|
Dr. Markus Huettel |
Markus Huettel is a marine benthic zoologist with strong interests in multidisciplinary research linking biology, biogeochemistry, hydrodynamics and sedimentology. After studying marine biology at the universities of Göttingen and Kiel in Germany he worked on a research project in Thailand investigating the diverse fauna in the mangroves and tidal flats on the island of Phuket. The research focused on small filtering Umbonium snails, that live buried in the sandy intertidal sediments, sometimes so abundant that no space is left between the snails.
After completion of that project and a 2 year project at the University of South Florida, Huettel joined the Max Planck Institute for Marine Microbiology in Bremen/Germany in 1993, where he worked for 10 years as a research group leader. Central topics in his group were zoology of intertidal zones, ecology of coral reefs, hydrodynamical processes in sea grass beds and sediment water exchange processes in sandy shelf sediments. Research included field studies in the North Sea, Baltic, Chilean Shelf, Australia and Hawaii, and studies in laboratory flumes and wave tanks.
In 2003, Huettel moved to Florida where he started the Coastal Benthic Ecology Group at Florida State University in Tallahassee. Main study areas here are the northern Gulf of Mexico and the Florida Keys. In the Northern Gulf, Apalachicola Bay offers excellent research opportunities: It is a highly productive area with large oyster banks, abundant fish and crustaceans and a diverse benthic fauna. Seagrass beds are typical for the shallow estuarine and coastal zones and presently are a focal area of research.
Besides research, Huettel's professional activities include teaching of courses in Coastal and Estuarine Ecology, Coral Reef Ecology, Marine Pollution and Oceanography. He has published more than 70 research papers and is reviewer for numerous scientific journals.
ABSTRACT
"Why Sediment Ripples Are Important"".
Does it make a difference for water quality whether water flows in an aquarium are strong or weak? Does it matter whether the sediment consists of fine or coarse sands? or of carbonate or silicate grains? The short answer to these questions is yes.
In my presentation I will address filtration in permeable sand sediments and discuss the consequences of these processes for organic matter degradation and water quality. When water currents flow over rough sediments, they produce small pressure gradients that can drive water into the sediment and pore waters from deeper layers to the surface. This filtration process can reach tens of centimeters depth and converts permeable sand beds into effective filter systems. Because every single sand grain is colonized by microbial communities that produce a variety of enzymes that break down organic matter, the sands can efficiently degrade organic solutes and particles that are filtered into the bed.
The pore water flows carries substrates through different reaction zones within the sediment, which results in rapid degradation of the material. Degradation products (e.g. carbon dioxide, nutrients, sulfide) are carried out of the sediments by the pore water flows, closing the recycling loop. I will show examples from laboratory flume and wave tank studies, from intertidal sand flats and coral reefs and link these results to aquaria systems.
