Balch is concerned that only half of industrial carbon dioxide emissions can be found in the atmosphere. That means the other half must be sinking into the sea, which covers three quarters of our planet. Recent reports show that while carbon dioxide has been increasing since the Industrial Revolution that began in England at the end of the 18th century, half of all emissions have taken place since 1980. Human-made carbon dioxide has been found in the ocean to depths of 1,000 meters.
Carbon dioxide levels are higher than theyve been in geological time, or millions of years, he says. If you dissolve carbon dioxide in water, youre making it acidic. If you start to acidify the ocean, that could have amazing impacts on everything from the physiology of animals and plants to the survival of phytoplankton.
Phytoplankton and carbon
Also known as limestone, calcium carbonate acts like miniature antacid tablets buffering the oceans acidity to a neutral range. As human-produced carbon dioxide from fossil fuels works its way into the sea, coccolithophore calcite helps stabilize the oceans acidity, keeping it from increasing to unhealthful levels.
Balch and his colleagues recently returned from a month-long voyage to the equatorial Pacific Ocean to investigate how carbon dioxide is being cycled between the atmosphere and ocean. Emissions of carbon dioxide are significantly high in the region. It is also an area of intense upwelling and high concentrations of nutrients. These two factors should encourage algae production, yet biomass is low. Balch suspects some of the reasons for the low productivity include the limited availability of iron or silica acid, which would stimulate growth.
Another possibility is intense grazing of phytoplankton by microzooplankton. As he explains it in his travel log of the voyage, Imagine a highly productive field that is being regularly mowed so the biomass of grass remains low, even though it is still highly productive.
All this effort will help answer questions such as, Are our oceans getting warmer? If they are, it could be part of global climate change and it could mean drastic changes in habitat and species affecting commercial fishing. Such subtle things as Arctic oscillationthe global forces that ultimately drive winds in our tiny Gulf of Maine are studied to determine changes over decades.
Were not just an isolated body of water here in the Gulf of Maine, Balch says. Very large-scale climatic changes affect the mixing in our gulf, which affects the phytoplankton and zooplankton all the way up to the upper trophic levels on which we humans rely.
Balchs federally funded research trips are basically work and not much play. On his voyage to the equatorial Pacific, he started a typical day at 1:30 a.m., worked till 9 a.m., took an hours nap, worked till dinner, practiced jazz trombone for a half-hour, and turned in about 8 p.m. The ship, and the work on board, continues 24 hours a day. A welcome diversion was stopping at a National Oceanic and Atmospheric Adminstration buoy near the Equator, which acted as a fish magnet, and Balch and others caught enough Wahoo and tuna to feed all hands for two dinners, plus make sushi.
There were moments of beauty, too. Balch wrote in his log: During our steam to Tahiti, there were clear skies and no moon early in the evening, which provided the most spectacular star-gazing of the trip. My New Years Eve was spent on the forepeak of the Revelle, picking out constellations and watching spectacular bioluminescence in the bow wake.
Balch said we comprehend only a small percentageperhaps five percentof the inner workings of the worlds oceans. That leaves scientists with a long way to go. Balch and company have embarked on that voyage, traveling vast distances to study some of the smallest things in the sea. These organisms have such a profound effect, not just on people, but on the whole biosphere, he says.
© 2005 The Gulf of Maine Times