Marcelo Ketzer

I am a professor in sustainability sciences with focus on environmental geochemistry at the Department of Biology and Environmental Science. My current research interests are on the chemistry of sediments and soils (and related pore waters and gases) in their pristine state and when altered by human activities. I am also interested in the relationships between life and chemistry in geological environments.

Teaching

I am involved in teaching geosciences and environmental science in the Environmental Analyst Programme (undergraduate level) and in the Environmental Science and Sustainability Programme (master level). Both programmes are in the Faculty of Life and Health Sciences. I am also an examiner for B.Sc. theses and a Ph.D. supervisor.

Research

I am participating of several research projects with focus on the response of natural systems to climate change. We are investigating, for instance, how climate change may affect biogeochemical cycles in sediments of the Baltic Sea and, therefore, how environmental conditions (such as oxygen levels) may be modified in the future. Understanding the natural systems and how they are affected by climate change will be important to plan for remediation actions in a global warming scenario. Another important consequence of climate change to the marine environment is the stability of large reservoirs of methane trapped as gas hydrates in deep sea. The stability of such systems is sensitive to glacial- interglacial changes in water pressure (sea-level) and temperature, but also to the poorly understood dynamics of venting structures observed to release gas to the oceans. An improved understanding of gas release over time is of wide scientific and social relevance, due to its impacts on global carbon budgets, marine life, seabed slope stability and resource assessments. I am participating of research projects in the Amazon deep-sea fan and in the Rio Grande Cone (Atlantic Ocean), and in the Nile deep-sea fan (Mediterranean Sea) to help unravelling the impact of climate change on stability of gas hydrates in marine environments.

Another important part of my research activities involves the study of metal contamination of marine sediments in the Baltic Sea and soils in Southern Sweden. In the latter case, we are investigating the leaching of metals from recently discovered acid sulphate soils. Such soils may form when water table is artificially lowered to allow cultivation. Sulphides present in soil are exposed and react with oxygen and form sulphuric acid that promotes metal leaching and possible contamination of water resources. We are also initiating a study to understand the distribution of heavy metals in sediments of the Baltic Sea. Recent studies show that despite rigorous controls for the emissions of metals to air and water, pollution levels may not be diminishing.