World leaders attending the U.N. climate conference in Copenhagen most likely will not discuss the invasion of the jellyfish, but perhaps they should. While it might sound like the stuff of a B horror movie, millions of jellyfish – some the size of refrigerators – are swarming coastlines from Spain to New York and Japan to Hawaii. Last month, these marauders sank a 10-ton fishing trawler off the coast of Japan after the boat’s crew tried to haul in a net containing dozens of huge Nomura jellyfish – giants who can weigh up to 450 pounds each.

The best way to fight this growing menace is with our forks.

Scientists believe that a combination of climate change, pollution and overfishing is causing the boom in jellyfish populations. Leaving animals, including fish, off our dinner plates will combat all three problems.

Unless you’ve been living under a rock – or perhaps in a McDonald’s – you probably know that raising animals for food is not doing the planet any favors. Today’s meat factories spew greenhouse gases, gobble up precious resources, contaminate the air and pollute the water. According to a U.N. report, the meat industry generates 40 percent more greenhouse gases than all the cars, trucks, SUVs, ships and planes in the world combined. Hello, jellies: Almost all jellyfish breed better and faster in warmer waters.

Animal factories are also among the causes of ocean “dead zones,” as excrement from factory farms makes its way to streams and rivers and, ultimately, to the open seas, resulting in toxic algae blooms. While other sea animals die off in dead zones – hence the name – jellyfish not only survive but also thrive.

The commercial fishing industry must also share the blame for the jelly boom.

The U.N.’s Food and Agriculture Organization reports that 80 percent of the world’s fisheries are now either overexploited, fully exploited, significantly depleted or recovering from overexploitation. That’s not surprising: Indiscriminate fishing practices, such as the use of miles-long nets and longlines with thousands of individually baited hooks, are stripping the oceans clean of sea life. And fish farms make the devastation of our oceans even worse, as many farmed fish are fed ocean-caught fish. It takes about 3 pounds of ocean-caught fish to produce just 1 pound of farmed fish.

A study published in the journal Nature found that the number of large predatory fish – such as tuna and swordfish – has declined by 90 percent. These are the same fish who help keep jellyfish populations in check. In the Mediterranean, overfishing of both large and small fish has left jellyfish with few predators and little competition for food.

While jellyfish invasions are a nuisance to beachgoers and a burden to businesses – swarms of jellyfish have decimated fishing industries in the Bering and Black seas, clogged water-intake pipes at nuclear power plants in Japan and forced beach closings from the Great Barrier Reef of Australia to Waikiki in the United States – they are also a sign of a more profound problem.

According to Dr. Josep-Maria Gili, a leading jellyfish expert in Spain, “These jellyfish near shore are a message the sea is sending us saying, ‘Look how badly you are treating me.'”

We need to take steps now to improve the health of our oceans – before they become fit only for jellyfish. While our world leaders debate the best ways to curb climate change and end overfishing, we don’t have to wait. Each of us can start eating our way to a smaller ecological footprint simply by choosing healthy, sustainable vegan foods that are easier on the planet and its inhabitants.

Paula Moore is a research specialist for People for the Ethical Treatment of Animals. Content was made available by MCTCampus.