Kozerski, H. H P. Institute of Freshwater Ecology and Inland Fisheries, Berlin, + 49 30 648 407 10
Koehler, J. H P. Institute of Freshwater Ecology and Inland Fisheries, Berlin, + 49 30 648 407 10
Wanner, S. S. Institute of Freshwater Ecology and Inland Fisheries, Berlin, + 49 30 648 407 10
SESTON SEDIMENTATION IN MOVING WATERS, AN APPROACH USING A NEW PLATE TRAP
Ecosystem mass balances indicated that large quantities of the pelagic POC are decomposed in the benthal. In the lowland river Spree (Germany, near Berlin) for instance, 70 % of POC come on different ways to the bottom. To determine the settling flux in moving waters a round plate sediment trap (d = 35 cm) was developed. To overcome the technical problem of material losses during surfacing, the collection area can be lowered into the trap body and sealed by a cover.Tests of these traps proofed that it works correct.
First measurements in the river Spree, its marginal zones and side arms showed sedimentation rates up to a maximum of 70 gDW/mē/d. Typical rates for this plankton dominated river were between 3 and 25 g/mē/d, indicating that even in running waters sedimentation is a very important ecological process. The rates were mostly three to twenty times lower than the rates measured by the traditional cylindrical sediment traps and were strongly dependent on flow velocity. Highest rates were found in zones of slow flow. This new technique simulates the hydrodynamic conditions much better than cylindrical traps and enables us to study sedimentation in moving water more realistically in future.
Day: Wednesday, Feb. 3
Time: 10:45 - 11:00am
Location: Eldorado Hotel