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Content archived on 2024-04-19

Oxic-anoxic interfaces as productive sites

Objective



The overall objectives of the project are:

- To define the structure of biological communities at
oxic-anoxic interfaces in relation to the geochemical
gradients and to identify the organisms involved in the
major biogeochemical transformations;

- To quantify the chemolithotrophic production and
secondary production at interfaces and to understand the
physiological and structural adaptations to enable
organisms to live in these habitats.

Chemical and biological processes will be studied over a range of interface types including shallow-water sulphidic
hydrothermal springs, cold methane seeps, the water column and intertidal sediments.
The sites have been chosen for their accessibility for
fine-scale studies. Chemical gradients will be examined using micro-scale techniques such as submersible microelectrodes,
for pH, oxygen and sulphide, and sensitive HPLC techniques,
for other sulphur species and organic compounds. The structure and function of bacterial populations in mats will be studied. Chemoautolithotrophic production will be quantified using
direct carbon fixation rates as well as being estimated from diffusion gradients. The growth of heterotrophic bacteria,
living on the products of the autotrophs and mineralizing
biomass, will be related to the environmental conditions at
the interface. Since many bacterial interactions are difficult to study in situ, they will be examined in mixed cultures
maintained in chemostats. Distribution patterns of eukaryotes at interfaces and the production of relevant species will be determined. Physiological, genetic and ultrastructural
analyses will show how animals adapt to conditions in the
boundary.

Call for proposal

Data not available

Coordinator

Marine Biological Association of the United Kingdom
EU contribution
No data
Address
Citadel Hill
PL1 2PB Plymouth
United Kingdom

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Total cost
No data

Participants (6)