Off the shores of North Island New Zealand, a unique, potentially dangerous phenomenon continues to intrigue scientists and oceanographers worldwide. A huge methane seep, large enough to wreak havoc on Earth’s atmosphere by emission of greenhouse gas, sits 600-1200 meters from the shoreline. The cool waters off the coast of New Zealand teem with a growing ecosystem that teaches environmentalists and scientists how the Earth naturally balances nature.
Methane gas contributes 23 times more pollutants to global warming than carbon dioxide and the seep, discovered in 2006, has concerned environmentalists around the world. The findings, so far, point to the Earth’s natural balancing mechanisms in saving the atmosphere while creating a unique food web.
Fearing the large seep capable of causing an atmospheric disaster, the close monitoring of the region is teaching science about an ecosystem that thrives on the gas emissions and grows constantly.
Worms release methane gas
Black worms called polychaetes, from the Ampharetidae family, dig into the sediment to form tubes, from which methane gas escapes. The seep near New Zealand supports the largest population of these worms of any seep discovered to date.
Bacteria eat methane gas
Microscopic bacteria eat much of the escaping methane. These bacteria metabolize the gas as carbon dioxide. The worms, in turn, feast on the bacteria. This thriving ecosystem is the first science can link to a naturally occurring environmental system protecting the atmosphere from the threat of greenhouse gas emissions.
The number of worms astounds science, as the sea floor is black with them. The more worms that burrow into the sediment, the larger the concentration of methane released into the ocean.
The ongoing study
Funding for the ongoing study of global warming and the biological processes happening to balance the system include the U.S. National Oceanic and Atmospheric Administration and the Federal Ministry of Education and Research in Germany. Each has published its findings on the Internet and in the Limnology and Oceanography journal.
Methane seeps in other areas have undergone studies but do not match the New Zealand discovery is size or worm population. The other seeps sit in deeper waters and do not receive oxygen-rich cooler water flows like the New Zealand seep gets from the Southern Ocean.
The oxygen-rich waters add fuel to the bacteria’s ability to consume gases. With this added factor, the worm population grows with the number of bacteria, and the bacteria multiply as the methane concentration increases.
Too many worms, not enough bacteria
One worry is the worms will over-feed on the bacteria, which would cause methane gases to be released into the atmosphere. The amounts of methane released in the region now could have devastating environmental effects if the bacteria population were to suddenly decline. As of yet, no methane burps appear to escape the waters as the bacteria consume enough to keep the methane from being released into the air.
No one knows how long the ecosystem will stay in balance, as no one has witnessed such a food web before. At present, the worm-methane-bacteria balance keeps the air above the ocean methane-free and the new system thriving. The study will continue into the natural balancing of Earth’s cycles, and this methane seep, not far from New Zealand, is the ideal classroom.
