Night deployment of benthic paired light and dark chambers for estimating benthic primary production
and respiration in permeable sandy sediments on the Georgia shelf. Shown (left to right) are
Rick Jahnke; research associate Mary Richards; and Todd Recicar, 2nd mate aboard the R/V Savannah.

People:

Rick Jahnke, Professor

Mary Richards, Research Assistant II

Debbie Jahnke, Research Specialist II

Research Interests and Projects:

The study of sediment chemical, biological and physical processes that control the chemistry of benthic and marine systems. Specific examples of recent research interests and projects include:

1. development of ocean observatory infrastructure via the ORION Program and coastal observatory research via the CoOP Program, including the Coastal Benthic Exchange Dynamics (CBED) project BOTTOMS-UP.
2. biogeochemistry of permeable sediments including advective porewater transport and groundwater inputs (Jahnke et al. (2005) CSR 25:1433-1452; Niencheski and Jahnke (2002) Aquat. Geochem. 8:135-152; Jahnke et al. (2003) ECSS 56:641-653.)
3. continental shelf biogeochemistry including benthic primary production (Jahnke et al. (2000) CSR 20:109-127)
4. denitrification pathways in sediments, in collaboration with former graduate student Alex Rao, now at Woods Hole Oceanographic Institution.
5. the metabolic and chemical processes controlling the dissolution and preservation of calcium carbonate on the deep sea floor (Jahnke and Jahnke (2004) GCA 68:47-59)
6. the magnitude and distribution of the global flux of organic carbon to the deep ocean and sediments (Jahnke (1996) GBC 10:71-88)

In all of these projects, particular emphasis is placed on designing, constructing or adapting new instrumentation that permits novel sampling and observation. Specific recent examples include autonomous benthic flux chamber instruments for the deep ocean; paired light and dark chambers for continental shelf benthic primary production measurements; a simple adaptation to a spade box corer and acrylic core barrel to collect sandy sediments with intact porewaters; and a deep sea corer that recovers sediments without decompression or warming.