The effects of morphology and water velocity on nutrient transport at the community scale: A partnership in research and education

Florence Thomas
Dauphin Island Sea Lab

Wednesday, August 5, 1998
3:30 p.m.—Pacific Forum

This talk describes a research program that is integrated with an education component that includes minority research fellowships, early childhood education, and public outreach. The research focuses on the effects that predominant members of communities have on the transport of nutrients to the entire community. In marine and aquatic communities, numerous species modify the characteristics of water flow within their habitat. This modification of flow affects the delivery of resources to other members of the community by controlling rates of chemical transport between the benthos and the water column. These are clear examples of "ecosystem engineering."

The effects of the morphology of predominant community members on rates of chemical transport are examined. Ammonium uptake by seagrass and coral communities are measured over a range of velocities using field and laboratory flumes. The relationship between uptake rate, water velocity, and morphology are compared to expected relationships based on engineering correlation of heat and mass transfer to non-biotic surfaces. Using engineering analysis, simple morphological characteristics of the predominant species in a community can be used to predict uptake rates to within 95% of those measured in the field. These results indicate that the predominant community members can be "ecosystem engineers" and that their engineering role can be verified using engineering analysis.

Next: Top down versus bottom up- What affects common murres the most?