Tag Archives: global biogeochemical cycles

Deep Biosphere Harbors Active, Growing Communities of Microorganisms

By Guest PostJuly 9, 2013Environmentamino acids, archaea, bacteria, bill orsi, biochemical mechanisms, carbon, cell, cell populations, data analysis, deep biosphere, ecologist, ecosystem, fungi, glenn christman, global biogeochemical cycles, messenger rna, metatranscriptome, microorganisms, model, molecule atp, mrna, nitrogen cycling, ocean drilling program, sulfate reduction, ud, university of delaware, virginia edgcomb, whoi

The deep biosphere—the realm of sediments far below the seafloor—harbors a vast ecosystem of bacteria, archaea, and fungi that are actively metabolizing, proliferating, and moving, according a new study by scientists at Woods Hole Oceanographic Institution (WHOI) and the University of Delaware (UD).

“This is the first molecular evidence for active cell division in the deep biosphere,” says WHOI postdoctoral investigator Bill Orsi, who was the lead author on the study. Previous studies and models had suggested cells were alive, but whether the cells were actually dividing or not had remained elusive. (more…)

Nitrogen From Humans Pollutes Remote Lakes For More Than A Century

By Guest PostJanuary 4, 2012Environmentacid rain, agricultural fertilizers, alexander wolfe, Anthropocene, aquatic archeology, atmosphere, atmospheric currents, biologically active nitrogen, bottom deposits, carbon, chemical composition, chemical signals, climate, daniel schindler, double whammy, earth, effects of pollution, excess nitrogen, fertilizer use, fingerprint, global biogeochemical cycles, gordon holtgrieve, high lake, historical changes, human activities, human derived nitrogen, journal science, lakes, natural sources of nitrogen, new geological era, nitrogen, nitrogen characteristics of lake sediments, nitrogen cycle, nitrogen pollution, northern europe, northern hemisphere, peter leavitt, planetary scale changes, remote ecosystems, smog, southwest alaska, statistical models, university of Alberta, university of washington, us rocky mountains, vital nutrient for life, water pollution

Nitrogen derived from human activities has polluted lakes throughout the Northern Hemisphere for more than a century and the fingerprint of these changes is evident even in remote lakes located thousands of miles from the nearest city, industrial area or farm.

The findings, published in the journal Science Dec. 16, are based on historical changes in the chemical composition of bottom deposits in 36 lakes using an approach similar to aquatic archeology. More than three quarters of the lakes, ranging from the U.S. Rocky Mountains to northern Europe, showed a distinctive signal of nitrogen released from human activities before the start of the 20^th century, said Gordon Holtgrieve, a postdoctoral researcher at University of Washington School of Aquatic and Fishery Sciences and lead author of the report. The UW and a dozen other research institutions contributed to the research. (more…)