Non-invasive flux Measurements at the Benthic Interface: The Aquatic Eddy Covariance Technique

Abstract

The oxygen flux between benthic systems and the water above is a widely used proxy for benthic primary production and organic carbon mineralization and is one of the most measured variables in marine and freshwater research. This presentation reviews the relatively new aquatic eddy covariance technique for measuring this flux. Because the approach relies on measurements that integrate over a large area (multiple m²) without disturbing the benthic system or the natural drivers of flux, it allows non-invasive studies of whole-system benthic metabolism that are not possible with any other approach. After summarizing the basic principles of eddy covariance, the instruments used, and key steps in the data evaluation, the rapidly growing body of research utilizing aquatic eddy covariance is presented with examples of the new kinds of insights that can be attained. These examples focus on benthic surfaces where traditional flux methods are difficult or problematic to apply and include highly dynamic benthic environments such as coral reefs, Arctic sediments, dense seagrass meadows, and permeable sands. Finally, future applications of the technique, new areas for development, and avenues to disseminate data and outcomes between new and experienced users are recommended.