Optical microsensors and microprobes

• Main Authors: Holst, G., Klimant, I., Kühl, M., Kohls, O.
• Format: Book Part
• Language: English
• Published: 1999
• Subjects: Planktonic foraminifera
• Online Access: http://hdl.handle.net/21.11116/0000-0004-78DE-C; http://hdl.handle.net/21.11116/0000-0004-78E0-8

Biogeochemical processes in the ocean are (to a large extent) regulated by the physico-chemical characteristics of the microenvironment where the processes occur. In the pelagic, phytoplankton, bacteria and small grazers interact and regulate the productivity in response to environmental variables like temperature, salinity or availability of nutrients and trace elements. Hot spots of metabolic activities are found in aggregates of microalgae or e.g. in planktonic foraminifera or radiolaria harbouring microalgal symbionts. Also, during the continuous export ofbiomass (e.g. dead or dying phytoplankton, faecal material and other organic debris) from the euphotic zone of the ocean, ca. 0.5-5 mm large aggregates (marine snow) are formed that are rapidly mineralised during their journey to the sea floor. In the open ocean, recycling of carbon and other essential elements thus mainly takes place in the water column, while only refractory material reaches the seafloor, where it is slowly degraded and buried. The deep sea sediment is thus a major sink for carbon on a global scale.