Cold Ocean Chemistry: Ocean Acidification turns Alaska’s seas into science lab
Kelsey Gobroski / Sun Star Reporter
May 30, 2011
Jessica Cross loves ocean spray. The oceanography graduate student at the University of Alaska Fairbanks accompanied two lead scientists and a lab technician to deploy a research buoy in March. The weather in the Gulf of Alaska was fair, and they wore bright survival jackets and hard hats. They released the buoy, went home and waited.
Jeremy Mathis was in Washington, DC in late April when he felt a rough tug from his research in Alaska. His new buoy wasn’t broadcasting. The Gulf of Alaska was silent.
They had tested it in the lab – the new buoy was supposed to stream real-time data about ocean chemistry back to researchers. But nothing, save for spurts of information, was coming in. The buoy is tethered to the sea floor, telling scientists what a location in the ocean looks like at multiple depths, Cross said.
“The buoy should send data everyday automatically,” Mathis said. “When it didn’t, we knew there was a problem.”
In April, the buoy still held the data it was collecting internally, but had no way to back itself up without a satellite link, Cross said. Satellite reception starts going funny at high latitudes like Alaska, she said. The only way to know how to adjust the buoy is to put it in the sea and wait for it to soak. When Mathis returned to Fairbanks on May 2, he set to diagnosing what was wrong and how to fix it.
The buoy is part of Alaska’s response to a flurry of research on what will happen to ocean chemistry in the wake of climate change. If you could put cameras in Alaska’s oceans and fast-forward from 1900 to 2100, you would see life change – ocean temperatures rise, populations of shelled animals flounder and entire ecosystems move north with the sea ice retreat.
Without a drop in carbon dioxide emissions, the oceans will continue to harmfully acidify and warm. They will keep changing even when humans stop contributing to the oceans’ new chemistry because the oceans and atmosphere take time to balance out. Scientists know the oceans will change. The changes will be widespread. They do not know what this means for ocean life as we know it – but something will happen. The life that humans depend upon for food and recreation probably won’t be the same. Alaska’s oceans will become Earth’s guinea pig. Scientists can use Alaska to know what to expect elsewhere, because Alaska will change first and will likely change the most. They can chase these effects up the ocean currents, moving ahead to teach communities what to anticipate. Research today helps humanity mitigate tomorrow.
In the middle of March, three students greeted me at UAF’s Ocean Acidification Research Center in Irving. Cross hoisted herself onto a cabinet counter, motioned with an empty Pepsi bottle, and explained what is happening to the oceans.
Plants are the basis of the food chain on land and at sea, Cross said. Little plant-like organisms called phytoplankton munch up carbon dioxide near the surface of the ocean, turning it into oxygen in the same process, photosynthesis, that governs trees and tulips. Once their food is gone, the phytoplankton die. They sink a little, and zooplankton, small floating creatures, gobble them up. The zooplankton also die and sink, down in the ocean where sunlight doesn’t reach, into the grasp of bacteria.
Bacteria are the mushrooms of the ocean, Cross said. They break up the zooplankton and reduce them to carbon dioxide. This carbon sinks further, and the ocean absorbs it.
That carbon dioxide builds up and interacts with the ocean to produce hydrogen ions. Ocean acidification happens when the oceans compensate for all the extra carbon dioxide in the atmosphere. Since the Industrial Revolution, there has been a 25 percent gain in hydrogen ions in the oceans. If humanity were to stop pumping out the carbon dioxide that sinks into the oceans, this process would only continue – another 25 percent, and another 25 percent, thanks to an irreversible lag.
Alaska’s known for its extremes, but contemporary ecosystems depend on year-to-year cycles keeping the same ups and downs. Destructive fire rejuvenates forests, but plants and animals also rely on the steady hand of constants: permafrost, glaciers, sea ice. It is the same in the ocean. The marine ecosystem depends on the cycles of ocean currents and extreme seasons.
The Alaskan coastline is a “hotbed of activity,” Cross said. Phytoplankton blooms intensely in the spring in Alaska, because the cold waters here absorb more carbon dioxide than tropical regions. Carbon dioxide-laden water, which normally drifts deep in the oceans, surges upward once it hits the continental shelf and funnels through underwater canyons around Alaska. The water stirs together, and the new water drifts from the Bering Sea, through the Bering Strait to the Chukchi Sea and on to Canada, Cross said.
“In other regions, you may see similar processes, but here they’re so extreme … and so easy to document and see and look at,” Cross said.
Alaska will be the first to experience ocean acidification. Soon, scientists will be able to watch. Mathis is deploying another buoy in the Bering Sea, and will place one in the Chukchi in October.
Mathis fixed the Gulf of Alaska buoy by boosting the satellite signal. The newborn buoy system will be wobbly at first, but slight adjustments like these will give oceanographers eyes into the seas’ chemistry. The oceans are changing now.
“We are already finding places where the environment could be harmful to certain species during different times of the year,” Mathis said.
There is no way to reverse ocean acidification, but Alaskans try to understand them as scientists, fishers, and consumers. Alaska’s oceans will change first – perhaps the Arctic can lead the world in its mitigation of ocean acidification, too.
This is part 1 of a 3 part series on ocean acidification research at UAF.