country more resilient to the effects.

Jumeau says his government is thrilled with the deal, and now other countries including Palau, the Marshall Islands, and Jamaica have expressed interest in trying something similar. The Nature Conservancy also is experimenting with taking out insurance policies on coral reefs, trying to get the tourism industry financially vested in making sure they stay healthy for the long run.

"We're trying to shift the narrative on oceans," says Andrew Deutz, with the Nature Conservancy. "They should be thought of as part of the solution. There are all kinds of things we can do if we really try."